Project Details
Projekt
Chemical and microphysical properties of natural cirrus and contrail cirrus
Subject Area
Atmospheric Science
Term
from 2009 to 2011
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 111635694
Cirrus clouds influence the earth´s climate directly through trapping of terrestrial and reflection of solar radiation – and indirectly through heterogeneous processing of trace gases modifying ozone concentrations in the tropopause region. Controversial results of recent field, modeling and laboratory studies have promoted an active debate on trace gas uptake in ice crystals in its consequences for global climate. Open questions remain e.g. the dependence of the nitric acid uptake in ice crystals on HNO3 partial pressure, denitrification and chlorine activation by cirrus clouds. Hence we will develop a chemical ionization quadrupole mass spectrometer for the high altitude long range aircraft HALO to detect HNO3 and HCl concentrations in the tropopause region. Particle shattering on the inlets of airborne instruments questioned the quality of previous microphysical cirrus and contrail data sets. To surmount these problems, we will implement a new cloud combination probe (CCP) on the HALO to observe cirrus ice crystals in the size range between 3 and 1550 μm. The detection of the particle interarrival times will allow for the correction of shattering effects. Hence the CCP will provide new data on microphysical particle properties, which help to better quantify the radiative impact of cirrus and contrail cirrus. The chemical ionization mass spectrometer will be deployed within the HALO demo missions TACTS, ML-CIRRUS and POLSTRACC and the CCP will be integrated in the ML-CIRRUS and the POLSTRACC mission.
DFG Programme
Infrastructure Priority Programmes
