Marra John F.

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Marra
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John F.
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  • Book chapter
    Global Oceans [in “State of the Climate in 2020”]
    (American Meteorological Society, 2021-08-01) Johnson, Gregory C. ; Lumpkin, Rick ; Alin, Simone R. ; Amaya, Dillon J. ; Baringer, Molly O. ; Boyer, Tim ; Brandt, Peter ; Carter, Brendan ; Cetinić, Ivona ; Chambers, Don P. ; Cheng, Lijing ; Collins, Andrew U. ; Cosca, Cathy ; Domingues, Ricardo ; Dong, Shenfu ; Feely, Richard A. ; Frajka-Williams, Eleanor E. ; Franz, Bryan A. ; Gilson, John ; Goni, Gustavo J. ; Hamlington, Benjamin D. ; Herrford, Josefine ; Hu, Zeng-Zhen ; Huang, Boyin ; Ishii, Masayoshi ; Jevrejeva, Svetlana ; Kennedy, John J. ; Kersalé, Marion ; Killick, Rachel E. ; Landschützer, Peter ; Lankhorst, Matthias ; Leuliette, Eric ; Locarnini, Ricardo ; Lyman, John ; Marra, John F. ; Meinen, Christopher S. ; Merrifield, Mark ; Mitchum, Gary ; Moat, Bengamin I. ; Nerem, R. Steven ; Perez, Renellys ; Purkey, Sarah G. ; Reagan, James ; Sanchez-Franks, Alejandra ; Scannell, Hillary A. ; Schmid, Claudia ; Scott, Joel P. ; Siegel, David A. ; Smeed, David A. ; Stackhouse, Paul W. ; Sweet, William V. ; Thompson, Philip R. ; Trinanes, Joaquin ; Volkov, Denis L. ; Wanninkhof, Rik ; Weller, Robert A. ; Wen, Caihong ; Westberry, Toby K. ; Widlansky, Matthew J. ; Wilber, Anne C. ; Yu, Lisan ; Zhang, Huai-Min
    This chapter details 2020 global patterns in select observed oceanic physical, chemical, and biological variables relative to long-term climatologies, their differences between 2020 and 2019, and puts 2020 observations in the context of the historical record. In this overview we address a few of the highlights, first in haiku, then paragraph form: La Niña arrives, shifts winds, rain, heat, salt, carbon: Pacific—beyond. Global ocean conditions in 2020 reflected a transition from an El Niño in 2018–19 to a La Niña in late 2020. Pacific trade winds strengthened in 2020 relative to 2019, driving anomalously westward Pacific equatorial surface currents. Sea surface temperatures (SSTs), upper ocean heat content, and sea surface height all fell in the eastern tropical Pacific and rose in the western tropical Pacific. Efflux of carbon dioxide from ocean to atmosphere was larger than average across much of the equatorial Pacific, and both chlorophyll-a and phytoplankton carbon concentrations were elevated across the tropical Pacific. Less rain fell and more water evaporated in the western equatorial Pacific, consonant with increased sea surface salinity (SSS) there. SSS may also have increased as a result of anomalously westward surface currents advecting salty water from the east. El Niño–Southern Oscillation conditions have global ramifications that reverberate throughout the report.
  • Preprint
    Phytoplankton bloom phenomena in the North Atlantic Ocean and Arabian Sea
    ( 2014-12) Marra, John F. ; Dickey, Thomas D. ; Plueddemann, Albert J. ; Weller, Robert A. ; Kinkade, Christopher S. ; Stramska, Malgorzata
    We review bio-optical and physical data from three mooring experiments, the Marine Light–Mixed Layers programme in spring 1989 and 1991 in the Iceland Basin (59°N/21°W), and the Forced Upper Ocean Dynamics Experiment in the central Arabian Sea from October 1994 to 1995 (15.5°N/61.5°E). In the Iceland Basin, from mid-April to mid-June in 1989, chlorophyll-a concentrations are sensitive to small changes in stratification, with intermittent increases early in the record. The spring increase occurs after 20 May, coincident with persistent water column stratification. In 1991, the bloom occurs 2 weeks earlier than in 1989, with a background of strong short-term and diurnal variability in mixed layer depth and minimal horizontal advection. In the Arabian Sea, the mixing response to the northeast and southwest monsoons, plus the response to mesoscale eddies, produces four blooms over the annual cycle. The mixed layer depth in the Arabian Sea never exceeds the euphotic zone, allowing interactions between phytoplankton and grazer populations to become important. For all three mooring experiments, change in water column stratification is key in producing phytoplankton blooms.
  • Article
    Challenges of modeling depth-integrated marine primary productivity over multiple decades : a case study at BATS and HOT
    (American Geophysical Union, 2010-09-15) Saba, Vincent S. ; Friedrichs, Marjorie A. M. ; Carr, Mary-Elena ; Antoine, David ; Armstrong, Robert A. ; Asanuma, Ichio ; Aumont, Olivier ; Bates, Nicholas R. ; Behrenfeld, Michael J. ; Bennington, Val ; Bopp, Laurent ; Bruggeman, Jorn ; Buitenhuis, Erik T. ; Church, Matthew J. ; Ciotti, Aurea M. ; Doney, Scott C. ; Dowell, Mark ; Dunne, John P. ; Dutkiewicz, Stephanie ; Gregg, Watson ; Hoepffner, Nicolas ; Hyde, Kimberly J. W. ; Ishizaka, Joji ; Kameda, Takahiko ; Karl, David M. ; Lima, Ivan D. ; Lomas, Michael W. ; Marra, John F. ; McKinley, Galen A. ; Melin, Frederic ; Moore, J. Keith ; Morel, Andre ; O'Reilly, John ; Salihoglu, Baris ; Scardi, Michele ; Smyth, Tim J. ; Tang, Shilin ; Tjiputra, Jerry ; Uitz, Julia ; Vichi, Marcello ; Waters, Kirk ; Westberry, Toby K. ; Yool, Andrew
    The performance of 36 models (22 ocean color models and 14 biogeochemical ocean circulation models (BOGCMs)) that estimate depth-integrated marine net primary productivity (NPP) was assessed by comparing their output to in situ 14C data at the Bermuda Atlantic Time series Study (BATS) and the Hawaii Ocean Time series (HOT) over nearly two decades. Specifically, skill was assessed based on the models' ability to estimate the observed mean, variability, and trends of NPP. At both sites, more than 90% of the models underestimated mean NPP, with the average bias of the BOGCMs being nearly twice that of the ocean color models. However, the difference in overall skill between the best BOGCM and the best ocean color model at each site was not significant. Between 1989 and 2007, in situ NPP at BATS and HOT increased by an average of nearly 2% per year and was positively correlated to the North Pacific Gyre Oscillation index. The majority of ocean color models produced in situ NPP trends that were closer to the observed trends when chlorophyll-a was derived from high-performance liquid chromatography (HPLC), rather than fluorometric or SeaWiFS data. However, this was a function of time such that average trend magnitude was more accurately estimated over longer time periods. Among BOGCMs, only two individual models successfully produced an increasing NPP trend (one model at each site). We caution against the use of models to assess multiannual changes in NPP over short time periods. Ocean color model estimates of NPP trends could improve if more high quality HPLC chlorophyll-a time series were available.
  • Technical Report
    The Marine light - mixed layer experiment cruise and data report, R/V Endeavor : cruise EN-224, mooring deployment, 27 April-1 May 1991, cruise EN-227, mooring recovery, 5-23 September 1991
    (Woods Hole Oceanographic Institution, 1993-05) Plueddemann, Albert J. ; Weller, Robert A. ; Dickey, Thomas D. ; Marra, John F. ; Tupper, George H. ; Way, Bryan S. ; Ostrom, William M. ; Bouchard, Paul R. ; Oien, Andrea L. ; Galbraith, Nancy R.
    The Marine Light - Mixed Layer experiment took place in the sub-Arctic North Atlantic ocean, approximately 275 miles south of Reykjavik, Iceland. The field program included a central surface mooring to document the temporal evolution of physical, biological and optical properties. The surface mooring was deployed at approximately 59°N, 21°W on 29 April 1991 and recovered on 6 September 1991. The Upper Ocean Processes Group of the Woods Hole Oceanographic Institution was responsible for design, preparation, deployment, and recovery of the mooring. The Group's contrbution to the field measurements included four different types of sensors: a meteorological observation package on the surface buoy, a string of 15 temperature sensors along the mooring line, an acoustic Doppler current profiler, and four instruments for measuring mooring tension and accelerations. The observations obtained from the mooring are sufficient to describe the air-sea fluxes and the local physical response to surface forcing. The objective in the analysis phase will be to determine the factors controlling this physical response and to work towards an understanding of the links among physical, biological, and optical processes. This report describes the deployment and recovery of the mooring, the meteorological data, and the subsurface temperature and current data.
  • Technical Report
    Arabian Sea mixed layer dynamics experiment data report
    (Woods Hole Oceanographic Institution, 1997-07) Baumgartner, Mark F. ; Brink, Nancy J. ; Ostrom, William M. ; Trask, Richard P. ; Weller, Robert A. ; Dickey, Thomas D. ; Marra, John F.
    The Arabian Sea is characterized by strong, large-scale atmospheric forcing during the summer (southwest) and winter (northeast) monsoons. To investigate air-sea interactions related to this unique surface forcing, a moored array was deployed from 15 October 1994 to 19 October 1995 just south of a region that experiences the climatological maximum winds during the summer monsoon. The array consisted of two Scripps Institution of Oceanography surface toroid buoys, two University of Washington subsurface moorings and a surface 3 m discus buoy deployed by the Woods Hole Oceanographic Institution (WHOI). The WHOI buoy carried redundant meteorological packages to measure wind speed and direction, air temperature, relative humidity, barometrc pressure, incoming short- and long-wave radiation and precipitation. Oceanographic instrumentation was deployed on the WHOI buoy's bridle and mooring line to collect time series of temperatue, salinity and velocity at various depths. Four multi-varable moored systems (MVMS) were also deployed along the mooring line by the Lamont-Doherty Earth Observatory and the University of California at Santa Barbara to record both bio-optical and physical parameters. This report describes the instrumentation deployed on the WHOI buoy and the processing and editing of the returned data. The data are then summarized in graphical and tabular formats.
  • Preprint
    Assessing the uncertainties of model estimates of primary productivity in the tropical Pacific Ocean
    ( 2008-03) Friedrichs, Marjorie A. M. ; Carr, Mary-Elena ; Barber, Richard T. ; Scardi, Michele ; Antoine, David ; Armstrong, Robert A. ; Asanuma, Ichio ; Behrenfeld, Michael J. ; Buitenhuis, Erik T. ; Chai, Fei ; Christian, James R. ; Ciotti, Aurea M. ; Doney, Scott C. ; Dowell, Mark ; Dunne, John P. ; Gentili, Bernard ; Gregg, Watson ; Hoepffner, Nicolas ; Ishizaka, Joji ; Kameda, Takahiko ; Lima, Ivan D. ; Marra, John F. ; Melin, Frederic ; Moore, J. Keith ; Morel, Andre ; O'Malley, Robert T. ; O'Reilly, Jay ; Saba, Vincent S. ; Schmeltz, Marjorie ; Smyth, Tim J. ; Tjiputra, Jerry ; Waters, Kirk ; Westberry, Toby K. ; Winguth, Arne
    Depth-integrated primary productivity (PP) estimates obtained from satellite ocean color based models (SatPPMs) and those generated from biogeochemical ocean general circulation models (BOGCMs) represent a key resource for biogeochemical and ecological studies at global as well as regional scales. Calibration and validation of these PP models are not straightforward, however, and comparative studies show large differences between model estimates. The goal of this paper is to compare PP estimates obtained from 30 different models (21 SatPPMs and 9 BOGCMs) to a tropical Pacific PP database consisting of ~1000 14C measurements spanning more than a decade (1983- 1996). Primary findings include: skill varied significantly between models, but performance was not a function of model complexity or type (i.e. SatPPM vs. BOGCM); nearly all models underestimated the observed variance of PP, specifically yielding too few low PP (< 0.2 gC m-2d-2) values; more than half of the total root-mean-squared model-data differences associated with the satellite-based PP models might be accounted for by uncertainties in the input variables and/or the PP data; and the tropical Pacific database captures a broad scale shift from low biomass-normalized productivity in the 1980s to higher biomass-normalized productivity in the 1990s, which was not successfully captured by any of the models. This latter result suggests that interdecadal and global changes will be a significant challenge for both SatPPMs and BOGCMs. Finally, average root-mean-squared differences between in situ PP data on the equator at 140°W and PP estimates from the satellite-based productivity models were 58% lower than analogous values computed in a previous PP model comparison six years ago. The success of these types of comparison exercises is illustrated by the continual modification and improvement of the participating models and the resulting increase in model skill.
  • Dataset
    An ocean productivity database using consistent, globally-acquired data from in situ primary productivity based on 14C assimilation, and including ancillary data, 1985-2008
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2022-11-15) Marra, John F.
    In situ primary productivity based on 14C assimilation and nutrients from samples collected by many research projects and on numerous cruises globally, 1985-2008. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/814803