Show simple item record

contributor authorDearden, C.
contributor authorConnolly, P. J.
contributor authorLloyd, G.
contributor authorCrosier, J.
contributor authorBower, K. N.
contributor authorChoularton, T. W.
contributor authorVaughan, G.
date accessioned2017-06-09T17:32:01Z
date available2017-06-09T17:32:01Z
date copyright2014/09/01
date issued2014
identifier issn0027-0644
identifier otherams-86843.pdf
identifier urihttp://onlinelibrary.yabesh.ir/handle/yetl/4230446
description abstractn situ measurements associated with the passage of a kata cold front over the United Kingdom on 29 November 2011 are used to initialize a Lagrangian parcel model for the purpose of calculating rates of diabatic heating and cooling associated with the phase changes of water within the cloud system. The parcel model calculations are performed with both bin-resolved and bulk treatments of microphysical processes. The in situ data from this case study reveal droplet number concentrations up to 100 cm?3, with planar ice crystals detected at cloud top, as well as columnar crystals produced by rime splinter ejection within the prefrontal warm sector. The results show that in terms of magnitude, the most significant rates of diabatic heating and cooling are produced by condensation growth of liquid water within the convective updrafts at the leading edge of the front. The peak temperature tendencies associated with condensation are typically found to be at least an order of magnitude larger than those associated with the ice phase, although the cooling effect from sublimation and melting occurs over a wide region. The parcel model framework is used in conjunction with the observations to assess the suitability of existing bulk microphysical treatments, of the kind used in operational weather forecast models. It is found that the assumption of spherical ice crystals (with diameters equal to the maximum dimension of those sampled), along with the use of negative exponential functions to describe ice particle size distributions, can lead to an overestimation of local diabatic heating and cooling rates by a factor of 2 or more.
publisherAmerican Meteorological Society
titleDiabatic Heating and Cooling Rates Derived from In Situ Microphysics Measurements: A Case Study of a Wintertime U.K. Cold Front
typeJournal Paper
journal volume142
journal issue9
journal titleMonthly Weather Review
identifier doi10.1175/MWR-D-14-00048.1
journal fristpage3100
journal lastpage3125
treeMonthly Weather Review:;2014:;volume( 142 ):;issue: 009
contenttypeFulltext


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record