The Study Of The Spatial And Temporal Distribution Characteristics Of The Elements Of The Tropopause Inversion Layer In East Asia

This paper used the daily temperature profile data of Constellation Observing System for Meteorology, Ionosphere, and Climate(COSMIC) from January 2007 to December 2013 and the monthly reanalysis data of radiation from the National Centers for Environmental Prediction(NCEP), analyzed the spatial and temporal distribution characteristics of the Tropopause Inversion Layer(TIL) in East Asia by the methods of statistical analysis and Empirical Orthogonal Function(EOF), and use the methods of Singular Value Decomposition(SVD) to study the relationship between various elements of TIL and the radiation flux. The results show that TIL is a pervasive climatic characteristics of East Asia in different seasons and different latitudes. The various elements of TIL are different between the different latitude and different seasons, low latitude tropospheric cooling and stratospheric warming strenuous than high latitudes. In recent years the lower boundary of TIL (Cold Point Tropopasue, CPT) and the upper boundary of TIL (Tropopause Inversion Layer Top, TILT) has a slight decreasing trend, but the thickness of TIL remain unchanged, the average temperature decreasing rate in TIL slightly increase.The altitude of the lower boundary of TIL(CPT) distributions are centered in 11～14km, the height of the south area of 40°N is mostly above 13.5km, and very stable. the height of the north area of 40°N is decreased with increase of latitude and The weft distribution is more obvious. Analysis results of EOF show that the height of CPT is the opposite on the sides of 35°N, in summer half year CPT raised north of 35°N reduced south of 35°N, but winter half year is opposited. The height of the south area of 35°N during the year was changed as "V" but the north area of 35°N is opposited.The altitude of Tropopause Inversion Layer Top(TILT) is focused on 14-20km, the maximum center appear on the Iran Plateau and the Northern Ibetan Plateau and the Loess Plateau between 30°N-40°N in winter and spring, and its range larger.the maximum center appear on Kazakhstan between 45°N-50°N in summer and its range smaller, and that appear near the Turanian plateau in the 40°N and the range is further shrinking. In the north of the maximum center the altitude of TILT is decreased with increase of latitude and The weft distribution is more obvious, the altitude of TILT increased with the seasonal changes reached a year of relative maxima in summer, and then began to decrease. But in the south of the maximum center is opposited. The thickness of TIL is concentrated in 1-6.5km, and it’s time-space variation law is consistent with TILT.The average vertical temperature lapse rate in TIL within the 0.4-2K/100m and it’s spatial distribution is contrary other elements.The value of the maximum center all above 1.2K/100m which appeared near the equator between 10°N-10°N, in the region the biggest temperature decline rate in winter, summer and autumn, the second, and the minimum spring. In the middle latitude region of 30°N-50°N, the temperature decrease rate is relatively small in below the 0.8K/100m, there is no obvious seasonal difference in strength, but the range maximum in winter, followed by spring, summer and autumn minimum.The thickness of TIL changes mainly affected by the distribution of the TILT. Although TIL have a consistent zonal structure, but has a significant difference between tropical and temperate, tropopause strong inversion layer structure mainly appear in the tropopause inversion layer thinner tropical Marine areas, the structure of TIL show the tropopause fracture characteristics, its deeper but intensity is weak in subtropical.There is a certain correlation between the upward longwave radiation flux at surface, the latent heat net flux at surface and the thickness of TIL, the average vertical temperature lapse rate in TIL. When the land in East Asia and the North Indian Ocean region radiation intensity is larger, the thickness of TIL is larger in the northern part, the Aral Sea and Kazakhstan area of 45°N-55°N、40°E-100°E, but it’s smaller in middle and low latitude, the average vertical temperature lapse rate in TIL is smaller in middle latitude of 10°N-40°N and north-eastern of East Asia, but its larger in near the equator and near the caspian sea, and vice versa. The thickness of TIL change relatively slowly, about one-month lag change behind the change of radiation. But change of the average vertical temperature lapse rate in TIL with the radiation is in sync in winter and summer, other seasons there is a certain lag, but the lag time is not long with the thickness of TIL.