The Heidelberg Airborne Imaging DOAS Instrument (HAIDI) – a novel imaging DOAS device for 2-D and 3-D imaging of trace gases and aerosols

摘要

Many relevant processes in tropospheric chemistry take place on rather smallscales (e.g., tens to hundreds of meters) but often influence areas ofseveral square kilometer. Thus, measurements of the involved trace gases withhigh spatial resolution are of great scientific interest. In order toidentify individual sources and sinks and ultimately to improve chemicaltransport models, we developed a new airborne instrument, which is based onthe well established Differential Optical Absorption Spectroscopy (DOAS)method. The Heidelberg Airborne Imaging DOAS Instrument (HAIDI) is a passiveimaging DOAS spectrometer, which is capable of recording horizontal andvertical trace gas distributions with a resolution of better than 100 m.Observable species include NO₂, HCHO, C₂H₂O₂,H₂O, O₃, O₄, SO₂, IO, OClO andBrO.Here we give a technical description of the instrument including itscustom-built spectrographs and CCD detectors. Also first results frommeasurements with the new instrument are presented. These comprise spatialresolved SO₂ and BrO in volcanic plumes, mapped at Mt. Etna(Sicily, Italy), NO₂ emissions in the metropolitan area ofIndianapolis (Indiana, USA) as well as BrO and NO₂distributions measured during arctic springtime in context of the BRomine,Ozone, and Mercury EXperiment (BROMEX) campaign, which was performed 2012 inBarrow (Alaska, USA).