Sergio Signorini

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Sergio Signorini

  • SCIENTIST
  • 301.286.9891 | 301.286.0268
  • NASA/GSFC
  • Mail Code: 616.2
  • Greenbelt , MD 20771
  • Employer: Science Application International Corp.
  • Brief Bio

    Dr. Sergio Signorini has worked under a Science Applications International Corp. SAIC contract with NASA Goddard Space Flight (GSFC) as a research scientist and lead data analyst since 1995. He obtained an undergraduate degree in Physics from the University of São Paulo (USP) in 1969, a M. Sc. in Physical Oceanography from USP in 1972, and a Ph. D. in Physical Oceanography from the University of Rhode Island in 1980. He was an assistant professor in Physical Oceanography at USP in 1980-1983, a senior data analyst at EG&G Consultants in 1983-1986, a senior scientist at Greenhorne & O’Mara in 1986-1992, a program manager at the NSF Geosciences Division in 1992-1994, and a visiting research professor at Rutgers University in 1994-1995. Once at GSFC his interests turn to satellite ocean color processing and analysis and ecosystem and carbon cycle modeling.

    Research Interests

    Physical and Biogeochemical Processes that Influence the Ocean Carbon Cycle

    Biogeochemical and carbon cycle ocean processes affecting the uptake of atmospheric COand assessment of carbon fluxes and organic and inorganic carbon budgets. Research relies on a combination of satellite algorithms, field observations, and numerical models. 

    Algorithm Development and Applications

    Development and application of satellite-based algorithms using ocean color and other remote sensing data. These include pCO2 algorithms for the US East Coast and the north North Atlantic using sea-surface temperature (SST) and chlorophyll (Chl) remote sensing products. Algorithms are evaluated with in situ data.

    Ocean Acidification

    A key parameter to monitor ocean acidification (OA) is the partial pressure of carbon dioxide (pCO2) in seawater. With the knowledge of pCO2 and another key parameter of the CO2 system in the ocean (such as alkalinity or dissolved inorganic carbon) and carbonate chemistry equations, it is straightforward to derive important Ocean Acidification (OA) environmental quantities, such as pH, calcite and aragonite saturation states, that are crucial indicators of potential harmful effects on marine organisms.
    Satellite data provide an invaluable global view of the oceans with temporal and spatial resolutions far superior to what can be achieved with more traditional methods of collecting data (ship surveys, time series stations, buoys, and floats). The combination of the two methods provides a powerful tool to monitor changes in the state of the oceans and further the understanding of physical and biogeochemical processes affecting OA. Development and validation of satellite-based algorithms benefit immensely from research-specific in situ surveys and comprehensive community-based data repositories such as the Surface Ocean CO2 Atlas. This method of combining in situ observations and satellite data to investigate the spatial and temporal variability of OA parameters is one of my main research interests.

    Current Projects

    Synergistic impacts of population growth, urbanization, and climate change on watersheds and coastal ecology of the northeastern United States

    This study focuses on two important estuaries of the northeastern U.S., Chesapeake and Delaware Bays, the watersheds that feed them, and the continental shelf waters of the Mid-Atlantic Bight (MAB) that link them (Fig. 1). These selected estuaries are among the most vulnerable estuaries of the U.S.
    because of the high population density in their watersheds and the high degree of climate change they are experiencing, including increases in temperature, sea level, precipitation, and precipitation
    intensity.
    I am a member of the interdisciplinary investigative team that has the requisite breadth and experience to comprehensively assess impacts of land-use and climate change on the ecology of this coastal region. We are in the process of linking a suite of models that have been extensively calibrated and evaluated with observations, including remote sensing products. This modeling system is the central tool for investigating the impacts of land-use and climate change on the coastal ecology of this region. Three broad coastal ecological endpoints will be considered: (1) phytoplankton speciation, representing the base of the coastal food web; (2) Eastern oysters (Crassostrea virginica) and Atlantic surfclams (Spisula solidissima), upper-trophic keystone species for the region’s estuaries and shelf waters, respectively; and (3) hypoxia, representing an index of threats to the overall health of the region’s ecology.

    Spatial Resolution Requirements for GEO-CAPE to Capture the Spatial Dynamics Phytoplankton and CDOM across Estuaries and Adjacent Coastal Ocean

    The goal of this task is to study the spatial distribution of phytoplankton and CDOM (chromophoric dissolved organic matter) within several river mouths and plume regions using full-resolution data from MERIS and HICO to determine what spatial resolution requirements are necessary for the GEO-CAPE coastal sensor to capture the variability of phytoplankton and CDOM.
    Existing field measurements from the northeastern U.S. estuaries and continental shelf, Chesapeake Bay (CBODAQ) and Gulf of Mexico (GoMEX) are being applied to re-tune existing algorithms for retrieval of phytoplankton (chlorophyll-a and phytoplankton absorption) and CDOM absorption from MERIS and HICO. Spatial resolution is one of the biggest cost drivers for the GEO-CAPE ocean color sensor. Hence, it is imperative that we demonstrate what spatial resolution is required to resolve the two constituents that dominate optical properties and biogeochemistry within estuaries and the coastal ocean.

    Assessment of Carbon Fluxes and Budgets for the Mid Atlantic Bight

    Assessment of integrated organic carbon tracer fluxes using satellite-based algorithms combined with ocean model products. Near surface retrievals of dissolved and particulate organic carbon are extended throughout the continental shelf water column using in situ observations and a neural networks model. Carbon stocks and fluxes will be used to evaluate a continental shelf biogeochemical model.

    Positions/Employment

    12/1996 - Present

    Senior Scientist/Lead Data Analyst

    Science Applications International Corporation, On site at GSFC Under a contract with NASA Goddard Space Flight Center, Dr. Signorini conducts satellite data analysis, develops, evaluates, and applies algorithms and numerical models to investigate ocean carbon cycle and ocean acidification studies. In addition, Dr. Signorini participates in proposal development, publication in scientific journals, scientific meetings, and collaborates with national and international investigators.
    Dr. Signorini has been involved in the development and application of ecosystem-carbon cycling models in the Equatorial Pacific, sub-Arctic Pacific, and Nordic Seas. Through the use of satellite-based algorithms he has studied phytoplankton dynamics and identification of functional groups in the Patagonian Shelf, Barents Sea, and subpolar North Atlantic.
    6/1995 - 11/1996

    Visiting Research Professor

    Rutgers University, New Brunswick, NJ In the Ocean Modeling Group of the Institute of Marine and Coastal Science, Dr. Signorini was co-investigator in a study of the dynamics of Barrow Canyon, sponsored by the Office of Naval Research. The goal of the study was to characterize the physical processes affecting the flow in and around the canyon, and to understand the role of the canyon in the exchange of water mass properties between the Chukchi Sea shelf and the Arctic Ocean. A paper addressing the key findings of the Barrow Canyon investigation was published in the Journal of Geophysical Research. Dr. Signorini also acquired remote sensing experience downloading and analyzing SST images from NOAA-series AVHRR satellite sensors using a TERA SCAN/SEA SPACE system. These images were used to monitor upwelling events and oceanographic fronts in the Mid-Atlantic Bight.
    2/1992 - 6/1995

    Oceanographer/Associate Program Director

    National Science Foundation, Washington D.C. The major duties of this position were to advise and assist the Program Director with development for research plans and budget, implementing allocation of program funds (about $30M/year), and maintain appropriate merit of scientific proposals. In addition, the position required program coordination, as appropriate, with other elements of NSF, other agencies, and the scientific community, and to represent the program and NSF to the scientific community, other agencies, and the public. Dr. Signorini's accomplishments included the coordination, funding, and award processing for two special projects: (1) the Geophysical Fluid Dynamics interdisciplinary research and graduate training program held each summer at the Woods Hole Oceanographic Institution since 1959; and, (2) the UCAR Postdoctoral Program. which focused on the training of  an interdisciplinary pool of Ph. D.s in ocean modeling research. In addition, Dr Signorini was instrumental in the planing, coordination, and implementation of an interdisciplinary high performance computing and communications (HPCC) initiative for the Ocean Sciences Community.
    11/1986 - 2/1992

    Senior Scientist/Project manager

    Greenhorne & O'Mara, Inc., Greenbelt, MD In the division of Coastal Emgineering and Marine Sciences, Dr. Signorini was involved in Arctic Ocean modeling, coastal oceanography, storm surge prediction, and environmental impact assessment. Dr. signorini's duties included the development of new business elements, overseeing performance of subcontractors, and budget planing and monitoring. Dr. Signorini was responsible for obtaining a $1.2 million contract from DOI/MMS to conduct a multi-year study of Beaufort, Chukchi, and Bering Seas with focus on the environmental conditions of the Alaska Outer Continental Shelf regions and their impact on the motion, spreading, and weathering of oil spills.
    6/1983 - 10/1986

    Senior Scientist

    EG&G Washington Analytical Service Center, Inc, Waltham MA and Washington DC Under this position Dr. Signorini conducted data analysis, interpretation and reporting of several environmental studies in the Bering Sea and Gulf of Alaska. He was also involved in the analysis and prediction of tides and tidal currents in Cook Inlet; development, verification, and application of two numerical models; a model of storm surge and storm-driven currents in the Bering Sea, and one-dimensional mixed-layer model for the near-surface ocean response to tropical and extra-tropical storms. He also conducted a comparison study between several types of current meters, including an Acoustic Doppler Current Profiler (ADCP). He had experience in writing proposals for government and industry solicitations as well as contract management.
    1/1980 - 5/1983

    Assistant Professor

    Oceanographic Institute, University of S. Paulo (IOUSP), S. Paulo, SP, Brazil Dr. Signorini designed, prepared, and taught a course in numerical ocean modeling at the Post-Graduate School of Oceanography in S. Paulo, Brazil. He taught physical oceanography courses to undergraduate students and participated in several oceanographic cruises in the North and South Atlantic Oceans to collect and process physical and chemical data. He was the PI for three major projects off the coast of Brazil: (1) a study of the Brazil Current through a cooperative agreement between IOUSP and the University of Rhode Island, RI, USA, (2) a study of the sea-breeze and ocean currents off the northern Brazilian coast, and (3) modeling of envirinmental parameters in the Santos Estuary. As chief scientist of a Brazil Current investigation, he coordinated cruise operations, satellite data acquisition, and in situ data collection to assess the total volume transport and circulation patterns of this important west boundary current. The study was conducted using expendable bathythermographs (XBTs), remote sensing SST, and an acoustically-tracked current profiler (Pegasus probes). This was the first direct measurement of the Brazil Current velocity field.

    Teaching Experience

    I have no recent experience in teaching. However in the mid 70s I designed, prepared, and taught a course in numerical ocean modeling at the Post-Graduate School of Oceanography in S. Paulo, Brazil. I also taught physical oceanography courses to undergraduate students during the same time period..

    Education

    Ph. D. in Oceanography, 1980, University of Rhode Island, Kingston, RI
    Thesis Title: A Study of the Circulation in Ilha Grande and Sepetiba Bays

    M. Sc. in Oceanography, 1974, Oceanographic Institute, University of S. Paulo, SP, Brazil
    Thesis Title:  A Study of the Brazil Current Circulation and Volume Transport beteen the Cape of Sao Tome and Guanabara Bay

    B. S. in Physics, 1970, Institute of Physics, University of S. Paulo, SP, Brazil

    Professional Societies

    American Geophysical Union, 1982 - Present

    Professional Service

    Served in several NASA panels for the Carbon Cycle Science, Ocean Biology and Biogeochemistry and Education programs.,

    Grants

    09/30/2011 Carbon Cycle Science, NASA
    Assessment and Impact of Carbon Variability in the Nordic Seas ; Co-I ; 0.84 FTE
    05/14/2014 Carbon Cycle Science, NASA
    Impacts of Changing Climate and Land Use on Carbon Cycling and Budgets of the Coastal Ocean Margin: Observations, Analysis, and Modeling.

    Other Professional Information

    Fluent in Portuguese and Italian

    Amateur Radio Extra Class License

    Publications

    Refereed

    Marrari, M., S. Signorini, C. McClain, et al. M. Pajaro, P. Martos, M. D. Vinas, J. Hansen, R. Dimauro, G. Cepeda, and C. Buratti. 2013. "Reproductive success of the Argentine anchovy, Engraulis anchoita, in relation to environmental variability at a mid-shelf front (Southwestern Atlantic Ocean)." Fisheries Oceanography, 22 (3): 247-261 [10.1111/fog.12019]

    Signorini, S., A. Mannino, R. G. Najjar Jr., et al. M. A. Friedrichs, W.-J. Cai, J. Salisbury, Z. A. Wang, H. Thomas, and E. Shadwick. 2013. "Surface ocean pCO2 seasonality and sea-air CO2 flux estimates for the North American east coast." Journal of Geophysical Research, 118 (10): 5439-5460 [10.1002/jgrc.20369]

    Signorini, S., S. Hakkinen, K. Gudmundsson, et al. A. Olsen, A. Omar, J. Olafsson, G. Reverdin, S. Henson, C. McClain, and D. Worthen. 2012. "The role of phytoplankton dynamics in the seasonal and interannual variability of carbon in the subpolar North Atlantic – a modeling study." Geosci. Model Dev., 5 (3): 683-707 [10.5194/gmd-5-683-2012]

    Chierici, M., S. Signorini, M. Mattsdotter-Bjork, A. Fransson, and A. Olsen. 2012. "Surface water fCO2 algorithms for the high-latitude Pacific sector of the Southern Ocean." Remote Sensing of Environment, 119: 184-196 [10.1016/j.rse.2011.12.020]

    Signorini, S., and C. R. McClain. 2011. "Subtropical gyre variability as seen from satellites." Remote Sensing Letters, 3 (6): 471-479 [10.1080/01431161.2011.625053]

    Druon, J., A. Mannino, S. R. Signorini, et al. C. R. McClain, M. Friedrichs, J. Wilken, and K. Fennel. 2010. "Modeling the dynamics and export of dissolved organic matter in the northeastern U.S. continental shelf.." Estuarine Coastal and Shelf Science, 88: 488-507.

    Signorini, S., and C. R. Mc Clain. 2009. "Environmental factors controlling the Barents Sea spring-summer phytoplankton blooms." Geophys Res Lett, 36 (10): L10604 [10.1029/2009GL037695]

    Signorini, S., and C. R. Mc Clain. 2009. "Effect of uncertainties in climatologic wind, ocean pCO2, and gas transfer algorithms on the estimate of global sea-air CO2 flux." Global Biogeochem. Cycles, 23 (2): GB2025 [10.1029/2008GB003246]

    Garcia, T., C. A. Garcia, M. Mata, et al. R. Pollery, A. Piola, S. R. Signorini, C. R. McClain, and M. Iglesias-Rodriguez. 2008. "Environmental factors controlling the phytoplankton blooms at the Patagonia shelf-break in spring." Deep Sea Research Part I: Oceanographic Research Papers, 55 (9): 1150-1166 [10.1016/j.dsr.2008.04.011]

    Signorini, S. R., and C. R. McClain. 2007. "Large-scale forcing impact on biomass variability in the South Atlantic Bight." Geophys Res Lett, 34 (L21605): 6 pp.

    Signorini, S. R., V. M. Garcia, A. Piola, et al. C. A. Garcia, M. Mata, and C. R. McClain. 2006. "Seasonal and interannual variability of calcite in the vicinity of the Patagonian shelf break (38°S—52°S)." Geophys Res Lett, 33 (L16610): 5 pp.

    Garcia, V. M., S. Signorini, C. A. Garcia, and C. R. Mcclain. 2006. "Empirical and semi-analytical chlorophyll algorithms in the south-western Atlantic coastal region (25–40°S and 60–45°W)." Int J Remote Sens, 27 (8): 1539-1562 [10.1080/01431160500382857]

    Mcclain, C. R., J. R. Christian, and S. R. Signorini. 2004. "Subtropical gyre variability observed by ocean-color satellites." Deep-Sea Res II, 51: 281-301.

    McClain, C. R., J. R. Christian, S. R. Signorini, et al. M. R. Lewis, I. Asanuma, and D. Turk. 2002. "Satellite ocean-color observations of the tropical Pacific Ocean." Deep-Sea Research II, 49: 2533-2560.

    Signorini, S., and D. J. Cavalieri. 2002. "Modeling of dense water production and salt transport from Alaskan coastal polynyas." J. Geophys. Res., 107 (C9): [10.1029/2000JC000491]

    Signorini, S., R. G. Murtugudde, C. R. McClain, J. R. Christian, and J. Picaut. 1999. "Biological and physical signatures in the tropical and subtropical Atlantic." Journal of Geophysical Research, 104 (C8): 18,367-18,382.

    Signorini, S., C. R. McClain, and Y. Dandonneau. 1999. "Mixing and phytoplankton bloom in the wake of the Marquesas Islands." Geophysical Research Letters, 26 (20): 3121-3124.

    Brief Bio

    Dr. Sergio Signorini has worked under a Science Applications International Corp. SAIC contract with NASA Goddard Space Flight (GSFC) as a research scientist and lead data analyst since 1995. He obtained an undergraduate degree in Physics from the University of São Paulo (USP) in 1969, a M. Sc. in Physical Oceanography from USP in 1972, and a Ph. D. in Physical Oceanography from the University of Rhode Island in 1980. He was an assistant professor in Physical Oceanography at USP in 1980-1983, a senior data analyst at EG&G Consultants in 1983-1986, a senior scientist at Greenhorne & O’Mara in 1986-1992, a program manager at the NSF Geosciences Division in 1992-1994, and a visiting research professor at Rutgers University in 1994-1995. Once at GSFC his interests turn to satellite ocean color processing and analysis and ecosystem and carbon cycle modeling.

    Publications

    Refereed

    Marrari, M., S. Signorini, C. McClain, et al. M. Pajaro, P. Martos, M. D. Vinas, J. Hansen, R. Dimauro, G. Cepeda, and C. Buratti. 2013. "Reproductive success of the Argentine anchovy, Engraulis anchoita, in relation to environmental variability at a mid-shelf front (Southwestern Atlantic Ocean)." Fisheries Oceanography 22 (3): 247-261 [10.1111/fog.12019]

    Signorini, S., A. Mannino, R. G. Najjar Jr., et al. M. A. Friedrichs, W.-J. Cai, J. Salisbury, Z. A. Wang, H. Thomas, and E. Shadwick. 2013. "Surface ocean pCO2 seasonality and sea-air CO2 flux estimates for the North American east coast." Journal of Geophysical Research 118 (10): 5439-5460 [10.1002/jgrc.20369]

    Signorini, S., S. Hakkinen, K. Gudmundsson, et al. A. Olsen, A. Omar, J. Olafsson, G. Reverdin, S. Henson, C. McClain, and D. Worthen. 2012. "The role of phytoplankton dynamics in the seasonal and interannual variability of carbon in the subpolar North Atlantic – a modeling study." Geosci. Model Dev. 5 (3): 683-707 [10.5194/gmd-5-683-2012]

    Chierici, M., S. Signorini, M. Mattsdotter-Bjork, A. Fransson, and A. Olsen. 2012. "Surface water fCO2 algorithms for the high-latitude Pacific sector of the Southern Ocean." Remote Sensing of Environment 119 184-196 [10.1016/j.rse.2011.12.020]

    Signorini, S., and C. R. McClain. 2011. "Subtropical gyre variability as seen from satellites." Remote Sensing Letters 3 (6): 471-479 [10.1080/01431161.2011.625053]

    Druon, J., A. Mannino, S. R. Signorini, et al. C. R. McClain, M. Friedrichs, J. Wilken, and K. Fennel. 2010. "Modeling the dynamics and export of dissolved organic matter in the northeastern U.S. continental shelf.." Estuarine Coastal and Shelf Science 88 488-507

    Signorini, S., and C. R. Mc Clain. 2009. "Environmental factors controlling the Barents Sea spring-summer phytoplankton blooms." Geophys Res Lett 36 (10): L10604 [10.1029/2009GL037695]

    Signorini, S., and C. R. Mc Clain. 2009. "Effect of uncertainties in climatologic wind, ocean pCO2, and gas transfer algorithms on the estimate of global sea-air CO2 flux." Global Biogeochem. Cycles 23 (2): GB2025 [10.1029/2008GB003246]

    Garcia, T., C. A. Garcia, M. Mata, et al. R. Pollery, A. Piola, S. R. Signorini, C. R. McClain, and M. Iglesias-Rodriguez. 2008. "Environmental factors controlling the phytoplankton blooms at the Patagonia shelf-break in spring." Deep Sea Research Part I: Oceanographic Research Papers 55 (9): 1150-1166 [10.1016/j.dsr.2008.04.011]

    Signorini, S. R., and C. R. McClain. 2007. "Large-scale forcing impact on biomass variability in the South Atlantic Bight." Geophys Res Lett 34 (L21605): 6 pp

    Signorini, S. R., V. M. Garcia, A. Piola, et al. C. A. Garcia, M. Mata, and C. R. McClain. 2006. "Seasonal and interannual variability of calcite in the vicinity of the Patagonian shelf break (38°S—52°S)." Geophys Res Lett 33 (L16610): 5 pp

    Garcia, V. M., S. Signorini, C. A. Garcia, and C. R. Mcclain. 2006. "Empirical and semi-analytical chlorophyll algorithms in the south-western Atlantic coastal region (25–40°S and 60–45°W)." Int J Remote Sens 27 (8): 1539-1562 [10.1080/01431160500382857]

    Mcclain, C. R., J. R. Christian, and S. R. Signorini. 2004. "Subtropical gyre variability observed by ocean-color satellites." Deep-Sea Res II 51 281-301

    McClain, C. R., J. R. Christian, S. R. Signorini, et al. M. R. Lewis, I. Asanuma, and D. Turk. 2002. "Satellite ocean-color observations of the tropical Pacific Ocean." Deep-Sea Research II 49 2533-2560

    Signorini, S., and D. J. Cavalieri. 2002. "Modeling of dense water production and salt transport from Alaskan coastal polynyas." J. Geophys. Res. 107 (C9): [10.1029/2000JC000491]

    Signorini, S., R. G. Murtugudde, C. R. McClain, J. R. Christian, and J. Picaut. 1999. "Biological and physical signatures in the tropical and subtropical Atlantic." Journal of Geophysical Research 104 (C8): 18,367-18,382

    Signorini, S., C. R. McClain, and Y. Dandonneau. 1999. "Mixing and phytoplankton bloom in the wake of the Marquesas Islands." Geophysical Research Letters 26 (20): 3121-3124

                                                                                                                                                                                            
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