HR: 16:45h
AN: A12E-04    [PDF]
TI: Stratospheric HOx Sensitivity and Accuracy From Aura MLS Instrument
AU: * Pickett, H M
EM: Herbert M. Pickett@jpl.nasa.gov
AF: Jet Propulsion Lab, Caltech, Mail Stop 183-701 4800 Oak Grove Dr., Pasadena, CA 91109 United States
AB: The Aura Microwave Limb Sounder (MLS) instrument has channels devoted to measuring OH and HO$_{2}$ in the stratosphere. Sensitivity estimates show that daily zonal means of OH concentration will be obtained with better than 10 % precision from 10 hPa to 0.02 hPa with a vertical resolution of 6 per decade up to 0.1 hPa. The sensitivity for HO$_{2}$ is smaller by at least an order of magnitude because of spectroscopic line strength. Nonetheless, monthly zonal means can be measured with 30 % precision from 7 hPa to 0.07 hPa for HO$_{2}$ and 50 hPa to 0.003 hPa for OH. This precision can be improved to 10 % by regularization or modest reduction of vertical resolution. The vertical limits are imposed by water vapor absorption at the low altitude limit and by falloff of HOx concentrations at the high altitude limit. These precision estimates are based on measured noise performance and includes calibration factors for sideband ratio and field-of-view shape. The precision estimates also include the effect of uncertainty in temperature. Additional factors that influence the accuracy include knowledge of line widths, systematic errors in the field-of-view and spectral averaging, and errors in the estimation of water and ozone. All of these factors should be small compared to the precision errors.
UR: http://mls.jpl.nasa.gov
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0340 Middle atmosphere--composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting