Intensive radiosonde observations of lower tropospheric inversion layers over Yichang, China

Two lower tropospheric inversion layers (named as LTI1 and LTI2) over Yichang (111°18′E, 30°42′N) were studied by using the data from intensive radiosonde observations in January 2007 on an eight-times-daily basis. Our observations reveal that both the inversion layers are closely related to the intensive inertial gravity waves propagating in winter tropospheric jets. However, their formation mechanisms are likely to be different. Gravity-wave-induced intensive turbulence via convective instability may yield a downward energy transport and finally form the LTI1, while we speculate that the reflection of gravity waves by the strong tropospheric jet is responsible for the LTI2.