Examining the Oxidative Capacity of the Troposphere in the Remote Tropical Western Pacific Using Measurements from CONTRAST
Thursday, 18 December 2014: 2:10 PM
Hydroxyl radical (OH) is the main daytime oxidant in the troposphere and determines the atmospheric lifetimes of many compounds of interest. It has been hypothesized that a region of very low OH in the tropical western Pacific Ocean allows otherwise short-lived compounds (including biogenic ozone depleting substances) to be transported intact to the UTLS by deep convection. We use measurements from the CONTRAST field campaign in the tropical western Pacific to constrain a box model to examine the oxidative capacity of the troposphere in this region. Measurements reveal a background, unpolluted state of the troposphere, with pervasive high O3/low H2O filamentary structures existing in the mid-troposphere; we focus on modeling OH in these distinct chemical environments and investigating the resulting impact on instantaneous lifetimes of species of interest.