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An Introduction to the NASA GMAO Coupled Atmosphere-Ocean System - GEOS-S2S Version 3Recently NASA's Global Modeling and Assimilation Office (GMAO) has developed a new Subseasonal to Seasonal Prediction system Version 3 (GEOS-S2S-3). This upgrade replaces the GEOS-S2S-2 which is NASA's current contribution to the North American Multi-Model Experiment seasonal prediction project (Kirtman et al., 2014). The main improvements for our S2S-3 system include 1) a higher resolution MOM5 (Griffies et al., 2005) ocean model (now 0.25o x 0.25o x 50 layers), 2) an improved atmospheric/ocean interface layer (Akella and Suarez, 2018), and 3) assimilation of a long-track satellite salinity into the ocean model (Hackert et al, 2019). Atmospheric forcing is provided by the NASA MERRA-2 reanalysis (Gelaro et al., 2017). Initialization for the ocean relies on the GMAO ocean reanalysis system which assimilates all available in situ temperature and salinity, satellite sea surface salinity, and sea level using the Local Ensemble Transform Kalman Filter (LETKF) implementation of (Penny et al., 2013) on a 5 day assimilation cycle with 20 fixed ensemble members.In this presentation, we will authenticate our new S2S-3 ocean reanalysis using standard GODAE validation metrics. For example, we will compare gridded fields of mean and standard deviation of the ocean reanalysis versus observed fields. We will show correlation/RMS of model versus observations and temperature and salinity mean profiles for the various basins and latitude bands. Basin-scale volume transports, such as the Atlantic Meridional Overturning Circulation and the Indonesian Throughflow will be validated. Equatorial ocean waves will be compared by decomposing sea level into Kelvin and Rossby components. For each of these metrics, we plan to validate the results and then compare our new S2S-3 against the current production version, S2S-2. Finally, we will compare 9-month seasonal forecasts initialized from these two systems for the tropical Pacific NINO3.4 region over the period 1981-present.
Document ID
20200001250
Acquisition Source
Goddard Space Flight Center
Document Type
Presentation
Authors
Molod, Andrea
Hackert, Eric
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Akella, Santha
Andrews, Lauren
Arnold, Nathan
Barahona, Donifan
Borovikov, Anna
Cullather, Richard
Chang, Yehui
Kovach, Robin
Koster, Randal
Li, Zhao
Lim, Young-Kwon
Marshak, Jelena
Nakada, Kazumi
Schubert, Siegfried
Vikhliaev, Yury
Zhao, Bin
Vernieres, Guillaume
Carton, James
Date Acquired
February 28, 2020
Publication Date
February 16, 2020
Subject Category
Geosciences (General)
Report/Patent Number
GSFC-E-DAA-TN78568
Meeting Information
Meeting: AGU Ocean Sciences Meeting 2020
Location: San Diego, CA
Country: United States
Start Date: February 16, 2020
End Date: February 20, 2020
Sponsors: American Geophysical Union (AGU)
Distribution Limits
Public
Copyright
Public Use Permitted.
Technical Review
NASA Technical Management
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