The Oceanographic Remote Sensing Laboratory (ORSL) led by Dr. James J. Bisagni, Principal Investigator, is currently studying various coastal physical oceanographic processes and how they relate to productivity in the coastal ocean over various trophic levels from phytoplankton to fisheries. Processes of interest currently include the shelf break front, cross-frontal flows and transport due to eddies and Gulf Stream warm-core rings, wind-driven transport, and the effects of varying freshwater output from arctic regions. Studies usually require analysis of satellite-derived data along with in situ measurements, along with model output.
James J. Bisagni|
Professor of Marine Science
SMAST Department of Estuarine & Ocean Sciences
200 Mill Rd, Suite 325
Fairhaven, MA 02719
US-GLOBEC: The physical oceanography of Georges Bank and its impact on biology
(Dr. James J. Bisagni, Co-investigator; R. Beardsley, Principal Investigator), NSF, 2003-2007, $104,863 (Award OCE-0227679)
Sixteen-years (1985-2000) of satellite sea surface temperature (SST) data from eastern Georges Bank (GB) and western Scotian Shelf reveal strong inter-annual variability (IAV) for the presence of cold anomalies (colder than -1 °C), signifying Scotian Shelf Water Crossovers (Brunner et al., in revision; Brunner, 2007). Seasonal variability of the shelf slope front (SSF) position (Bisagni et al., 2006) between Cape Hatteras and the Tail of the Grand Banks shows a maximum seaward (shoreward) extent during winter (summer), but also shows that eastern-most and western-most monthly SSF anomalies, relative to a 20-year long-term (1973-1992) mean are 180° out of phase, with maximum seasonal SSF variability of Ο(±50 km) occurring generally east of 58°W. Seasonal westward propagation of the seaward-most (landward-most) SSF position is evident between 50° and 58° W from November to April (May to October), decreasing westward in amplitude. An Ekman coastal plume model reproduces the general seasonal cycle of the SSF along with the east-west phase shift, except in easternmost regions where SSF positional variability is maximal. IAV of the annual mean SSF position between Cape Hatteras (CH) and the Tail of the Grand Banks (TGB) from longitude-time plots reveals alternating bands of offshore (late-1970s, late-1980s, late-1990s) and onshore (early-1980s, early-1990s, early-2000s) annual mean SSF anomaly values, exhibiting a period of approximately 10 years (Bisagni et al., 2009). Complex empirical orthogonal function analysis reveals a wavelength scale of approximately 20 degrees of longitude, along with westward propagation of 1.2 to 2.4 cm s-1 (1 to 2 km d-1). Importantly, this study showed onshore (offshore) SSF position anomalies within the MAB corresponding to negative (positive) shelf water volume anomalies and positive (negative) shelf water salinity anomalies (Mountain, 2003).
US-GLOBEC: Patterns of energy flow and utilization on Georges Bank
(Dr. James J. Bisagni, Co-investigator; D. Gifford, Principal Investigator), NSF, 2003-2007, $127,593 (Award OCE-0217122)
This project synthesized key aspects of production and energy flow, based on US-GLOBEC Northwest Atlantic studies, and augmented US-GLOBEC data with information on production processes at the lower and upper levels of the food web. Objectives were to examine alternate model outcomes of GLOBEC studies to help address outstanding issues and reexamine patterns of energy flow on Georges Bank. Consideration of factors not addressed in earlier energy budgets included (1) the microbial food web, (2) new and recycled primary production, (3) spatial heterogeneity of primary and secondary production, (4) changes in biomass and production at higher trophic levels, and (5) effects of environmental forcing on production. Decadal-scale periods, reflecting differing environmental (temperature) and fish community regimes were considered: (1) the cold 1960s characterized by abundant groundfish fished by distant water fleets; (2) the 1970s, characterized by "average" water temperatures, increased domestic fishing effort, and depletion of groundfish; (3) the 1980s, characterized by "average" water temperatures, overfishing of groundfish, and increases in elasmobranchs; and (4) the "average" temperature, lower salinity 1990s, characterized by reduced fishing mortality, rebuilding of groundfish stocks, and increases in elasmobranchs and pelagic fish. Work performed by Dr. Bisagni included assembling a climatology of nutrient (NO3+NO2) data to calculate a proxy for new primary production, termed "potential new production" (PNP) as the difference between a "storage" term (integrated to the depth of the euphotic zone) and a vertical-flux term for three hydrographic provinces on Georges Bank.
US-GLOBEC Pan-Regional Synthesis: End-to-end energy budgets in US-GLOBEC regions
(Dr. James J. Bisagni, Principal Investigator), NSF, 2008-2012 $155,185 (Award OCE-0814391)
Physical, chemical and biological data sets have been obtained off the Western Antarctic Peninsula (WAP) region and for the US-GLOBEC Southern Ocean (SO) program in Marguerite Bay including light and nutrient profiles to estimate 'potential new production' (PNP), a proxy for actual new primary production. Additional data obtained include nutrient, light and CTD data from the US-GLOBEC SO Program and the Antarctic LTER research group for a series of stations covering the oceanic region located west of the WAP. We have computed the mean seasonal cycle of the 1% light level to determine the seasonal cycle of the euphotic zone depth. Temporal and spatial variability of primary production (PP) and chlorophyll-a (Chl-a) were studied off the continental shelf of the Western Antarctic Peninsula (WAP). Preliminary results indicate an offshore-onshore and north-south gradient in both PP and Ch-a. The primary production to chlorophyll-a ratio (PP ⁄ Chl-a) was also computed and showed an overall north-south gradient, with a positive increase southward. We speculate that this trend could be due to grazing, oceanographic processes, photosynthetic efficiencies of the plankton or a combination thereof. Three 'hotspot' sites within the WAP (off Anvers Island (AI), off Crystal Sound (CS) and off Marguerite Bay (MB)) were further investigated. All three sites showed above average rates and concentrations of PP and Chl-a, respectively, when compared with adjacent waters. Waters around MB had the highest PP rates (2.35 ± 0.69 g C m-2 day-1), while those off AI in the north had the lowest rates (1.04 ± 0.09 g C m-2 day-1). Overall PP for the WAP region during the peak growing season (January) was maximal on year day 23 (1.05 ± 0.12 g C m-2 day-1).
Satellite-Derived sea surface temperature (SST) data for southern New England,
(Dr. James J. Bisagni, Principal Investigator), UMass Dartmouth Chancellor's Research Fund and the Joseph P. Healey Endowment Grant, 2012-2013, $9,931
Through collaboration with Dr. Andrew Thomas' Satellite Oceanography Laboratory at the University of Maine Orono, we will be providing near real-time satellite-derived sea surface temperature (SST) images and data for the southern New England region important to fisheries, for immediate use by stakeholders as outlined below. This project will then archive all SST images and data for the region for non real-time use by stakeholders, allowing development of a regional, historical SST time series data base. These data will also provide preliminary data for process oriented oceanographic research to be proposed to the National Science Foundation (NSF) that will focus on the continental shelf off southern New England using the NSF's "Pioneer" instrument array scheduled to be deployed during the 2013-2014 time frame. This project will also provide important training in "operational oceanography" through a Research Assistantship to Mr. Marco Pedulli, Graduate Student.
Fundamental physical oceanographical processes important to coastal and open ocean environments. Included in the course are lectures by current researchers in specialized topics such as satellite oceanography and numerical modeling. (3 credits)
This course provides an overview of the use of satellite-based remote sensing for making measurements within the marine environment. Each of the primary satellite sensors used by oceanographers is introduced along with the principles behind their operation, measurement retrieval, data handling, and data interpretation/usage. (3 credits)
Physical oceanographic processes important to European and U.S. shallow seas, continental shelves and banks and their relationship to nutrients and biology (plankton and fish) in these regions. (3 credits)
Fundamental principles relating physical oceanographic processes to the biology of the ocean on a variety of spatial and temporal scales. (3 credits)
Marco Pedulli has broad interests in education, polar oceanography, photography and public outreach programs. He is currently part
of an ecosystem-modeling research group for the Southern Ocean. His research emphasizes on computing nutrient drawdown, potential
new production and export of particulate biogenic carbon out the euphotic zone in the waters off the western Antarctic Peninsula (WAP)
region using both observational and model data from the Southern Ocean - Global Ocean Ecosystem Dynamics (SO-GLOBEC – www.usglobec.org)
and Palmer Long Term Ecological Research (PAL LTER – pal.lternet.edu) Programs.
Marco holds a B.S. in Marine Biology and Fisheries and a M.S. in Coastal Management and worked in different capacities as educator and mentor of undergraduate students and volunteer in various aquaria. He is presently finalizing his doctoral studies in oceanography.