Biological and Environmental Research - Earth and Environmental System Sciences
Earth and Environmental System Modeling

Global microphysical sensitivity of superparameterized precipitation extremes

TitleGlobal microphysical sensitivity of superparameterized precipitation extremes
Publication TypeJournal Article
Year of Publication2021
JournalEarth and Space Science
Volume8
Abstract / Summary

A recent study found statistically significant differences in extreme precipitation distributions over the contiguous United States (CONUS) when changing the microphysics scheme in a superparameterized global climate model. Here, we repeat the analysis globally and similarly find that differences are widespread when varying the number of predicted moments in the microphysics parameterization, but not when comparing variants of the double‐moment scheme. However, contrary to the previous study in which differences largely disappeared over CONUS when 5‐day simulations were conducted, we find that the signal in these shorter integrations remains within the tropics, implying a direct local effect of microphysics on precipitation extremes in these regions. The effect on precipitation is traced back to changes in vertical velocity profiles–changes that are then amplified in the climatological simulations compared to the 5‐day ones. Finally, the superparameterized extremes, regardless of the microphysics scheme, are shown to be larger than those from the Global Precipitation Climatology Project One‐Degree Daily (GPCP 1DD) dataset and generally smaller than those from the Tropical Rainfall Measuring Mission (TRMM) 3B42 dataset.

URLhttp://dx.doi.org/10.1029/2020ea001308
DOI10.1029/2020ea001308
Journal: Earth and Space Science
Year of Publication: 2021
Volume: 8
Publication Date: 04/2021

A recent study found statistically significant differences in extreme precipitation distributions over the contiguous United States (CONUS) when changing the microphysics scheme in a superparameterized global climate model. Here, we repeat the analysis globally and similarly find that differences are widespread when varying the number of predicted moments in the microphysics parameterization, but not when comparing variants of the double‐moment scheme. However, contrary to the previous study in which differences largely disappeared over CONUS when 5‐day simulations were conducted, we find that the signal in these shorter integrations remains within the tropics, implying a direct local effect of microphysics on precipitation extremes in these regions. The effect on precipitation is traced back to changes in vertical velocity profiles–changes that are then amplified in the climatological simulations compared to the 5‐day ones. Finally, the superparameterized extremes, regardless of the microphysics scheme, are shown to be larger than those from the Global Precipitation Climatology Project One‐Degree Daily (GPCP 1DD) dataset and generally smaller than those from the Tropical Rainfall Measuring Mission (TRMM) 3B42 dataset.

DOI: 10.1029/2020ea001308
Citation:
Charn, A, W Collins, H Parishani, and M Risser.  2021.  "Global microphysical sensitivity of superparameterized precipitation extremes."  Earth and Space Science 8.  https://doi.org/10.1029/2020ea001308.