Earth System Science Center and Department of Atmospheric Science at The University of Alabama in Huntsville

Next Seminar

Coming up next:

Wednesday, October 15, 2014

12:45 pm;   Room 4065 

Methods to Diagnose Convective Clouds Using 1-Min Rapid Scan Observations from GOES

John Mecikalski

UAH/ASD

 

Geostationary satellites offer considerable information on cloud development and of pre-storm cloud fields that can be used within so-called convective initiation (CI) nowcasting algorithms that forecast thunderstorm development in the 0-1 hour time frame from present.  Significant research has occurred over the past decade on how to optimally use GOES satellite information for such CI nowcasting, with applications now having expanded to predict first-flash lightning and storm intensity, up to 0-90 min into the future.

A main conclusion of this analysis is that the 1-min observations capture two specific cumulus cloud growth periods, less rapid cloud growth between the level of free convection and the freezing level, followed by more rapid growth shortly after cloud-top glaciation (as denoted by 3.9 µm reflectance falling below 9%).  Very high correlation is found between estimated vertical motion (w) and the amount of convective available potential energy (CAPE) realized on a per-level basis as cloud grow, which affords an ability to retrieve CAPE profiles from w estimates in a “single channel sounding” methodology.


Last week:

Wednesday, October 8, 2014

12:45 pm;   Room 4065

ATS 781 Student Seminar Presentations



12:45pm — 1:05pm

Ryan Wade, PhD Candidate

“The Ontario Winter Lake-effect Systems (OWLeS) Field Project:

Preliminary Radar & Profiling Observations of Mesoscale Convective Snow Systems”

Faculty Advisor:  Kevin Knupp

The purpose of the OWLeS project is to better understand the atmospheric conditions and controlling mechanisms responsible for extreme snow accumulations downwind of the Great Lakes during winter.  An overview of the OWLeS field campaign, impressive radar examples, and a discussion of the significance of these radar structures will be presented.

1:05pm — 1:25pm
Andrew White, PhD Candidate

“Improving Cloud Simulation in Weather Research and

Forecasting (WRF) Through Assimilation of GOES Satellite Observations”
Faculty Advisor:  Arastoo Biazar

 

Unfortunately, numerical meteorological models fall short of accurately producing clouds at the correct time and location with respect to observations.  Knowing these disagreement areas, a method has been developed to analytically solve for vertical velocities necessary to produce or dissipate clouds within the model system.  Preliminary results of this method will be presented.

1:25pm — 1:45pm
Kelcy Brunner, MS Candidate

“Phenomenology of Intracloud Lightning Leaders”

Faculty Advisor:  Philip Bitzer

This study seeks to clarify and examine the characteristics of intracloud (IC) lightning leaders.  The relationships emerging between electric fields, radiation field pulses, and optical emissions are used to outline energetic characteristics of IC leaders and define the active portion of the IC lightning flash spatiotemporally.

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