Impact of Cloud Microphysics on the Development of Trailing Stratiform Precipitation in a Simulated Squall Line: Comparison of One- and Two-Moment Schemes

Morrison, H.; Thompson, G.; Tatarskii, V.
March 2009
Monthly Weather Review;Mar2009, Vol. 137 Issue 3, p991
Academic Journal
A new two-moment cloud microphysics scheme predicting the mixing ratios and number concentrations of five species (i.e., cloud droplets, cloud ice, snow, rain, and graupel) has been implemented into the Weather Research and Forecasting model (WRF). This scheme is used to investigate the formation and evolution of trailing stratiform precipitation in an idealized two-dimensional squall line. Results are compared to those using a one-moment version of the scheme that predicts only the mixing ratios of the species, and diagnoses the number concentrations from the specified size distribution intercept parameter and predicted mixing ratio. The overall structure of the storm is similar using either the one- or two-moment schemes, although there are notable differences. The two-moment (2-M) scheme produces a widespread region of trailing stratiform precipitation within several hours of the storm formation. In contrast, there is negligible trailing stratiform precipitation using the one-moment (1-M) scheme. The primary reason for this difference are reduced rain evaporation rates in 2-M compared to 1-M in the trailing stratiform region, leading directly to greater rain mixing ratios and surface rainfall rates. Second, increased rain evaporation rates in 2-M compared to 1-M in the convective region at midlevels result in weaker convective updraft cells and increased midlevel detrainment and flux of positively buoyant air from the convective into the stratiform region. This flux is in turn associated with a stronger mesoscale updraft in the stratiform region and enhanced ice growth rates. The reduced (increased) rates of rain evaporation in the stratiform (convective) regions in 2-M are associated with differences in the predicted rain size distribution intercept parameter (which was specified as a constant in 1-M) between the two regions. This variability is consistent with surface disdrometer measurements in previous studies that show a rapid decrease of the rain intercept parameter during the transition from convective to stratiform rainfall.


Related Articles

  • FEATURES OF THE WEATHER MODIFICATION ASSESSMENT PROJECT IN THE SOUTHWEST REGION OF SAUDI ARABI. Kucera, Paul A.; Axisa, Duncan; Burger, Roelof P.; Collins, Don R.; Li, Runjun; Chapman, Michael; Posada, Rafael; Krauss, Terry W.; Ghulam, Ayman S. // Journal of Weather Modification;Apr2010, Vol. 42 Issue 1, p78 

    This paper provides an overview of an ongoing rainfall assessment program that has been conducted in the southwest region of Saudi Arabia in the summers of 2008 and 2009 in conjunction with an intensive airborne measurement program. The goal of the study is to examine summertime convection that...

  • The microphysics of ice accretion on wires: Observations and simulations. Niu, ShengJie; Zhou, Yue; Jia, Ran; Yang, Jun; Lü, JingJing; Ke, YiMing; Yang, ZhiBiao // SCIENCE CHINA Earth Sciences;Mar2012, Vol. 55 Issue 3, p428 

    The weather system, meteorological conditions, and microphysics of cloud, fog, and rain droplets are studied during the formation, growth, maintenance, and shedding periods of ice accretion on wires in Enshi, Hubei Province in China using 2008/2009 and 2009/2010 winter observations. The...

  • Investigation of Microphysical Processes Occurring in Organized Convection during NAME. Rowe, Angela K.; Rutledge, Steven A.; Lang, Timothy J. // Monthly Weather Review;Jul2012, Vol. 140 Issue 7, p2168 

    A major objective of the North American Monsoon Experiment (NAME) was to quantify microphysical processes within convection occurring near the steep topography of northwestern Mexico. A previous study compared examples of isolated convection using polarimetric radar data and noted a dependence...

  • Sensitivity of Idealized Squall-Line Simulations to the Level of Complexity Used in Two-Moment Bulk Microphysics Schemes. Van Weverberg, Kwinten; Vogelmann, Andrew M.; Morrison, Hugh; Milbrandt, Jason A. // Monthly Weather Review;Jun2012, Vol. 140 Issue 6, p1883 

    This paper investigates the level of complexity that is needed within bulk microphysics schemes to represent the essential features associated with deep convection. To do so, the sensitivity of surface precipitation is evaluated in two-dimensional idealized squall-line simulations with respect...

  • Evaluation of Precipitating Hydrometeor Parameterizations in a Single-Moment Bulk Microphysics Scheme for Deep Convective Systems over the Tropical Central Pacific. Roh, Woosub; Satoh, Masaki // Journal of the Atmospheric Sciences;Jul2014, Vol. 71 Issue 7, p2654 

    Cloud microphysics of deep convective systems over the tropical central Pacific simulated by a cloud system-resolving model using satellite simulators are evaluated in terms of the joint histogram of cloud-top temperature and precipitation echo-top heights. A control experiment shows an...

  • Investigation of aerosol indirect effects on simulated flash-flood heavy rainfall over Korea. Lim, Kyo-Sun; Hong, Song-You // Meteorology & Atmospheric Physics;Nov2012, Vol. 118 Issue 3/4, p199 

    This study investigates aerosol indirect effects on the development of heavy rainfall near Seoul, South Korea, on 12 July 2006, focusing on precipitation amount. The impact of the aerosol concentration on simulated precipitation is evaluated by varying the initial cloud condensation nuclei (CCN)...

  • An Investigation of Warm Rainfall Microphysics in the Southern Appalachians: Orographic Enhancement via Low-Level Seeder-Feeder Interactions. Wilson, Anna M.; Barros, Ana P. // Journal of the Atmospheric Sciences;May2014, Vol. 71 Issue 5, p1783 

    Observations of the vertical structure of rainfall, surface rain rates, and drop size distributions (DSDs) in the southern Appalachians were analyzed with a focus on the diurnal cycle of rainfall. In the inner mountain region, a 5-yr high-elevation rain gauge dataset shows that light rainfall,...

  • The Relation Between Jet Stream Location and Cyclones Over the Western Iran. Farajzadeh, Manuchehr; Khorany, Asadolah; Lashkary, Hassan // American Journal of Applied Sciences;2008, Vol. 5 Issue 10, p1308 

    Daily rain data for the selected stations were obtained from the Meteorological Organization of Iran for the 1985-1999 period. The consecutive rain days of length 1 to 5 days and widespread over the study area were extracted. The jet tracks and speed surges were extracted from the daily weather...

  • Mechanisms Associated with Large Daily Rainfall Events in Northeast Brazil. Liebmann, Brant; Kiladis, George N.; Allured, Dave; Vera, Carolina S.; Jones, Charles; Carvalho, Leila M. V.; Bladé, Ileana; Gonzáles, Paula L. M. // Journal of Climate;Jan2011, Vol. 24 Issue 2, p376 

    The mechanisms resulting in large daily rainfall events in Northeast Brazil are analyzed using data filtering to exclude periods longer than 30 days. Composites of circulation fields that include all independent events do not reveal any obvious forcing mechanisms as multiple patterns contribute...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics