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Suppression of Arctic Air Formation with Climate Warming: Investigation with a Two-Dimensional Cloud-Resolving Model
- Source :
- Journal of the Atmospheric Sciences. 74:2717-2736
- Publication Year :
- 2017
- Publisher :
- American Meteorological Society, 2017.
-
Abstract
- Arctic climate change in winter is tightly linked to changes in the strength of surface temperature inversions, which occur frequently in the present climate as Arctic air masses form during polar night. Recent work proposed that, in a warmer climate, increasing low-cloud optical thickness of maritime air advected over high-latitude landmasses during polar night could suppress the formation of Arctic air masses, amplifying winter warming over continents and sea ice. But this mechanism was based on single-column simulations that could not assess the role of fractional cloud cover change. This paper presents two-dimensional cloud-resolving model simulations that support the single-column model results: low-cloud optical thickness and duration increase strongly with initial air temperature, slowing the surface cooling rate as the climate is warmed. The cloud-resolving model cools less at the surface than the single-column model, and the sensitivity of its cooling to warmer initial temperatures is also higher, because it produces cloudier atmospheres with stronger lower-tropospheric mixing and distributes cloud-top cooling over a deeper atmospheric layer with larger heat capacity. Resolving larger-scale cloud turbulence has the greatest impact on the microphysics schemes that best represent general observed features of mixed-phase clouds, increasing their sensitivity to climate warming. These findings support the hypothesis that increasing insulation of the high-latitude land surface by low clouds in a warmer world could act as a strong positive feedback in future climate change and suggest studying Arctic air formation in a three-dimensional climate model.
- Subjects :
- Atmospheric Science
geography
geography.geographical_feature_category
010504 meteorology & atmospheric sciences
Cloud cover
Global warming
Climate change
Arctic front
010502 geochemistry & geophysics
Atmospheric sciences
01 natural sciences
Cloud feedback
Arctic
Climatology
Sea ice
Environmental science
Climate model
0105 earth and related environmental sciences
Subjects
Details
- ISSN :
- 15200469 and 00224928
- Volume :
- 74
- Database :
- OpenAIRE
- Journal :
- Journal of the Atmospheric Sciences
- Accession number :
- edsair.doi...........73553e39e25f85fca94e4c3fc481502b