Collaborative Research: Lightning Studies in a Polluted Atmosphere

GSTDTAP

项目编号	1523305
	Collaborative Research: Lightning Studies in a Polluted Atmosphere
	Earle Williams
主持机构	Massachusetts Institute of Technology
项目开始年	2015
	2015-09-01
项目结束日期	2018-08-31
资助机构	US-NSF
项目类别	Continuing grant
项目经费	24119(USD)
国家	美国
语种	英语
英文摘要	The process of electrification of convective clouds involves collisions of large ice precipitation particles that are growing by collecting supercooled cloud droplets (graupel) with ice crystals that grow by vapor deposition. The negatively charged graupel fall and lower whereas the positively charged crystals ascend with the updraft, thus separating the charges and increasing the electric field until its breakdown in the form of lightning flashes. The existence of supercooled cloud droplets and strong updrafts that are required for the process can be ascribed to both thermodynamic and aerosol properties of the air mass. Disentangling the dynamic and aerosol effects is a long-standing question, because the aerosol and thermodynamic properties are often not independent. This study addresses this challenge with a new combination of observational tools that are applied to this problem for the first time. The cloud microstructure is retrieved by the new NPP/VIIRS satellite measurements that will provide retrieved cloud properties at a resolution of 375 m. Ground-truth aerosol measurements will be continuously available. The Houston Lightning Mapping Array (LMA) and the central Oklahoma LMA will provide accurate 3-dimensional mapping of the lightning sources and their polarity. The new polarimetric radars will provide the evolution of the precipitation in the clouds. These measurements will be conducted over the Houston area, which has refineries and other sources of air pollution. Similar clouds in and outside of the Houston pollution plume will be examined for separating the aerosol from thermodynamic effects on cloud microstructure, precipitation forming processes and electrification, including charging polarity. Similar studies will be conducted in central Oklahoma. This research will contribute to the education of several undergraduate and graduate students who will directly participate in the research, which will include their sharing in data acquisition and analysis. Included in this study is support for students who will write theses and dissertations and present their results at seminars and professional meetings. Research results will be incorporated into courses on cloud physics and mesoscale phenomena. The research team will continue to inform, engage, and disseminate information and data to the wider scientific community through the project website. Access to the LMA real-time lightning display is provided at no cost to the Houston community and surrounding areas.
来源学科分类	Geosciences - Atmospheric and Geospace Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/68571
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Earle Williams.Collaborative Research: Lightning Studies in a Polluted Atmosphere.2015.