Bias Correcting Precipitation Products From Next-Generation Global Atmospheric Reanalyses for the Arctic Ocean
Abstract
Precipitation is a fundamental input for snow accumulation-melt models developed to estimate snow thickness and density for use in laser and radar altimeter retrievals of sea ice thickness. Four atmospheric reanalyses will extend through the planned operations of ICESat2 and CryoSat2: NASA's MERRA2, NOAA's CFSRv2, ECMWF's ERA5 and the Japanese JRA55. Evaluations of precipitation products from these four reanalyses indicate that no one reanalysis is better than the others: MERRA2 and CFSRv2 have positive biases of about 50 mm based on pan-Arctic mean precipitation; JRA55 has a negative bias of 50 mm. However, these biases vary spatially: MERRA2 and CFSRv2 tend to have a wetter eastern Arctic than JRA55; ERA5 is still in production. A full run from 1979 to present is slated to be available by the end of 2018. In this presentation, we present methods and results of spatially dependent bias correction for each reanalysis. While precipitation observations are sparse, we use precipitation observations from Arctic coastal stations, North Pole drifting stations, and SHEBA to provide insights into accuracy of the different reanalysis products. These observations are used to correct statistical distributions or precipitation in a climatological sense. Bias corrected products are presented and evaluated using a reserved set of observations.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.C33F1623B
- Keywords:
-
- 0750 Sea ice;
- CRYOSPHEREDE: 0799 General or miscellaneous;
- CRYOSPHEREDE: 9315 Arctic region;
- GEOGRAPHIC LOCATIONDE: 1621 Cryospheric change;
- GLOBAL CHANGE