Featured Research

from universities, journals, and other organizations

Scientists Look At Moon To Shed Light On Earth's Climate

Date:
May 28, 2004
Source:
NASA/Goddard Space Flight Center
Summary:
According to a new NASA-funded study, insights into Earth's climate may come from an unlikely place: the moon.

This composite image of the dark side's Earthshine (left of image) and bright side's Moonshine (right of image) illustrates what scientists are looking at. Researchers used a blocking filter to dim the Moonshine crescent, typically about 10,000 times brighter than Earthshine.
Credit: BBSO/NJIT

According to a new NASA-funded study, insights into Earth's climate may come from an unlikely place: the moon.

Scientists looked at the ghostly glow of light reflected from Earth onto the moon's dark side. During the 1980s and 1990s, Earth bounced less sunlight out to space. The trend reversed during the past three years, as the Earth appears to reflect more light toward space.

Though not fully understood, the shifts may indicate a natural variability of clouds, which can reflect the sun's heat and light away from Earth. The apparent change in the amount of sunlight reaching Earth in the 1980s and 1990s is comparable to taking the effects of greenhouse gas warming since 1850 and doubling them. Increased reflectance since 2001 suggests change of a similar magnitude in the opposite direction.

Researchers from the New Jersey Institute of Technology (NJIT), Newark, N.J., and California Institute of Technology (Caltech), Pasadena, Calif., combined NASA cloud data from satellites with records of Earth's reflectance off the moon, called earthshine. The study, funded by NASA's Living With a Star Program, appears May 28 in the journal Science.

"Using a phenomenon first explained by Leonardo DaVinci, we can provide valuable data on the overall reflectance of the Earth, and indirectly, on global cloud cover," said Phil Goode, a physicist at NJIT, one of the paper's authors. He is director of Big Bear Solar Observatory (BBSO), Big Bear City, Calif. "Our method has the advantage of being very precise, and light reflected by large portions of Earth can be observed simultaneously," he said.

Recent news reports suggested sunshine reaching Earth declined from the late 1950s to the early 1990s. This new study suggests the opposite. Earth's surface may have been sunnier, or less cloudy, in the 1980s and 1990s. BBSO has conducted precision earthshine observations since 1994. Regular observations began in late 1997.

The research team improved upon an old method for monitoring earthshine. They compared earthshine measurements from 1999 to mid-2001 with overlapping satellite observations of global cloud properties. The cloud satellite record from 1983 to 2001 came from the NASA-managed International Satellite Cloud Climatology Project. By matching these two records, the researchers used the cloud data to extend the record and construct a substitute measure of Earth's albedo, the fraction of light reflected by a body or surface.

The data showed a steady decrease in Earth's albedo from 1984 to 2000. Between 1995 and 1996, Earth dimmed even more sharply. The data were consistent with satellite measurements of changing global properties. From 1997 to 2000, Earth continued to dim. The researchers suggest, during this time period, the decreases in Earth's reflectance may be related to an observed accelerated increase in mean global surface temperatures. From 2001 to 2003, Earth brightened to pre-1995 values. The researchers attributed the brightening to changes in cloud properties.

"At the moment, the cause of these variations is not known, but they imply large shifts in Earth's radiative budget," said co-author Steven Koonin, a Caltech physicist. "Continued observations and modelling efforts will be necessary to learn their implications for climate."

The research offers evidence Earth's average albedo varies considerably from year to year, and from decade to decade. "Our most likely contribution to the global warming debate is to emphasize the role of clouds in climate change must be accounted for, illustrating that we still lack the detailed understanding of our present and past climate system to confidently model future changes," said Enric Palle, a postdoctoral associate at NJIT, lead author of the paper. Pilar Montan?es-Rodriguez, a postdoctoral associate at NJIT, is another co-author.

"Even as the scientific community acknowledges the likelihood of human impact on climate, it must better document and understand climate changes," Koonin said. "Our ongoing earthshine measurements will be an important part of that process."

BBSO, operated by NJIT, is partially supported by NASA. NASA's Living with a Star Program develops the scientific understanding necessary to effectively address those aspects of the connected sun-Earth system that directly affect life and society.

For information and images about this research on the Internet, visit: http://space.mit.edu/HETE/http://www.gsfc.nasa.gov/topstory/2004/0528earthshine.html

- end -


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. "Scientists Look At Moon To Shed Light On Earth's Climate." ScienceDaily. ScienceDaily, 28 May 2004. <www.sciencedaily.com/releases/2004/05/040527233052.htm>.
NASA/Goddard Space Flight Center. (2004, May 28). Scientists Look At Moon To Shed Light On Earth's Climate. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2004/05/040527233052.htm
NASA/Goddard Space Flight Center. "Scientists Look At Moon To Shed Light On Earth's Climate." ScienceDaily. www.sciencedaily.com/releases/2004/05/040527233052.htm (accessed October 1, 2014).

Share This



More Earth & Climate News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: 12 More Bodies Found on Japan Volcano

Raw: 12 More Bodies Found on Japan Volcano

AP (Oct. 1, 2014) — A dozen more bodies were found Wednesday as Japanese rescuers resumed efforts to find survivors and retrieve bodies of those trapped by Mount Ontake's eruption. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. Video provided by Newsy
Powered by NewsLook.com
Raw: Trapped Scientist Rescued from Cave in Peru

Raw: Trapped Scientist Rescued from Cave in Peru

AP (Oct. 1, 2014) — A Spanish scientist, who spent 12 days trapped about 1300 feet underground in a cave in Peru's remote Amazon region, was rescued on Tuesday. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Media, Industry Groups React To Calif. Plastic Bag Ban

Media, Industry Groups React To Calif. Plastic Bag Ban

Newsy (Sep. 30, 2014) — California is the first state in the country to ban single-use plastic bags in grocery, liquor and convenience stores. Video provided by Newsy
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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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