[6] Multi-scale & multi-component treatments 1

[6-1] February 28, 09:30-10:00


Using ocean observations and ocean data assimilation to improve atmospheric reanalysis fluxes

J.A. Carton (University of Maryland), and G.A. Chepurin (University of Maryland)


Surface fluxes of heat, freshwater, and momentum play a crucial role in the development of many weather and climate phenomena. Yet different atmospheric reanalyses show big differences in these fluxes which may exceed 30W/m^2 in heat and 1mm/dy in freshwater. These differences suggest that atmospheric observations and assimilation systems alone are not sufficient to constrain these variables. Ocean observations of temperature and salinity offer additional constraints on heat, freshwater, and momentum fluxes but must be adjusted for the effects of ocean advection and entrainment. Here I discuss an approach using an oceanic application of data assimilation (SODA3) together with a set of ocean observations to reduce the seasonal errors in meteorological surface fluxes. In the second part of the talk I apply the approach to three recent atmospheric reanalyses: MERRA2, ERA-Int, and JRA55 for the 36 year period 1980-2015 and discuss the results, including the implications for estimating the decadal uptake of heat by the ocean and the climate hiatus.

  Presentation file: 06_1_J.Carton.pdf