Boundary Layer Clouds and Convection over Subtropical Oceans in our Current and in a Warmer Climate

Boundary Layer Clouds and Convection over Subtropical Oceans in our Current and in a Warmer Climate

Nuijens, Louise (TU Delft Atmospheric Remote Sensing)
Siebesma, A.P. (TU Delft Atmospheric Physics; Royal Netherlands Meteorological Institute (KNMI))

2019

Purpose of Review: We review our understanding of mechanisms underlying the response of (sub)tropical clouds to global warming, highlight mechanisms that challenge our understanding, and discuss simulation strategies that tackle them. Recent Findings: Turbulence-resolving models and emergent constraints provide probable evidence, supported by theoretical understanding, that the cooling cloud radiative effect (CRE) of low clouds weakens with warming: a positive low-cloud feedback. Nevertheless, an uncertainty in the feedback remains. Climate models may not adequately represent changing SST and circulation patterns, which determine future cloud-controlling factors and how these couple to clouds. Furthermore, we do not understand what mesoscale organization implies for the CRE, and how moisture-radiation interactions, horizontal advection, and the profile of wind regulate low cloud, in our current and in our warmer climate. Summary: Clouds in nature are more complex than the idealized cloud types that have informed our understanding of the cloud feedback. Remaining major uncertainties are the coupling of clouds to large-scale circulations and to the ocean, and mesoscale aggregation of clouds.

Atmosphere-ocean coupling
Cloud-circulation coupling
Emergent constraints
Low-cloud feedback
Mesoscale aggregation
Moisture-radiation interactions
Turbulence-resolving models

http://resolver.tudelft.nl/uuid:f2fe428f-f5ba-42ca-a27b-016c2f1e5866

https://doi.org/10.1007/s40641-019-00126-x

Current Climate Change Reports, 5 (2), 80-94

Institutional Repository

review

© 2019 Louise Nuijens, A.P. Siebesma