Subgrid-scale aerosol–cloud interaction in the atmospheric chemistry model CMA_Meso5.1/CUACE and its impacts on mesoscale meteorology prediction
<p>Aerosol–cloud interaction (ACI) significantly influences global and regional weather and is a critical focus in numerical weather prediction (NWP), but subgrid-scale ACI effects are often overlooked. Here, a subgrid-scale ACI mechanism is implemented by explicitly treating cloud microphysic...
Saved in:
| Main Authors: | , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2025-08-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/25/9005/2025/acp-25-9005-2025.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | <p>Aerosol–cloud interaction (ACI) significantly influences global and regional weather and is a critical focus in numerical weather prediction (NWP), but subgrid-scale ACI effects are often overlooked. Here, a subgrid-scale ACI mechanism is implemented by explicitly treating cloud microphysics in the KFeta convective scheme with real-time size-resolved hygroscopic aerosol activation and introducing subgrid-scale cloud radiation feedback in an atmospheric chemistry model, CMA_Meso5.1/CUACE. With a focus on summer over central and eastern China, the performance evaluation shows that this developed model with subgrid-scale cloud microphysics and radiation feedback refines cloud representation, even in some grid-scale unsaturated areas, and subsequently leads to attenuated surface downward shortwave radiation (<span class="inline-formula">∼</span> 18.5 W m<span class="inline-formula"><sup>−2</sup></span>) that is more realistic. The increased cloud radiative forcing results in lower temperature (<span class="inline-formula">∼</span> 0.35 °C) and higher relative humidity (<span class="inline-formula">∼</span> 2.5 %) at 2 m, with regional mean bias (MB) decreasing by <span class="inline-formula">∼</span> 40 % and <span class="inline-formula">∼</span> 18.1 %. Temperature vertical structure and relative humidity below <span class="inline-formula">∼</span> 900 hPa are improved accordingly due to cooling and humidifying. The underestimated precipitation is enhanced, especially at the grid scale, thus reducing regional MB by <span class="inline-formula">∼</span> 34.4 % (<span class="inline-formula">∼</span> 1.1 mm). The performance differences between various subregions are related to convective conditions and model local errors. Additionally, compared to simulations with anthropogenic emissions turned off, subgrid-scale actual aerosol inhibits cumulative precipitation during a typical heavy rainfall event by <span class="inline-formula">∼</span> 4.6 mm, aligning it with observations, associated with lower autoconversion at the subgrid scale and less available water vapor for grid-scale condensation, suggesting competition between subgrid- and grid-scale cloud. This study contributes to the understanding of the impact of subgrid-scale ACI on NWP.</p> |
|---|---|
| ISSN: | 1680-7316 1680-7324 |