HR: 12:00h
AN: A32B-07    [Abstracts]
TI: PyroCb Warming of the Stratosphere and Cooling of the Surface: First Indications
AU: * Fromm, M
EM: mike.fromm@nrl.navy.mil
AF: Naval Research Laboratory, 4555 Overlook Ave., S.W., Washington, DC 20375 United States
AB: Since first being discovered in recent years, pyrocumulonimbus "eruptions" have been identified on a number of occasions, in both northern and southern hemispheres. The so-called "pyroCb" is an especially potent intensification of wild fire mixed with convection, resulting in an enduring plume of smoke aerosols (as well as other biomass burning emissions) as high as the stratospheric overworld. However, it is still unknown whether the pyroCb is at most a geophysical curiosity, or whether it can have an important impact on weather or climate. In this paper we explore the relation between temperature and the increased stratospheric loading of absorbing aerosol that has been attributed to previously-documented pyroCb events. We use temperature analyses derived from the Microwave Sounding Unit (MSU) and gridded temperature from the United Kingdom Met Office. In addition, we compute tropopause height from the Met Office fields to correlate with pyroCb-related stratospheric smoke pollution. Preliminary indications are that temperature departs substantially from normal in both the lower stratosphere (warming) and troposphere (cooling) in concert with increased stratospheric aerosol optical depth, leading to an alteration of the tropopause height.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 1610 Atmosphere (0315, 0325)
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3311 Clouds and aerosols
DE: 3362 Stratosphere/troposphere interactions
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005