TY - JOUR
T1 - Exploratory cloud-resolving simulations of boundary-layer Arctic stratus clouds Part I
T2 - warm-season clouds
AU - Olsson, Peter Q.
AU - Harrington, Jerry Y.
AU - Feingold, Graham
AU - Cotton, William R.
AU - Kreidenweis, Sonia M.
N1 - Funding Information:
This research was supported by the Environmental Sciences Division of the U.S. Department of Energy (under contract number DE-FG03-95ER61958) as part of the Atmospheric Radiation Measurement Program which is part of the DOE Biological and Environmental Research (BER) Program. J. Harrington was supported by the Augmentation Awards for Science and Engineering Training under Contract F49620-95-1-0386. G. Feingold received support from the NASA/FIRE III program. P. Olsson received support in part from the Geophysical Institute, University of Alaska Fairbanks. The authors thank Bjorn Stevens for his assistance with the model development and two anonymous reviewers for their helpful comments.
PY - 1998/6
Y1 - 1998/6
N2 - Two-dimensional simulations of arctic stratus clouds (ASC) were conducted using a sophisticated cloud-resolving model with explicit microphysics and a two-stream radiative transfer model. The effects of varying cloud condensation nuclei (CCN) concentrations upon the subsequent cloud and its microphysical, radiative and dynamical structure were studied. In this study CCN concentrations were varied within the ranges found in warm-season arctic boundary layers (ABLs) to produce non-drizzling and weakly drizzling stratus decks. Experiments that included all model physics, no-drizzle, and no shortwave radiation were conducted to elucidate the effects of microphysics and radiation on the simulated stratus. Both simulations that did and that did not include the effects of drizzle showed that the higher CCN concentrations produced a cloud with larger reflectivity and absorptivity, but also produced eddies that were weaker than with lower CCN concentrations. Simulations that included the effects of drizzle showed a similar response to changes in CCN concentrations. Simulations with no drizzle produced nmore vigorous eddies than their drizzling counterparts because cooling due to evaporation below cloud tends to stabilize the ABL. The simulations without the effects of short-wave radiation produced very vigorous eddies that penetrated more deeply into the ABL. In this case, the simulation with higher CCN concentrations produced the most vigorous eddies. This resulted from a subtle interplay of microphysics, radiation and dynamics.
AB - Two-dimensional simulations of arctic stratus clouds (ASC) were conducted using a sophisticated cloud-resolving model with explicit microphysics and a two-stream radiative transfer model. The effects of varying cloud condensation nuclei (CCN) concentrations upon the subsequent cloud and its microphysical, radiative and dynamical structure were studied. In this study CCN concentrations were varied within the ranges found in warm-season arctic boundary layers (ABLs) to produce non-drizzling and weakly drizzling stratus decks. Experiments that included all model physics, no-drizzle, and no shortwave radiation were conducted to elucidate the effects of microphysics and radiation on the simulated stratus. Both simulations that did and that did not include the effects of drizzle showed that the higher CCN concentrations produced a cloud with larger reflectivity and absorptivity, but also produced eddies that were weaker than with lower CCN concentrations. Simulations that included the effects of drizzle showed a similar response to changes in CCN concentrations. Simulations with no drizzle produced nmore vigorous eddies than their drizzling counterparts because cooling due to evaporation below cloud tends to stabilize the ABL. The simulations without the effects of short-wave radiation produced very vigorous eddies that penetrated more deeply into the ABL. In this case, the simulation with higher CCN concentrations produced the most vigorous eddies. This resulted from a subtle interplay of microphysics, radiation and dynamics.
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U2 - 10.1016/S0169-8095(98)00066-0
DO - 10.1016/S0169-8095(98)00066-0
M3 - Article
AN - SCOPUS:0031692897
SN - 0169-8095
VL - 47-48
SP - 573
EP - 597
JO - Atmospheric Research
JF - Atmospheric Research
ER -