Earth's climatic transition from the Last Glacial Maximum (LGM) to the Holocene is still not fully understood. The associated rise in atmospheric CO2 remains unexplained although it is important for the global warming. Ocean circulation changes during the deglaciation have been linked to the rates of CO2 increase. However, the exact mechanism of that link is unclear and quantifying changes in the ocean's circulation and carbon storage remain challenging tasks. This workshop will contribute to making progress through new regional syntheses of carbon isotope data throughout the last deglaciation and comparisons of these syntheses to other paleoclimate proxy reconstructions and isotope enabled model simulations. We plan to address questions such as the following:
- When, at what depths, and by how much did carbon isotopes started to change after the LGM in the Atlantic, Pacific, Indian, and Southern Oceans?
- What do these changes imply about ocean circulation?
- How much did the Atlantic Meridional Overturning Circulation (AMOC) decrease during Heinrich Stadial 1 (HS1)? Was it only weakened or completely shut-down?
- Are carbon isotopes consistent with the idea that an AMOC shutdown weakened the biological pump and triggered the initial CO2 rise during HS1?
- Why did CO2 concentrations during the subsequent Bolling-Allerod stay constant?
- What caused the CO2 rise during the final phases of the deglaciation?
- What role did changes in the Southern Ocean and North Pacific play?
Objectives of the workshop are to
- bring together sea-going paleoceanographers, modelers, and database managers
- discuss database issues such as format, links to other databases, LinkedEarth ontology
- discuss methods and uncertainties of age model construction
- discuss how the database can be used to constrain models of ocean circulation change and our ideas about the release of CO2
- create regional syntheses of benthic carbon isotope measurements
- analyze the syntheses, compare them with each other and with other paleoclimate data and models
- draft manuscripts describing the syntheses and analyses suitable for publication in a special issue of a peer-reviewed journal
- discuss what advances need to be made beyond this compilation
The workshop will be limited to ~40 participants. The format will be a limited number of oral presentations (e.g. from the leaders of the regional syntheses). Most presentations will be in poster format with short (2-3 min) lightning talks. A large amount of time will be devoted to detailed discussions and drafting of manuscripts. A detailed program will be published after the registration deadline.
Stakeholder Engagement
We will work with the Paleoclimate Modeling Intercomparison Project's (PMIP) working group Last Deglaciation. The purpose of that working group is to co-ordinate climate model simulations of the last deglaciation including comparison with reconstructions. For the latter purpose our carbon isotope syntheses and data constraints of ocean circulation will be useful. Members of this working group are encouraged to attend the meeting.
LinkedEarth is an NSF funded EarthCube project that aims at facilitating paleoclimate data syntheses. LinkedEarth team members are welcome to attend.
College of Earth, Ocean, and Atmospheric Sciences at Oregon State University. The meeting room will be Burt 193. Use the Campus Map to locate Burt Hall.
From the International Airport in Portland (PDX) take the hutshuttle bus to Corvallis Hilton Garden Inn or rent a car. The bus takes about 2.5 h. Please plan to arrive on the 26th. We plan to start the meeting early morning on the 27th. Please plan to stay at least until noon on the 29th.
We have reserved rooms in the Hilton Garden Inn for $139/night from the 26th to the 30th. Call 541 752-5000 and mention "OC3 Workshop" to book your room there before June 5th. Of course you're free to book a different hotel or motel in Corvallis or camp in my backyard (just kidding).
- Registration, abstract submission, and application for travel support: Apr. 3, 2017
To register send abstract via email to Andreas Schmittner: aschmitt(at)coas.oregonstate.edu with subject line "OC3 Workshop 2017". Applicants for travel support will be notified of the decision and the amount of support by Apr. 5, 2017
Limited funding for travel support is available. Early career and scientists from developing countries are particularly encouraged to apply. This workshop is funded by the Marine Geology and Geophysics Program of the National Science Foundation and by the Past Global Changes (PAGES) project.
- We have agreed to upload the final OC3 downcore database on LinkedEarth . LinkedEarth will also serve as a long-term platform to crowdsource the curation of the database past the end of the OC3 project.
- The regional syntheses groups will choose a leader who will be first author on the corresponding publication. Each group chooses their own approach of data selection and quality control depending on the scientific questions. However, at least one person, preferably two, will need to quality check each core and add quality flags. Information on data quality including species used, age model and uncertainty, time resolution, and analytical errors will be reported.
- Alan Mix is leading the Pacific synthesis supported by Liz Sikes and Gema Martinez. The Pacific synthesis is already quite well progressed. A paper will be prepared for publication within about 3 months.
- The South Atlantic group (Steve Barker, Stefan Muliza, Dave Lund, and Gema Martinez) will need to 'volunteer' a leader.
- The North Atlantic group (Claire Waelbroeck, Janne Repschlaeger, and Steve Barker) will build on an ongoing effort by Claire. We also need a designated leader for that group.
- The Indian ocean group (Elisabeth Michel, Carlye Peterson) also still needs experts and a designated leader.
- Data from the Southern Ocean sectors will be included in the above groups.
- One paper on the comparison between S. Atlantic and S. Pacific is currently in preparation by Liz Sikes and David Lund.
- Policy for co-authorship: each data contributor will become a co-author on a paper. If the data are not included in one of the above regional syntheses it will be included in the final global data synthesis paper led by Lorraine Lisiecki. Of course, contributors of ideas can also become co-authors depending on the judgement of the lead author.
- We have agreed on the following timeline:
Dec 2017: finalize regional syntheses (each regional group can have an earlier deadline depending on their plans, but we need all regional syntheses completed by the end of this year)
Jun 2018: finalize global synthesis
- Juan Muglia, a postdoc with NSF funding to work on the project, will assist with data management and coordination between groups. He will also lead a paper on model-data comparison focused on the early parts of the last deglaciation that will use the global synthesis. Juan will split the current spreadsheet, which contains all published data, into four spreadsheets that contain only data in the corresponding regions (Pacific, S. Atl., N. Atl, Indian). He will also clean it up by removing time slice data (e.g. only core-top) and then send the resulting regional spreadsheets to the individual groups. The individual groups then need to quality check the data, solicit and include unpublished data, analyze the data and write a paper.
Carlye Peterson's notes from the breakout groups are here.
