TY - JOUR
T1 - An application of the tilted independent pixel approximation to cumulonimbus environments
AU - Frame, Jeffrey W.
AU - Petters, Jonathan L.
AU - Markowski, Paul M.
AU - Harrington, Jerry Y.
N1 - Funding Information:
Insightful discussions with Drs. Eugene Clothiaux and Tamas Varnai, as well as comments from two anonymous reviewers have greatly improved both the ideas and the results presented herein. J. Frame and P. Markowski have been supported by NSF Grants ATM-0338661 and ATM-0644533. J. Petters was supported by the Atmospheric Radiation Measurement (ARM) program, U. S. Department of Energy, Grant No. DE-FG02-90ER61071. J. Harrington was supported by the Office of Science (BER), U. S. Department of Energy, Grant No. DE-FG02-05ER64058. ARPS was developed by the Center of Analysis and Prediction of Storms at the University of Oklahoma. The Monte Carlo code was originally developed by Dr. Jason N. S. Cole at the University of British Columbia.
PY - 2009/1
Y1 - 2009/1
N2 - Most radiative transfer parameterizations in numerical cloud models transfer radiation in the vertical direction only, utilizing the independent pixel approximation. This method cannot correctly simulate neither the location nor the shape of cloud shadows because shortwave radiation only propagates vertically, and thus it does not account for the slanted path the direct solar beam takes through the atmosphere. Herein, the tilted independent pixel approximation, which more properly accounts for the geometry of the direct solar beam, is applied to a cumulonimbus cloud field. This computationally inexpensive method results in a more accurately modeled cloud shadow at the surface, allowing for more accurate computations of near-surface air temperatures.
AB - Most radiative transfer parameterizations in numerical cloud models transfer radiation in the vertical direction only, utilizing the independent pixel approximation. This method cannot correctly simulate neither the location nor the shape of cloud shadows because shortwave radiation only propagates vertically, and thus it does not account for the slanted path the direct solar beam takes through the atmosphere. Herein, the tilted independent pixel approximation, which more properly accounts for the geometry of the direct solar beam, is applied to a cumulonimbus cloud field. This computationally inexpensive method results in a more accurately modeled cloud shadow at the surface, allowing for more accurate computations of near-surface air temperatures.
UR - http://www.scopus.com/inward/record.url?scp=56949092096&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=56949092096&partnerID=8YFLogxK
U2 - 10.1016/j.atmosres.2008.05.005
DO - 10.1016/j.atmosres.2008.05.005
M3 - Article
AN - SCOPUS:56949092096
SN - 0169-8095
VL - 91
SP - 127
EP - 136
JO - Atmospheric Research
JF - Atmospheric Research
IS - 1
ER -