Trajectory Analysis of Cloud Properties During the 2014-2015 Holuhraun Lava Field Fissure Eruption in Iceland
Abstract
One of the major uncertainties in climate models and our understanding of anthropogenic effects on the atmosphere is the effect of aerosols on clouds. Anomalously high concentrations of cloud condensation nuclei (CCN) tend to increase cloud droplet concentrations and decrease droplet size leading to cloud brightening, known as the first indirect effect, and reduce the efficiency of precipitation processes leading to longer persistence times, known as the second indirect effect. In pre-industrial times, volcanoes were believed to be a primary source of CCN. The 2014-2015 fissure eruption at the Holuhraun lava field in Iceland, lasting from August 31, 2014 to February 28, 2015, released up to 120kt of sulfur dioxide per day at its peak, dwarfing all anthropogenic sulfur sources in the region. The continuity, magnitude, and length of the eruption makes it an ideal opportunity to examine the cloud-aerosol first indirect effect. Previous studies have shown the average cloud droplet effective radius in the region to drop to its lowest value recorded in the MODIS data record during September and October when the eruption was strongest. We aim to understand how this alteration of cloud properties occurred along parcel paths during the height of the eruption and establish a parcel relative mean magnitude change and activation time. Utilizing MODIS AQUA measurements and HYSPLIT forward trajectories, we composite cloud droplet effective radius, optical depth, and other cloud variables along trajectories, then compare to previous years with similar meteorology. We hope to provide a real world case by which to verify Lagrangian framed cloud-aerosol interactions and pre-industrial models.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.A53D0317B
- Keywords:
-
- 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSESDE: 3354 Precipitation;
- ATMOSPHERIC PROCESSES