The oxygen collisional complex (O2-O2, or O4) is a greenhouse gas, and a calibration trace gas used to infer aerosol and cloud properties by Differential Optical Absorption Spectroscopy (DOAS). Recent reports suggest the need for an O4 correction factor (CFO4) when comparing simulated and measured O4 differential slant column densities (dSCD) by passive DOAS. We investigate the sensitivity of O4 dSCD simulations at ultraviolet (360 nm) and visible (477 nm) wavelengths towards separately measured aerosol extinction profiles. Measurements were conducted by the University of Colorado 2D-MAX-DOAS instrument and NASA’s multispectral High Spectral Resolution Lidar (HSRL-2) during the Two Column Aerosol Project (TCAP) at Cape Cod, MA in July 2012. During two case study days with (1) high aerosol load (17 July, AOD ~ 0.35 at 477 nm), and (2) near molecular scattering conditions (22 July, AOD
Revised: September 13, 2016 |
Published: June 10, 2016
Citation
Ortega I., L.K. Berg, R. Ferrare, J. Hair, C.A. Hostetler, and R.M. Volkamer. 2016.Elevated aerosol layers modify the O2-O2 absorption measured by ground-based MAX-DOAS.Journal of Quantitative Spectroscopy and Radiative Transfer 176.PNNL-SA-116820.doi:10.1016/j.jqsrt.2016.02.021