Validation of the Aura Microwave Limb Sounder HNO3 Measurements
Journal article, 2007
[1] We assess the quality of the version 2.2 (v2.2) HNO(3) measurements from the Microwave Limb Sounder (MLS) on the Earth Observing System Aura satellite. The MLS HNO(3) product has been greatly improved over that in the previous version (v1.5), with smoother profiles, much more realistic behavior at the lowest retrieval levels, and correction of a high bias caused by an error in one of the spectroscopy files used in v1.5 processing. The v2.2 HNO(3) data are scientifically useful over the range 215 to 3.2 hPa, with single-profile precision of similar to 0.7 ppbv throughout. Vertical resolution is 3-4 km in the upper troposphere and lower stratosphere, degrading to similar to 5 km in the middle and upper stratosphere. The impact of various sources of systematic uncertainty has been quantified through a comprehensive set of retrieval simulations. In aggregate, systematic uncertainties are estimated to induce in the v2.2 HNO(3) measurements biases that vary with altitude between +/- 0.5 and +/- 2 ppbv and multiplicative errors of +/- 5-15% throughout the stratosphere, rising to similar to +/- 30% at 215 hPa. Consistent with this uncertainty analysis, comparisons with correlative data sets show that relative to HNO(3) measurements from ground- based, balloon- borne, and satellite instruments operating in both the infrared and microwave regions of the spectrum, MLS v2.2 HNO(3) mixing ratios are uniformly low by 10-30% throughout most of the stratosphere. Comparisons with in situ measurements made from the DC-8 and WB-57 aircraft in the upper troposphere and lowermost stratosphere indicate that the MLS HNO(3) values are low in this region as well, but are useful for scientific studies (with appropriate averaging).
Author
M.L. Santee
California Institute of Technology (Caltech)
A. Lambert
California Institute of Technology (Caltech)
W.G. Read
California Institute of Technology (Caltech)
N.J. Livesey
California Institute of Technology (Caltech)
R.E. Coeld
California Institute of Technology (Caltech)
D.T. Cuddy
California Institute of Technology (Caltech)
W.H. Daffer
California Institute of Technology (Caltech)
B.J. Drouin
California Institute of Technology (Caltech)
L. Froidevaux
California Institute of Technology (Caltech)
R.A. Fuller
California Institute of Technology (Caltech)
R.F. Jarnot
California Institute of Technology (Caltech)
B.W. Knosp
California Institute of Technology (Caltech)
G.L. Manney
New Mexico Institute of Mining and Technology
California Institute of Technology (Caltech)
V.S. Perun
California Institute of Technology (Caltech)
W.V. Snyder
California Institute of Technology (Caltech)
P.C. Stek
California Institute of Technology (Caltech)
R.P. Thurstans
California Institute of Technology (Caltech)
P.A. Wagner
California Institute of Technology (Caltech)
J.W. Waters
California Institute of Technology (Caltech)
G. Muscari
National Institute of Geophysics and Volcanology
R.L. de Zafra
Stony Brook University
J.E. Dibb
University of New Hampshire
D.W. Fahey
National Oceanic and Atmospheric Administration
P.J. Popp
National Oceanic and Atmospheric Administration
University of Colorado at Boulder
T.P. Marcy
National Oceanic and Atmospheric Administration
University of Colorado at Boulder
K.W. Jucks
Harvard-Smithsonian Center for Astrophysics
G.C. Toon
California Institute of Technology (Caltech)
R.A. Stachnik
California Institute of Technology (Caltech)
P.F. Bernath
University of Waterloo
University of York
C.D. Boone
University of Waterloo
K.A. Walker
University of Waterloo
University of Toronto
Joachim Urban
Chalmers, Department of Radio and Space Science, Global Environmental Measurements
Donal Murtagh
Chalmers, Department of Radio and Space Science, Global Environmental Measurements
Journal of Geophysical Research
01480227 (ISSN) 21562202 (eISSN)
Vol. 112 D24 D24S40Subject Categories (SSIF 2011)
Meteorology and Atmospheric Sciences
DOI
10.1029/2007JD008721