The Lightning Team
A Lightning Primer
File Cabinet and Bookshelf
Global Lightning Image
Global lightning strikes from January 1998 to present day from the NASA/MSFC Lightning Imaging Sensor
Lightning Imaging Sensor (LIS) Overview
The Lightning Imaging Sensor (LIS), is a space based instrument used to detect the distribution
and variability of total lightning (cloud-to-cloud, intracloud, and cloud-to-ground lightning)
that occurs in the tropical regions of the globe. The LIS is a science instrument aboard the TRMM Observatory, which was launched on
28 November 1997 from the Tanegashima
Space Center in Japan.
This lightning sensor consists of a staring imager which is optimized to locate and detect
lightning with storm-scale resolution (4 to 7 km) over a large region (600 x 600 km) of the
Earth's surface. The TRMM Satellite travels a distance of 7 kilometers every second (nearly
16,000 miles per hour) as it orbits the Earth, thus allowing the LIS to observe a point on
the Earth or a cloud for almost 90 seconds as it passes overhead. Despite the brief duration
of an observation, it is long enough to estimate the flashing rate of most storms. The instrument
records the time of occurrence, measures the radiant energy, and determines the location of
lightning events within its field-of-view.
This calibrated lightning sensor uses a wide field-of-view expanded optics lens with a narrow-band
filter in conjunction with a high speed charge-coupled device detection array. A Real Time Event
Processor (RTEP) inside the electronics unit is used to determine when a lightning flash occurs,
even in the presence of bright sunlit clouds.
Weak lightning signals that occur during the day are hard to detect because of background
illumination. The RTEP will remove the background signal, thus enabling the system to detect
weak lightning and achieve a 90% detection efficiency.
Data from the Lightning Imaging Sensor is being used to study mesoscale phenomena such as
storm convection, dynamics, and microphysics. These will be related to global rates and
amounts and distribution of convective precipitation, as well as to the release and transport
of latent heat, which are all influenced by global scale processes.
The LIS instrument was designed by the GHCC Lightning Team and
was manufactured at the Marshall Space Flight Center in Huntsville, Alabama. LIS will contribute significantly to
several TRMM mission objectives by providing a global lightning and thunderstorm climatology
from which changes (even subtle temperature variations) might be easily detected.
The LIS instrument is part of the Tropical
Rainfall Measuring Mission (TRMM). TRMM is a joint mission between NASA and the JAXA (formerly NASDA) designed to monitor and study tropical rainfall and
the associated release of energy that helps to power the global atmospheric circulation shaping
both weather and climate around the globe.
LIS EOS Mission Objectives
■ Cloud Characterization
■ Hydrologic Cycle Studies
■ Storm Convection
■ Microphysics and Dynamics
■ Seasonal and Interannual Variability of Thunderstorms
Example Lightning Observations
The image below depicts some lightning activity that was observed by the Lightning Imaging
Sensor (LIS) on its first day of operation (November 30,1997). The thunderstorms that produced
this lightning activity were located near the eastern coast of Australia.
An examination of this example image demonstrates that not all clouds produce lightning. Due
to the relationship between lightning and updraft velocity, lightning activity can be used to
identify locations of strong upward convection.
Three months of LIS data were combined to form a "lightning climatology map", shown below.
This period corresponds with the summer season in the Southern Hemisphere and the winter
season in the Northern Hemisphere.
The orbit of the TRMM Observatory has an inclination of 35 degrees. As a result, the LIS
instrument, which is part of the TRMM Observatory, can observe lightning activity where it
occurs the most: between 35 degrees South latitude and 35 degrees North latitude.
- Christian, H. J., R. J. Blakeslee, S. J. Goodman, D. A. Mach, M. F.
Stewart, D. E. Buechler, W. J. Koshak, J. M. Hall, W. L. Boeck, K. T. Driscoll, and D. J.
Boccippio, "The Lightning Imaging Sensor,"
Proceedings of the 11th International Conference on Atmospheric Electricity, Guntersville,
Alabama, June 7-11, 1999, pp. 746-749.
- Christian, H. J., "Optical Detection of Lightning from Space," Proceedings
of the 11th International Conference on Atmospheric Electricity, Guntersville, Alabama,
June 7-11, 1999, pp. 715-718.
■ Browse LIS Data
■ Order LIS Data using HyDRO
■ Optical Transient Detector
■ Tropical Rainfall Measuring Mission
■ Algorithm Theoretical Basis Document - (PDF Document)