Featured Research

from universities, journals, and other organizations

Surprise! Lightning Has Big Effect On Atmospheric Chemistry

Date:
March 20, 2003
Source:
NASA/Goddard Space Flight Center
Summary:
Scientists were surprised to learn summer lightning over the U.S. significantly increases regional ozone and other gases that affect air chemistry 3 to 8 miles above Earth's surface.The amounts of ozone and nitrogen oxides created by lightning surpass those generated by human Scientists were surprised to learn summer lightning over the U.S. significantly increases regional ozone and other gases that affect air chemistry 3 to 8 miles above Earth's surface. The amounts of ozone and nitrogen oxides created by lightning surpass those generated by human activities in that level of the atmosphere.

Scientists were surprised to learn summer lightning over the U.S. significantly increases regional ozone and other gases that affect air chemistry 3 to 8 miles above Earth's surface. The amounts of ozone and nitrogen oxides created by lightning surpass those generated by human activities in that level of the atmosphere.

Typically over the U.S., fossil fuel burning is the main cause of nitrogen oxides (NOx), which lead to the formation of ozone near the Earth's surface. However, above the Earth's surface in the free troposphere (3-8 miles high), during the summer months, lightning activity increases NOx by as much as 90 percent and ozone by more than 30 percent.

Renyi Zhang of Texas A&M University, lead author of a paper that recently appeared in the Proceedings of the National Academy of Sciences, suggests lightning has distinct impacts on air chemistry over the U.S. Human activities dominate the creation of these gases near the Earth's surface, but lightning plays a bigger role in the free troposphere.

Depending on where ozone resides, it can protect or harm life on Earth. Most ozone resides in the stratosphere (a layer of atmosphere between 8 and 25 miles high), where it shields life on Earth from the sun's harmful ultraviolet radiation. At the surface, ozone is a harmful pollutant that causes damage to lung tissue and plants. In the tropopause (surface to 8 miles high) ozone also is a radiatively active gas that affects climate.

About 77 million lightning bolts annually strike the U.S. Measurements before and after lightning strikes have confirmed the generation of nitrogen oxides in the atmosphere.

"Ironically, over the United States lightning accounts for only about 5 percent of the total U.S. nitrogen oxide annual emissions and about 14 percent of the total emissions in July," said Zhang. Although the largest source of NOx over the U.S. is fossil fuel burning, lightning still plays a dominant role in influencing the regional air chemistry.

The explanation is NOx from fossil fuel burning is released close to the Earth's surface and is consumed rapidly by chemical reactions before being transported upward. Lightning, however, directly releases NOx throughout the entire troposphere. The lightening source over North America for NOx is sufficiently large, so that it has implications on free troposphere NOx over other parts of the world, most notably Europe, which is downwind of the U.S., given the prevailing westerly flow in the Northern Hemisphere mid-latitudes.

NASA funded this research, because one mission of NASA's Earth Science Enterprise is to assess and understand the primary causes of changes in Earth's system, including man-made and natural causes.

The objective of Zhang's work is to assess the impact of how the U.S. human-induced (mainly fossil fuel burning) and natural (lightning) sources contribute to air pollution in the lower and upper troposphere. He collaborated with Dr. Xuexi Tie of the National Center for Atmospheric Research (NCAR).

Zhang used lightning measurements from the ground-based National Lightning Detection Network and the Optical Transient Detector (OTD) instrument to obtain the number of lightning flashes over the U.S. The OTD, aboard the Microlab satellite, is the world's first space-based sensor capable of detecting and locating lightning events during day and night, with high detection efficiency.

This research was partially supported by NASA's New Investigator Program in Earth Science and the Texas Air Research Center. The National Science Foundation supports NCAR.


Story Source:

The above story is based on materials provided by NASA/Goddard Space Flight Center. Note: Materials may be edited for content and length.


Cite This Page:

NASA/Goddard Space Flight Center. "Surprise! Lightning Has Big Effect On Atmospheric Chemistry." ScienceDaily. ScienceDaily, 20 March 2003. <www.sciencedaily.com/releases/2003/03/030320073502.htm>.
NASA/Goddard Space Flight Center. (2003, March 20). Surprise! Lightning Has Big Effect On Atmospheric Chemistry. ScienceDaily. Retrieved August 28, 2014 from www.sciencedaily.com/releases/2003/03/030320073502.htm
NASA/Goddard Space Flight Center. "Surprise! Lightning Has Big Effect On Atmospheric Chemistry." ScienceDaily. www.sciencedaily.com/releases/2003/03/030320073502.htm (accessed August 28, 2014).

Share This




More Earth & Climate News

Thursday, August 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Scientists Have Figured Out Why Rocks Move In Death Valley

Scientists Have Figured Out Why Rocks Move In Death Valley

Newsy (Aug. 28, 2014) The mystery of the moving rocks in Death Valley, California, has finally been solved. Scientists are pointing to a combo of water, ice and wind. Video provided by Newsy
Powered by NewsLook.com
Big Waves, Minor Flooding from Hurricane

Big Waves, Minor Flooding from Hurricane

AP (Aug. 27, 2014) Thundering surf spawned by Hurricane Marie pounded the Southern California coast Wednesday, causing minor flooding in a low-lying beach town. High surf warnings were posted for Los Angeles County south through Orange County. (Aug. 27) Video provided by AP
Powered by NewsLook.com
Calif. Quake Underscores Need for Early Warning

Calif. Quake Underscores Need for Early Warning

AP (Aug. 26, 2014) Researchers at UC Berkeley are testing a prototype of an earthquake early warning system that California is pursuing years after places like Mexico and Japan already have them up and running. (August 26) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins