92nd American Meteorological Society Annual Meeting (January 22-26, 2012)

Wednesday, 25 January 2012: 11:15 AM
Studies of Cloud Microphysics in Arctic Mixed-Phase Cloud: Long ARM Data Time-Series Take Us Beyond Case Studies
Room 244 (New Orleans Convention Center )
Johannes Muelmenstaedt, SIO/Univ. Of California, San Diego, CA; and D. Lubin and L. M. Russell

Arctic clouds continue to be a challenging aspect of climate simulations. The objective of this work is to determine how long time series of cloud property and radiation measurement data can be used to test and refine climate model parameterizations of mixed-phase Arctic cloud. We determine the time periods in which the NSA site is under the influence of major meteorological regimes (e.g., Aleutian Low, Siberian High, Central Arctic/Beaufort Sea High) in two ways: (1) inspection of daily mean NCEP reanalysis data, and (2) k-means clustering on surface meteorological data from the North Slope of Alaska (NSA) site of the Atmospheric Radiation Measurement (ARM) Climate Research Facility in Barrow, AK. We then describe the cloud properties and their ranges for each of these significant regimes and for each season, as derived from ARSCL, MWR, SKYRAD, and other sensors. In this way, we create "ensembles" of test cases for cloud properties, physically relevant to actual meteorological states, that can be used to robustly test climate model parameterizations. This enables testing of the climate model parameterizations over the full range of meteorological variability found in nature and explained by large-scale dynamical forcing. We present this technique as a potentially valuable supplement to the more common method of testing climate model parameterizations against individual "case studies" from intensive aircraft field campaigns such as ISDAC and M-PACE; we show preliminary results from the application of the method to a decade-long single-column simulation of cloud over Barrow.

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