GOES Infrared and Reflectance 0-1 hour Lightning Initiation Indicators: Development and Initial Testing within a Convective Nowcasting System
Abstract
Within cumulus cloud fields that develop in conditionally unstable air masses, only a fraction of the cumuli may eventually develop into deep convection. Identifying which of these convective clouds most likely to generate lightning often starts with little more than a qualitative visual satellite analysis. The goal of this study is to identify the observed satellite infrared (IR) signatures associated with growing cumulus clouds prior to the first lightning strike, so-called lightning initiation (LI). This study quantifies the behavior of ten Geostationary Operational Environmental Satellite (GOES-12) IR interest fields in the 1-hour in advance of LI. A total of 172 lightning-producing storms that occurred during the 2009 convective season are manually tracked and studied over four regions: Northern Alabama, Central Oklahoma, the Kennedy Space Center and Washington D.C. Four-dimensional and cloud-to-ground lightning array data provide a total cloud lightning picture (in-cloud, cloud-to-cloud, cloud-to-air, cloud-to-ground) and thus precise LI points for each storm in both time and space. Statistical significance tests are conducted on observed trends for each of the ten LI fields to determine the unique information each field provides in terms of behavior prior to LI. Eight out of ten LI fields exhibited useful information at least 15 min in advance of LI, with 35 min being the average. Statistical tests on these eight fields are compared for separate large geographical areas. IR temperature thresholds are then determined as an outcome, which may be valuable when implementing a LI prediction algorithm into real-time satellite-based systems. The key LI indicators from GOES IR data (as well as 3.9 μm reflectance) will be presented. Beginning in 2010, the feasibility of using the satellite-based LI indicators found in the above analysis to forecast first lightning will be assessed within the Federal Aviation Administration’s (FAA) CoSPA nowcasting system. The goal is to provide advanced warning of cloud-to-ground lightning to improve ground airport operations across the Gulf of Mexico region. Preliminary results will be presented on how the GOES LI indicators performed towards nowcasting LI, and what improvements to the current system are being considered.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFMAE21A0259M
- Keywords:
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- 3304 ATMOSPHERIC PROCESSES / Atmospheric electricity;
- 3314 ATMOSPHERIC PROCESSES / Convective processes;
- 3324 ATMOSPHERIC PROCESSES / Lightning;
- 3360 ATMOSPHERIC PROCESSES / Remote sensing