Comparison of Primary Production Models
Do you estimate marine photosynthesis using a model? Would you like to quantify the
performance of the model you use? Would you like to know how your model compares
with other models? This is your chance!
We are conducting a study to compare models that estimate primary productivity (PP)
from either ocean-color based models or biogeochemical ocean circulation models,
thanks to funding from NASA’s Ocean Biology and Biogeochemistry Program. This
project continues previous comparison studies (Primary Production Algorithm Round
Robins, PPARR). PPARR3 (Carr et al., 2006; Friedrichs et al., submitted) included over
30 investigators running ~20 distinct satellite-based PP models or model variants and 9
coupled biogeochemical ocean circulation models.
The fourth round robin study (PPARR4) includes comparisons to high quality in situ
primary productivity data, including HNLC conditions, intense bloom dynamics,
oligotrophy, coastal dynamics, micronutrient limitation, and high latitude systems. We
believe this broad array of environmental conditions will allow a comprehensive
assessment of model estimates of PP, and their associated uncertainties.
In the PPARR studies, input data (chlorophyll, SST, PAR, and mixed layer depth for
specific locations and dates) are provided by the organizers to the participating modeling
groups, who in turn estimate integrated primary productivity. These results are sent back
to the organizers, who compare and analyze the results. We are preparing to distribute the
PPARR4 data set shortly. The resulting comparisons will be presented at Ocean Sciences
in March 2008.
We welcome the participation of satellite-based PP model users (or developers) as well as
of coupled biogeochemical-circulation modelers who estimate productivity rates in any of
the following regions: BATS, HOT, NABE, Northeast Atlantic, Arabian Sea, Southern
Ocean, Black Sea, and the Mediterranean Sea.
Please write marjy@vims.edu if you are interested in participating in this comparison or
if you have further questions about the PPARR project.
Thank you,
Marjy Friedrichs, Mary-Elena Carr and Vince Saba
References:
Mary-Elena Carr, Marjorie A. M. Friedrichs, Marjorie Schmeltz, Maki Noguchi Aita,
David Antoine, Kevin R. Arrigo, Ichio Asanuma, Oliver Aumont, Richard Barber,
Michael J. Behrenfeld, Robert Bidigare, Erik T. Buitenhuis, Janet Campbell, Aurea M.
Ciotti, Heidi Dierssen, Mark Dowell, John Dunne, Wayne Esaias, Bernard Gentili,
Watson Gregg, Steve Groom, Nicolas Hoepffner, Joji Ishizaka, Takahiko Kameda,
Corinne Le Quere, Steven Lohrenz, John Marra, Frédéric Mélin, J. Keith Moore, André
Morel, Tasha E. Reddy, John Ryan, Michele Scardi, Tim J. Smyth, Kevin Turpie, Gavin
Tilstone, Kirk Waters, Yasuhiro Yamanaka, 2006. A comparison of global estimates of
marine primary production from ocean color. Deep-Sea Research II 53, 741-770.
Marjorie A. M. Friedrichs, Mary-Elena Carr, Richard T. Barber, Michele Scardi, David
Antoine, Robert A. Armstrong, Ichio Asanuma, Michael J. Behrenfeld, Erik T.
Buitenhuis, Fei Chai, James R. Christian, Aurea M. Ciotti, Scott C. Doney, Mark Dowell,
John Dunne, Bernard Gentili, Watson Gregg, Nicolas Hoepffner, Joji Ishizaka, Takahiko
Kameda, Ivan Lima, John Marra, Frédéric Mélin, J. Keith Moore, André Morel, Robert
T. O’Malley, Jay O’Reilly, Vincent S. Saba, Marjorie Schmeltz, Tim J. Smyth, Jerry
Tjiputra, Kirk Waters, Toby K. Westberry, Arne Winguth, 2007. Assessing the
uncertainties of model estimates of primary productivity in the tropical Pacific Ocean.
Submitted to Journal of Marine Systems, special issue on biological/physical model skill
assessment.
__________________________________________
Marjorie A. M. Friedrichs
Virginia Institute of Marine Science
Mail: P.O. Box 1346
Deliveries: Route 1208, Greate Road
Gloucester Point, VA, 23062-1346, USA
tel. +1-804-684-7695, fax. +1-804-684-7889
email: marjy@vims.edu
http://www.vims.edu/bio/faculty/friedrichs_m.html