Project Details
Projekt
CIRRUS-HL - The HALO mission on cirrus in high latitudes Umbrella Proposal HALO2020 - CIRRUS-HL
Applicant
Professorin Dr. Christiane Voigt
Subject Area
Atmospheric Science
Term
since 2020
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 442648575
The CIRRUS-HL experiment will deploy the research aircraft HALO together with satellites and models to gain new insights into nucleation, properties, and climate impact of ice clouds in high latitudes, hence in a region of the world with strongest anthropogenic increase in surface temperatures. AbstractMost rapid climate change occurs in high latitudes. Here, in polar winter, ice clouds exert a substantial positive forcing onto surface temperatures. However, direct observations of cirrus properties in high latitudes and their variability are sparse, and ice clouds and related aerosol effects are not adequately represented in today’s climate models which currently limits our understanding of cirrus effects on climate. CIRRUS-HL, the only HALO cloud mission combining in situ and remote sensing cloud instrumentations since 2014, will use state-of-the-art cloud probes, and novel ice residual, aerosol, trace gas and radiation instruments to investigate nucleation, life cycle and radiative impact of ice clouds in high latitudes. The aircraft observations will be accompanied by remote sensing from satellite and by numerical simulations with global and process-based models. The campaign will complementary be linked to international polar research activities by focusing on the physics of ice clouds.From October to December 2020, HALO will perform 20 flights in the Arctic and Northern Europe with a focus on high-latitude cirrus induced by different meteorological regimes including synoptic cirrus with slow updrafts, frontal or warm conveyor belt cirrus with moderate updrafts and orographic or convective cirrus characterized by high updrafts. A differentiation will be made between in situ cirrus which formed homogeneously or heterogeneously at temperatures below 238 K and liquid origin cirrus. To get more insight into liquid origin cirrus and ice nucleation, mixed phase and ice clouds will also be probed at temperatures above 238 K. Hence, CIRRUS-HL will provide 1) comprehensive observations of microphysical properties of ice clouds and their variability in the poorly probed high latitudes for process studies as well as satellite and model evaluation, 2) new insights into aerosol transport into the Arctic and heterogeneous ice nucleation, and 3) novel observations of radiative properties of ice clouds in high latitudes in early winter. Summarized, CIRRUS-HL will provide a comprehensive data set on ice clouds in high latitudes to enhance our understanding of their climate impact.
DFG Programme
Infrastructure Priority Programmes
