scholarly journals Cloud‐resolving model intercomparison of an MC3E squall line case: Part I—Convective updrafts

2017 ◽  
Vol 122 (17) ◽  
pp. 9351-9378 ◽  
Author(s):  
Jiwen Fan ◽  
Bin Han ◽  
Adam Varble ◽  
Hugh Morrison ◽  
Kirk North ◽  
...  
Keyword(s):  
Squall Line ◽  
Model Intercomparison ◽  
Cloud Resolving Model ◽  
Case Part

scholarly journals Cloud‐Resolving Model Intercomparison of an MC3E Squall Line Case: Part II. Stratiform Precipitation Properties

2019 ◽  
Vol 124 (2) ◽  
pp. 1090-1117 ◽  
Author(s):  
Bin Han ◽  
Jiwen Fan ◽  
Adam Varble ◽  
Hugh Morrison ◽  
Christopher R. Williams ◽  
...  
Keyword(s):  
Squall Line ◽  
Model Intercomparison ◽  
Stratiform Precipitation ◽  
Cloud Resolving Model ◽  
Case Part

scholarly journals Sensitivity of a Cloud-Resolving Model to Bulk and Explicit Bin Microphysical Schemes. Part I: Comparisons

2009 ◽  
Vol 66 (1) ◽  
pp. 3-21 ◽  
Author(s):  
Xiaowen Li ◽  
Wei-Kuo Tao ◽  
Alexander P. Khain ◽  
Joanne Simpson ◽  
Daniel E. Johnson
Keyword(s):  
Cloud Microphysics ◽  
Squall Line ◽  
Mature Stage ◽  
High Temporal Resolution ◽  
Stratiform Region ◽  
Storm Flow ◽  
Cloud Resolving Model ◽  
Storm Dynamics ◽  
Convective Cells ◽  
Heating Profiles

Abstract A two-dimensional cloud-resolving model is used to study the sensitivities of two microphysical schemes, a bulk scheme and an explicit spectral bin scheme, in simulating a midlatitude summertime squall line [Preliminary Regional Experiment for Storm-Scale Operational and Research Meteorology (PRE-STORM), 10–11 June 1985]. In this first part of a two-part paper, the developing and mature stages of simulated storms are compared in detail. Some variables observed during the field campaign are also presented for validation. It is found that both schemes agree well with each other, and also with published observations and retrievals, in terms of storm structures and evolution, average storm flow patterns, pressure and temperature perturbations, and total heating profiles. The bin scheme is able to produce a much more extensive and homogeneous stratiform region, which compares better with observations. However, instantaneous fields and high temporal resolution analyses show distinct characteristics in the two simulations. During the mature stage, the bulk simulation produces a multicell storm with convective cells embedded in its stratiform region. Its leading convection also shows a distinct life cycle (strong evolution). In contrast, the bin simulation produces a unicell storm with little temporal variation in its leading cell regeneration (weak evolution). More detailed, high-resolution observations are needed to validate and, perhaps, generalize these model results. Interactions between the cloud microphysics and storm dynamics that produce the sensitivities described here are discussed in detail in Part II of this paper.

The Interaction of Simulated Squall Lines with Idealized Mountain Ridges

2006 ◽  
Vol 134 (7) ◽  
pp. 1919-1941 ◽  
Author(s):  
Jeffrey Frame ◽  
Paul Markowski
Keyword(s):  
Squall Line ◽  
Cold Pool ◽  
Cold Air ◽  
Advanced Regional Prediction System ◽  
Topographic Features ◽  
Squall Lines ◽  
Regional Prediction ◽  
Cloud Resolving Model ◽  
Orographic Enhancement ◽  
Flow Transitions

Abstract Numerical simulations of squall lines traversing sinusoidal mountain ridges are performed using the Advanced Regional Prediction System cloud-resolving model. Precipitation and updraft strength are enhanced through orographic ascent as a squall line approaches a ridge. The simulated squall line then weakens as it descends the ridge because some of the cold pool is blocked by the terrain, resulting in less lift along the gust front and weaker convective cells. The flow within the cold pool accelerates slightly and the depth of the cold air decreases owing to upstream blocking, transitioning the flow in the cold pool head from subcritical to supercritical, then back to subcritical at the bottom of the ridge. A hydraulic jump forms when the flow transitions the second time, enabling the development of a new convective line downwind of the mountain. These new updrafts grow and eventually replace the older updrafts that weakened during descent. This process results in the discrete propagation of a squall line just downstream of a ridge, resulting in the formation of rain shadows downstream from topographic features. Discrete propagation only occurs if a ridge is of sufficient height, however. This replacement process repeats itself if a squall line encounters multiple ridges. The risk of damaging winds from a squall line is greater on the lee side of ridges and on the top of high ridges. These terrain-forced intensity fluctuations increase with mountain height, because the higher terrain permits even less cold air to flow over it. A wider ridge results in a more gradual orographic enhancement and downslope-induced weakening.

scholarly journals Evaluation of cloud-resolving model intercomparison simulations using TWP-ICE observations: Precipitation and cloud structure

2011 ◽  
Vol 116 (D12) ◽  
Author(s):  
Adam Varble ◽  
Ann M. Fridlind ◽  
Edward J. Zipser ◽  
Andrew S. Ackerman ◽  
Jean-Pierre Chaboureau ◽  
...  
Keyword(s):  
Model Intercomparison ◽  
Cloud Structure ◽  
Cloud Resolving Model

A gcss model intercomparison for a tropical squall line observed during toga-coare. I: Cloud-resolving models

2000 ◽  
Vol 126 (564) ◽  
pp. 823-863 ◽  
Author(s):  
J.-L. Redelsperger ◽  
P. R. A. Brown ◽  
F. Guichard ◽  
C. How ◽  
M. Kawasima ◽  
...  
Keyword(s):  
Squall Line ◽  
Model Intercomparison ◽  
Toga Coare

scholarly journals Relating Convection to GCM Grid-Scale Fields Using Cloud-Resolving Model Simulation of a Squall Line Observed during MC3E Field Experiment

Atmosphere ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 523 ◽  
Author(s):  
Rui Cheng ◽  
Guang J. Zhang
Keyword(s):  
Vertical Velocity ◽  
Lead Time ◽  
Large Scale ◽  
The United States ◽  
Moisture Convergence ◽  
Coarse Grained ◽  
Convective Precipitation ◽  
Squall Line ◽  
Maximum Precipitation ◽  
Cloud Resolving Model

In this study, a WRF (Weather Research and Forecasting) model is used as a cloud-resolving model to simulate a squall line observed on 20 May 2011 in the Southern Great Plains (SGP) of the United States. The model output is then used to examine the relationships between convective precipitation and coarse-grained variables averaged over a range of subdomain sizes equivalent to various global climate model horizontal resolutions. The objective is to determine to what extent convection within the subdomains can be related to these “large-scale” variables, thus that they can potentially serve as closure in convective parameterization. Results show that convective precipitation is well correlated with the vertical velocity at 500 hPa, column integrated moisture convergence and CAPE change due to large-scale advective forcing (dCAPE) for various subdomain sizes, but the correlation decreases with decreasing subdomain size. dCAPE leads convective precipitation for all subdomain sizes examined; however, the lead time decreases with decreasing subdomain size. Moisture convergence leads convective precipitation for subdomain sizes greater than 32 km but has no lead time for smaller subdomain sizes. Mid-tropospheric vertical velocity has no lead time or slightly lags convective precipitation. The lead/lag composite analysis with respect to maximum precipitation time indicates that peaks of large-scale variables increase with decreasing subdomain size. The peaks of 500 hPa vertical velocity and column integrated moisture convergence occur at the same time as maximum precipitation, but maximum dCAPE leads maximum precipitation by twelve minutes.

Correction to “Evaluation of cloud-resolving model intercomparison simulations using TWP-ICE observations: Precipitation and cloud structure”

2012 ◽  
Vol 117 (D16) ◽  
pp. n/a-n/a
Author(s):  
Adam Varble ◽  
Ann M. Fridlind ◽  
Edward J. Zipser ◽  
Andrew S. Ackerman ◽  
Jean-Pierre Chaboureau ◽  
...  
Keyword(s):  
Model Intercomparison ◽  
Cloud Structure ◽  
Cloud Resolving Model
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