Abstract
The Atmospheric Chemistry Experiment (ACE) satellite (SCISAT-1) was launched into an inclined orbit on 12 August 2003 and is now recording high signal-to-noise 0.02 cm(-1) resolution solar absorption spectra covering 750-4400 cm(-1) (2.3-13 mu m). A procedure has been developed for retrieving average dry air CO2 mole fractions (X-CO2) in the altitude range 7-10 km from the SCISAT-1 spectra. Using the N-2 continuum absorption in a window region near 2500 cm(-1), altitude shifts are applied to the tangent heights retrieved in version 2.2 SCISAT-1 processing, while cloudy or aerosol-impacted measurements are eliminated. Monthly mean X-CO2 covering 60 degrees S to 60 degrees N latitude for February 2004 to March 2008 has been analyzed with consistent trends inferred in both hemispheres. The ACE X-CO2 time series have been compared with previously reported surface network measurements, predictions based on upper tropospheric aircraft measurements, and space-based measurements. The retrieved X-CO2 from the ACE-FTS spectra are higher on average by a factor of 1.07 +/- 0.025 in the Northern Hemisphere and by a factor of 1.09 +/- 0.019 on average in the Southern Hemisphere compared to surface station measurements covering the same time span. The ACE-derived trend is similar to 0.2% per year higher than measured at surface stations during the same observation period.
| Original language | English |
|---|---|
| Article number | D03105 |
| Pages (from-to) | - |
| Number of pages | 12 |
| Journal | Journal of Geophysical Research |
| Volume | 115 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 3 Feb 2010 |
Keywords
- COLLISION-INDUCED ABSORPTION
- FOURIER-TRANSFORM SPECTROMETER
- UPPER TROPOSPHERE
- LOWER STRATOSPHERE
- SOURCE INVERSIONS
- ERROR ANALYSIS
- CO2 BANDS
- SPECTRA
- INSTRUMENT
- PROFILES