By Heather Benway (OCB) and Marjy Friedrichs (VIMS), edited by Gyami Shrestha (US Carbon Cycle Science Program, USGCRP)

A Coastal CARbon Synthesis (CCARS) community workshop was held at the Woods Hole Oceanographic Institution (WHOI) in Woods Hole, MA from August 19 to 21, 2014 with representation and support from multiple federal agencies (NASA, USGS, NOAA, NSF). Since its initiation in 2007, this long-term CCARS activity brings together scientists involved in two core elements of the USGCRP: the North American Carbon Program (NACP) and the Ocean Carbon and Biogeochemistry Program (OCB). Sixty scientists working in different coastal systems of North America attended the workshop. Throughout the discussions that took place during plenary and breakout and poster sessions, participants distilled near-term coastal carbon science priorities, including coastal observations, modeling approaches and developments, and process studies. These will be summarized in a science plan that will be developed in the Fall of 2014.

The workshop opened with an overview talk on the current status and recent history of coastal carbon science in the U.S., including relevant programmatic and scientific developments such as the coastal synthesis activities (2008-present) that have been coordinated by the Ocean Carbon & Biogeochemistry (OCB) Program and the North American Carbon Program (NACP). The first plenary session of the workshop focused on key coastal carbon fluxes, exchanges, and processes spanning the land-ocean continuum. This included terrestrial inputs from rivers and groundwater, fluxes in tidal wetlands and their exchanges with estuarine and shelf waters, fluxes within estuarine and shelf waters such as air-sea, burial rates and sedimentary processes, biological processing (primary production, net ecosystem production), and exchange between coastal and open ocean waters.  A second plenary session included regionally focused talks on the outcomes of the OCB/NACP coastal synthesis activities, including the current status of regional coastal carbon budgets (east coast, west coast, Gulf coast, Arctic, Great Lakes).

Following the two plenary sessions, the workshop format shifted to smaller group discussions to highlight key issues and help formulate priorities for moving forward. The first breakout session focused on coastal fluxes and processes, with participants breaking out into the following five groups: Air-sea exchange, terrestrial inputs, estuarine and tidal wetland fluxes, biological transformations, and carbon loss terms (burial, exchange with open ocean). Discussions during Breakout 1 focused on addressing the remaining unknowns for each process that significantly hinder our quantitative and predictive understanding of the coastal carbon cycle. Participants brainstormed ideas for observing needs and process and modeling studies to improve future flux predictions, taking into consideration relevant time and space scales.

The second and third breakout sessions were divided into five groups by region, including east coast, west coast, Gulf of Mexico, Great Lakes, and Arctic. In Breakout 2, participants focused on identifying key observations within each region that would significantly improve flux estimates in coastal carbon budgets. Breakout 3 focused on the integration of observations and models to help scale up from relatively limited coastal data sets.

Presentations are available on http://www.whoi.edu/website/ccars/agenda and more details can be found on http://coastalcarbon.pbworks.com/w/page/15143273/FrontPage.The adjacent slide provides a quick overview.