An open invitation to participate in the 5th Primary Production Algorithm Round Robin focused on the Arctic Ocean | POGO

An open invitation to participate in the 5th Primary Production Algorithm Round Robin focused on the Arctic Ocean

Do you estimate marine photosynthesis using a model? Would you like to quantify the performance of the model you use in the Arctic Ocean? Would you like to know how your model compares with other models? This is your chance!

In the last decade, it appears that primary productivity (PP) in the Arctic Ocean has increased considerably, as estimated from remotely-sensed observations. However, consensus about the relative importance of variables and processes controlling PP in the Arctic Ocean at different times and in different regions is lacking. Sea ice, colored dissolved organic matter, persistent cloud cover and stratification are major controls of the light regime for phytoplankton while winter wind mixing, upwelling, eddies, river discharge and stratification are involved in nutrient replenishment. Given the projected high sensitivity of the Arctic Ocean to climate change, combined with the observed contemporary changes, a regional Arctic Ocean PP assessment will provide an essential step forward in this region.

A study is being conducted to compare models that estimate PP in the Arctic Ocean from either ocean-color based models, biogeochemical ocean circulation models, or earth system models thanks to funding from NASA’s Ocean Biology and Biogeochemistry Program. This project continues previous comparison studies (Primary Production Algorithm Round Robins, PPARR). PPARR-4 (Saba et al. 2010; 2011) included over 50 investigators running ~22 distinct satellite-based PP models or model variants and 14 coupled physical-biogeochemical circulation models. This fifth round robin study (PPARR-5) will be the first one to focus on the Arctic Ocean.

PPARR-5 will include comparisons to high quality in situ primary productivity data, over a broad array of locations, which will allow a comprehensive assessment of model estimates of PP, and their associated uncertainties. In this study, 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 net primary productivity and, if possible, depth-resolved profiles of primary production and chlorophyll a. These results are sent back to the organizers, who compare and analyze the results. We are preparing to distribute the PPARR-5 Arctic Ocean data set shortly.

We welcome the participation of satellite-based PP model users (or developers), of coupled physical-biogeochemical modelers and earth system modelers, who estimate productivity rates in the Arctic Ocean.

Please write to and if you are interested in participating in this comparison or if you have further questions about the PPARR-5 Arctic Ocean project.

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