VERTICAL PROFILES OF N2O5, HO2NO2, AND NO2 INSIDE THE ARCTIC VORTEX, RETRIEVED FROM NOCTURNAL MIPAS-B2 INFRARED LIMB EMISSION MEASUREMENTS IN FEBRUARY 1995
G. Wetzel et al., VERTICAL PROFILES OF N2O5, HO2NO2, AND NO2 INSIDE THE ARCTIC VORTEX, RETRIEVED FROM NOCTURNAL MIPAS-B2 INFRARED LIMB EMISSION MEASUREMENTS IN FEBRUARY 1995, JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 102(D15), 1997, pp. 19177-19186
Vertical profiles of N2O5, HO2NO2, and NO2 inside the arctic vortex we
re retrieved from nighttime infrared limb emission spectra measured by
the Michelson Interferometer for Passive Atmospheric Sounding, Balloo
n-borne version 2 (MIPAS-B2) instrument from Kiruna (Sweden, 68 degree
s N) on February 11, 1995, as part of the Second European Stratospheri
c Arctic and Midlatitude Experiment (SESAME). Spectra were analyzed by
a multiparameter nonlinear least squares fitting procedure in combina
tion with an onion-peeling retrieval algorithm. The N2O5, HO2NO2, and
NO2 results were derived from spectral features within the bands near
8.0 mu m, 12.5 mu m, and 6.2 mu m, respectively. Peak mixing ratios of
1.14 parts per billion by volume (ppbv) N2O5 and 80 parts per trillio
n by volume (pptv) HO2NO2 at 17.1 hPa as well as 2.79 ppbv NO2 at 12.0
hPa corresponding to 25.8 km and 28.0 km altitude were inferred from
the spectra. NO2 mixing ratios measured by MIPAS fit well to the data
observed by concurrent flights. A comparison with calculations perform
ed with a three-dimensional chemistry transport model for the time and
location of the measurements shows that the best agreement of measure
d and calculated profiles is reached between 17 and 28 hPa correspondi
ng to 25.8 and 22.7 km altitude, while below and above this altitude r
egion there are some discrepancies between the modeled and observed da
ta.