The thermohaline structure at 4 °S, 156 °E was analyzed based on CTD data acquired during theTOGA COARE Intensive Observing Period(IOP) from November,1992 to February,1993. The ocean re-sponses during two Ma...The thermohaline structure at 4 °S, 156 °E was analyzed based on CTD data acquired during theTOGA COARE Intensive Observing Period(IOP) from November,1992 to February,1993. The ocean re-sponses during two Madden-Julian Oscillation(MJO)events were preliminarily studied based onmeteorological field observation.The main water masses at the observation point were Tropical SurfaceWater, Southern Subtropical Lower Water and Southern Intermediate Water from surface downward. Therewas good correlation of sea surface temperature with the wind field,and of the surface salinity with windspeed and rainfalls. Both of the two surface variables were also modulated by upwelling caused by west-erly winds at the observation point. The isohaline layer was not always shallower than the isothermal lay-er in this observation and could be considered as the lower limit of the diurnal variation of theisothermal layers in most cases. The existence of large variations of the maximum salinity core is sug-gested to be related to展开更多
With a hybrid atmosphere-ocean coupled model we carried out an experimental forecast of a well documented Madden-Julian Oscillation (MJO) event that was observed during the period of Tropical Ocean Global Atmosphere C...With a hybrid atmosphere-ocean coupled model we carried out an experimental forecast of a well documented Madden-Julian Oscillation (MJO) event that was observed during the period of Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA-COARE). The observed event, originated in the western Indian Ocean around 6 January 1993, moved eastward with a phase speed of about 6.2 m s 1 and reached the dateline around February 1. The hybrid coupled model reasonably forecasts the MJO initiation in the western Indian Ocean, but the predicted MJO event propagates too slow (～ 4.4 m s 1 ). Results from previous observational studies using unprecedented humidity profiles obtained by NASA Aqua/AIRS satellite suggested that two potential physical processes may be responsible for this model caveat. After improving the cumulus parameterization scheme based on the observations, the model is able to forecast the same event one month ahead. Further sensitivity experiment confirms that the speed-up of model MJO propagation is primarily due to the improved convective scheme. Further, air-sea coupling plays an important role in maintaining the intensity of the predicted MJO. The results here suggest that MJO prediction skill is sensitive to model cumulus parameterization and air-sea coupling.展开更多
文摘The thermohaline structure at 4 °S, 156 °E was analyzed based on CTD data acquired during theTOGA COARE Intensive Observing Period(IOP) from November,1992 to February,1993. The ocean re-sponses during two Madden-Julian Oscillation(MJO)events were preliminarily studied based onmeteorological field observation.The main water masses at the observation point were Tropical SurfaceWater, Southern Subtropical Lower Water and Southern Intermediate Water from surface downward. Therewas good correlation of sea surface temperature with the wind field,and of the surface salinity with windspeed and rainfalls. Both of the two surface variables were also modulated by upwelling caused by west-erly winds at the observation point. The isohaline layer was not always shallower than the isothermal lay-er in this observation and could be considered as the lower limit of the diurnal variation of theisothermal layers in most cases. The existence of large variations of the maximum salinity core is sug-gested to be related to
基金supported by NASA Earth Science Program, NSF Climate Dynamics Programthe Japan Agency for Marine-Earth Science and Technology (JAMSTEC), NASA+1 种基金NOAA through their sponsorship of the IPRCsupported by APEC Climate Center (APCC) as a part of APCC international research project
文摘With a hybrid atmosphere-ocean coupled model we carried out an experimental forecast of a well documented Madden-Julian Oscillation (MJO) event that was observed during the period of Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA-COARE). The observed event, originated in the western Indian Ocean around 6 January 1993, moved eastward with a phase speed of about 6.2 m s 1 and reached the dateline around February 1. The hybrid coupled model reasonably forecasts the MJO initiation in the western Indian Ocean, but the predicted MJO event propagates too slow (～ 4.4 m s 1 ). Results from previous observational studies using unprecedented humidity profiles obtained by NASA Aqua/AIRS satellite suggested that two potential physical processes may be responsible for this model caveat. After improving the cumulus parameterization scheme based on the observations, the model is able to forecast the same event one month ahead. Further sensitivity experiment confirms that the speed-up of model MJO propagation is primarily due to the improved convective scheme. Further, air-sea coupling plays an important role in maintaining the intensity of the predicted MJO. The results here suggest that MJO prediction skill is sensitive to model cumulus parameterization and air-sea coupling.
基金This paper is supported by the National Natural Science Foundation of China(Projects under contracts No.49676275,49976002,40506007)Microwave Imaging National Key Laboratory Foundation(No.51442020103JW1002).
