"reveals that recent warming in the Indian Ocean and in the Pacific 'warm pool' has caused a cooling near the top of the tropical troposphere above, leading to less water vapour entering the stratosphere."
"Water vapour in the stratosphere is a greenhouse gas. It is constrained from entering the stratosphere in the tropics by the thermal boundary between the stratosphere and troposphere1 — the tropical tropopause, the coldest point in the lower atmosphere. Cold-point temperatures at the tropical tropopause (Fig. 1a) have important implications for both stratospheric chemistry2 and global climate change3."
"The model simulation shows that less water vapour enters the stratosphere as a result of the cooling near the cold-point tropopause over the Indo-Pacific warm pool, driven by the increased SST there."
"Garfinkel et al. show that there is a cooling near the tropical tropopause over the Indo-Pacific warm-pool region and thus less water vapour entering the stratosphere. This response to the SST change is due to the enhanced equatorial planetary waves. A decrease in stratospheric water vapour may lead to a slight cooling of global surface temperatures. This study demonstrates that it is of paramount importance to pay attention to, and understand the cause of, the patterns of SST changes that are related to global warming."Climate models instead predict water vapor to increase in the upper tropical troposphere to produce the mythical "hot spot" and amplification of global warming, but the "hot spot" has not been found despite millions of radiosonde and satellite observations.