130 likes | 273 Views
Validation des flux de surface radiatifs grande échelle ERAinterim, correction et application à la configuration globale 1/4° Mercator G. Garric (Mercator Océan) et N. Verbrugge (CLS). Objectives
E N D
Validation des flux de surface radiatifs grande échelle ERAinterim, correction et application à la configuration globale 1/4° Mercator G. Garric (Mercator Océan) et N. Verbrugge (CLS) • Objectives • Correct atmospheric surface conditions for future global oceanic reanalysis (2002-present) and (1989-present) • Validate the near real time of the ECMWF IFS surface conditions? • (ERAinterim=version IFS Sept. 2007-Jun. 2008) and propose corrections for forecasts? • Tools • Global ¼° NEMO3.1 • Daily Forcing from ECMWF/ERA_interim • ECUME/CORE/CLIO • ISCCP/GEWEX/OAFLUX/HOAPS… • Methodology • Impact on upper ocean T27=ERAinterim+ECUME (1999-2002) T28=ERAinterim+CORE (1999-2002) GLORYS=ECMWFAnalysis+CLIO +Assim SST (2002-2008) T09=ECMWFAnalysis+CLIO (2000-2008) T10=ECMWFAnalyis+ECUME (2000-2006) PSY3V2=ECMWFAnalyis+CLIO+ Assim SST (2008-present) 1
Links between SST and SW biases ERAinterim - GEWEX Downward SW Global ¼° SST – RTG SST
Net Surface dataset SW Comparisons The World Climate Research Programme (WCRP) initiated the Global Energy and Water Cycle Experiment (GEWEX) in 1988 Period: January, 1984 – June, 2007 Resolution: Daily data set ; 1°x1°
Corrections of downward GEWEX SW+LW surface fluxes ERAI GEWEX GEWEXcorrec Similar corrections applied by (Large & Yeager,2004) for ISCCP (CORE fields) 6% for SW 3% for LW
Correction of SW and LW Flux ERA_Interim • MG: 28-day Gewex Climatology: 365 mean values. Filtering (3°x2°) • MA: 28-day ERA_Interim Climatology: 365 mean values. Filtering (3°x2°) • Calculate a corrective factor : α=MG/MA for MA>1. • Production of a 365 corrective factors (i,j) for the whole ERA_interim period and rebuild the field : F= α * FL + FS (FL : Large Scale, FS :Small Scale) • Keep the interannual variability and the short-term (< 1 month) variability.
MEAN SST bias (2002) – Impact GEWEX CLIO/ECMWF/24H GLORYS CLIO/ECMWF/24H (1) CORE/ERAI/6H/24H CORE/ERAI/GEWEX/6H/24H (2) (1) Impact CORE/ERAI/6H (2) Impact ERAI + GEWEX (SW+LW) corrigé
MEAN SST bias (2002)– Impact Cycle Diurne CLIO/ECMWF/24H GLORYS CLIO/ECMWF/24H CORE/ERAI/GEWEX/3H/Cycle Diurne CORE/ERAI/GEWEX/6H/24H (3) (3) Impact 3H/cycle diurne dans Tropiques. CORE/ERAI/GEWEX/3H/Cycle diurne : fonction de forçage choisie pour le futur PSY3V3 et les futures réanalyses GLORYS1V2 (2002-2009) et GLORYS2 (1992-2009).
MEAN SST bias (2002)– Impact ERAinterim corrigé. CLIO/ECMWF/24H GLORYS CLIO/ECMWF/24H CORE/ERAI/GEWEX/3H/Cycle Diurne CORE/ERAIcorrected/3H/Cycle Diurne (4) (4) Impact méthode de correction ERAinterim. Application pour une expérience 1989-2009.
SST/Surface Heat Budget Qnet (W/M2) Mean SST Bias (°C) Mean SST (°C)
Surface Freshwater Budget SSH (m) Freshwater Budget (mm/day)
Perspectives • Method of correction applied to a 20yrs run (1989-2009) • Correction for the rainfalls (SSH trend)? • High latitudes? • Application to the real time? • Other source of surface radiative fluxes. Use of CMS products could be done by Mercator (S. Cailleau) and tested over the IBI domain.
Surface Heat Budget SW Net LW Net Flux air/mer stables avec ERAI corrigé SW: [166;168]W.M2 LW: [-55, -53]W.M2 Latent: [-94,-92W.M2 Sensible: [-16,-15]W.M2 Sensible Latent