Solar IR Remote Sensing
As solar radiation passes through the atmosphere, trace gases selectively absorb at specific wavelengths of the light. The measurement of the sun's spectrum thus provides a wealth of information about atmospheric composition, as well as information on the amount of UV exposure plants and animals are experiencing at the earth's surface. Our measurements at Wollongong involve high resolution infrared spectroscopy, as part of the international Network for the Detection of Stratospheric Change NDSC programme. In conjunction with the solar infrared observations spectra covering the visible and ultraviolet are recorded as well.
High resolution ground-based FTIR spectrometers are capable of quantifiying the total column amounts of numerous tropospheric and stratospheric trace gases. Some vertical profile information can also be retrieved. At present the following species are retrieved from the Wollongong solar spectra:
O3 (ozone), ClONO2, HNO3, HCl, CFC-11, CFC-12, CFC-22, NO2, N2O, NO, HF, C2H2, C2H4,
C2H6, CH4, CO, COF2, H2O, HCN, HO2NO2, NH3, N2, and OCS
Additionally, for water vapor and ozone the isotopic ratios are determined for the most common isotopomers.
Selected research topics related to solar observations:
- interpretation of seasonal and interannual changes in trace gas amounts
- chemical ozone depletion by observation of key species (O3, ClONO2, HNO3, HCl, ..)
- details of the ozone formation process by isotopic studies in ozone
- profile retrieval to detect dynamical changes
- transport studies of chemical tracers and tropospheric pollutants
- satellite validation
- extension of isotopic studies into further species