The Variation Of The Latent Heat Flux And Its Relationship With The Winter Air Temperature In China

Based on the latent heat flux, sea level pressure, height and wind monthly mean data from NCEP, the sea surface temperature data from NOAA and the air temperature data in 160 stations in China, the latent heat fluxes over the Pacific ocean and the air temperature in China were examined.The latent heat anomalies are analyzed by using EOF method. It is found that the 1st modes describe the contrary phrase of Kuroshio Extension and the equatorial mid-east Pacific Ocean in winter and fall, and the contrary phrase of the east of Australia and equatorial mid-east Pacific ocean in spring and summer. The time series show that there are declines during the recent 55 years and abrupt in the middle of 1970's.In the decadal scale, there is an abrupt in 1975/1976 for the latent heat over the Pacific Ocean in winter. After the abrupt, the ocean releases latent heat in Kuroshio Extension, while the ocean gets latent heat in the equatorial mid-east Pacific Ocean. At the same time, the SLP over the Europe-Asian continent is 'south high north low' mode, the Siberian High becomes weaker, the ridge over the Ural mountain becomes weaker, so does the East Asian Trough, and over China the wind is from south. The winter air temperature in China rises up, and the changing extent is larger in North China than in South China, and vice versa.In the annual scale, the winter air temperatures in the northeast of China rise up, while the air temperatures in the middle of China and South China go down, when the ocean gets latent heat in Kuroshio Extension and releases latent heat in the northeast of the Pacific ocean, and vice versa. In addition, the annual connections among the latent heat flux over the Pacific Ocean, the air cell and the winter air temperature in China are different, under different decadal backgrounds. Before the abrupt, the latent heat anomaly is positive in the equatorial Pacific Ocean, the East Siberian High and the Aleutian Low become weaker, the north range of the East Asian Trough strengthen and the south range weaken, and so the prevalent wind is from north in northeast of China, where the air temperature goes down, while the prevalent wind is from south in South China, where the air temperature rises up. Additionally, SST becomes warmer in the equatorial mid-east Pacific Ocean, while its linkage to the winter air temperature is not prominent. After the abrupt, the latent heat anomaly is negative in the Kuroshio Extension and positive in the northeast of the Pacific Ocean, the Siberian High and the Aleutian Low weaken, the north range of the East Asian Trough strengthen and the south range weaken, the ridge over the Ural mountain weaken, and so the prevalent wind is from south in the east of China and HETAO area, where the air temperature rises up. In addition, SST becomes warmer in the equatorial mid-east Pacific Ocean, and its linkage to the winter air temperature is prominent.