NSSL Research: Lightning
NSSL researchers have studied lightning for almost half a century and continue learn more about lightning structure and behavior, and ways to use lightning data to improve severe weather forecasts and warnings.
Lightning Field Equipment
Mobile Ballooning Facility
NSSL researchers modified a 15-passenger van by mounting a Cross-Chain Loran Atmospheric Sounding System inside, and invented a high-wind launch device for releasing helium-filled balloons in very high winds. This pioneering capability allowed NSSL to collect data in the vicinity of tornadoes and drylines, gathering critically needed observations in the near-storm environment of thunderstorms. In addition, these mobile labs and ballooning systems provided the first vertical profiles of electric fields inside a thunderstorm leading to a new conceptual model of electrical structures within convective storms.
The NSSL Field Observing Facilities and Support group (FOFS) built a special balloon-borne instrument called a PArticle Size, Image, and Velocity probe (PASIV), designed to capture high-definition images of water and ice particles as it is launched into, and rises up through a thunderstorm. The instrument is flown as part of a “train” of other instruments connected one after another to a balloon. These other instruments measure electrical field strength and direction, and other important atmospheric variables such as temperature, dewpoint, pressure and winds. Data from these systems helps researchers understand the relationships between the many macro and microphysical properties in thunderstorms.
Lightning Field Projects
The Deep Convective Clouds and Chemistry (DC3) field experiment (2012) used aircraft and ground-based instruments to investigate thunderstorms. These data will help us understand how thunderstorm updrafts carry electrically charged particles, water vapor and other chemicals to other parts of the atmosphere.
TELEX, the Thunderstorm Electrification and Lightning EXperiment (2004-2005) studied how lighting and other electrical storm properties are dependent on storm structure, updrafts, and precipitation.
STEPS (2000), the Severe Thunderstorm Electrification and Precipitation Study, made meteorological and electrical observations of supercell thunderstorms
MEaPRS, the MCS Electrification and Polarimetric Radar Study (1998), investigated polarization radar signatures and electrification processes in Mesoscale Convective Systems.
Oklahoma lightning Mapping Array (OKLMA)
The Oklahoma Lightning Mapping Array (OKLMA) provides three-dimensional mapping of lightning channel segments over Oklahoma. Thousands of points can be mapped for an individual lightning flash to reveal its location and the development of its structure. We are investigating how lightning characteristics relate to updrafts, precipitation and severe storm processes, and how to use lightning data in weather forecast models.
We study lightning mapping data to learn how changes in lightning behavior can be associated with different types of storms. Lightning mapping has shown that some supercell thunderstorms have “lightning holes” where updrafts are located and precipitation is scarce, just before a storm becomes severe. This information could alert forecasters about developing severe conditions.
We have shown that rapid increases in total lightning activity are often observed tens of minutes in advance of severe weather occurring at the ground. These rapid increases in lightning activity have been termed “lightning jumps.” The goal of our study is to develop operationally applicable lightning jump algorithm that can be used with either total lightning observations made from the ground, or in the near future from space using the Geostationary Operational Environmental Satellite Series R (GOES-R) Geostationary Lightning Mapper.
Satellite Lightning Detection
The Geostationary Operational Environmental Satellite-R Series (GOES-R) is the next generation of geostationary weather satellites, scheduled to launch in 2015. This satellite will be equipped with a Geostationary Lightning Mapper (GLM) that will detect both cloud-to-ground and inter-cloud lightning. This will help severe weather forecasters identify rapidly intensifying thunderstorms so they can issue accurate and timely severe thunderstorm and tornado warnings.
NSSL partners in the GOES-R Proving Ground, a unique opportunity to interact with and study new products available from GOES-R satellite. The GOES-R PG environment provides forecasters with the knowledge, training and experience needed to effectively use the products in day to day operations once they become available.
Pseudo-Geostationary Lightning Mapper (PGLM) is the primary lightning training tool for the GOES-R program in preparation for the launch of the Geostationary Lighting Mapper (GLM). It uses total lightning data from three Lightning Mapping Array (LMA) networks and the Lightning Detection and Ranging network that detects VHF radiation from lightning charges. The flashes are sorted, and a Flash Extent Density product is created.
Predicting Lightning Threats
Collaborators are using NSSL's research forecast model to ingest PGLM data for very short-range (0 to 60 minute) forecasts of severe weather events. Forecast models that are able to ingest Doppler radar, lightning or satellite data of thunderstorms improve predictions of thunderstorms and associated severe weather.
In the NOAA Hazardous Weather Testbed (HWT), NSSL partners with the SPC and NWS to develop, test and evaluate severe weather forecast and warning techniques for the entire United States. The cornerstone of the HWT is the Spring Experiment held each year during the active spring severe weather season. The exchange provides forecasters with a first-hand look at the latest research concepts and products, while research scientists gain valuable understanding of the challenges, needs and constraints of front-line forecasters.
NSSL/CIMMS scientists simulated realistic cloud-to-ground lightning flashes for the first time using a 3-D cloud model that generates complex precipitation such as graupel (soft hail), which is known to affect lightning production. They also use the model to make comparisons between simulated and observed flashes, and analyze lightning more closely.
Storm Electricity Research Partnerships
NSSL works with NASA's Short-term Prediction Research and Transition (SPoRT), the Cooperative Institute for Meteorological Satellite Studies (CIMSS), New Mexico Institute of Mining and Technology (NMIMT), the Cooperative Institute for Research in the Atmosphere (CIRA) and the NOAA National Environmental Satellite, Data and Information Center (NESDIS), in addition to working closely with the NOAA Storm Prediction Center (SPC) and the NOAA National Weather Service (NWS).
NSSL researchers actively promote lightning safety education. They designed posters about the dangers of taking shelter under trees, and more than 16,000 copies were distributed to teachers, NWS staff, and others. NSSL researchers provided valuable input to the NCAA Committee on Competitive Safeguards and Medical Aspects of Sports as they developed guidelines for lightning safety at NCAA sporting events. They also helped create a position statement regarding lightning safety for athletics and recreation for the National Athletic Trainers' Association. NSSL researchers have studied how close is “too close” for lightning. They found that 80% of the next lightning strikes in a storm are within 2 to 3 miles of each other in certain weather conditions in Florida, but more typically lightning strikes are about 6 miles from each other. Their research was incorporated into a paper on updated recommendations for lightning safety.
The Electrical Nature of Storms
NSSL's Don MacGorman and Dave Rust wrote The Electrical Nature of Storms, a textbook discussion of atmospheric electricity and the electrical processes that occur in storms.
NSSL scientists have reported on the climatologies of lightning in different states including AZ, FL, GA, SC, NM, KS, CO, and OK.
NSSL worked with the NWS to carefully evaluate the performance on the WSR-88D lightning protection system and make recommendations for improvement. Part of the process included creating a 3-D computer simulation of cloud-to-ground lightning striking a radar antenna tower.