NESDIS Center for Satellite Applications and Research (STAR) has been developing consistent, SNO (simultaneous nadir overpass) inter-calibrated radiance sensor data record (SDR) and upper air temperature thematic climate data records (TCDR) from MSU/AMSU/SSU observations for climate trend investigations.However, we find that inter-satellite biases are particularly large over the Tibetan area, causing its long-term temperature trend inconsistent with the rest area of China.In particular, cooling trend was found in the mid-troposphere over Tibetan, while warming trend was found over the plain area in China.We know that uncertainties in diurnal cycle over Tibetan caused large inter-satellite biases, which further leads to climate trend uncertainties.On the other hand, glacier retreat may also cause less warming over Tibetan since it absorbs a lot of heat that would otherwise heat and warm the atmosphere.To understand if the cooling trend over Tibet is caused by data problem or real physical processes, accurate Tibetan diurnal information is the key to resolve these issues.In this presentation, we call for attention from the Chinese research community to plan field campaign project to measure the Tibetan diurnal cycle.