AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Climate Implications of Coal Fly Ash Particles Due to Ice Cloud Formation
SARVESH GARIMELLA, Daniel Rothenberg, Martin Wolf, Maria Zawadowicz, Costa Christopoulos, Karl D. Froyd, Yi-wen Huang, Daniel Murphy, Chien Wang, Daniel Cziczo, MIT
Abstract Number: 669 Working Group: Aerosols, Clouds, and Climate
Abstract This study investigates the impact fly ash particles have on cloud formation and climate. It examines the physical and chemical properties of several types of fly ash particles and the efficiency with which they form cloud droplets and ice crystals in the laboratory. Fly ash particles are found to be moderately hygroscopic and are found to form ice in the deposition mode at temperatures colder than ~ -30ºC and in the immersion mode at temperatures colder than ~ -20ºC. The laboratory results are used to investigate the impacts of fly ash emissions on the properties of cirrus clouds and climate in a global climate model. Single particle mass spectrometry data from aircraft campaigns are used to estimate the abundance of fly ash in the atmosphere and constrain the sensitivity of the cloud forcing response to fly ash emissions. Overall, current levels of fly ash emissions are estimated to contribute ~ 0.1-0.6 W/m^2 of extra warming through their role in cirrus cloud formation.