DOAS Messungen von der NASA Global Hawk während des NASA-ATTREX Projektes

• Antragsteller: Professor Dr. Klaus Pfeilsticker
• Fachliche Zuordnung: Physik und Chemie der Atmosphäre
• Förderung: Förderung von 2013 bis 2017
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 242853511

The present project addresses differential optical absorption spectrometry (DOAS) measurements in scanning limb geometry from aboard the unmanned high-flying aircraft NASA Global Hawk (GH). The DOAS measurements are made within the NASA sponsored ATTREX (Airborne Tropical TRopopause EXperiment) project, by a 3 channel (UV/vis/nearer) optical spectrometer financed by NASA, but mostly built in Heidelberg. In fall 2011 and winter 2012/13 successful flights were already successfully performed and the DOAS instrument peformed. Within ATTREX three field campaigns are planned to take place in the Western Pacific (from EAFB, GUAM, and Darwin) in the years 2013 to 2014 (Jan./Feb. 2013, Jan./Feb. 2014 and June/July 2014). The field campaigns comprise about 50 GH sorties with 600 flight hours spent air-borne. Major scientific foci of the NASA-ATTREX project are the photochemistry, the microphysics of aerosols and cloud particles, and air mass transport into and within the tropical tropopause layer (TTL). The DOAS measurements aim to measure the vertical profiles in the TTL of ozone relevant species such as O3, HONO, NO2, C2H2O2, CH2O, O4, BrO, OClO, IO, and OIO, and of some microphysical properties aerosols and clouds, i.e., the particle phase function, Mie scattering extinction coefficient, the ice water path (IWP) and probably the ice water content (IWC). Together with complementary observations made by other instruments aboard the GH, the DOAS measurements may serve to particularily provide new insights into (a) the photochemistry of halogen oxides (OClO, BrO and IO) in the TTL, in particular on the contribution of so called halogenated Very Short Lived Species (VSLS) to the budgets of stratospheric halogens, (b) the impact of lightning produced NOx and HOx (NO2, and HONO) and other of radicals (c.f. CH2O, BrO, IO) to the oxidation capacity of air in the outflow region of deep convection, and (c) to the abundance and micro-physical properties of frozen aerosols and cloud particles in the upper tropical troposphere and TTL.

• DFG-Verfahren: Sachbeihilfen
• Internationaler Bezug: USA
• Beteiligte Person: Professor Dr. Jochen Stutz, Ph.D.