Lower Tropospheric Processes: A Control on the Global Mean Precipitation Rate
Abstract The spread in global mean precipitation among climate models is explored in two ensembles using the complementary perspectives of surface evaporation and energy budgets. Models with higher global mean precipitation have stronger oceanic evaporation, driven by drier near‐surface air. The dri...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2021-03-01
|
| Series: | Geophysical Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2020GL091169 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850205124615471104 |
|---|---|
| author | Jacob M. Hendrickson Christopher R. Terai Michael S. Pritchard Peter M. Caldwell |
| author_facet | Jacob M. Hendrickson Christopher R. Terai Michael S. Pritchard Peter M. Caldwell |
| author_sort | Jacob M. Hendrickson |
| collection | DOAJ |
| description | Abstract The spread in global mean precipitation among climate models is explored in two ensembles using the complementary perspectives of surface evaporation and energy budgets. Models with higher global mean precipitation have stronger oceanic evaporation, driven by drier near‐surface air. The drier surface conditions occur alongside increases in near‐surface temperature and moisture at 925 hPa, which point to stronger boundary layer mixing. Correlations suggest that the degree of lower tropospheric mixing explains 18%–49% of the intermodel precipitation variance. To test this hypothesis, the degree of mixing is indirectly varied in a single‐model experiment by adjusting the relative humidity threshold that controls low‐cloud fraction. Indeed, increasing lower tropospheric mixing results in more global mean precipitation. Energetically, increased precipitation rates are associated with more downwelling longwave radiation to the surface and weaker sensible heat fluxes. These results highlight how lower‐tropospheric processes must be better constrained to reduce the precipitation discrepancy among climate models. |
| format | Article |
| id | doaj-art-a61ed8ddc40e4e3eb43fedcb635ef007 |
| institution | OA Journals |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2021-03-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-a61ed8ddc40e4e3eb43fedcb635ef0072025-08-20T02:11:09ZengWileyGeophysical Research Letters0094-82761944-80072021-03-01486n/an/a10.1029/2020GL091169Lower Tropospheric Processes: A Control on the Global Mean Precipitation RateJacob M. Hendrickson0Christopher R. Terai1Michael S. Pritchard2Peter M. Caldwell3Department of Earth System Science University of California Irvine CA USADepartment of Earth System Science University of California Irvine CA USADepartment of Earth System Science University of California Irvine CA USALawrence Livermore National Laboratory Livermore CA USAAbstract The spread in global mean precipitation among climate models is explored in two ensembles using the complementary perspectives of surface evaporation and energy budgets. Models with higher global mean precipitation have stronger oceanic evaporation, driven by drier near‐surface air. The drier surface conditions occur alongside increases in near‐surface temperature and moisture at 925 hPa, which point to stronger boundary layer mixing. Correlations suggest that the degree of lower tropospheric mixing explains 18%–49% of the intermodel precipitation variance. To test this hypothesis, the degree of mixing is indirectly varied in a single‐model experiment by adjusting the relative humidity threshold that controls low‐cloud fraction. Indeed, increasing lower tropospheric mixing results in more global mean precipitation. Energetically, increased precipitation rates are associated with more downwelling longwave radiation to the surface and weaker sensible heat fluxes. These results highlight how lower‐tropospheric processes must be better constrained to reduce the precipitation discrepancy among climate models.https://doi.org/10.1029/2020GL091169boundary layer processesglobal climate modelingwater cycle |
| spellingShingle | Jacob M. Hendrickson Christopher R. Terai Michael S. Pritchard Peter M. Caldwell Lower Tropospheric Processes: A Control on the Global Mean Precipitation Rate Geophysical Research Letters boundary layer processes global climate modeling water cycle |
| title | Lower Tropospheric Processes: A Control on the Global Mean Precipitation Rate |
| title_full | Lower Tropospheric Processes: A Control on the Global Mean Precipitation Rate |
| title_fullStr | Lower Tropospheric Processes: A Control on the Global Mean Precipitation Rate |
| title_full_unstemmed | Lower Tropospheric Processes: A Control on the Global Mean Precipitation Rate |
| title_short | Lower Tropospheric Processes: A Control on the Global Mean Precipitation Rate |
| title_sort | lower tropospheric processes a control on the global mean precipitation rate |
| topic | boundary layer processes global climate modeling water cycle |
| url | https://doi.org/10.1029/2020GL091169 |
| work_keys_str_mv | AT jacobmhendrickson lowertroposphericprocessesacontrolontheglobalmeanprecipitationrate AT christopherrterai lowertroposphericprocessesacontrolontheglobalmeanprecipitationrate AT michaelspritchard lowertroposphericprocessesacontrolontheglobalmeanprecipitationrate AT petermcaldwell lowertroposphericprocessesacontrolontheglobalmeanprecipitationrate |