The formation of cloud droplets on aerosol particles, technically known as the activation of cloud condensation nuclei (CCN), is the fundamental process driving the interactions of aerosols with clouds and precipitation. Knowledge of these interactions is foundational to our understanding of weather and climate. The Intergovernmental Panel on Climate Change (IPCC) and the Decadal Survey
(NRC 2007) indicate that the uncertainty in how clouds adjust to aerosol perturbations dominates the uncertainty in the overall quantification of the radiative forcing attributable to human activities.
The Clouds, Hazards, and Aerosols Survey for Earth Researchers (CHASER) satellite mission concept responds to the IPCC and Decadal Survey concerns by studying the activation of CCN and their interactions with clouds and storms. The CHASER satellite mission was developed to remotely sense quantities necessary for determining
the interactions of aerosols with clouds and storms. The links between the Decadal Survey recommendations and the CHASER goals, science objectives, measurements, and instruments are described in
Table 1. Measurements by current satellites allow a rough determination of profiles of cloud particle size but not of the activated CCN that seed them. CHASER will use an innovative technique (Freud et al. 2011; Freud and Rosenfeld 2012; Rosenfeld et al. 2012) and
high-heritage (flown in a previous spaceflight mission) instruments to produce satellite-based remotely sensed observations of activated CCN and the properties of the clouds associated with them. CHASER will estimate updraft velocities at cloud base to calculate
the number density of activated CCN as a function of the water vapor supersaturation. CHASER will determine the CCN concentration and cloud thermodynamic forcing (i.e., forcing caused by changes
in the temperature and humidity of the boundary layer air) simultaneously, allowing their effects to be distinguished. Changes in the behavior of a group of weather systems in which only one of the quantities varies (a partial derivative of the intensity of the
weather system with respect to the desirable quantity) will allow the determination of each effect statistically.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:13464 |
| Date | January 2013 |
| Creators | Rennó, Nilton O., Williams, Earle, Rosenfeld, Daniel, Fischer, David G., Fischer, Jürgen, Kremic, Tibor, Agrawal, Arun, Andreae, Meinrat O., Bierbaum, Rosina, Blakeslee, Richard, Boerner, Anko, Bowles, Neil, Christian, Hugh, Cox, Ann, Dunion, Jason, Horvath, Akos, Huang, Xianglei, Khain, Alexander, Kinne, Stefan, Lemos, Maria C., Penner, Joyce E., Pöschl, Ulrich, Quaas, Johannes, Seran, Elena, Stevens, Bjorn, Walati, Thomas, Wagner, Thomas |
| Contributors | University of Michigan, Massachusetts Institute of Technology, Hebrew University of Jerusalem, NASA Glenn Research Center, Freie Universität Berlin, Max-Planck-Institut für Chemie, NASA Marshall Space Flight Center, Deutsches Zentrum für Luft- und Raumfahrt (DLR), University of Oxford, University of Alabama in Huntsville, Orbital Sciences Corporation, University of Miami, Max-Planck-Institut für Meteorologie, Universität Leipzig, University of Paris VI, Universität Heidelberg |
| Publisher | American Meteorological Society |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | doc-type:article, info:eu-repo/semantics/article, doc-type:Text |
| Source | Bulletin of the American Meteorological Society (2013) 94, S. 685-694 |
| Rights | info:eu-repo/semantics/openAccess |
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