Using Digital Cloud Photogrammetry to Characterize the Onset and Transition from Shallow to Deep Convection over Orography

Zehnder, Joseph A.; Liyan Zhang; Hansford, Dianne; Radzan, Anshuman; Selover, Nancy; Brown, Constance M.
September 2006
Monthly Weather Review;Sep2006, Vol. 134 Issue 9, p2527
Academic Journal
An automated method for segmenting digital images of orographic cumulus and a simple metric for characterizing the transition from shallow to deep convection are presented. The analysis is motivated by the hypothesis that shallow convection conditions the atmosphere for further deep convection by moistening it and preventing the evaporation of convective turrets through the entrainment of dry air. Time series of convective development are compared with sounding and surface data for 6 days during the summer of 2003. The observations suggest the existence of a threshold for the initiation of shallow convection based on the surface equivalent potential temperature and the saturated equivalent potential temperature above the cloud base. This criterion is similar to that controlling deep convection over the tropical oceans. The subsequent evolution of the convection depends on details of the environment. Surface fluxes of sensible and latent heat, along with the transport of boundary layer air by upslope flow, increase the surface equivalent potential temperature and once the threshold value is exceeded, shallow convection begins. The duration of the shallow convection period and growth rate of the deep convection are determined by the kinematic and thermodynamic structure of the mid- and upper troposphere.


Related Articles

  • Distribution of convective energy at upper level in South Korea and the possibility of artificial showery rain caused by activated CAPE. Lee, Sang-Min; Byun, Hi-Ryong // Theoretical & Applied Climatology;Oct2011, Vol. 105 Issue 3/4, p537 

    This paper reports a theoretical study on the possibility of inducing artificial showery rain using the convective available potential energy, which is naturally stored in the troposphere. We calculated the environmental parameters (frequency of climatic values, extreme value of stability index,...

  • The Deep Convective Clouds and Chemistry (DC3) Field Campaign. Barth, Mary C.; Cantrell, Christopher A.; Brune, William H.; Rutledge, Steven A.; Crawford, James H.; Huntrieser, Heidi; Carey, Lawrence D.; MacGorman, Donald; Weisman, Morris; Pickering, Kenneth E.; Bruning, Eric; Anderson, Bruce; Apel, Eric; Biggerstaff, Michael; Campos, Teresa; Campuzano-Jost, Pedro; Cohen, Ronald; Crounse, John; Day, Douglas A.; Diskin, Glenn // Bulletin of the American Meteorological Society;Aug2015, Vol. 96 Issue 8, p1281 

    The Deep Convective Clouds and Chemistry (DC3) field experiment produced an exceptional dataset on thunderstorms, including their dynamical, physical, and electrical structures and their impact on the chemical composition of the troposphere. The field experiment gathered detailed information on...

  • Observations of Kinematics and Thermodynamic Structure Surrounding a Convective Storm Cluster over a Low Mountain Range. Groenemeijer, Pieter; Barthlott, Christian; Behrendt, Andreas; Corsmeier, Ulrich; Handwerker, Jan; Kohler, Martin; Kottmeier, Christoph; Mahlke, Holger; Pal, Sandip; Radlach, Marcus; Trentmann, Jörg; Wieser, Andreas; Wulfmeyer, Volker // Monthly Weather Review;Feb2009, Vol. 137 Issue 2, p585 

    Measurements of a convective storm cluster in the northern Black Forest in southwest Germany have revealed the development of a warm and dry downdraft under its anvil cloud that had an inhibiting effect on the subsequent development of convection. These measurements were made on 12 July 2006 as...

  • Equatorial Convectively Coupled Waves in a Simple Multicloud Model. Khouider, Boualem; Majda, Andrew J. // Journal of the Atmospheric Sciences;Nov2008, Vol. 65 Issue 11, p3376 

    Linear stability results for the multicloud model recently developed by the authors on an equatorial beta plane are presented here. The linearized equations, about a realistic radiative–convective equilibrium (RCE) are projected in the meridional direction via a Galerkin truncation...

  • Seasonal Contrasting Features of Heat and Moisture Budgets between the Eastern and Western Tibetan Plateau during the GAME IOP. Ueda, Hiroaki; Kamahori, Hirotaka; Yamazaki, Nobuo // Journal of Climate;Jul2003, Vol. 16 Issue 14, p2309 

    Using the Global Energy and Water Cycle Experiment (GEWEX) Asian Monsoon Experiment (GAME) four-dimensional data assimilation (4DDA) upper-air data, the large-scale heat source ( (Q[SUP1]) and moisture sink (Q[SUP2]) over the western and eastern Tibetan Plateau are examined for a 4-month period...

  • Organization of tropical convection in a GCM with varying vertical resolution; implications for the simulation of the Madden-Julian Oscillation. Inness, P.M.; Slingo, J.M.; Woolnough, S.J.; Neale, R.B.; Pope, V.D. // Climate Dynamics;Jul2001, Vol. 17 Issue 10, p777 

    Experiments using a GCM with two different vertical resolutions show differences in the amount of variability in the tropical upper tropospheric zonal wind component associated with the Madden-Julian Oscillation (MJO). The GCM with lower vertical resolution shows very little variability in this...

  • Reproducibility by Climate Models of Cloud Radiative Forcing Associated with Tropical Convection. Ichikawa, Hiroki; Masunaga, Hirohiko; Tsushima, Yoko; Kanzawa, Hiroshi // Journal of Climate;Feb2012, Vol. 25 Issue 4, p1247 

    In this study, cloud radiative forcing (CRF) associated with convective activity over tropical oceans is analyzed for monthly mean data from twentieth-century simulations of 18 climate models participating in phase 3 of the Coupled Model Intercomparison Project (CMIP3) in comparison with...

  • A Simple Multicloud Parameterization for Convectively Coupled Tropical Waves. Part II: Nonlinear Simulations. Khouider, Boualem; Majda, Andrew J. // Journal of the Atmospheric Sciences;Feb2007, Vol. 64 Issue 2, p381 

    Observations in the Tropics point to the important role of three cloud types, congestus, stratiform, and deep convective clouds, besides ubiquitous shallow boundary layer clouds for both the climatology and large-scale organized anomalies such as convectively coupled Kelvin waves, two-day waves,...

  • Influence of Sea Surface Temperature on Humidity and Temperature in the Outflow of Tropical Deep Convection. Luo, Zhengzhao Johnny; Kley, Dieter; Johnson, Richard H.; Liu, G. Y.; Nawrath, Susanne; Smit, Herman G. J. // Journal of Climate;Feb2012, Vol. 25 Issue 4, p1340 

    Multiple years of measurements of tropical upper-tropospheric temperature and humidity by the Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC) project are analyzed in the vicinity of deep convective outflow to study the variations of temperature and humidity and to...


Read the Article


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

Try another library?
Sign out of this library

Other Topics