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Bibliography of the Maurice Lamontagne Institute

Pierre LAROUCHE

PETTIGREW, B., P. LAROUCHE, D. GILBERT, 2011. Validation des images composites des températures de surface produites au laboratoire de télédétection de l’Institut Maurice- Lamontagne. Rapp. tech. can. hydrogr. sci. océan., 270, 39 p .

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An entirely automated operational system having the task to produce composite images of sea surface temperature (SST) of Canadian waters has been set up at the remote sensing laboratory of Maurice Lamontagne Institute (MLI) using data from Advanced Very High Resolution Radiometer (AVHRR) sensors. In situ sea surface temperatures from six stations located in the Estuary and the Gulf of St. Lawrence have been used to validate composite images from August 1995 to August 2004. Differences over all stations between mean SST and mean in situ temperature for averaging periods of 1, 7 and 15 days were respectively -0,26 °C (1,06 °C), -0,21 °C (0,90 °C) and -0,13 °C (0,84 °C) where the values in parentheses are the standard deviations. Results showed that the accuracy of the daily mean is highly correlated to the number of measurements used to compute it. However for most validation stations, that correlation decreased rapidly for the 7 and 15 days averages. Finally, we estimated the maximum daily and weekly absolute error at the 95 % confidence level for most stations.

GALBRAITH, P.S., J. CHASSÉ, D. GILBERT, P. LAROUCHE, D. BRICKMAN, B. PETTIGREW, L. DEVINE, A. GOSSELIN, R.G. PETTIPAS, C. LAFLEUR, 2011. Physical oceanographic conditions in the Gulf of St. Lawrence in 2010 ; Conditions océanographiques physique dans le golfe du Saint-Laurent en 2010. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2011/045, 86 p .

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An overview of physical oceanographic conditions in the Gulf of St. Lawrence in 2010 is presented. Air temperatures reached record highs when averaged from January to March and from October through December as well as annually. The monthly averaged freshwater runoff measured at Québec City was normal overall in 2010 but was unusually high during winter and fall, and the spring freshet was almost absent. Near-surface water temperatures in the Gulf were normal or above normal all year and in all regions except for the Mécatina Trough and Esquiman Channel in June. Maximum sea-ice volume within the Gulf and on the Scotian Shelf was 11 km³, a record low since 1969. The duration of the 2009–2010 ice season was shorter than normal and associated with the early ice melt. Winter inflow of cold and saline water from the Labrador Shelf occupied the Mécatina Trough over the entire column in winter 2010. The spread of the intrusion was confined close to the Strait of Belle Isle, leading to an overall small volume of 809 km³. However, this intrusion volume represented 29 % of the unusually small volume of mixed layer waters that were colder than -1 °C. The winter cold mixed layer volume in the Gulf, excluding the Estuary, was 13 900 km³, a value higher than the 1996–2009 average by 0.7 SD. This cold-water volume corresponded to 42 % of the total water volume of the Gulf. However, it was very warm, on average about 1 °C above the freezing point. This is the first time in 15 years of winter surveys that such high temperatures were recorded. The cold intermediate layer (CIL) index for summer 2010 was - 0.04 °C, which is similar to observations in 2000. This is an increase of 0.38 °C since 2009. On the Magdalen Shallows, none of the bottom area was covered by water with temperatures < 0 °C in September 2010, similar to conditions in 2005, 2006, 2007, and 2009. In other regions of the Gulf, very few areas had bottom temperatures below 0 °C. Regional patterns of the August and September CIL show that the layers for T < 1 °C and < 0 °C were much thinner in most parts of the Gulf in 2010 than in 2009 and had a generally higher core temperature everywhere. Conditions in March 2010 were characterized by a very thick winter mixed layer, although very warm, including a thick intrusion of Gulf waters into the Estuary. By June 2010, the CIL thickness returned to nearnormal but still had above-normal minimum temperatures. The CIL warming rate appeared to be slower than usual because core temperatures were closer to normal in certain regions by August and more so by November. The warm deep waters in the Estuary in 2009 were replaced by colderthan- normal waters by June 2010. Colder-than-normal deep waters also occupied the northwest Gulf at that time. Very warm waters occupied Cabot Strait in June at 250 m—the depth of the temperature maximum—and there is a hint that the top portion of this water mass was sampled during the March survey. The warm deep waters were still present in Cabot Strait in August as well as in November. Gulf-wide average temperatures were below normal at 200 to 300 m and salinities were below normal from 150 to 300 m. Temperatures at 300 m increased marginally overall but significantly (by 1 SD) at Cabot Strait, where the anomaly is now +1 SD. Salinity at 200 m and 300 m decreased overall by 0.6 SD but increased at Cabot Strait to reach +0.6 SD at 200 m. The 300 m waters of the Estuary are expected to cool further during the next two years, but it will be interesting to follow the warm anomaly present in 2010 at Cabot Strait as it progresses up the channel toward the Estuary. The surface mixed layer in November was anomalously thick but more importantly very warm, warmer in fact than in November 2009 which were the preconditions for the record conditions of March 2010.

SMIRNOV, A., B.N. HOLBEN, D.M. GILES, I. SLUTSKER, I., N.T. O'NEILL, T.F., ECK, A. MACKE, P. CROOT, Y. COURCOUX, S.M. SAKERIN, T.J. SMYTH, T. ZIELINSKI, G. ZIBORDI, G., J.I. GOES, M.J. HARVEY, P.K. QUINN, N.B. NELSON, V.F. RADIONOV, C.M. DUARTE, R. LOSNO, J. SCIARE, K.J. VOSS, S. KINNE, N.R. NALLI, E. JOSEPH, K. KRISHNA MOORTHY, D.S. COVERT, S.K. GULEV, G. MILINEVSKY, P. LAROUCHE, S. BÉLANGER, E. HORNE, M. CHIN, L.A. REMER, R.A. KAHN, J.S. REID, M. SCHULZ, C.L. HEALD, J. ZHANG, K. LAPINA, R.G. KLEIDMAN, J. GRIESFELLER, B.J. GAITLEY, Q. TAN, T.L. DIEHL, 2011. Maritime Aerosol Network as a component of AERONET : first results and comparison with global aerosol models and satellite retrievals. Atmos. Meas. Tech. Discuss., 4(1): 1-32 .

The Maritime Aerosol Network (MAN) has been collecting data over the oceans since November 2006. Over 80 cruises were completed through early 2010 with deployments continuing. Measurements areas included various parts of the Atlantic Ocean, the 5 Northern and Southern Pacific Ocean, the South Indian Ocean, the Southern Ocean, the Arctic Ocean and inland seas. MAN deploys Microtops hand-held sunphotometers and utilizes a calibration procedure and data processing traceable to AERONET. Data collection included areas that previously had no aerosol optical depth (AOD) coverage at all, particularly vast areas of the Southern Ocean. The MAN data archive provides 10 a valuable resource for aerosol studies in maritime environments. In the current paper we present results of AOD measurements over the oceans, and make a comparison with satellite AOD retrievals and model simulations.©2011 Copernicus Publications on behalf of the European Geosciences Union

GALBRAITH, P.S., P. LAROUCHE, 2011. Sea-surface temperature in Hudson Bay and Hudson Strait in relation to air temperature and ice cover breakup, 1985-2009. J. Mar. Syst., 87(1) 66-78 .

Sea-surface weekly average temperatures derived from NOAA–AVHRR remote sensing data are analyzed for the period 1985–2009 for Hudson Bay and Hudson Strait, and compared to weekly ice cover data obtained from the Canadian Ice Service for the period 1971–2009 as well as to monthly average air temperature at four stations around Hudson Bay and to four around Hudson Strait. Results show a decreasing trend in the breakup date of the sea-ice in Hudson Strait of 5.6 days per decade since 1971 as well as an interannual variability of 5 °C in the Hudson Bay average SST in August between extreme years. There is good correlation in Hudson Bay between average SST in August and average air temperature anomalies at four meteorological weather stations (R2=0.80) and with the percentage of open water from June to August (R2=0.80). Climatology for SST of the warmest week of the year is presented, and the variability of different regions within Hudson Bay is discussed. One area in southwestern Hudson Bay is shown to exhibit the highest interannual variability, having nearly the warmest surface waters in some years and nearly the coldest in others. The historical observed variability of SST and ice cover is compared to expected changes in the literature that are associated with climate change.©2011 Elsevier B.V.

DJAGOUA, E.V, P. LAROUCHE, J.B. KASSI, K. AFFIAN, B. SALEY, 2011. Seasonal and inter-annual variability of the chlorophyll concentration in the coastal area of Gulf of Guinea using SeaWIFS images. Int. J. Remote Sens., 32(14): 3851-3874 .

GALBRAITH, P.S., P. LAROUCHE, 2011. Reprint of "Sea-surface temperature in Hudson Bay and Hudson Strait in relation to air temperature and ice cover breakup, 1985-2009". J. Mar. Syst., 88(3) 463-475 .

Sea-surface weekly average temperatures derived from NOAA-AVHRR remote sensing data are analyzed for the period 1985-2009 for Hudson Bay and Hudson Strait, and compared to weekly ice cover data obtained from the Canadian Ice Service for the period 1971-2009 as well as to monthly average air temperature at four stations around Hudson Bay and to four around Hudson Strait. Results show a decreasing trend in the breakup date of the sea-ice in Hudson Strait of 5.6 days per decade since 1971 as well as an interannual variability of 5 °C in the Hudson Bay average SST in August between extreme years. There is good correlation in Hudson Bay between average SST in August and average air temperature anomalies at four meteorological weather stations (R2=0.80) and with the percentage of open water from June to August (R2=0.80). Climatology for SST of the warmest week of the year is presented, and the variability of different regions within Hudson Bay is discussed. One area in southwestern Hudson Bay is shown to exhibit the highest interannual variability, having nearly the warmest surface waters in some years and nearly the coldest in others. The historical observed variability of SST and ice cover is compared to expected changes in the literature that are associated with climate change. © 2011 Published by Elsevier B.V.

DUFOUR, R., H. BENOIT, M. CASTONGUAY, J. CHASSÉ, L. DEVINE, P. GALBRAITH, M. HARVEY, P. LAROUCHE, S. LESSARD, B. PETRIE, L. SAVARD, C. SAVENKOFF, L. ST-AMAND, M. STARR, 2010. 2010 Canadian marine ecosystem status and trends report. Advis. Sec. Sci. Advis. Rep. 2010/030(Revised), 38 p .

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GALBRAITH, P.S., R.G. PETTIPAS, J. CHASSÉ, D. GILBERT, P. LAROUCHE, B. PETTIGREW, A. GOSSELIN, L. DEVINE, C. LAFLEUR, 2010. Physical Oceanographic Conditions in the Gulf of St. Lawrence in 2009 Conditions d’océanographie physique dans le golfe du Saint-Laurent en 2009. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2010/035, 77 p .

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An overview of physical oceanographic conditions in the Gulf of St. Lawrence in 2009 is presented. Air temperatures were close to normal when averaged from January to March. Air temperatures were in general either normal or above normal for the remainder of the year. The monthly averaged freshwater runoff measured at Québec City was normal overall in 2009 but consisted of aboveaverage runoff in July compensated later by lower runoff in the fall. Near-surface water temperatures in the Gulf were above normal in all regions except the Northwest Gulf and the Estuary in June and in every region in August. Maximum sea-ice volume within the Gulf and on the Scotian Shelf was 65 km³, a value that is below normal using updated ice volume estimates for 1971-2000. The duration of the 2008-09 ice season was longer than normal in the Estuary, normal in the central Gulf and Cabot Strait, and shorter elsewhere. This was mostly associated with the variability of the first occurrence of ice. Winter inflow of cold and saline water from the Labrador Shelf occupied the Mécatina Trough over the entire column in winter 2009. The spread of the intrusion was confined a bit closer to the coast compared to 2008 conditions, leading to an overall smaller volume of 1270 km³, which is similar to the 2002 observations. The winter cold mixed layer volume in the Gulf, excluding the Estuary, was 14 000 km³, a value higher than the 1996–2009 average by 0.7 SD. This cold-water volume corresponded to 42% of the total water volume of the Gulf. The cold intermediate layer (CIL) index for summer 2009 was -0.42°C, which is similar to observations in 2002, 2004, 2005 and 2007. This is an increase of 0.32°C since 2008. On the Magdalen Shallows, almost none of the bottom area was covered by water with temperatures < 0°C in September 2009, similar to conditions in 2005, 2006 and 2007. Regional patterns of the August and September CIL show that the layers for T < 1°C and < 0°C were much thinner in most parts of the Gulf in 2009 than in 2008 and had a generally higher core temperature everywhere. In the northern Gulf, the area covered by low temperature water (< 1°C) decreased in 2009 relative to 2008 conditions. Temperatures in March 2009 were characterized by a very thick cold layer, including a thick intrusion of Gulf CIL waters into the Estuary. By June 2009, CIL temperatures returned to normal with a warming trend that continued into August, especially on the Magdalen Shallows. By October–November, CIL conditions were normal in most regions except the estuary and Northwest Gulf, where the CIL and the surface mixed layer were anomalously deep. Overall, temperature and salinity were generally normal from 150 m to 200 m, and slightly lower than normal at 250 and 300 m. Temperature and salinity at 300 m decreased for a third consecutive year, from 2008 to 2009. The lower-than-normal Gulf-wide water temperatures at 300 m were composed of normal waters in the Estuary and northwest and colder waters in the centre and coming into the Gulf at Cabot Strait. This cold anomaly has propagated inward in the last few years and is expected to continue toward the Estuary during the next few years.

DUFOUR, R., H. BENOIT, M. CASTONGUAY, J. CHASSÉ, L. DEVINE, P. GALBRAITH, M. HARVEY, P. LAROUCHE, S. LESSARD, B. PETRIE, L. SAVARD, C. SAVENKOFF, L. ST-AMAND, M. STARR, 2010. Rapport sur l'état et les tendances des écosystèmes marins canadiens en 2010. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2010/030(révisé), 43 p .

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DUFOUR, R., H. BENOIT, M. CASTONGUAY, J. CHASSÉ, L. DEVINE, P. GALBRAITH, M. HARVEY, P. LAROUCHE, S. LESSARD, B. PETRIE, L. SAVARD, C. SAVENKOFF, L. ST-AMAND, M. STARR, 2010. Ecosystem status and trends report: Estuary and Gulf of St. Lawrence ecozone. Rapport sur l’état et les tendances des écosystèmes : écozone de l’estuaire et du golfe du Saint Laurent. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche; 2010/030, 193 p .

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This document was produced under the umbrella of the national ecosystem status and trends report program and deal with the estuary and gulf of St.Lawrence ecozone. It is structured around the status and trends of some important marine species and physico-chemical variables of the ecosystem. The national ecosystem status and trends report will support prioruty-setting for a national biodiversity agenda and will integrate national and provincial exosystem-bases information. It will report on many large terrestrial and marine ecozones.

LAROUCHE, P., U. BOYER-VILLEMAIRE, 2010. Suspended particulate matter in the St. Lawrence estuary and Gulf surface layer and development of a remote sensing algorithm. Estuar. Coast. Shelf Sci., 90:241-249 .

Remote sensing of chlorophyll concentration is potentially affected by the presence of inorganic matter in the water column. Seasonal variability of total suspended particulate matter (SPM) concentration and its partition into organic and inorganic fractions was thus measured in the estuary and Gulf of St. Lawrence during five cruises. These measures were made in the surface layer down to the depth of the 0.1% light level. Results indicate that vertical variability was small for the entire study area. Data analysis lead to the definition of two main regions having different SPM characteristics: 1) the estuary zone characterized by a strong spatial variability, intermediate SPM concentrations and a clear spring phytoplankton bloom that is combined to an increased inorganic matter load; 2) the gulf region characterized by a relatively low SPM concentration and phytoplankton blooms in the spring and fall periods. Combined with in situ measurements of remote sensing reflectances, the database was used to validate existing inorganic matter retrieval algorithms and develop a new one better adapted to the low concentrations encountered in the St. Lawrence estuary and Gulf. ©2010 Published by Elsevier Ltd.

GALBRAITH, P., R.G. PETTIPAS, J. CHASSÉ, D. GILBERT, P. LAROUCHE, B. PETTIGREW, A. GOSSELIN, L. DEVINE, C. LAFLEUR, 2009. Physical oceanographic conditions in the Gulf of St. Lawrence in 2008 ; Conditions d’océanographie physique dans le golfe du Saint-Laurent en 2008. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2009/014, 73 p .

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An overview of physical oceanographic conditions in the Gulf of St. Lawrence in 2008 is presented. Air temperatures were close to normal when averaged from January to March, contributing to an ice cover volume that was also close to the climatological mean. Air temperatures were in general either normal or above normal for the remainder of the year. The monthly averaged freshwater runoff measured at Québec City was normal overall in 2008, but consisted of above-average runoff in summer compensated later by lower runoff in the fall. The high summer runoff contributed to higher-than-normal stratification. Near-surface water temperatures were generally above normal throughout the Gulf for the months of May, July and November and were also above-normal on the Magdalen Shallows in June and in the northern Gulf from August to October. In August the northern parts of the Gulf saw positive anomalies while the southern parts experienced negative anomalies. This lead to the unusual occurrence that the waters around Prince Edward Island and in Northumberland Strait had higher temperature in July than in August 2008. On the Magdalen Shallows, a large area of the bottom was covered by water with temperatures < 0 °C in September 2008, similar to the cold period observed in the 1990s and in contrast to conditions in September 2005, 2006 and 2007 when such cold waters were not observed. Maximum sea-ice volume within the Gulf and on the Scotian Shelf was 81 km3, a value now considered about normal using updated ice volume estimates for 1971-2000. Ice first appeared early in the season and stayed later than normal (later by about 8 days later on the Magdalen Shallows). Winter inflow of cold and saline water from the Labrador Shelf occupied the Mécatina Trough from top to bottom in winter 2008. The spread of the intrusion was confined a bit closer to the coast compared to 2007 conditions, leading to an overall smaller volume of 1850 km3, which is similar to 2001 and 2006 observations. The winter cold mixed layer volume was 13 700 km3, a value higher than the 1996–2008 average by 0.8 SD, and corresponded to 41 % of the total water volume of the Gulf. The summer CIL (cold intermediate layer) index for 2008 was -0.70 °C, comparable to the very cold conditions observed in 2003 and a large decrease (by 0.47 °C) from the previous summer. Regional patterns of the August and September CIL show that the layers for T < 1 °C and < 0 °C were much thicker in most parts of the Gulf in 2008 than in 2007 and had a generally lower core temperature throughout the Gulf. In the Northern Gulf, the area covered by water of low temperature (from < -1 °C through < 1 °C) increased in August 2008 relative to August 2007. Temperatures in the water column in June 2008 were characterized by a very thick and cold CIL in most regions except the Estuary and by warm deep waters in the Estuary and the northwest Gulf. This overall pattern persisted in the August– September mean conditions. By October and into November, CIL conditions were still thick and cold, while waters above the CIL were anomalously warm. Overall, temperature and salinity were generally normal from 150 m to 300 m, with the exception of slightly lower than normal (by 0.6 SD) temperature at 150 m. Temperature and salinity in this depth range decreased for a second consecutive year. The near-normal Gulf-wide water temperatures at 300 m were composed of warmer waters in the Estuary, near-normal temperatures in the northwest and central, and colder waters flowing into the Gulf at Cabot Strait.

MATSUOKA, A., P. LAROUCHE, M. POULIN, VINCENT, W., H. HATTORI, 2009. Phytoplankton community adaptation to changing light levels in the southern Beaufort Sea, Canadian Arctic. Estuar. Coast. Shelf Sci., 82(3): 537-546 .

The chlorophyll a specific absorption coefficient of phytoplankton, a*φ(λ) is an important parameter to determine for primary production models and for the estimation of phytoplankton physiological condition. Knowledge of this parameter at high latitudes where nutrient rich cold water submitted to low incident light is a common environment is almost nonexistent. To address this issue, we investigated the light absorption properties of phytoplankton as a function of irradiance, temperature, and nutrients using a large data set in the southern Beaufort Sea during the open water to ice cover transition period. The a*φ(λ) tended to increase from autumn when open water still existed to early winter when sea ice cover was formed, resulting from a biological selection of smaller-size phytoplankton more efficient to absorb light. There was no significant correlation between a*φ(λ) and irradiance or temperature for both seasons. However, a*φ(λ) showed a significant positive correlation with NO3 + NO2. Implications of the results for phytoplankton community adaptation to changing light levels are discussed. ©2009 Elsevier Ltd.

SMIRNOV, A., B.N. HOLBEN, I. SLUTSKER, D.M. GILES, C.R. McCLAIN, T.F. ECK, S.M. SAKERIN, A. MACKE, P. CROOT, G. ZIBORDI, P.K. QUINN, J. SCIARE, S. KINNE, M. HARVEY, T.J. SMYTH, S. PIKETH, T. ZIELINSKI, A. PROSHUTINSKY, J.I. GOES, N.B. NELSON, P. LAROUCHE, V.F. RADIONOV, P. GOLOUB, K. KRISHNA MOORTHY, R.B., R. MATARRESE, E.J. ROBERTSON, F. JOURDIN, 2009. Maritime aerosol network as a component of aerosol robotic network. J. Geophys. Res. (D Atmospheres), 114(6), art. no. D06204, 10 p .

The paper presents the current status of the Maritime Aerosol Network (MAN), which has been developed as a component of the Aerosol Robotic Network (AERONET). MAN deploys Microtops handheld Sun photometers and utilizes the calibration procedure and data processing (Version 2) traceable to AERONET. A web site dedicated to the MAN activity is described. A brief historical perspective is given to aerosol optical depth (AOD) measurements over the oceans. A short summary of the existing data, collected on board ships of opportunity during the NASA Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project is presented. Globally averaged oceanic aerosol optical depth (derived from island-based AERONET measurements) at 500 nm is ˜0.11 and Angstrom parameter (computed within spectral range 440-870 nm) is calculated to be ˜0.6. First results from the cruises contributing to the Maritime Aerosol Network are shown. MAN ship-based aerosol optical depth compares well to simultaneous island and near-coastal AERONET site AOD.©2009 American Geophysical Union

GALBRAITH, P.S., D. GILBERT, R.G. PETTIPAS, J. CHASSÉ, C. LAFLEUR, B. PETTIGREW, P. LAROUCHE, L. DEVINE, 2008. Physical oceanographic conditions in the Gulf of St. Lawrence in 2007 ; Conditions d'océanographie physique dans le golfe Saint-Laurent en 2007. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2008/001, 59 p .

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An overview of physical oceanographic conditions in the Gulf of St. Lawrence in 2007 is presented. Air temperatures ranged from normal to cooler than normal for most of the year in the western parts of the Gulf; however, the eastern regions were only significantly cooler than normal in April and May. Averaged over the whole Gulf for the entire year, air temperature was normal. The monthly averaged runoff at Québec City was below normal during all months of 2007. Near-surface water temperatures were much cooler in 2007 overall than in 2006 in all regions of the Gulf. Near-surface waters were warm in the St. Lawrence Estuary in January and February. Summer maximum surface temperatures occurred earlier than usual, followed by earlier-than-usual cooling. Surface temperatures were generally below normal for the rest of the year except for October in the Estuary. On the Magdalen Shallows, there was (almost) no bottom area covered by water with temperatures <0 °C in September 2007. Maximum sea-i ce volume within the Gulf and on the Scotian Shelf was below normal but still much higher than the volume recorded in 2006. Winter inflow of cold and saline water from the Labrador Shelf occupied the Mecatina Trough from top to bottom. The spread of the intrusion had an area similar to that of 2006, but its volume was much larger and similar to that observed in 2004. The winter cold mixed layer volume was 13100 km3, slightly above the 1996-2007 average, and corresponded to 39 % of the total water volume of the Gulf. The higher winter volume of cold water compared with 2006 conditions led to a decrease of 0.44 °C in the Cold Intermediate Layer (CIL) index, reaching -0.23 °C in summer 2007, which is comparable to conditions observed in 2004. The index saw a large decrease after three consecutive years of warming. Regional patterns of the CIL show that the layer for T < 1 °C and < 0  °C was much thicker in the northern half of the Gulf in 2007 than in 2006 and had a generally lower core temperature almost everywhere as well. Seasonal and regional patterns of water column temperatures in June were generally close to the 1971-2000 climatology at all depths, except for the very thick and cold CIL in the Anticosti Channel and warm deep waters in the northwest. This overall pattern persisted from August to September, but by late fall conditions were about normal everywhere except for the anomalously warm nearsurface mixed layers in the northwest and warm near-surface waters on the Magdalen Shallows and in Cabot Strait. Averaged annually for the entire Gulf, the temperature and salinity from 150 m to 300 m were normal in 2007. Spatially, at 300 m, this was composed of warmer than normal waters near the Estuary, near-normal temperatures in the centre and colder than normal waters coming into the Gulf at Cabot Strait. The outlook for 2008 from the March 2008 survey is for a slight cooling of the CIL index to -0.47 °C resulting from a thicker cold winter surface layer.

DONIOL-VALCROZE, T., D. BERTEAUX, P. LAROUCHE, R. SEARS, 2008. Influence of thermal fronts on habitat selection by four rorqual whale species in the Gulf of St. Lawrence. Mar. Ecol. Prog. Ser., 335: 207-216 .

Understanding the factors influencing habitat selection is critical to improving management and conservation plans for large whales. Many studies have linked the distribution of cetaceans to basic environmental features such as underwater topography and sea surface temperature (SST), but the mechanisms underlying these relationships are poorly understood. Dynamic mesoscale processes like thermal fronts are prime candidates to link physiographic factors to whale distribution because they increase biological productivity and aggregate prey. However, previous studies of large whales have found little evidence of such associations, possibly because they were not at the appropriate spatio-temporal scales. We quantified the relationship between SST fronts and the distribution of blue Balaenoptera musculus, finback B. physalus, humpback Megaptera novaeangliae and minke B. acutorostrata whales in the northern Gulf of St. Lawrence. We compared the distribution of 1094 whale sightings collected from boat surveys conducted in 1996 to 2000 to the locations of frontal areas determined from 61 satellite maps. The distributions of whales and thermal fronts were highly correlated (random resampling and Mantel tests of matrix similarity). Spatial distributions differed among species, probably reflecting differences in feeding strategies. Identification of surface fronts from satellite imagery thus effectively complemented field observations of whales. These findings significantly increase our understanding of habitat quality in rorqual whales, and encourage a greater use of dynamic environmental variables in future studies of whale habitat use. ©2007 Inter-Research

BÉLANGER, S., M. BABIN, P. LAROUCHE, 2008. An empirical ocean color algorithm for estimating the contribution of chromophoric dissolved organic matter to total light absorption in optically complex waters. J. Geophys. Res. (C Oceans), 113(4), art. no C04027, 14 p .

To estimate the depth-integrated rate of photochemical processes involving chromophoric dissolved organic matter (CDOM) in coastal waters, the contribution of CDOM to the total absorption coefficient must be known from UV to green. At 307 sites sampled in various coastal marine environments, the ratio between CDOM and the total absorption coefficient ([aCDOM/at]) at 412 nm was found to vary over a wide range, from 0.20 to 0.95. An empirical algorithm was developed to retrieve [aCDOM/at ](412) from satellite remote sensing reflectance. The absolute uncertainty on the [aCDOM/at ] retrieval was 0.14. As exemplified with the data from the Baltic and North Seas, the algorithm provides a means to distinguish the contribution of CDOM to the absorption coefficient of colored detrital material (i.e., CDM = CDOM + nonalgal particles) at the regional scale. The implications of the variability in the magnitude and spectral shape of [aCDOM/at ] for the assessment of depth-integrated production of any photoproducts involving CDOM photolysis are discussed in details. We applied the algorithm to a Sea-viewing Wide Field-of-View Sensor (SeaWiFS) image of the Southeastern Beaufort Sea where terrestrial inputs are abundant. The spatial variability in the [aCDOM/at ] reaches as much as threefold over the continental shelf and beyond. These results clearly show that it is necessary to account for the spatial variability of [aCDOM/at ] when quantifying CDOM-related photochemical processes in the ocean.©2008 American Geophysical Union

LAVOIE, D., M. STARR, B. ZAKARDJIAN, P. LAROUCHE, 2007. Identification of ecologically and biologically significant areas (EBSA) in the Estuary and Gulf of St. Lawrence: primary production ; Identification de zones d’importance écologique et biologique (ZIEB) pour l’estuaire et le golfe du Saint-Laurent: production primaire. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2007/079, 33 p .

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In this report, we analyse of a large set of chlorophyll a, nitrate, and primary production observations gathered from the early 70's as well as results from a 3D coupled physical-biological model to identify ecologically and biologically significant areas (EBSAs) for primary production in the Gulf and Estuary of St. Lawrence. High phytoplankton production and Chl a concentration are found successively in all regions of the Gulf and Estuary of St. Lawrence, and thus all regions are important for phytoplankton production at one time or another during the year. However, only a few regions stand out as EBSAs if we consider their importance on an annual basis, based on uniqueness and aggregation criteria as defined in CSAS Ecosystem Status Report 2004/006. The most important zones are the Lower Estuary, the Gaspé Current, and the Northwestern Gulf.

GALBRAITH, P.S., D. GILBERT, C. LAFLEUR, P. LAROUCHE, B. PETTIGREW, J. CHASSÉ, R.G. PETTIPAS, W.M. PETRIE, 2007. Physical oceanographic conditions in the Gulf of St. Lawrence in 2006 ; Conditions d'océanographie physique dans le golfe Saint-Laurent en 2006. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2007/024, 51 p .

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An overview of physical oceanographic conditions in the Gulf of St. Lawrence in 2006 is presented. Air and surface water temperatures were above normal except for late summer in most parts of the Gulf. Bottom water temperatures on the Magdalen Shallows were unusually warm; no observations below 0 °C were recorded in September. The yearly total freshwater runoff at Québec City was normal but included an anomalous strong fall peak. Sea ice coverage and volume within the Gulf during the winter was the lowest recorded since 1969. The winter cold mixed layer volume was the smallest recorded in the 11 year history of the winter helicopter survey and corresponded to 29 % of the total water volume of the Gulf. This shallow winter mixed layer led to the CIL index for summer 2006 increasing to +0.21 °C. This is the warmest value since 1983, but only 0.1 °C warmer than in 2000 which was the second warmest. Regional patterns of the CIL minimum temperatures show that increases between 2005 and 2006 were more pronounced in the Laurentian Channel than elsewhere. The minimum temperature actually decreased in Mecatina Trough, presumably due to the increased inflow of a thick layer of cold and highly saline water, which was observed from the annual March survey, through the Strait of Belle Isle. Regional patterns similar to those found for the CIL minimum temperatures were seen in the regional CIL thickness distribution. The CIL volume (T <1 °C) for the Magdalen Shallows during the September groundfish survey was the lowest since 1982. Water temperatures were generally one standard deviation above the mean, based on the 1971-2000 climatology at all depths for most of the year. Exceptions to this included the CIL in Esquiman Channel and Mecatina Trough and the deeper waters (>300 m) of the southern half of the Laurentian Channel which were colder. The most noteworthy thermal features in November were the anomalously deep CIL in the Estuary and northwestern Gulf regions and the anomalously warm waters above the CIL everywhere in the Gulf. The outlook for 2007 based on the March 2007 survey is for a 0.6 °C cooling of the summer CIL index forecast from a thicker winter cold surface layer and increased inflow of Labrador Shelf water through the Strait of Belle Isle.

DU, Y., P. LAROUCHE, P.W. VACHON, 2007. Multi-scale feature tracking in sequential satellite images with wavelet analysis to measure sea surface currents in the Gulf of St. Lawrence. Can. J. Remote Sensing, 33(6): 534-540 .

Measuring sea surface currents is a technological challenge in oceanography. Feature tracking in time series of remote sensing imagery has been proposed as a way to address this problem. The most commonly used approach is the maximum cross-correlation (MCC) method, originally developed to track cloud motion. We propose a new technique that makes use of Daubechies wavelet analysis combined with the MCC method. In our approach, satellite images are decomposed into various spatial scales using the wavelet transform, and the location with the MCC coefficient among all the scales is selected as the most likely new position of the tracked feature. Results from the analysis of five pairs of sequential National Oceanic and Atmospheric Administration (NOAA) advanced very high resolution radiometer (AVHRR) images of the Gulf of St. Lawrence area show that wavelet analysis improves the estimated sea surface current field by increasing the number of current vectors about 20 % under the same confidence level (0.9) as compared with that using the MCC method alone. ©2007 Government of Canada

OUELLET, P., L. SAVARD, P. LAROUCHE, 2007. Spring oceanographic conditions and northern shrimp Pandalus borealis recruitment success in the northwestern Gulf of St. Lawrence. AZMP Bull. PMZA, 6: 47-52 .

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[Abstract only available in French]
Des séries temporelles de la température de surface (TS), de la profondeur de la couche mélangée (en température) et du taux de réchauffement de TS au printemps au moment de l’émergence des larves de crevettes ont été corrélées à des indices de recrutement de la crevette nordique (Pandalus borealis) entre 1994 et 2004 dans le nord-ouest du golfe du Saint-Laurent, Canada. L’indice de la survie larvaire était corrélé négativement avec la moyenne journalière de TS au moment de l’émergence des larves de crevettes. L’indice de la survie larvaire était corrélé positivement avec le taux de réchauffement de TS et la profondeur de la couche mélangée au moment de l’émergence des larves. Dans leur ensemble, les analyses ont révélé que l’émergence des larves de crevettes pendant une période de faibles stratifications de densité et de faibles TS au printemps, suivi d’un taux de réchauffement relativement élevé dans la couche supérieure de la colonne d’eau est favorable à la survie des larves. Notre étude montre aussi l’importance d’un monitorage des conditions océanographiques tôt au printemps dans l’écosystème du nord du golfe du Saint-Laurent.

OUELLET, P., L. SAVARD, P. LAROUCHE, 2007. Spring oceanographic conditions and northern shrimp Pandalus borealis recruitment success in the north-western Gulf of St. Lawrence. Mar. Ecol. Prog. Ser., 339 : 229-241 .

Time series of sea-surface temperature (SST), thermally mixed layer depth, and the SST warming rate in spring at the time of larval emergence were correlated with indices of northern shrimp Pandalus borealis recruitment (cohort abundance and larval survival index) between 1994 and 2003 in the northwest Gulf of St. Lawrence, Canada. The recruitment index and larval survival index were negatively correlated to daily mean SST at the time of larval emergence. The recruitment index and larval survival index were positively correlated with the SST warming rate and with the mixed layer depth at the time of larval emergence. Overall, the analysis reveals that larval emergence during a period of weak density stratification and low SST in the spring, but followed by relatively high warming rates of the upper layer of the water column, is favourable for larval survival. We suggest that the observed relationships support the hypothesis that oceanographic conditions in the upper layer of the water column, which initiate and sustain high levels of biological production at the time of larval emergence and early development, are favourable for northern shrimp recruitment success. Thus, interannual variability in northern shrimp recruitment in the northwest Gulf of St. Lawrence may be explained by Cushing’s match/mismatch hypothesis. ©2007 Inter-Research

DONIOL-VALCROZE, T., D. BERTEAUX, P. LAROUCHE, R. SEARS, 2007. Influence of thermal fronts on habitat selection by four rorqual whale species in the Gulf of St. Lawrence. Mar. Ecol. Prog. Ser., 335: 207-216 .

Understanding the factors influencing habitat selection is critical to improving management and conservation plans for large whales. Many studies have linked the distribution of cetaceans to basic environmental features such as underwater topography and sea surface temperature (SST), but the mechanisms underlying these relationships are poorly understood. Dynamic mesoscale processes like thermal fronts are prime candidates to link physiographic factors to whale distribution because they increase biological productivity and aggregate prey. However, previous studies of large whales have found little evidence of such associations, possibly because they were not at the appropriate spatio-temporal scales. We quantified the relationship between SST fronts and the distribution of blue Balaenoptera musculus, finback B. physalus, humpback Megaptera novaeangliae and minke B. acutorostrata whales in the northern Gulf of St. Lawrence. We compared the distribution of 1094 whale sightings collected from boat surveys conducted in 1996 to 2000 to the locations of frontal areas determined from 61 satellite maps. The distributions of whales and thermal fronts were highly correlated (random resampling and Mantel tests of matrix similarity). Spatial distributions differed among species, probably reflecting differences in feeding strategies. Identification of surface fronts from satellite imagery thus effectively complemented field observations of whales. These findings significantly increase our understanding of habitat quality in rorqual whales, and encourage a greater use of dynamic environmental variables in future studies of whale habitat use. ©2007 Inter-Research

BÉLANGER, S., H. XIE, N. KROTKOV, P. LAROUCHE, W. F. VINCENT, M. BABIN, 2006. Photomineralization of terrigenous dissolved organic matter in Arctic coastal waters from 1979 to 2003: Interannual variability and implications of climate change. Global Biogeochem. Cycles, 20(GB4005), 13 p .

Photomineralization of terrigenous dissolved organic matter (Tdom) in the Arctic Ocean is limited by persistent sea ice cover that reduces the amount of ultraviolet (UV) radiation reaching the underlying water column. UV-dependent processes are likely to accelerate as a result of shrinking sea ice extent and decreasing ice thickness caused by climatic warming over this region. In this study, we made the first quantitative estimates of photomineralization of tDOM in a coastal Arctic ecosystem under current and future sea ice regimes. We used an optical-photochemical coupled model incorporating water column optics and experimental measurements of photoproduction of dissolved inorganic carbon (DIC), the main carbon product of DOM photochemistry. Apparent quantum yields of DIC photoproduction were determined on water samples from the Mackenzie River estuary, the Mackenzie Shelf, and Amundsen Gulf. UV irradiances just below the sea surface were estimated by combining satellite backscattered and passive microwave radiance measurements with a radiative transfer model. The mean annual DIC photoproduction between 1979 and 2003 was estimated as 66.5 ± 18.5 Gg carbon in the surface waters of the southeastern Beaufort Sea, where UV absorption is dominated by chromophoric dissolved organic matter discharged by the Mackenzie River. This value is equivalent to 10 % of bacterial respiration rates, 8 % of new primary production rates and 2.8 ± 0.6 % of the 1.3 Tg of dissolved organic carbon (DOC) discharged annually by the Mackenzie River into the area. During periods of reduced ice cover such as 1998, the latter value could rise to 5.1 % of the annual riverine DOC discharge. Under an ice-free scenario, the model predicted that 150.5 Gg of DIC would be photochemically produced, mineralizing 6.2 % of the DOC input from the Mackenzie River. These results show that the predicted trend of ongoing contraction of sea ice cover will greatly accelerate the photomineralization of tDOM in Arctic surface waters.&Copy2006 the American Geophysical Union.

LAROUCHE, P., 2006. Activities of the remote sensing laboratory at the Maurice Lamontagne Institute;Les activités du laboratoire de télédétection à l’Institut Maurice-Lamontagne. AZMP Bull. PMZA, 5: 53-56 .

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This article describes research projects and operational activities of the remote sensing laboratory at the Maurice Lamontagne Institute (DFO Quebec Region) since its beginning in 1988.

DJAGOUA, E.V., K. AFFIAN, P. LAROUCHE, M.B. SALEY, 2006. Variabilité saisonnière et interannuelle de la chlorophylle en surface de la mer sur le plateau continental de la Côte d'Ivoire à l'aide des images de SeaWiFS, de 1997 à 2004 ; Seasonal and interannual variability of the sea surface chlorophyll on the continental shelf of the Ivory Coast : an investigation using SeaWiFS and AVHRR data from 1997 to 2004. Télédétection, 6(2): 143-151 .

Remote sensing is the principal tool used in this study. This study tries to show how to connect the characteristics of sea water and fish catches. The analysis of the phytoplankton biomass was carried out in the marine ecosystem of the Ivory Coast from September, 1997 to December, 2004. The adopted procedure is to analyze the remote sensing data in order to have the same seasonal and interannual informations. Thus, the harmonious use of the data resulting from the analysis of the time series data derived from the visible channel (SeaWiFS/Obview-2) and thermal infrared images (AVHRR/NOAA) showed that : When the sea surface temperature is low (<24 °C), the chlorophyll concentration is maximum (>1,5mg/m3); Yearly, the chlorophyll concentration presents an accentuated seasonal variation between July and September; Annually, strong concentrations are observed from July to September 2002 and 2004; The large fish catches coincide with the presence of upwelling, characterized by the fall of the sea surface temperature and an increase in the sea surface chlorophyll oncentration.©2006 Contemporary Publishing International

MUSTAPHAL, S.B., P. LAROUCHE, S. BÉLANGER, M. BABIN, 2006. Evaluation of ocean color algorithms in the Cape Bathurst polynya using MODIS and SeaWiFS spectral bands. 8 p. in Proceedings of Ocean Optics Conference XVIII, Montréal, Canada, 9-13 October 2006 .

BÉLANGER, S., M. BABIN, H. XIE, N. KROTKOV, P. LAROUCHE, W. F. VINCENT, 2006. CDOM photooxidation in the Arctic coastal waters: new approach using satellite informations and implications of climate change. 13 p in Proceedings of Ocean Optics Conference XVIII, Montréal, Canada, 9-13 October 2006 .

YAYLA, M., N.T. O’NEILL, P. LAROUCHE, S. ÇIZMELI, S.-E. ZIDANE, 2006. Local remote sensing algorithm development for chlorophyll estimation in the estuary and gulf of Saint Lawrence. 10 p in Proceedings of Ocean Optics Conference XVIII, Montréal, Canada, 9-13 October 2006 .

ZIDANE, S-E, N.T. O’NEILL, P. LAROUCHE, S. ÇIZMELI, M. YAYLA, 2006. Use of multi-altitude imaging spectrometry for validating the SeaWiFS atmospheric correction algorithm over the St. Lawrence Estuary and the Gulf of St. Lawrence. 5 p. in Proceedings of Ocean Optics Conference XVIII, Montréal, Canada, 9-13 October 2006 .

MATSUOKA, A., P. LAROUCHE, M.-È. GARNEAU, K. SIMPSON, S.-I. SAITOH, H. HATTORI, 2006. Dramatic change of bio-optical properties before and after sea ice production in the mouth of the Mackenzie River and the Cape Bathurst polynya regions, Canadian Artic. 10 p in Proceedings of Ocean Optics Conference XVIII, Montréal, Canada, 9-13 October 2006 .

ÇIZMELI, S.A., N. O'NEILL, S. ROY, M. YAYLA, P. LAROUCHE, B. CEMBELLA, 2006. Inherent optical properties of the St. Lawrence estuary and gulf. 16 p in Proceedings of Ocean Optics Conference XVIII, Montréal, Canada, 9-13 October 2006 .

LAROUCHE, P., J.-M. BOUCHER, É. THOMASSIN, 2006. Development of a surface feature motion estimation system for the Gulf of St. Lawrence using SST images. Can. Tech. Rep. Hydrogr. Ocean Sci., 250, 21 p .

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We present an image processing system to evaluate sea surface feature motion using pairs of sequential sea surface temperature images. The system uses a set of filters to produce the best possible tracers and a combination of shape-matching and Hough transform to evaluate tracer motion. A set of optimal parameters was defined, balancing the number of vectors produced and their quality for the Gulf of St. Lawrence region. This set was used to process 19 image pairs representing diverse time intervals and seasons. When false vectors generated by clouds were eliminated, approximately 50 % of the calculated displacement vectors were of good quality. This could be improved but at the detriment of the number of vectors. The best results are obtained when the images are separated by only one satellite orbital period.

HUDIER, E., P. LAROUCHE, 2005. A potential of polarimetric SAR data in mapping first year sea ice pressure ridges from the coherent and non-coherent components of HH and VV channels. EARSeL eProc., 4(1), 130-138 .

During the early melt period, the air-ice and air-snow temperature conditions may vary from melting to freezing within 12 hours. When solar irradiance and air temperature are at their maximum, the increased wetness of the snow layer coupled with the development of a liquid film on exposed ice faces increases the contrast between ridges and flat ice areas. We present two images recorded at 4 am and 4 pm that show this natural enhancement process of ridges when a liquid phase is present on ice blocks (4 pm). Besides, it also shows that, on the contrary, the development of new ice crystals during the night create conditions that highly reduce the contrast between ridges and flat ice areas (4 am image). For smooth wet surfaces the backscattering at normal incidence is dominated by the coherent component. In addition, the non-coherent component is maximum at normal incidence. The variability in surface slope orientations being a characteristic of ridge areas, we computed probability densities that pixels from ridge regions would be identified as ridge pixels. Both coherent and non-coherent models show a dependence on block size and the applied threshold value. As anticipated, the coherent model gives the highest probability levels with a maximum for cubic blocks of 0.4 m. The maximum value with non-coherent backscattering is reached for 1 m blocks. ©2005 European Association of Remote Sensing Laboratories/BIS-Verlag

LAROUCHE, P., U. BOYER-VILLEMAIRE, 2005. A SeaWiFS algorithm to measure low concentrations of suspended matter in the St. Lawrence estuary. 5 p. in 8th International Conference on Remote Sensing for Marine and Coastal Environments, Halifax, Nova Scotia, Canada, 17-19 May 2005 : proceedings .

Since 1997, the Remote Sensing Laboratory of the Maurice-Lamontagne Institute (Dept. Of Fisheries and Oceans, Canada) has been conducting an ocean optics research program. This paper presents the development of an algorithm to evaluate total suspended sediment in the mixed type I and II waters of the St. Lawrence estuary and gulf using SeaWiFS data. The algorithm was developped using a set of multispectral light profiles taken during an optics research cruise in 2001 and validated against 40 independent SeaWiFS overpass and in situ measurements taken during 4 other cruises (1997-2000). Many algorithms were tested but the best one is based on a regression of the total suspended sediment concentration with the 670 nm band. Results of the validation test show that the algorithm performs very well for the St. Lawrence sediment concentration range (0-3 mg -1) with a mean RMS error of 0,21 mg -1. This development now offers us a potential tool to evaluate the spatial and temporal variability of suspended sediment in the surface layer using the 7 years of available SeaWiFS data.©2005 Her Majesty in Right of Canada as represented by the Minister of Fisheries and Oceans

LAROUCHE, P., J.-M. DUBOIS, 2004. Introduction au numéro 4(2): La télédétection en océanographie. Télédétection, 4(2): 99-101 .

LAROUCHE, P., 2004. L'estimation des courants de surface par télédétection ; Estimation of surface currents by remote sensing. Télédétection, 4(2): 139-155 .

Surface currents are an important oceanographic parameter to measure for the monitoring of oceanographic features such as gyres,coastal currents and other dynamical features. Remote sensing tools can be used to measure these currents over large marine areas. We present a review of the use of statistical (cross correlation, wavelets, Hough transform, shape-matching, and neural networks), physical models (heat conservation equation), feature tracking in ice covered regions (free drift motion equation) and radar interferometric tools to process either pairs or single images. We discuss forces and weaknesses of each approach and present a series of examples from the literature to show their potential to evaluate surface current.©2004 Contemporary Publishing International

BARBIERI, M.A., C. SILVA, P. LAROUCHE, K. NIETO, E. YANEZ, 2004. Detection of mesoscale oceanic features using RADARSAT-1, AVHRR and SeaWIFS images and the possible link with jack mackerel (Trachurus murphyi) distribution in Central Chili. Gayana (Concepc.), 68(2), supl. T.I. Proc.: 29-39 .

In order to verify the ability of RADARSAT-1 images to detect mesoscale oceanic features and the possible link of these oceanographic patterns with jack mackerel (Trachurus murphyi) distribution in the waters off central Chile, a project was developed as part of the Canada Centre for Remote Sensing Globesar-2 program. The combined use of simultaneously acquired RADARSAT-1, AVHRR sea surface temperature (SST), SeaWiFS Chlorophyll a concentration (Chl), TOPEX/ERS altimeter and ERS-2 catterometer wind data greatly enhanced SAR imaging capabilities for the detection of oceanic features. Results show that detection of coastal wind-driven upwellings, eddies, frontal boundaries and phytoplankton blooms is possible using SAR imagery, given the proper environmental conditions. Results also suggest that jack mackerel distribution coastal resources is mainly associated with frontal boundaries, upwelling waters and high chlorophyll concentrations detected by the remotely sensing images.©2005 Universidad de Concepción.Facultad de Ciencias Naturales y Oceanográficas

LAROUCHE, P., B. PETTIGREW, R. PIGEON, 2003. Optical buoy network in the St. Lawrence Estuary and Gulf. Pages 1-13 in Larouche P., B. Pettigrew & R. Pigeon. Seventh International Conference on Remote Sensing for Marine and Coastal Environments, Miami, 20-22 May 2002 .

LAROUCHE, P., M. EL-MOUTTAKI, A. DJOUAI, 2003. Spectroradiométrie de la matière particulaire dans l'Oued Sebou (Maroc) : application aux données de télédétection. Télédétection, 3(1): 85-96 .

LAROUCHE, P., B. PETTIGREW, 2003. Oceanographic buoy network in the Gulf of St. Lawrence. AZMP Bull. PMZA, 3: 42-45 .

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[Abstract only available in French]
Le Laboratoire de Télédétection de l'Institut Maurice-Lamontagne reçoit et traite des images NOAA-AVHRR et SeaWiFS afin d’utiliser la couleur et la température de surface de l’eau comme outils de suivi de l’environnement. Pour ce faire, des algorithmes standards développés à l’aide de données océanographiques sont utilisés. Cependant, l’utilisation de ces algorithmes pour les eaux des mers intérieures comme celles du golfe du Saint-Laurent et de la baie d’Hudson cause problème puisque ces environnements sont fortement influencés par de forts débits d’eau douce qui transportent avec eux une grande quantité de matières organiques particulaires et dissoutes qui ont une influence significative sur les mesures de télédétection. De plus, l’atmosphère au-dessus de ces mers intérieures est influencée par des aérosols de type continentaux, ce qui affecte la qualité des mesures. Il est donc très important de pouvoir valider ces algorithmes avec des mesures de terrain et/ou encore, d’en développer de nouveaux qui sont mieux adaptés aux conditions particulières des régions sous forte influence des débits d’eau douce. Nous avons entrepris un tel projet dans le golfe du Saint-Laurent avec l’aide de l’Agence Spatiale Canadienne. Comme la fréquence d’échantillonnage (toutes les deux semaines) aux stations fixes du Programme de Monitorage de la Zone Atlantique (PMZA) n’est pas bien adaptée à ce type de travail de validation d’images satellites, nous avons opté pour le développement d’une nouvelle bouée océanographique qui permettrait d’obtenir des mesures de terrain en temps réel. Nous avons donc décidé de mettre en place un réseau d’observation du Saint-Laurent composé, dans un premier temps, de 3 bouées localisées dans des régions très différentes de l’écosystème du Saint-Laurent (l’estuaire, le sud et le nord-est du Golfe). L’accès en temps réel aux résultats des bouées peut se faire en consultant l’adresse Internet suivante: www.osl.gc.ca. Dans le présent article, nous décrivons le projet plus en détail et nous présentons quelques résultats provenant des deux premières années d’échantillonnage de la bouée mouillée à la station de Rimouski (IML-4). Ces résultats indiquent qu’il existe une relativement bonne concordance entre les données provenant de la bouée et celles provenant du monitorage régulier à cette station pour le suivi de la variabilité saisonnière. Toutefois, les données de la bouée indiquent également qu’il existe une grande variabilité à plus courte échelle de temps et qu’il est possible de détecter des événements océanographiques importants qui peuvent passer complètement inaperçus à l’échelle de temps du monitorage régulier (deux semaines). En plus de contribuer au monitorage environnemental, les données obtenues par les bouées océanographiques peuvent aussi servir à des projets de recherche scientifique de nature plus fondamentale. Par exemple, les données optiques obtenues indiquent qu’il pourrait être possible de développer un algorithme utilisant des données de télédétection de couleur de la mer pour mesurer la salinité dans les milieux possédant de forts gradients horizontaux. La mise en place de notre réseau de bouées n’est pas encore terminée. Nous comptons ajouter une seconde bouée en 2004 à la station de monitorage de Shédiac (sud du golfe, IML-6) et une troisième bouée est prévue pour 2005 à la station du Banc Beaugé (nord-est du golfe, IML-2). Il convient en terminant de noter qu’il sera facilement possible d’intégrer de nouveaux senseurs aux bouées de base afin de les rendre plus polyvalentes et ainsi participer encore plus fortement aux activités du PMZA.

KLEIN, B., B. LEBLANC, Z.-P. MEI, R. BERET, J. MICHAUD, C.-J. MUNDY, C.H. VON QUILLFELDT, M.-È. GARNEAU, S. ROY, Y. GRATTON, J. KIRK COCHRAN, S. BÉLANGER, P. LAROUCHE, J. DEAN PAKULSKI, R.B. RIVKIN, L. LEGENDRE, 2002. Phytoplankton biomass, production and potential export in the North Water. Deep-Sea Res., Part II, 49: 4983-5002 .

MEI, Z.-P., L. LEGENDRE, Y. GRATTON, J.-É. TREMBLAY, B. LEBLANC, C.J. MUNDY, B. KLEIN, M. GOSSELIN, P. LAROUCHE, T.N. PAPAKYRIAKOU, C. LOVEJOY, C.H. VON QUILLFELDT, 2002. Physical control of spring-summer phytoplankton dynamics in the North Water, April-July 1998. Deep-Sea Res., Part II, 49: 4959-4982 .

BOOTH, B.C., P. LAROUCHE, S. BÉLANGER, B. KLEIN, D. AMIEL, Z.P. MEI, 2002. Dynamics of Chaetoceros socialis blooms in the North Water. Deep-Sea Res., Part II, 49: 5003-5025 .

THIBAULT, B., P. LAROUCHE, J.-M. M. DUBOIS, 2002. Variabilité des phénomènes hydrodynamiques de l'estuaire supérieur du Saint-Laurent à l'aide des données thermiques TM de Landsat-5. Int. J. Remote Sens., 23: 511-524 .

RINGUETTE, M., L. FORTIER, M. FORTIER, J.A. RUNGE, S. BÉLANGER, P. LAROUCHE, J.-M. WESLAWSKI, S. KWASNIEWSKI, 2002. Advanced recruitment and accelerated population development in Arctic calanoid copepods of the North Water. Deep-Sea Res., Part II, 49: 5081-5099 .

B. PETRIE, J.-C. THERRIAULT, G. HARRISON, V. SOUKHOVTSEV, P. PEPIN, M. HARVEY, M. STARR, P. LAROUCHE, S. SAMEOTO, 2001. The Atlantic Zone Monitoring Program;Le programme de monitorage de la zone atlantique. AZMP Bull. PMZA, 1: 1-12 .

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LAROUCHE, P., 2000. Field intercomparison of two current meters in an under-ice environment under conditions of low current speeds. Can. Tech. Rep. Hydrogr. Ocean Sci., 210, 17 p .

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Data from two current meters moored in an under-ice environment were compared to estimate their response in the absence of wind-induced current meter motion. The instruments were an Aanderaa RCM4S and an Applied Microsystems VACM-12. Results show that the RCM4S overread the VACM by about 1 cm s-1 over the entire speed range encountered (0-15 cm s-1). A large mean direction difference (20°) was also noted between the two instruments. The source of this problem may be that the mooring anchor was too close to the instruments. Finally, the VACM direction sensor showed a tendency to stall and give the same reading over many consecutive samples while the RCM4S direction was changing. No explanation has been found for this behavior

ACKER, J., P. LAROUCHE, 2000. Ocean color spectrum : a compilation of international news relevant to the ocean color research community. Backscatter, Feb.: 21-22 .

LAROUCHE, P., 2000. Results from the 2nd St. Lawrence estuary and Gulf SeaWIFS validation cruise. Pages I351-I358 in Proceeding of the 6th International Conference on Remote Sensing for Marine and Coastal Environments, Charleston, South Carolina, May 1-3 .

SAVARD, L., 2000. Comparison of in situ-and satellite-derived quantities of CDOM and chlorophyll A in the St. Lawrence Estuary and Gulf, Canada. 1 page in Ocean Optics XV Conference, Monaco, 16-20 October, 2000 .

HUDIER, E., C. FUENTES, P. LAROUCHE, 1999. Extraction des crêtes de pression sur images Radarsat en mode fin. Pages 629-636 in Fourth International Airborne Remote Sensing Conference and Exhibition/21st Canadian Symposium on Remote Sensing, Ottawa, Canada, 21-24 June 1999 .

HABBANE, M., J.-M. DUBOIS, M.I. EL-SABH, P. LAROUCHE, 1998. Empirical algorithm using Sea WiFS hyperspectral bands : a simple test. Int. J. Remote Sens., 19: 2161-2169 .

LAROUCHE, P., 1998. SeaWiFS validation program in the St. Lawrence estuary and gulf. Pages II-349 - II-359 in Proceedings of the 5th International Conference on Remote Sensing for Marine and Coastal Environments, San Diego, California, 5-7 october, 1998 .

LAROUCHE, P., É. THOMASSIN, J.-M. BOUCHER, H. DUBOIS, 1998. Mesure de courants de surface par suivi de traceurs sur des images satellitaires. Pages 199-206 in J.M.M. Dubois, M. Bernier, J.-P. Fortin & F. Boivin (éd.). La réalité de terrain en télédétection : pratiques et méthodes. (Actes des 7e Journées scientifiques du Réseau Télédétection de l'AUPELF-UREF, Sainte-Foy, Québec, 13-17 oct 1997) .

[Abstract only available in French]
La mesure des courants de surface repose généralement sur des techniques lagrangiennes utilisant des dériveurs de surface. Une variation de cette approche consiste à estimer le déplacement de traceurs visibles sur des images satellitaires A VHRR de NOAA consécutives. Dans cet article, on présente le développement d'une méthode opérationnelle servant à estimer le courant de surface à l'aide de séries d'images de température de surface de la mer et d'une combinaison des techniques de transformée de Hough et de reconnaissance de formes (shape-matching). Divers tests réalisés ont montré que la méthode peut évaluer des vecteurs de déplacement acceptables environ 50  % du temps. Les meilleures performances sont atteintes lorsque les images ne sont séparées que de quelques heures.©1998 AUPELF-UREF

FUENTES-YACO, C., A.F. VÉZINA, M. GOSSELIN, Y. GRATTON, P. LAROUCHE, 1997. Influence of late-summer storms on the horizontal variability of phytoplankton pigment determined by Coastal Zone Color Scanner images in the Gulf of St. Lawrence, Canada. Pages 678-683 in S.G. Ackleson & R.J. Frouin (ed.). Ocean Optics XIII : proceedings .

The western Gulf of St. Lawrenoe (GSL) is characterized by high, persistent phytopIankton production and functions as the principal supplier of phytoplankton biomass for the central and eastern Gulf. The main objective of this study was to report on the evolution of a wind-induced phytopIankton bloom in this region. We used Coastal Zone Color Scanner images taken on 20, 22, 28, and 30 August 1980 to calculate phytoplankton pigment concentration, sea surface temperature and water reflectance fields. We coupled the satellite information with storm track, wind, air temperature, and bright sunshine data. A strong storm blew over the Gulf between 15 and 17 August, triggering upwelling and mixing processes that resumably made high nutrient concentrations available in the euphotic layer. High atmospheric pressure and southwesterly winds between 18 and 25 August allowed air and water temperatures to rise, stabilizing the water column and stimulating phytoplankton growth. A northern storm between 25 and 27 August associated with clear weather and low temperatures between 28 and 30 August, coinciding with the bloom decline. Water-normalized reflectance values suggested that the estuarine region was characterized by diatoms, the western-central GSL by a mixed composition of diatoms/small flagellates/coccolithophorids, and the eastern-central region by coccolithophorids and small flagellates. These blooms may be critical for fish recruitment. Cooling and warming of the water column by meteorological events seem to be intermittent but frequent at this time of year. The resulting nutrient input may support phytoplankton blooms of intensities similar to or higher than those recorded during spring in the western region of the Gulf.©1997 SPIE

LAROUCHE, P., 1997. Les techniques de télédétection au service des sciences de la mer. Naturaliste can., 121(1): 58-62 .

FUENTES-YACO, C., A.F. VÉZINA, P. LAROUCHE, Y. GRATTON, M. GOSSELIN, 1997. Phytoplankton pigment in the Gulf of St. Lawrence, Canada, as determined by the Coastal Zone Color Scanner - Part II : Multivariate analysis. Cont. Shelf Res., 17: 1441-1459 .

FUENTES-YACO, C., A.F. VÉZINA, P. LAROUCHE, C. VIGNEAU, M. GOSSELIN, M. LEVASSEUR, 1997. Phytoplankton pigment in the Gulf of St. Lawrence, Canada, as determined by the Coastal Zone Color Scanner - Part I : Spatio-temporal variability. Cont. Shelf Res., 17(12): 1421-1439 .

LAROUCHE, P., É. THOMASSIN, J.-M. BOUCHER, H. DUBOIS, 1997. Sea surface velocity estimations using SST images. Pages I-431-I438 in 4th International Conference on Remote Sensing for Marine and Coastal Environments, Orlando, Florida, 17-19 March 1997 .

THERRIAULT, J.-C., D. GILBERT, P. LAROUCHE, D. LEFAIVRE, B. PELCHAT, 1997. L'estuaire et le golfe du Saint-Laurent scrutés de près. Le Fleuve : bull. d’inf., 8(1) : 2-4 .

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[Abstract only available in French]
La mer n’est pas inépuisable. La chute des stocks de morue dans l’est du Canada et les manchettes faisant état depuis quelques années des difficultés des pêcheurs aux deux extrémités du pays ont puissamment contribué à sensibiliser le grand public à la nécessité de mieux connaître le milieu marin, si l’on veut en gérer les ressources durablement.©1997 Saint-Laurent Vision 2000

SIMARD, N., J.-C. THERRIAULT, P. LAROUCHE, A. VÉZINA, J. PLOURDE, J. PERCY, D.A. STEEL, 1996. Données d'océanographie physique et biologique recueillies dans l'est et le nord de la baie d'Hudson et dans le détroit d'Hudson en août et septembre 1993. Rapp. stat. can. sci. halieut. aquat., 978, 199 p .

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This report presents physical and biological oceanograpahic data of the eastern and northern parts of Hudson Basin that were obtained during a sampling mission of 84 stations conducted between 22 August and l5 September l993. A summary table identifies variables measured at each station. The vertical profiles of temperature, salinity, in situ fluorescence, chlorophyll a, particulate organic carbon and nitrogen, and nutrients are presented as well as phytoplankton and zooplankton counts and zooplankton biomass determination. Photosynthetic parameters calculated from P-l curves and estimates of total primary production at the surface are also provided. (DBO).

GILBERT, M., D. GAUTHIER, J.A. GAGNÉ, Y. GRATTON, P. LAROUCHE, B. MORIN, R. MORIN, J.A. PERCY, T.G. SMITH, G.-H. TREMBLAY, G. WALSH, 1996. Hypothèses reliées aux effets environnementaux du projet Grande Baleine sur l'écosystème marin côtier du sud-est de la baie d'Hudson. Rapp. tech. can. sci. halieut. aquat., 2127, 67 p .

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The possible realization of the Grande Baleine hydroelectric development project could have significant biophysical impacts on the coastal marine environment of southeastern Hudson Bay.This document presents the results of discussions held within a working group composed of scientific personnel of the Department of Fisheries and Oceans - Laurentian Region that defined, in the form of hypotheses and research proposals, the environmental aspects related to the realization of the Grande Baleine hydroelectric project. These aspects mainly concern the physical, chemical, and biological oceanography of southeastern Hudson Bay as well as the biology of some important species of fish and marine mammals inhabiting this region. A brief description of the actual and planned hydroelectric developments in the hydrographic basin of James and Hudson bays, as well as a synthesis of ongoing research activities and knowledge acquired to date on the marine environment of this region, are also presented.

LAVOIE, D., Y. SIMARD, J. BENOÎT, P. LAROUCHE, B. THIBEAULT, 1996. Distribution des masses d'eau à la tête du chenal laurentien dans l'estuaire du Saint-Laurent aux étés 1994 et 1995. Rapp. tech. can. hydrogr. sci. océan., 176, 126 p .

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Satellite thermal images and temperature and salinity profiles, taken during the summers of 1994 and 1995, are used to describe the water masses at the head of the Laurentian channel. The three typical water masses of this system; the surface, the intermediate and the bottom layers showed : 1) a thinning and an elevation of the cold intermediate layer at the end of the summer, associated with a thickening of the bottom layer, 2) a colder intermediate layer in 1995, 3) a recurrent spatial structure, characterized by a convergence of the cold intermediate layer off Les Escoumins. Upwelling of intermediate cold waters at the head of the Laurentian channel was observed most of the time, as well as many fronts associated with its contact with adjacent waters from the Saguenay and the upper estuary. Our results suggest that the intensity and occurrence of these phenomena were modulated by the fortnightly tidal cycle and by the wind which regularly generated cold water upwelling along the north shore.

LAROUCHE, P., C. FUENTES-YACO, A.F. VÉZINA, 1996. Spatio-temporal variability of phytoplankton pigments in the Gulf of St. Lawrence as measured by CZCS. International Archives of Photogrammetry and Remote Sensing, 31(B7): 406-411 .

LAROUCHE, P., 1996. Observation of the Gaspé current using ERS-1 SAR. Can. J. Remote Sensing, 22: 420-427 .

LAROUCHE, P., A. LAVOIE, 1996. Applications de la télédétection à l'étude des océans. Pages 345-392 in F. Bonn (éd.). Précis de télédétection. Vol. 2, Applications thématiques. Presses de l'Université du Québec .

FUENTES-YACO, C., P. LAROUCHE, A. VÉZINA, C. VIGNEAU, M. GOSSELIN, 1995. Catalogue of phytoplankton pigment images from the Gulf of St. Lawrence : Coastal Zone Color Scanner data from 1979 to 1981. Can. Data Rep. Hydrogr. Ocean Sci., 135, 91 p .

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This catalog presents surface phytoplankton pigments concentrations (chlorophyll a plus phaeophytin) calculated using Coastal Zone Color Scanner (CZCS) images of the St. Lawrence Gulf. The data set consists of 80 images taken between March and September for the years 1979 to 1981.

SAUCIER, F., P. LAROUCHE, J. DIONNE, 1994. Moored physical oceanographic data from northeastern Hudson Bay between August 1992 and September 1993. Can. Data Rep. Hydrogr. Ocean Sci., 132, 78 p .

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Ten moorings (28 current-meters, 4 tide guages and 4 thermistor chains) were deployed between August 1992 and September 1993 in the four straits bounding northern Hudson Bay. The objective was to measure the annual cycle in mass, heat, and salt exchange between Hudson Bay, Hudson Strait, and Foxe Basin. Validated hourly data are presented. The means and standard deviations of temperature, salinity, density and velocity data are also presented, along with the main tidal constituent analyses of the current stream and tide guage records.

LAROUCHE, P., 1994. Observations of a coastal current using ERS-1 SAR. Pages 249-251 in Proceedings of the WMO/IOC Technical conference on space-based ocean observations, Bergen, Norway, Sept. 1993 (WMO/TD, 649) .

LAROUCHE, P., A. GOSSELIN, 1994. Ocean monitoring using a small AVHRR receiving system : data acquisition, management and analysisL. Pages I-441-I-443 in Oceans 94 : oceans engineering for today's technology and tomorrow's preservation : proceedings, volume I. Institute of Electrical and Electronics Engineers, New York .

De LISLE, D.A., G. DRAPEAU, P. LAROUCHE, C. BJERKELUND, 1994. Coastal evolution monitoring using remote sensing. Pages 119-124 in Proceedings of the WMO/IOC Technical conference on space-based ocean observations, Bergen, Norway, Sept. 1993 (WMO/TD, 649) .

De LISLE, D.A., G. DRAPEAU, P. LAROUCHE, C. BJERKELUND, 1993. Potentiel du radar à antenne synthétique pour caractériser l'évolution des littoraux. Pages 307-310 in P. Gagnon & N. O'Neil (éd.). Actes du 16e Symposium canadien sur la télédétection ; 8e Congrès de l'Association québécoise de télédétection, 7-10 juin 1993, Sherbrooke (Québec) .

LAROUCHE, P., 1993. Profils de salinité et de température recueillis dans le courant de Gaspé. Volume 1, Septembre 1991. Rapp. stat. can. hydrogr. sci. océan., 119(1), 119 p .

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Salinity and temperature profiles were collected between 1991 and 1993 in the Gaspe current between Les Mechins and Mont- Louis. These measurements were made during the course of a research project focusing on the possibility of coastal current detection using remote sensing and on the internal dynamics of the Gaspe current. This volume is the first of a serie of four and includes data collected during a fall 1991 survey.

FUENTES-YACO, C., P. LAROUCHE, A.F. VÉZINA, 1993. Primary production in the Gulf of St. Lawrence : 1979-80, CZCS Imagery. Pages 113-118 in P. Gagnon & N. O'Neil (ed.). Proceedings of the 16th Canadian Symposium on Remote Sensing; 8e Congrès de l'Association québécoise de télédétection, June 7-10, 1993, Sherbrooke (Quebec) .

HUDIER, E.J.-J., D. De LISLE, P. LAROUCHE, 1993. Analyse de la distribution des crêtes de pression sur image satellitaire. Journal canadien de télédétection, 19: 83-87 .

LAROUCHE, P., 1993. Profils de salinité et de température recueillis dans le courant de Gaspé. Volume 2, Mai 1992. Rapp. stat. can. hydrogr. sci. océan., 119(2), 134 p .

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Salinity and temperature profiles were collected between 1991 and 1993 in the Gaspe current between Les Mechins and Mont-Louis. These measurements were made during the course of a research project focusing on the possibility of coastal current detection using remote sensing and on the internal dynamics of the Gaspe current. This volume is the second of a serie of four and includes data collected during a spring 1992 cruise.

LAROUCHE, P., 1993. Profils de salinité et de température recueillis dans le courant de Gaspé. Volume 3, Août 1992. Rapp. stat. can. hydrogr. sci. océan., 119(3), 96 p .

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Salinity and temperature profils were collected between 1991 and 1993 in the Gaspe current between Les Mechins and Mont- Louis. These measurements were made during the course of a research project focusing on the possibility of coastal current detection using remote sensing and on the internal dynamics of the Gaspe current. This volume is the third of a serie of four and includes data collected during a summer 1992 cruise.

LAROUCHE, P., 1993. Profils de salinité et de température recueillis dans le courant de Gaspé. Volume 4, Juin 1993. Rapp. stat. can. hydrogr. sci. océan., 119(4), 46 p .

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Salinity and temperature profiles were collected between 1991 and 1993 in the Gaspe current between Les Mechins and Mont- louis. These measurements were made during the course of a research project focusing on the possibility of coastal current detection using remote sensing and on the internal dynamics of the Gaspé current. This volume is the last of a serie of four and includes data collected during a summer 1993 survey.

PETTIGREW, B., P. LAROUCHE, 1992. Données courantométriques et météorologiques dans le sud-est de la baie d'Hudson durant l'hiver 1986. Rapp. stat. can. hydrogr. sci. océan., 113, 87 p .

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Oceanographic and meteorological data were taken during the winter of 1986 in southeastern Hudson Bay between the Great Whale River mouth and Belcher islands. These measurements were part of a study to understand the influence of the atmospheric pressure gradient on the evolution of the Great Whale River plume. Data from current meters (current, temperature and salinity) and from a meteorological station (winds, atmospheric pressure, solar radiation and relative humidity) are presented in this report. A statistical analysis of current meter data, a harmonic tidal analysis and a spectral analysis of current components are also included. (DBO).

LAROUCHE, P., C. CARIOU, 1992. Directional wave spectra estimation in a marginal ice zone using linear prediction. J. Phys. Oceanogr., 22: 196-206 .

LAROUCHE, P., G. DRAPEAU, C. CARIOU, 1991. Detection of 2-D nearshore wave patterns using linear prediction and SAR data. Pages 2645-2652 in Coastal Zone '91 : proceedings of the Seventh Symposium on Coastal and Ocean Management, Long Beach, California July 8-12 .

LAROUCHE, P., J.-M.M. DUBOIS, 1990. Dynamical evaluation of the surface circulation using remote sensing of drifting ice floes. J. Geophys. Res. (C Oceans), 95(C6): 9755-9764 .

LAROUCHE, P., 1990. Winter offshore/onshore wind differences in southeastern Hudson Bay, Canada. Arctic, 43: 55-59 .

REEVES, R.R., E.G. ATKINSON, J. BOULVA, A. GASTON, J. GREEN, P. LAROUCHE, D. MUDRY, J. PERCY, T.G. SMITH, 1990. Report of marine birds and mammals working group. Pages 33-38 in J.A. Percy (ed.). Proceedings of a workshop : Marine Ecosystem Studies in Hudson Strait, November 9-10, 1989, Montréal, Québec. Dept. of Fisheries and Oceans (Can. Tech. Rep. Fish. Aquat. Sci., 1770) .

LAROUCHE, P., 1989. Spring surface circulation patterns detected using remote sensing of drifting ice floes in Hudson Bay, Canada. Pages 780-782 in Proceedings of the International Geoscience and Remote Sensing Symposium, 12-14 July 1989, Vancouver, Canada .

LAROUCHE, P., J.-C. DEGUISE, 1989. Field intercomparison of three current meters in an environment free from high frequency motion. Cont. Shelf Res., 9: 555-568 .

TAGGART, C.T., K.F. DRINKWATER, K.T. FRANK, J. McRUER, P. LAROUCHE, 1989. Larval fish, zooplankton community structure, and physical dynamics at a tidal front. Rapp. P-v. Réun. CIEM, 191: 184-194 .

LAROUCHE, P., J.-C. DEGUISE, 1989. Field intercomparison of three current meters in an environment free from high frequency motion. Cont. Shelf Res., 9(6): 555-568 .

An intercomparison of three different types of current meter was performed in an Arctic environment where wave action was absent, permitting the evaluation of the instruments under natural conditions of weak currents and cold water. The instruments were an Aanderaa RCMS4S, an Inter Ocean S4 and an EG&G–Neil Brown Smart Acoustic Current Meter (SACM). The S4 and the SACM both showed their ability to measure very small currents as opposed to the RCM4S which is limited by a mechanical rotor threshold. The agreement of the direction was better between the RCM4S and the SACM than between the RCM4S and the S4. Due to the isalignment of the Aanderaa vane in very weak currents, direction differences between the instruments of either pair can, however, reach 180 °. The misalignment also shields the Aanderaa rotor leading to underestimation of current speed. The threshold for a good speed reading for the Aanderaa can be put conservatively at 5 cm s-1. Above this value, the RCM4S over-responded compared to both the S4 and the SACM. The source of that problem seems to be related to different calibrations of the instruments. Finally a power spectrum analysis showed that the RCM4S, when not influenced by wave action, can produce a measure of the energy as good as that of a vector averaging instrument.©1989 Maxwell Pergamon Macmillan plc.

LAROUCHE, P., P.S. GALBRAITH, 1989. Factors affecting fast-ice consolidation in southeastern Hudson Bay, Canada. Atmos.-Ocean, 27: 367-375 .

LAROUCHE, P., V. HAEBERLÉ, 1988. Sub-ice instrument trials in Hudson Bay. Entrefilets, 9(9): 11-12 .

LAROUCHE, P., V. HAEBERLÉ, 1988. Projet d'essai d'instrumentation sous la glace dans la Baie d'Hudson. Entrefilets, 9(9): 11-12 .

LAROUCHE, P., J.-M.M. DUBOIS, 1988. Évaluation dynamique de la circulation de surface utilisant la dérive de blocs de glace (baie d'Hudson, Canada). Photo-Interprétation, 6(3): 19-28 .

CARIOU, C., J.M. BOUCHER, C. ROUX, P. LAROUCHE, 1988. Spectral analysis of ocean wave imagery using 2-D linear prediction. Pages 127-130 in Proceedings of the International Geoscience and Remote Sensing Symposium 1988, Sept. 13-16, 1988, Edinburgh, Scotland .

INGRAM, R.G., P. LAROUCHE, 1987. Changes in the under-ice characteristic of La Grande Rivière plume due to discharge variations. Atmos.-Ocean, 25: 242-250 .

INGRAM, R.G., P. LAROUCHE, 1987. Variability of an under-ice river plume in Hudson Bay. J. Geophys. Res. (C Oceans), 92(C9): 9541-9547 .

LAROUCHE, P., V.G. KOUTITONSKY, J.P. CHANUT, M.I. EL-SABH, 1987. Lateral stratification and dynamic balance at the Matane transect in the Lower Saint Lawrence Estuary. Estuar. Coast. Shelf Sci., 24: 859-871 .