The Indonesian Throughflow(ITF), which connects the tropical Pacific and Indian oceans, plays important roles in the inter-ocean water exchange and regional or even global climate variability. The Makassar Strait is t...The Indonesian Throughflow(ITF), which connects the tropical Pacific and Indian oceans, plays important roles in the inter-ocean water exchange and regional or even global climate variability. The Makassar Strait is the main inflow passage of the ITF, carrying about 77% of the total ITF volume transport. In this study, we analyze the simulated ITF in the Makassar Strait in the Simple Ocean Data Assimilation version 3(SODA3) datasets. A total of nine ensemble members of the SODA3 datasets, of which are driven by different surface forcings and bulk formulas, and with or without data assimilation, are used in this study. The annual mean water transports(i.e.,volume, heat and freshwater) are related to the combination of surface forcing and bulk formula, as well as whether data assimilation is employed. The phases of the seasonal and interannual variability in water transports cross the Makassar Strait, are basically consistent with each other among the SODA3 ensemble members. The interannual variability in Makassar Strait volume and heat transports are significantly correlated with El Ni?oSouthern Oscillation(ENSO) at time lags of-6 to 7 months. There is no statistically significant correlation between the freshwater transport and the ENSO. The Makassar Strait water transports are not significantly correlated with the Indian Ocean Dipole(IOD), which may attribute to model deficiency in simulating the propagation of semiannual Kelvin waves from the Indian Ocean to the Makassar Strait.展开更多
This study compares the seasonal and interannual-to-decadal variability in the strength and position of the Kuroshio Extension front(KEF)using high-resolution satellite-derived sea surface temperature(SST)and sea surf...This study compares the seasonal and interannual-to-decadal variability in the strength and position of the Kuroshio Extension front(KEF)using high-resolution satellite-derived sea surface temperature(SST)and sea surface height(SSH)data.Results show that the KEF strength has an obvious seasonal variation that is similar at different longitudes,with a stronger(weaker)KEF during the cold(warm)season.However,the seasonal variation in the KEF position is relatively weak and varies with longitude.In contrast,the low-frequency variation of the KEF position is more distinct than that of the KEF strength even though they are well correlated.On both seasonal and interannual-to-decadal time scales,the western part of the KEF(142°–144°E)has the greatest variability in strength,while the eastern part of the KEF(149°–155°E)has the greatest variability in position.In addition,the relationships between wind-forced Rossby waves and the low-frequency variability in the KEF strength and position are also discussed by using the statistical analysis methods and a wind-driven hindcast model.A positive(negative)North Pacific Oscillation(NPO)-like atmospheric forcing generates positive(negative)SSH anomalies over the central North Pacific.These oceanic signals then propagate westward as Rossby waves,reaching the KE region about three years later,favoring a strengthened(weakened)and northward(southward)-moving KEF.展开更多
基金The Fund of Laoshan Laboratory under contract No. LSKJ202202700the National Natural Science Foundation of China under contract Nos 42076023, 42076024 and 41876027the Global Change and Air-Sea Interaction Ⅱ Project under contract No.GASI-01-AIP-STwin。
文摘The Indonesian Throughflow(ITF), which connects the tropical Pacific and Indian oceans, plays important roles in the inter-ocean water exchange and regional or even global climate variability. The Makassar Strait is the main inflow passage of the ITF, carrying about 77% of the total ITF volume transport. In this study, we analyze the simulated ITF in the Makassar Strait in the Simple Ocean Data Assimilation version 3(SODA3) datasets. A total of nine ensemble members of the SODA3 datasets, of which are driven by different surface forcings and bulk formulas, and with or without data assimilation, are used in this study. The annual mean water transports(i.e.,volume, heat and freshwater) are related to the combination of surface forcing and bulk formula, as well as whether data assimilation is employed. The phases of the seasonal and interannual variability in water transports cross the Makassar Strait, are basically consistent with each other among the SODA3 ensemble members. The interannual variability in Makassar Strait volume and heat transports are significantly correlated with El Ni?oSouthern Oscillation(ENSO) at time lags of-6 to 7 months. There is no statistically significant correlation between the freshwater transport and the ENSO. The Makassar Strait water transports are not significantly correlated with the Indian Ocean Dipole(IOD), which may attribute to model deficiency in simulating the propagation of semiannual Kelvin waves from the Indian Ocean to the Makassar Strait.
基金The National Natural Science Foundation of China under contract Nos 41975066,41605051 and 41406003the Open Research Fund of State Key Laboratory of Estuarine and Coastal Research under contract No.SKLEC-KF201707+1 种基金the High-Tech Innovation Think-Tank Youth Project under contract No.DXB-ZKQN-2016-019Jiangsu Provincial Natural Science Foundation under contract No.BK20130064。
文摘This study compares the seasonal and interannual-to-decadal variability in the strength and position of the Kuroshio Extension front(KEF)using high-resolution satellite-derived sea surface temperature(SST)and sea surface height(SSH)data.Results show that the KEF strength has an obvious seasonal variation that is similar at different longitudes,with a stronger(weaker)KEF during the cold(warm)season.However,the seasonal variation in the KEF position is relatively weak and varies with longitude.In contrast,the low-frequency variation of the KEF position is more distinct than that of the KEF strength even though they are well correlated.On both seasonal and interannual-to-decadal time scales,the western part of the KEF(142°–144°E)has the greatest variability in strength,while the eastern part of the KEF(149°–155°E)has the greatest variability in position.In addition,the relationships between wind-forced Rossby waves and the low-frequency variability in the KEF strength and position are also discussed by using the statistical analysis methods and a wind-driven hindcast model.A positive(negative)North Pacific Oscillation(NPO)-like atmospheric forcing generates positive(negative)SSH anomalies over the central North Pacific.These oceanic signals then propagate westward as Rossby waves,reaching the KE region about three years later,favoring a strengthened(weakened)and northward(southward)-moving KEF.