Accession Number:

AD1096009

Title:

Examination of Effects of Aerosols on a Pyrocb and their Dependence on Fire Intensity and Aerosol Perturbation

Descriptive Note:

Journal Article - Open Access

Corporate Author:

Naval Research Laboratory Washington United States

Personal Author(s):

• Lee ,Seoung Soo
• Kablick ,George
• Li ,Zhanqing
• Jung ,Chang-Hoon
• Choi ,Yong-Sang
• Um ,Junshik
• Choi ,Won-Jun

Report Date:

2020-03-23

Pagination or Media Count:

15.0

Abstract:

Using a modeling framework, this study investigates how a pyrocumulonimbus pyroCb event influences water vapor concentrations and cirrus-cloud properties near the tropopause, specifically focusing on how fire-produced aerosols affect this role. Results from a case study show that when observed fire intensity is high, there is an insignificant impact of fire-produced aerosols on the development of the pyroCb and associated changes in water vapor and cirrus clouds near the tropopause. However, as fire intensity weakens, effects of those aerosols on microphysical variables and processes such as droplet size and autoconversion increase. Due to this, aerosol-induced invigoration of convection is significant for pyroCb with weak-intensity fires and associated weak surface heat fluxes. This leads to a situation where there is a greater aerosol effect on the transport of water vapor to the upper troposphere and the production of cirrus clouds with weak-intensity fires, whereas this effect is muted with strong-intensity fires.

Descriptors:

• PRECIPITATION
• clouds
• water vapor
• phase transformations
• thermodynamic processes
• condensation
• cirrus clouds
• stratosphere
• convection
• Ice

Subject Categories:

• Atmospheric Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE