Accurate sea surface flux measurements are crucial for understanding the global water and energy cycles. The oceanic evaporation, which is a major component of the global oceanic fresh water flux, is useful for predic...Accurate sea surface flux measurements are crucial for understanding the global water and energy cycles. The oceanic evaporation, which is a major component of the global oceanic fresh water flux, is useful for predicting oceanic circulation and transport. The global Goddard Satellite-based Surface Turbulent Fluxes Version-2 （GSSTF2; July 1987–December 2000） dateset that was o？cially released in 2001 has been widely used by scientific community for global energy and water cycle research, and regional and short period data analyses. We have recently been funded by NASA to resume processing the GSSTF dataset with an objective of continually producing a uniform dataset of sea surface turbulent fluxes, derived from remote sensing data. The dataset is to be reprocessed and brought up-to-date （GSSTF2b） using improved input datasets such as a recently upgraded NCEP/DOE sea surface temperature reanalysis, and an upgraded surface wind and microwave brightness temperature V6 dataset （Version 6） from the Special Sensor Microwave Imager （SSM/I） produced by Remote Sensing Systems （RSS）. A second new product （GSSTF3） is further proposed with a finer temporal （12-h） and spatial （0.25° × 0.25°） resolution. GSSTF2b （July 1987–December 2008） and GSSTF3 （July 1999–December 2009） will be released for the research community to use by late 2009 and early 2011, respectively.展开更多
An operational weather forecast model,coupled to an oceanic model,was used to predict the initiation and propagation of two major Madden–Julian Oscillation(MJO)events during the dynamics of the MJO(DYNAMO)campaign pe...An operational weather forecast model,coupled to an oceanic model,was used to predict the initiation and propagation of two major Madden–Julian Oscillation(MJO)events during the dynamics of the MJO(DYNAMO)campaign period.Two convective parameterization schemes were used to understand the sensitivity of the forecast to the model cumulus scheme.The first is the Tiedtke(TDK)scheme,and the second is the Simplified Arakawa–Schubert(SAS)scheme.The TDK scheme was able to forecast the MJO-1 and MJO-2 initiation at 15-and45-day lead,respectively,while the SAS scheme failed to predict the convection onset in the western equatorial Indian Ocean(WEIO).The diagnosis of the forecast results indicates that the successful prediction with the TDK scheme is attributed to the model capability to reproduce the observed intraseasonal outgoing longwave radiation–sea surface temperature(OLR–SST)relationship.On one hand,the SST anomaly(SSTA)over the WEIO was induced by surface heat flux anomalies associated with the preceding suppressed-phase MJO.The change of SSTA,in turn,caused boundary layer convergence and ascending motion,which further induced a positive column-integrated moist static energy(MSE)tendency,setting up a convectively unstable stratification for MJO initiation.The forecast with the SAS scheme failed to reproduce the observed OLR–SST–MSE relation.The propagation characteristics differed markedly between the two forecasts.Pronounced eastward phase propagation in the TDK scheme is attributed to a positive zonal gradient of the MSE tendency relative to the MJO center,similar to the observed,whereas a reversed gradient appeared in the forecast with the SAS scheme with dominant westward propagation.The difference is primarily attributed to anomalous vertical and horizontal MSE advection.展开更多
基金supported by the Making Earth System data records for Use in Research En-vironments (MEaSUREs) Program of NASA Science Mission Directorate-Earth Science Division
文摘Accurate sea surface flux measurements are crucial for understanding the global water and energy cycles. The oceanic evaporation, which is a major component of the global oceanic fresh water flux, is useful for predicting oceanic circulation and transport. The global Goddard Satellite-based Surface Turbulent Fluxes Version-2 （GSSTF2; July 1987–December 2000） dateset that was o？cially released in 2001 has been widely used by scientific community for global energy and water cycle research, and regional and short period data analyses. We have recently been funded by NASA to resume processing the GSSTF dataset with an objective of continually producing a uniform dataset of sea surface turbulent fluxes, derived from remote sensing data. The dataset is to be reprocessed and brought up-to-date （GSSTF2b） using improved input datasets such as a recently upgraded NCEP/DOE sea surface temperature reanalysis, and an upgraded surface wind and microwave brightness temperature V6 dataset （Version 6） from the Special Sensor Microwave Imager （SSM/I） produced by Remote Sensing Systems （RSS）. A second new product （GSSTF3） is further proposed with a finer temporal （12-h） and spatial （0.25° × 0.25°） resolution. GSSTF2b （July 1987–December 2008） and GSSTF3 （July 1999–December 2009） will be released for the research community to use by late 2009 and early 2011, respectively.
基金Supported by the NOAA of U.S.(NA18OAR4310298)National Natural Science Foundation of U.S.(AGS-1643297)National Natural Science Foundation of China(41875069).
文摘An operational weather forecast model,coupled to an oceanic model,was used to predict the initiation and propagation of two major Madden–Julian Oscillation(MJO)events during the dynamics of the MJO(DYNAMO)campaign period.Two convective parameterization schemes were used to understand the sensitivity of the forecast to the model cumulus scheme.The first is the Tiedtke(TDK)scheme,and the second is the Simplified Arakawa–Schubert(SAS)scheme.The TDK scheme was able to forecast the MJO-1 and MJO-2 initiation at 15-and45-day lead,respectively,while the SAS scheme failed to predict the convection onset in the western equatorial Indian Ocean(WEIO).The diagnosis of the forecast results indicates that the successful prediction with the TDK scheme is attributed to the model capability to reproduce the observed intraseasonal outgoing longwave radiation–sea surface temperature(OLR–SST)relationship.On one hand,the SST anomaly(SSTA)over the WEIO was induced by surface heat flux anomalies associated with the preceding suppressed-phase MJO.The change of SSTA,in turn,caused boundary layer convergence and ascending motion,which further induced a positive column-integrated moist static energy(MSE)tendency,setting up a convectively unstable stratification for MJO initiation.The forecast with the SAS scheme failed to reproduce the observed OLR–SST–MSE relation.The propagation characteristics differed markedly between the two forecasts.Pronounced eastward phase propagation in the TDK scheme is attributed to a positive zonal gradient of the MSE tendency relative to the MJO center,similar to the observed,whereas a reversed gradient appeared in the forecast with the SAS scheme with dominant westward propagation.The difference is primarily attributed to anomalous vertical and horizontal MSE advection.
