Smaller Sensitivity of Precipitation to Surface Temperature Under Massive Atmospheres

• Published in: Geophysical research letters 2022-09, Vol.49 (18), p.n/a
• Main Authors: Xiong, Junyan, Yang, Jun, Liu, Jiachen
• Format: Article
• Language: English
• Subjects: Air masses; Atmospheric circulation; Atmospheric circulation models; Atmospheric General Circulation Models; atmospheric mass; Climate; Climate system; Climatic evolution; Earth; Energy balance; Extrasolar planets; Gases; General circulation models; Greenhouse effect; Greenhouse gases; Habitability; Lapse rate; Mars; Multiple scatter; Multiple scattering; Oceans; planetary climate; Planetary evolution; Precipitation; Pressure broadening; Rayleigh scattering; Solar flux; Strength; Surface energy; Surface energy balance; Surface properties; Surface temperature; Terrestrial planets
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2022GL099599

Precipitation and its response to forcing is an important aspect of planetary climate system. In this study, we examine the strength of precipitation in the experiments with different atmospheric masses and their response to surface warming, using three global atmospheric general circulation models and one regional cloud‐resolving model. We find that precipitation is weaker when atmospheric mass is larger for a given surface temperature. Furthermore, the increasing rate of precipitation with increasing surface temperature under a larger atmospheric mass is smaller than that under a smaller atmospheric mass. These behaviors can be understood based on atmospheric or surface energy balance. Atmospheric mass influences Rayleigh scattering, multiple scattering in the atmosphere, pressure broadening, lapse rate, and thereby precipitation strength. These results have important implications on the climate and habitability of early Earth, early Mars, and exoplanets with oceans. Plain Language Summary Precipitation is one of the key variables of the planetary climate system. Many factors can influence the strength of precipitation, such as solar flux, land‐sea distribution, greenhouse gases, and aerosols. In this study, we show that another factor, atmospheric mass, can also strongly influence precipitation. The strength of precipitation increases with increasing surface temperature but decreases with increasing atmospheric mass. Furthermore, the increasing rate of precipitation with surface temperature becomes smaller under a larger atmospheric mass. These results have important implications for the climate evolution of early Earth, early Mars, and extra‐solar rocky planets, which may have higher or lower air mass than that of modern Earth. Key Points Numerical simulations show that under a given surface temperature, the precipitation is weaker if the air mass is larger The increasing rate of global‐mean precipitation with surface temperature under a larger air mass is also smaller The combined effect of air mass on Rayleigh scattering, multiple scattering, pressure broadening, and lapse rate is the mechanism