Tropospheric lapse rate: observations and modeling of past, present and future variations

The tropospheric lapse rate is the gradient of temperature though the troposphere. In tropical and subtropical regions, it plays a key role in the global climate, through its impact on the large-scale circulation and on convection. As climate warms, the warming is expected to be larger at higher altitude, which contributes to climate feedbacks. Atmospheric lapse rate also directly impacts mountain weather and climate and glaciers mass budget. How will lapse rate change with global warming? How as it changed in a recent past? What mechanisms control the lapse rate and its spatial distribution? Can past climate reconstructions of lapse rate better constrain its controlling mechanisms and its future variations? The goal of this workshop is to investigate these questions, by gathering different communities working on tropospheric lapse rate in tropical and subtropical regions. The idea of this workshop is to bolster interactions between different communities that seldomly interact, but who share the same science objectives: - convection community working on mechanisms controlling lapse rates, for example using cloud-resolving models or conceptual models; - present-day observation community, observing lapse rate distribution and evolution through radiosondes, satellites and ground-based along-slope observations in mountains; - mountain weather and climate community working with observations or models, who can shed light on the relationship between tropospheric and along-slope lapse rates; - paleo-climate community, reconstructing and modeling past changes of lapse rate in various tropical regions.