annual

• Main Author: Thierry Penduff
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Quasiglobal. 1993-2006; Langmuir; Sea ice
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.424.2389; http://www.aviso.oceanobs.com/fileadmin/documents/OSTST/2007/penduff.pdf

ABSTRACT In order to guide physical investigations, characterize the structure of model biases, and assess the impact of numerical and physical choices, DRAKKAR simulations are evaluated against altimetric sea-level anomalies (AVISO: 1993-present, see Poster by Penduff et al), and temperature/salinity profiles (ENACT/ENSEMBLES: 1956-present). Model outputs are first sub-sampled like actual observations to build altimetric and hydrographic "synthetic observations". Real and synthetic observations and more integral quantities (mixed layer depth cycle, heat/salt contents, etc.) are then compared over various regions, periods, and timescales. This study presents the methods and a validation of DRAKKAR simulations with respect to hydrography Snapshot of 1/4 ° MODEL SSH + ice cover 1/4 ° GLOBAL MODEL SETUP • NEMO code (OPA9 ocean + LIM sea-ice + CFC / 14 C tracers) • Partial steps+BBL, TKE mixed layer (waves+Langmuir cells) • Advection: enstr./energy conserv. (momentum). FCT (tracers) • Isopycnal laplacian tracer mix. Biharmonic momentum mix. 1958-2004 FORCING (see Brodeau, Barnier et al) • CORE bulk formulae. Dai & Trenberth monthly runoffs. • 6-hourly ERA40 (T,q,wind) + CORE LW/SW radiative fluxes • No SST restoring. But SSS restoring (τ=36 days on 1 st level) DATA PROCESSING Validation procedure of DRAKKAR runs against altimetry and hydrography: • Collocation of model fields ( SSH(x,y,t) and T,S(x,y,z,t) ) on the observation space from various simulations. We build simulated counterparts of:-weekly 1/3°x1/3 ° SLA maps (1993-2004)- instantaneous T,S profiles (1956-2004). Flagged hydrographic observations are rejected. • Computation of derived quantities from collocated observed/simulated databases • Quantitative assessment of model skill in space and time AVISO SLA(x,y,t) database