Characteristics of Tropopause OveryWuhan and Haikou

The temporal variation characteristics of local tropopause are derived from the routine Radiosonde data obtained at Wuhan (30.5$^{\circ}$N, 114$^{\circ}$E) and Haikou (20$^{\circ}$N, 114$^{\circ}$E) from 2000 to 2004. The annual variations of temperature, altitude and potential temperature of tropopause are compared with those over a tropical site, Truk. A similar annual trend between Haikou and Truk was found that maximum and minimum values were reached in summer and winter, separately, while an inverse annual variation over Wuhan was shown. By discussing the temperature disturbance, lapse rate at certain pressure levels and tropospheric thickness, it's concluded that tropopause was more determined by the stratospheric behavior. And this can be further confirmed by an intensive radiosonde observation over Wuhan from Jan 11 to 15 in 2006, conducted with a 3 hours interval. By that radiosonde observation, the diurnal variation of tropopause over Wuhan was studied and an obviously regular variation similar to that of Gandanki was found, although little difference exists between them