Aerosol-Cloud Interactions from Hawaii's Kilauea Volcano
Abstract
Aerosols, clouds, and their interactions play significant roles in both the radiative budget and the hydrologic cycle in the Earth's climate system. In order to understand current and future climate a thorough understanding of these critical parts of the climate system is necessary. In particular, the complex feedbacks involved in aerosol-cloud interactions (ACI) remain poorly understood and account for much of the current uncertainty in global climate models. Kīlauea Volcano on the Big Island of Hawaii provides a unique opportunity to investigate ACI, in a setting where sulfur is continuously emitted into a clean marine boundary layer. This "natural laboratory" allows for a simplified analysis of sulfur ACI in warm trade wind cumulus clouds downwind of the Kīlauea Volcano.
In this study we combine Level-2 Collection 6 satellite retrievals of cloud-top properties (pressure, temperature, and cloud fraction) and cloud optical and microphysical properties (effective radius, thickness, liquid water path) from the MODerate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua platform, together with Vog Measurement and Prediction Project (VMAP) Vog model results to compare cloud properties within the Kīlauea plume to nearby clean clouds. VMAP data are used to identify when clouds are in the Kilauea plume and compared with several out of plume cases (including and not including orographic effects). Results using 127 cases from the months June, July, and August in 2011-2017 showed polluted clouds to have smaller cloud droplet effective radii, increased cloud water paths, higher liquid water contents, and have higher cloud optical thickness than pristine clouds. These results are consistent with previous works and show evidence for both the first and second aerosol indirect effects. Cloud top height showed overall little difference, though in general cloud tops were higher for clouds in the plume.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.V43J0257Y
- Keywords:
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- 8499 General or miscellaneous;
- VOLCANOLOGY