Validation of NO, NO2, ClONO2, HNO3, N2O5 and N2O Measurements by the Atmospheric Chemistry Experiment
Abstract
The Atmospheric Chemistry Experiment has been in orbit since its launch on 12 August 2003. ACE is a Canadian-led satellite mission, also known as SCISAT, which carries two instruments, the Fourier Transform Spectrometer (ACE-FTS) and the Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (ACE-MAESTRO). Both instruments record solar occultation spectra, ACE-FTS in the infrared (IR), and MAESTRO in the ultraviolet-visible-near-IR, from which vertical profiles of atmospheric trace gases, temperature, and aerosol extinction are retrieved. The SCISAT spacecraft is in a circular orbit at 650-km altitude, with a 74-degree inclination angle, providing up to 15 sunrise and 15 sunset solar occultations per day. The choice of orbital parameters results in coverage of the tropics, mid-latitudes and polar regions with an annually repeating pattern, and a sampling frequency that is greatest over the Arctic and Antarctic. The primary scientific objective of the ACE mission is to understand the chemical and dynamical processes that control the distribution of ozone in the stratosphere and upper troposphere, particularly in the Arctic The accuracy and reliability of the measurements from the ACE mission have been validated by comparing them to a series of coincident measurements made by other instruments. Both vertical profile and column measurements have been used in the validation of NO, NO2, ClONO2, HNO3, N2O5 and N2O from ACE-FTS version 2.2 (and updates) and NO2 from MAESTRO version 1.2. In this presentation, the quality of the ACE vertical profiles is discussed through comparisons with coincident measurements made by other satellite, aircraft, and balloon-borne instruments. In addition, ACE measurements are compared with ground-based measurements by Fourier transform infrared spectrometers (which provide total or partial columns of NO, NO2, ClONO2, HNO3 and N2O) and with ultraviolet-visible grating spectrometers (which give NO2 total columns, and in some cases, low-resolution NO2 profiles). This presentation will provide an overview of the ACE validation results for the nitrogen species NO, NO2, ClONO2, HNO3, N2O5 and N2O.
- Publication:
-
37th COSPAR Scientific Assembly
- Pub Date:
- 2008
- Bibcode:
- 2008cosp...37.3063S