Overview In 2014, the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project was launched with a vision to enable a transformative shift in scientific and public understanding of the role of the Southern Ocean in climate change and biogeochemistry. Led by Jorge Sarmiento at Princeton University, SOCCOM draws on the strengths of teams of investigators across the U.S. as well as participating in international observational and simulation efforts. In the past 6 years, SOCCOM researchers have: Deployed a network of 156 biogeochemical floats operating in all 3 basins of the Southern Ocean; Developed a high-resolution biogeochemical Southern Ocean State Estimate (B-SOSE) that is assimilating float data; Calculated float-based climatological seasonal cycles of oxygen, nitrate, and carbon system variables and air/sea carbon fluxes across the Southern Ocean, including seasonal ice zones; Carried out model simulations that suggest a new climate feedback mechanism from Antarctic meltwater Led a Southern Ocean Model Intercomparison Project (SOMIP), simulations from which have already produced significant and unexpected results; Published over 110 manuscripts on SOCCOM technology and early results, including 18 papers in a SOCCOM special issue of JGR-Oceans; and Successfully transferred SOCCOM float and sensor technology to the commercial float industry. In addition, a substantial education effort has contributed to the training and education of 16 postdocs, 15 graduate students, and 42 undergraduate students at five different institutions. More broadly, SOCCOM’s outreach efforts have engaged thousands of members of the public through online events and via social media with compelling stories highlighting SOCCOM research. With 119 floats adopted so far, the popular Adopt-a-Float program partners teachers and classrooms around the world with SOCCOM researchers by providing students the chance to name and track their very own float and educating them about Southern Ocean biogeochemistry and climate change. Year 6 Progress As of July 2020, the project has 159 active floats with 27 to be deployed next year, and is within sight of its goal of ~180 floats deployed in the Southern Ocean. SOCCOM floats have collected a total of over 17,000 profiles, totaling over 400 float years of biogeochemical measurements made publicly available in real time via the SOCCOM website and the Argo data system. SOCCOM adjusted biogeochemical data are providing an unparalleled view of Southern Ocean biogeochemistry. Results from Year 6 include: Observations von Berg, et al. (2020). Weddell Sea phytoplankton blooms modulated by sea ice variability and polynya formation Rosso, et al. (2020). Water mass and biogeochemical variability in the Kerguelen sector of the Southern Ocean: A machine learning approach for a mixing hot spot. Narayanan, Gille, et al. (2019). Water mass characteristics of the Antarctic margins and the production and seasonality of dense shelf water. JGR. Meijers, Sallée, et al. 2019: Southern Ocean [in “State of the Climate in 2018”]. Bull. Amer. Meteor. Soc., 100 (9), S181–S185. Developed an improved design for profiling float pH sensors and deployed the first prototype off California. Claustre et al. (2019) reviewed developments in BGC-Argo, including Southern Ocean science. Chai et al. (2020) reviewed global observing systems based on autonomous platforms with a particular emphasis on BGC-Argo. Southern Ocean State Estimate Released an improved 2013-2018 B-SOSE solution with 1/6 degree resolution Numerous model developments implemented to improve BSOSE realism. These include improved handling of size dependent limitation and export fraction; now using real freshwater fluxes, self-shading, and prognostic phytoplankton. Enabling science. The Verdy and Mazloff (2017) BSOSE publication has 45 citations. Ten publications used BSOSE this year. Seven of these are external publications and thus we list them here: Demuynck et al. Spatial variations in silicate-to-nitrate ratios in Southern Ocean surface waters are controlled in the short term by physics rather than biology. Biogeosciences. 2020 Pardo et al.. Surface ocean carbon dioxide variability in South Pacific boundary currents and Subantarctic waters. Scientific reports. 2019 Song. Explaining the zonal asymmetry in the air‐sea net heat flux climatology over the Antarctic Circumpolar Current. Journal of Geophysical Research: Oceans, 2020 Uchida et al. The contribution of submesoscale over mesoscale eddy iron transport in the open Southern Ocean. Journal of Advances in Modeling Earth Systems. 2019 Uchida, et al. Southern Ocean Phytoplankton Blooms Observed by Biogeochemical Floats. Journal of Geophysical Research. 2019 Uchida et al. Vertical eddy iron fluxes support primary production in the open Southern Ocean. Nature communications. 2020 Zhou, et al. Influence of tides on mass transport in the Bransfield Strait and the adjacent areas, Antarctic. Polar Science. 2020 Internal publications using BSOSE include: Comparison to CMIP models (Beadling et al. 2019 and 2020). Analysis of Drake Passage properties and seasonal cycle (Freeman et al 2019). Internal publications towards advancing assimilation, mapping, and regional modeling capabilities: Geyer, et al. (2020). Using a regional ocean model to understand the structure and variability of acoustic arrivals in Fram Strait. Mazloff, et al. (2020). The Importance of Remote Forcing for Regional Modeling of Internal Waves. Bushinsky, et al. (2019). Reassessing Southern Ocean air-sea CO2 flux estimates with the addition of biogeochemical float observations. Global Biogeochemical Cycles. Kuhn,et al. (2019). Temporal and spatial scales of correlation in marine phytoplankton communities. JGR. Physical Processes SOSE was used to assess the effects of sea ice export from the Ross Sea on cooling and freshening in the Southeast Pacific (Cerovečki et al., 2019) and identify a deep eastern boundary current that carries Indian Deep Water along the southern boundary of Australia to the Southern Ocean (Tamsitt et al., 2019). Modeling SOCCOM float observations successfully simulated through SOMIP protocol: extra wind stress and ice melt are essential to explain observations since 2014 (Bronselaer et al. (2020), Nature Geosciences, doi: 10.1038/s41561-019-0502-8, Importance of wind and Meltwater for Observed Chemical and Physical Changes in the Southern Ocean) SOMIP experiments carried out in GFDL-CM4 (GFDL’s contribution to CMIP6) The package with SOCCOM’s metrics (from Russell et al. 2018) is now available at ESMValTool V2.0. The paper on which these metrics are based was cited as one of the 20 most read articles in JGR-Oceans for 2018 and one of the most downloaded articles in 2019 (in the top 10%). The documentation paper for ESMValTool V2 (Eyring et al. 2020, https://doi.org/10.5194/gmd-2019-291) had three SOCCOM-affiliated coauthors (Russell, Goodman, Pandde) Two CMIP intercomparisons published: Beadling et al. 2019 (https://doi.org/10.1175/JCLI-D-19-0263.1) revisited the factors affecting the Southern Ocean circulation and overturn first documented in Russell et al. (2006, https://doi.org/10.1175/JCLI3869.1); Beadling et al. (2020, https://doi.org/10.1175/JCLI-D-19-0970.1) documented the progression of modeling over the last 13 years from CMIP3 through CMIP6 highlighting both strengths (things we do much better) and weaknesses (persistent, continuing issues) Jeong, et al. (2020): Impacts of ice-shelf melting on water mass transformation in the Southern Ocean from E3SM simulations Broader Impacts Southern Ocean Model Intercomparison Project (SOMIP): SOMIP is officially part of FAFMIP and at least 3 of the climate modeling centers have agreed to, or already started, running the SOMIP experiments. Knowledge Transfer: MBARI and UW have a long history of transferring float control and sensor technology to industry. Collaboration with two partner companies, SeaBird Electronics and Teledyne Webb Research, has resulted in first-generation commercial SOCCOM-type floats that are now available for use by the research community. pH sensors used in the SOCCOM program are now available as commercial option from a variety of profiling float manufacturers. Outreach: A new graphic and animation highlighting SOCCOM’s vision for using robotic floats, as part of a suite of tools, to collect ocean health data autonomously. A video looking back at key SOCCOM accomplishments is currently in production and will be complete by August 31, 2020. A second video highlighting a recent SOCCOM research paper is also slated to be complete by August 31, 2020. (COVID-19 hampered our ability to shoot interviews.) A “video abstract template” was created. This template will allow SOCCOM scientists to create their own video abstracts when they publish a paper. Coordinated successfully with SOCCOM partner institutions on two press releases. Social Media: SOCCOM’s social media following grew 30% in Year 6 to more than 3,220 followers across Twitter, Facebook and Instagram by providing multiple posts on a daily basis. We also provided science communication guidance for early career scientists on how to become active on social media. Adopt-a-Float: Adopted and named 31 SOCCOM floats this year in schools across the United States and internationally. In addition, SOCCOM scientist Robert Key visited 5 schools (one in person and four virtually) in three states and two countries to talk about the important role the Southern Ocean plays in our climate system and how autonomous floats allow us to better quantify and understand changes in ocean geochemistry. Four expedition blogs were posted. A science communication seminar was given during the CAPSTAN cruise. A B-SOSE Workshop was held on 16 June 2020 with the goal of increasing involvement in biogeochemical state estimation.