290 likes | 308 Views
Introduction to Lightning Data. 2009 Experimental Warning Program. Outline. Storm Electrification Background Lightning Mapping Array Products in AWIPS and Google Earth Feedback & Surveys. +. –. Storm Electrification (Noninductive Charging). Simplified storm charge structure.
E N D
Introduction to Lightning Data 2009 Experimental Warning Program
Outline • Storm Electrification Background • Lightning Mapping Array • Products in AWIPS and Google Earth • Feedback & Surveys EWP Spring Experiment 2009
+ – Storm Electrification (Noninductive Charging)
Simplified storm charge structure • Dipole / Tripole : Normal / Inverted
Simplified storm charge structure • In-cloud and Cloud-to-ground lightning: *Disclaimer: In reality, storm charge can be much more complex than a tripole
Lightning and Updraft • Total lightning activity (In-cloud [IC] and cloud-to-ground [CG]; dominated by IC) is a natural precursor to microbursts and other severe weather at the ground • updraft size and strength noninductive charging: • (updraft drives storm electrification) • IC activity will precede CG activity; areas of greatest IC activity represent areas of greatest charge replenishment: at (or just downshear from) the updraft core NSSL Laboratory Review February 17-19, 2009
Lightning Mapping Array (LMA) • Detects VHF radiation emitted as lightning propagates • Time-of-arrival technique to determine x,y, z, and t of VHF source point • We use a minimum detection by 6 stations to include a point (reduces noise) • Accuracy: x = 6-12 m; z = 20-30 m
NLDN vs. LMA *NLDN: CG flashes Ground strike location only Gives polarity of flash *LMA: Maps points along flash IC and CG flashes Highest density of points corresponds with highest density of lightning NSSL Laboratory Review February 17-19, 2009
NLDN vs. LMA *NLDN: CG flashes Ground strike location only Gives polarity of flash *LMA: Maps points along flash IC and CG flashes Highest density of points corresponds with highest density of lightning NSSL Laboratory Review February 17-19, 2009
Animation of a lightning flash • VHF source points (3d) NSSL Laboratory Review February 17-19, 2009
Animation of a lightning flash • VHF source points (3d) NSSL Laboratory Review February 17-19, 2009
Oklahoma LMA • OKLMA • 11 stations; • spaced 10-22 km apart • First operational: May 1999 • Since 2001-2002
Washington D.C. LMA • DC LMA • 10 Stations • Operational since 2007
Northern Alabama LMA • NALMA • 10 stations • operational since Nov. 2001 NSSL Laboratory Review February 17-19, 2009
Benefits of lightning data From Williams et al (1999) • Increased Situational Awareness, Confidence Limits • Rapid Update- Potential for increased lead time, reduced FAR • Identification of intensifying and weakening storms, potential severe storms, microburst wind shears, CG threat area • Fills gaps in radar coverage (e.g., edge of radar coverage)
Linkage between storm strength and lightning • **Trends of total lightning (not just CG lightning) can give us clues to when a storm is increasing or decreasing in intensity** • (via noninductive charging) Total lightning CG only Courtesy Dennis Buechler
Data in Google Earth • Will be examining trends of lightning sources for each cluster in GE. • Flash “Jump” often precedes severe weather at the ground • Keep in mind: • “Jump” may not always be associated with severe weather • Can see artifacts of storms moving from edge of network to the center (increased detection efficiency)
Global Lightning Mapper (GOES-R) proxy data NSSL Laboratory Review February 17-19, 2009
GLM proxy (AWIPS) NSSL Laboratory Review February 17-19, 2009
Surveys and Feedback • Following an archive or real-time event forecasters will complete a survey evaluating the use of lightning data during that particular event. • Additional open feedback (comments, suggestions, criticisms) will occur during an event through the online EWP blog: • https://secure.nssl.noaa.gov/projects/ewp/blog/ NSSL Laboratory Review February 17-19, 2009
Questions: • Contact: Kristin.Kuhlman@noaa.gov • Experimental Warning Program: • http://ewp.nssl.noaa.gov/ • Real-time LMA: • http://lightning.nmt.edu/oklma/ • http://branch.nsstc.nasa.gov/cgi-bin/LMAdp.pl • http://branch.nsstc.nasa.gov/PUBLIC/DCLMA NSSL Laboratory Review February 17-19, 2009
Linkage between storm strength and lightning • **Trends of total lightning (not just CG lightning) can give us clues to when a storm is increasing or decreasing in intensity** (via noninductive charging)