Estimation of aerosol and cloud radiative heating rate in the tropical stratosphere using a radiative kernel method
<p>A layer of aerosols has been identified in the upper troposphere and lower stratosphere above the Asian summer monsoon (ASM) region, typically referred to as the Asian Tropopause Aerosol Layer (ATAL). This layer is fed by atmospheric pollutants over southern and eastern Asia lifted to the u...
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2025-05-01
|
| Series: | Geoscientific Model Development |
| Online Access: | https://gmd.copernicus.org/articles/18/2569/2025/gmd-18-2569-2025.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | <p>A layer of aerosols has been identified in the upper troposphere and lower stratosphere above the Asian summer monsoon (ASM) region, typically referred to as the Asian Tropopause Aerosol Layer (ATAL). This layer is fed by atmospheric pollutants over southern and eastern Asia lifted to the upper troposphere by deep convection in summer. The radiative effects of this aerosol layer change local temperature, influence thermodynamic stability, and modulate the efficiency of air mass vertical transport near the tropopause. However, quantitative understanding of these effects is still very poor. To estimate aerosol radiative effects in the upper troposphere and above, a set of radiative kernels is constructed for the tropical upper troposphere and stratosphere to reduce the computational expense of decomposing the different contributions of atmospheric components to anomalies in radiative fluxes. The prototype aerosol kernels in this work are among the first to target vertically resolved heating rates, motivated by the linearity and separability of scattering and absorbing aerosol effects in the ATAL. Observationally derived lower boundary conditions and satellite observations of cloud ice within the upper troposphere and stratosphere are included and simplified in our Tropical Upper Troposphere–Stratosphere Model (TUTSM). Separate sets of kernels are derived and tested for the effects of absorbing aerosols, scattering aerosols, and cloud ice particles on both shortwave (solar) and longwave (thermal) radiative fluxes and heating rates. The results indicate that the kernels can reproduce aerosol radiative effects in the ATAL well. Similarly, these aerosol kernels could be used to simulate radiative effects of biomass burning and volcanic eruption above the troposphere. This approach substantially reduces computational expense while achieving good consistency with direct radiative transfer model calculations, and it can be applied to models that do not require high precision but have strict requirements for computing speed and storage space.</p> |
|---|---|
| ISSN: | 1991-959X 1991-9603 |