CU Airborne MAX-DOAS measurements over California during the CalNEx and CARES field campaigns

The University of Colorado Airborne Multi-Axis Differential Optical Absorption Spectroscopy (CU AMAX-DOAS) instrument was deployed aboard the NOAA Optical Remote Sensing Twin Otter Research Aircraft during the CalNEx 2010 and CARES field campaigns. A total of 52 flights (48 research + 4 transfer flights) were carried out between May 19 and July 19 2010 and included flights in the South California Air Basin, the High deserts, Northern Mexico, the Central Valley, Sacramento, and the San Francisco Bay Area. A particular component of the CU AMAX-DOAS deployment was to enhance the value of ground-based super sites in Pasadena and Bakersfield, as well as the CARES T0 and T1 sites. The CU AMAX-DOAS is measuring column amounts of NO2, HCHO, CHOCHO, O4 and other gases above and below the aircraft. The focus of this deployment was to map the horizontal and vertical distribution of these gases. Here we describe the CU AMAX-DOAS instrument and give an overview of the NO2 vertical columns below the plane along the flight tracks. A first comparison of NO2 vertical columns measured by AMAX-DOAS and two CU Ground based MAX-DOAS instruments which were deployed in Pasadena and Fontana Arrows during CalNEx and at the T1 site during CARES is also presented.