Nature of the Mesoscale Boundary Layer Height and Water Vapor Variability Observed 14 June 2002 during the IHOP_2002 Campaign

Couvreux, F.; Guichard, F.; Austin, P. H.; Chen, F.
January 2009
Monthly Weather Review;Jan2009, Vol. 137 Issue 1, p414
Academic Journal
Mesoscale water vapor heterogeneities in the boundary layer are studied within the context of the International H2O Project (IHOP_2002). A significant portion of the water vapor variability in the IHOP_2002 occurs at the mesoscale, with the spatial pattern and the magnitude of the variability changing from day to day. On 14 June 2002, an atypical mesoscale gradient is observed, which is the reverse of the climatological gradient over this area. The factors causing this water vapor variability are investigated using complementary platforms (e.g., aircraft, satellite, and in situ) and models. The impact of surface flux heterogeneities and atmospheric variability are evaluated separately using a 1D boundary layer model, which uses surface fluxes from the High-Resolution Land Data Assimilation System (HRLDAS) and early-morning atmospheric temperature and moisture profiles from a mesoscale model. This methodology, based on the use of robust modeling components, allows the authors to tackle the question of the nature of the observed mesoscale variability. The impact of horizontal advection is inferred from a careful analysis of available observations. By isolating the individual contributions to mesoscale water vapor variability, it is shown that the observed moisture variability cannot be explained by a single process, but rather involves a combination of different factors: the boundary layer height, which is strongly controlled by the surface buoyancy flux, the surface latent heat flux, the early-morning heterogeneity of the atmosphere, horizontal advection, and the radiative impact of clouds.


Related Articles

  • Simple Multicloud Models for the Diurnal Cycle of Tropical Precipitation. Part II: The Continental Regime. Frenkel, Yevgeniy; Khouider, Boualem; Majda, Andrew J. // Journal of the Atmospheric Sciences;Oct2011, Vol. 68 Issue 10, p2192 

    The variation of precipitation over land due to the diurnal cycle of solar heating is examined here in the context of a simple multicloud model for tropical convection with bulk atmospheric boundary layer (ABL) dynamics. The model utilizes three cloud types (congestus, deep, and stratiform) that...

  • Atmospheric Boundary-Layer Dynamics with Constant Bowen Ratio. Porporato, Amilcare // Boundary-Layer Meteorology;Aug2009, Vol. 132 Issue 2, p227 

    Motivated by the observation that the diurnal evolution of sensible and latent heat fluxes tends to maintain a constant Bowen ratio, we derive approximate solutions of the ordinary differential equations of a simplified atmospheric boundary-layer (ABL) model. Neglecting the early morning...

  • An Eddy Diffusivity-Mass Flux Approach to the Vertical Transport of Turbulent Kinetic Energy in Convective Boundary Layers. Witek, Marcin L.; Teixeira, Joao; Matheou, Georgios // Journal of the Atmospheric Sciences;Oct2011, Vol. 68 Issue 10, p2385 

    In this study a new approach to the vertical transport of the turbulent kinetic energy (TKE) is proposed. The principal idea behind the new parameterization is that organized updrafts or convective plumes play an important role in transferring TKE vertically within convectively driven boundary...

  • Evaluating Boundary Layer–Based Mass Flux Closures Using Cloud-Resolving Model Simulations of Deep Convection. Fletcher, Jennifer K.; Bretherton, Christopher S. // Journal of the Atmospheric Sciences;Jul2010, Vol. 67 Issue 7, p2212 

    High-resolution three-dimensional cloud resolving model simulations of deep cumulus convection under a wide range of large-scale forcings are used to evaluate a mass flux closure based on boundary layer convective inhibition (CIN) that has previously been applied in parameterizations of shallow...

  • Quantifying the deep convective temperature signal within the tropical tropopause layer (TTL). Paulik, L. C.; Birner, T. // Atmospheric Chemistry & Physics;2012, Vol. 12 Issue 24, p12183 

    Dynamics on a vast range of spatial and temporal scales, from individual convective plumes to planetary-scale circulations, play a role in driving the temperature variability in the tropical tropopause layer (TTL). Here, we aim to better quantify the deep convective temperature signal within the...

  • A simple equilibrium model for shallow-cumulus-topped mixed layers. Neggers, Roel; Stevens, Bjorn; Neelin, J. David // Theoretical & Computational Fluid Dynamics;Oct2006, Vol. 20 Issue 5/6, p305 

    A new equilibrium model for shallow-cumulus-topped mixed layers is presented. A variant on the w * closure for the shallow-cumulus mass flux is applied that retains the convective area-fraction in its formulation. As opposed to being constant, the fraction is explicitly modeled using a...

  • A Numerical Study of the Impacts of Dry Air on Tropical Cyclone Formation: A Development Case and a Nondevelopment Case. Fritz, Cody; Wang, Zhuo // Journal of the Atmospheric Sciences;Jan2013, Vol. 70 Issue 1, p91 

    The impacts of dry air on tropical cyclone formation are examined in the numerical model simulations of ex-Gaston (2010) and pre-Fay (2008). The former, a remnant low downgraded from a short-lived tropical cyclone, can be regarded as a nondeveloping system because it failed to redevelop, and the...

  • The Initiation of Moist Convection at the Dryline: Forecasting Issues from a Case Study Perspective. Ziegler, Conrad L.; Rasmussen, Erik N. // Weather & Forecasting;Dec98, Vol. 13 Issue 4, p1106 

    The processes that force the initiation of deep convection along the dryline are inferred from special mesoscale observations obtained during the 1991 Central Oklahoma Profiler Studies project, the Verification of the Origins of Rotation in Tornadoes Experiment 1994 (VORTEX-94), and the...

  • Mean Profiles of Moisture Fluxes in Snow-Filled Boundary Layers. Kristovich, David A. R.; Braham, Jr, Roscoe R. // Boundary-Layer Meteorology;May1998, Vol. 87 Issue 2, p195 

    Profiles of moisture fluxes have been examined for convective boundary layers containing clouds and snow, using data derived from aircraft measurements taken on four dates during the 1983/1984 University of Chicago lake-effect snow project. Flux profiles were derived from vertical stacks of...


Read the Article


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

Try another library?
Sign out of this library

Other Topics