Dates/Venue: May 5-6, 2020 (virtual meeting); Teleconferences: July 15, 2020, September 25, 2020
Summary: A number of recent studies have applied novel statistical and machine-learning methods to in situ surface ocean carbon dioxide (CO2) observations to estimate the ocean carbon sink with unprecedented spatio-temporal resolution. These studies suggest that the oceanic CO2 sink is more variable on multiyear timescales than previously estimated from biogeochemical model simulations. This newly identified variability challenges our model-based mechanistic understanding and puts into question our projections of the future ocean carbon sink. These observation-based estimates, however, rely on extensive interpolation of limited observations, and thus their reliability is unclear, particularly in data-sparse regions and seasons. Furthermore, inconsistencies regarding the area covered by open and coastal ocean estimates hampers our ability to constrain CO2 fluxes across the full marine continuum (i.e., all tidal waters). The goal of this working group is to assess critical uncertainties in existing observation-based products, determine how best to integrate observation-based open-ocean and coastal-ocean CO2 air–sea fluxes, and quantify uncertainties in the natural (pre-industrial) outgassing of CO2. These efforts will lead to better constraints on the contemporary ocean carbon sink and its variability. The results of this OCB Working Group will assist the global carbon community in understanding the state of the global carbon cycle so as to contribute to international efforts to address climate change.
Galen McKinley (Columbia / LDEO, USA)
Jessica Cross (NOAA PMEL, USA)
Tim DeVries (University of California - Santa Barbara, USA)
Judith Hauck (Alfred Wegener Institute, Germany)
Peter Landschützer (MPI-Hamburg, Germany)
Goulven G. Laruelle (Université Libre de Bruxelles, Belgium)
Nicole Lovenduski (University of Colorado, Boulder, USA)
Pedro Monteiro (CSIR, South Africa)
Ray Najjar (Penn State University, USA)
Christian Rödenbeck (Max Planck Institute for Biogeochemistry, Germany)
Laure Resplandy (Princeton University, USA)
Christopher Sabine (University of Hawaii Manoa, USA)
Adrienne Sutton (NOAA PMEL, USA)
Rik Wanninkhof (NOAA AOML, USA)
Nancy Williams (University of South Florida, USA)
Products & related papers
Hauck, Judith, Moritz Zeising, Corinne Le Quere, Nicolas Gruber, Dorothee C. Bakker, Laurent Bopp, Thi T. Chau, Özgür Gürses, Tatiana Ilyina, Peter Landschützer, Andrew Lenton, Laure Resplandy, Christian Rödenbeck, Jörg Schwinger, and Roland Seferian (2020) Consistency and challenges in the ocean carbon sink estimate for the Global Carbon Budget. Frontiers in Marine Science. doi: 10.3389/fmars.2020.571720
OCB Working Group on Carbon Gaps Virtual Meeting
Tuesday, May 5, 2020: Current state of understanding of the global ocean carbon sink
Who: Working Group and open webinar for interested attendees.
Key points for all speakers:
- How well do we know air-water fluxes and their variability across timescales?
- What are the most important uncertainties?
- How can this working group help to bridge from direct pCO2 observations to global and regional synthesis?
|11:00-11:35 EDT||Welcome and Introductions View recording on YouTube Welcome slides Introduction slides|
|11:35– 12:45||The Open Ocean View recording on YouTube
|Observationally-based products (Landschützer, 8 min) Slides|
|Hindcast ocean models (Lovenduski, 8 min) Slides|
|Outgassing of natural carbon input from rivers (Resplandy, 8 min) Slides|
|Evidence from interior observations (DeVries, 8 min) Slides|
|Gas Exchange Uncertainties, including OCB workshop on Ocean-Atmosphere Interaction (Wanninkhof, 8 min) Slides|
|12:50-13:35||The Coastal Ocean View recording on YouTube
|Coastal data and global products (Laruelle, 8 min) Slides|
|Processes in the coastal zone (Najjar, 8 min) Slides|
|Arctic (Cross, 8 min)|
|14:00-15:20||Synthesis and Observational Programs (Activities, Goals, Challenges, 2020-22 Plans) View recording on YouTube|
|Synthesis and Planning|
|RECCAP2 (DeVries, 8 min) Slides|
|Integrated Ocean Carbon Research (IOC-R) (Sabine, 8 min) Slides|
|Global Carbon Budget (Hauck, 8 min) Slides|
|WCRP grand challenge on decadal prediction and OMIP (Lovenduski, 8 min) Slides|
|Observing Systems and Projects|
|SOCONET, SOCAT, ICOS-OTC, ISOOS (Wanninkhof, 8 min) Slides|
|Bio-Argo, SOCCOM (Williams, 8 min)|
|SO-CHIC project - speaker was unable to connect for this presentation - for more information, please visit http://www.sochic-h2020.eu/|
|15:20-16:00||Plan Open and Coastal Discussion Points for Day 2 (some suggestions at end)|
Wednesday, May 6: Current state of understanding of the ocean carbon sink
Who: Working Group
|11:00 EDT||Introductions and summary of Day 1 (McKinley)|
|11:15-12:15||Discussion on Open Ocean, Part I (Discussion Leader: Landschutzer)|
|12:20 - 13:15||Discussion on Open Ocean, Part II (Discussion Leader: Landschutzer)|
|13:45 – 14:45||Discussion on Coastal Ocean (Discussion Leader: Najjar)|
|14:45 – 15:30||OCB Working Group Goals and Closing (Discussion Leader: McKinley)|
|What synthesis paper do we want to submit in spring 2022?|
|What are immediate action items for 2020-2021?|
Open Ocean Discussion Question possibilities:
- What are the critical uncertainties in observation-based products (skin effect, gas exchange formulation, interpolation technique, changing data density over time)? How can we better constrain these?
- The pre-industrial river flux challenge for global closure
- What is the best approach given current knowledge?
- What is needed in the next 5-10 years to independently constrain this flux?
- What steps are needed to make observation-based products open ocean results more directly comparable to hindcast model simulations in the RECCAP / Global Carbon Budget framework?
- Is there a need for a continuation of the SOCOM inter-comparison and what should this inter-comparison include?
Coastal Ocean Discussion Question possibilities:
- Is pCO2 enough? What are the coastal processes that are most likely to be globally significant, either on the mean or for anthropogenic change?
- What is needed to integrate open ocean and coastal ocean estimates?
- Can we infer interannual variability on a global scale from coastal estimates?