CU Airborne MAX-DOAS Measurements: Application for Satellite Validation
Abstract
An airborne scanning multi-axis differential optical absorption spectroscopy (CU AMAX-DOAS) instrument has been developed at the University of Colorado, Boulder to retrieve profile information of trace gases and multispectral aerosol extinction. The instrument collects scattered sunlight from different discrete viewing angles using a single telescope. A real time motion stabilisation system actively compensates for aircraft movements maintaining the elevation angle to ensure the accurate pointing of the telescope during the flight. This instrument was deployed on board the NOAA Twin Otter research aircraft during the CALNEX and CARES field campaigns in summer 2010. A subset of flight hours was dedicated to synchronise the overflight of the Twin Otter aircraft with the location of the OMI satellite instrument ground pixels. Airborne MAX-DOAS vertical column amounts are sampled over scales that resolve horizontal variability of trace gases within a satellite ground pixel and are thus ideally suited for satellite validation. In combination with two ground-based MAX-DOAS instruments and one in-situ LED cavity enhanced DOAS we assess spatial gradients, and validate the CU AMAX-DOAS observations. Further, AMAX-DOAS is able to resolve the vertical distribution of pollutants as well as simultaneously measure the aerosol extinction, and this information can be used to improve satellite retrievals. Our observations suggest the existence of aerosol layers aloft that can partly shield boundary layer gases for the view from space. This presentation will give an overview of the available data products of the CU AMAX-DOAS instrument, discuss the technique, and show first results for comparison with OMI NO2 data.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFM.A22D..05O
- Keywords:
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- 0345 ATMOSPHERIC COMPOSITION AND STRUCTURE / Pollution: urban and regional;
- 0394 ATMOSPHERIC COMPOSITION AND STRUCTURE / Instruments and techniques