HR: 08:00h
AN: A41C-01 INVITED     [Abstracts]
TI: Using measurements of OH, HO$_2$, and OH reactivity to study tropospheric oxidation processes
AU: * Brune, W H
EM: brune@ems.psu.edu
AF: Pennsylvania State University, Department of Meteorology, 503 Walker Building, University Park, PA 16802 United States
AU: Ren, X
AF: Pennsylvania State University, Department of Meteorology, 503 Walker Building, University Park, PA 16802 United States
AU: Lesher, R L
AF: Pennsylvania State University, Department of Meteorology, 503 Walker Building, University Park, PA 16802 United States
AU: Shirley, T R
AF: Pennsylvania State University, Department of Meteorology, 503 Walker Building, University Park, PA 16802 United States
AB: Much of tropospheric chemistry revolves around the hydroxyl radical, OH, and its reactions with a wide range of atmospheric constituents. Recognition of OH's importance more than three decades ago sparked an explosion in efforts to detect tropospheric OH. These efforts have in the last two decades culminated in a handful of different techniques that are now routinely being deployed around the globe in instrument complements designed to study tropospheric oxidation chemistry. Like other research groups, we have deployed our instruments to measure OH, HO$_2$, and OH reactivity in typically two intensive field campaigns a year for the last 5 years. What are the results of these recent studies? Modeled and measured OH and HO$_2$ generally agree to within a factor of two -- sometimes much better and sometimes much worse. However, two difficult-to-explain observations -- nighttime OH and the less-than-expected HO$_2$ decrease at high NO -- persist in most tropospheric environments. In this presentation, we discuss what our analyses of measurements have to say about tropospheric photochemistry and what we might want to do next.
DE: 0322 Constituent sources and sinks
DE: 0345 Pollution--urban and regional (0305)
DE: 0365 Troposphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting