Search Results

You are looking at 1 - 10 of 29,686 items for :

  • Convective-scale processes x
  • All content x
Clear All
B. A. White, A. M. Buchanan, C. E. Birch, P. Stier, and K. J. Pearson

al. 1989 ; Nesbitt et al. 2000 ). Additionally, the diurnal cycle of convection has an important role in the triggering and control of these systems. However, the processes responsible for convective organization, and the interactions between spatiotemporal scales of convection, are still poorly understood, and global and limited-area models (LAMs) often fail to represent organized convection. Idealized simulations performed over fixed sea surface temperatures (SST) in radiative–convective

Open access
Gerald A. Meehl and Aixue Hu

1. Introduction Droughts on the interannual time scale are a naturally occurring feature of the climate system, and, for North America, have been associated with sea surface temperature (SST) and convective heating anomalies in the tropical Pacific Ocean ( Trenberth and Branstator 1992 ). Droughts associated with Indian monsoon failure, also occurring on the interannual time scale, are similarly well-documented characteristics of climate in the south Asian region and are associated with SST

Full access
Siriluk Chumchean, Ashish Sharma, and Alan Seed

reflectivity resulting from increases in observation volume with range by using the scale transformation function. The improvements in the Z – R conversion process consist of classifying each instantaneous reflectivity value into either convective or stratiform types, and using climatological Z – R relations for each rainfall type to convert the instantaneous reflectivity into an instantaneous rainfall rate. This is then followed by an accumulation of the instantaneous rainfall data into hourly radar

Full access
Christopher A. Davis

large-scale structures. We envision that both synoptic-scale control and upscale organization from deep convection are important for producing a strong, moist, midtropospheric mesoscale vortex that is the hallmark of the precursor to genesis. Once the pre-TC vortex forms in the idealized model, we believe that the processes simulated henceforth are relevant to understanding genesis in the real atmosphere and, in particular, to answering the conundrum about the thermal structure and intensity of

Full access
Danhong Fu and Xueliang Guo

merging processes The sensitivity test is also performed without initial large-scale environmental winds in the model. The results displayed in Figs. 15 and 16 show that without large-scale environmental winds the initial convection has much weaker intensity. At 1515 BST ( Fig. 15a ), C WA and C WB have maximum echoes of only 15 and 5 dB Z , respectively. The perturbation pressure field at 4 km shows that C WA is located at the higher perturbation pressure area while C WB is located at the

Full access
Anthony C. Didlake Jr. and Robert A. Houze Jr.

manifestation of waves (inertia–gravity waves or vortex–Rossby waves) emanating from the storm center and propagating outward (e.g., Kurihara 1976 ; Montgomery and Kallenbach 1997 ). In the case of a principal rainband of the type studied here, convective-scale processes may also play a role in its growth and/or sustenance. Several studies have determined that the upwind portion of rainbands consists of active convection, while the downwind portion consists of decaying convective cells and stratiform

Full access
Julia Jeworrek, Gregory West, and Roland Stull

, resolution, and focus ( Coiffier 2011 ). The dynamical core solves the governing equations on a discrete grid, neglecting terms of approximated low significance ( Warner 2010 ). Unresolved processes, such as radiation, deep and shallow cumulus convection, cloud microphysics, precipitation, and turbulence, affect the resolved scales through a parameterized representation in NWP ( Stensrud 2007 ; Warner 2010 ; Coiffier 2011 ; Stull 2017 ). General circulation models (GCM) simulate the atmosphere often

Open access
A. Protat, S. Rauniyar, V. V. Kumar, and J. W. Strapp

oceanic and tropical continental cells, respectively. This result implies at least that oceanic convective cells are potentially more conducive to favorable HIWC–low reflectivity conditions than continental cells. In this paper, we derive a regional-scale climatology of selected properties of convective rainfall for the 15 January–15 March (JFM) period from the Tropical Rainfall Measuring Mission (TRMM; Huffman et al. 2007 ) to optimize the use of the 150 HAIC/HIWC campaign flight hours, and to

Full access
Robert J. Trapp and Joseph M. Woznicki

, ×10 −3 ), and THTA, HADV, and υ − V (m s −1 , ×10 −3 ) at z = 0.25 km, and ( x = 51, y = 86 km). These are from the 19 May 2013 simulation. This rapid cooling from horizontal advection might seem surprising, given that in deep continental convection, initial destabilization as well as recovery is generally considered to involve synoptic-scale processes, and thus be slow relative to the stabilization (e.g., Emanuel 1994 ). For example, let us simplify Eq. (1) as where Θ is the potential

Full access
Robert F. Rogers, Paul D. Reasor, and Jun A. Zhang

understanding these processes across the spatiotemporal range of scales, ranging from the environmental scale down to the microphysical scale. Some skill at predicting RI has been attained by using algorithms that rely primarily on environmental-scale parameters ( Kaplan et al. 2010 ). However, there is much room for improvement, suggesting that processes operating on scales smaller than the environmental scale also contribute to intensity change ( Hendricks et al. 2010 ). Vortex, convective, and boundary

Full access