CGD Seminar Series - Dan Amrhein, NCAR, How much of the uncertainty in paleoclimate reconstructions stems from uncertain climate physics?

Title: How much of the uncertainty in paleoclimate reconstructions stems from uncertain climate physics?

Speaker: Dan Amrhein, NCAR

Date: Tuesday, 7 January 2020

Time: 11 am - 12 pm

*Refreshments at 10:45*

Location: Mesa Lab, Main Seminar Room, ML - 132

Abstract: Reconstructing past climate conditions requires interpolating between sparse, noisy proxy observations. Because of this, errors and uncertainties arise not just from the data, but also from uncertain representations of climate processes (typically derived from models or instrumental records) used to relate climate variables across time and space. What are the origins of these errors, and how wrong should we expect reconstructions to be as a result?

Perfect-model ensemble optimal interpolation reconstructions of last-millennium climate illustrate that uncertainties from physics can be as large as those arising from observational noise, with regional covariances in space, suggesting that generating suitable model representations of past climates may be as important as new proxy records for reducing uncertainty. Reconstructions over the last deglaciation reveals qualitative differences in diagnostics of the Hadley and Walker circulation arising from different model physics. Inflation, multi-model ensembles, and other approaches from data assimilation provide promising ways forward to address these problems.

Building:

Room Number: 
ML-132

Type of event:

Will this event be webcast to the public by NCAR|UCAR?: 
Yes - CG1-Center Auditorium - https://www.ucar.edu/live?room=cg1aud
Announcement Timing: 
Monday, January 6, 2020 to Tuesday, January 7, 2020
Calendar Timing: 
Tuesday, January 7, 2020 - 11:00am to 12:00pm

Posted by Tracy Baker at ext. 1366, tbaker@ucar.edu

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