Featured Research

from universities, journals, and other organizations

Greenhouse Gases Main Reason For Quicker Northern Winter Warming

Date:
April 24, 2001
Source:
NASA/Goddard Space Flight Center
Summary:
Greenhouse gases are the main reason why the northern hemisphere is warming quicker during winter-time months than the rest of the world, according to new computer climate model results by NASA scientists.

Greenhouse gases are the main reason why the northern hemisphere is warming quicker during winter-time months than the rest of the world, according to new computer climate model results by NASA scientists.

Related Articles


Climatologists consider volcanic aerosols, polar ozone depletion, solar radiation, and greenhouse gases to be important factors in climate warming. NASA scientists input all of these factors in a climate model and concluded that greenhouse gases are the primary factor driving warmer winter climates in North America, Europe and Asia over the last 30 years. They found that greenhouse gases, more than any of the other factors, increase the strength of the polar winds that regulate northern hemisphere climate in winter.

Using a computer model that simulates climate through interactions of ocean and atmosphere, scientists input current and past levels of greenhouse gases such as carbon dioxide, methane, water vapor and nitrous oxide. They found that greenhouse gases such as those increase the strength of polar wind circulation around the North Pole.

The polar winds play a large role in the wintertime climate of the northern hemisphere. The winds blow from high up in the stratosphere down to the troposphere and eventually the Earth’s surface. When they strengthen, as they do from increases in greenhouse gases, they blow stronger over the warm, moist oceans picking up and transporting warmer air to the continents. Thus, warm air from the Pacific Ocean warms western North America, and the Atlantic Ocean warmth is shared with Eurasia. When winds are stronger, winters are warmer because air picks up heat as the winds blow over the oceans. When winds become weak winters become colder.

The findings by Drew Shindell, Gavin Schmidt, and other atmospheric scientists from NASA’s Goddard Institute for Space Studies and Columbia University, NY, appeared in the April 16 issue of the Journal of Geophysical Research – Atmospheres.

Shindell noted that increases in greenhouse gases make the stronger polar winds last longer into the springtime and contribute to a warmer early spring climate in the northern hemisphere.

The stronger wind circulation around the North Pole creates a large temperature difference between the pole and the mid-latitudes. Shindell noted that the Southern Hemisphere isn’t affected by increasing greenhouse gases the same way, because it’s colder and the polar wind circulation over the Antarctic is already very strong.

“Surface temperatures in the Northern Hemisphere have warmed during winter months up to 9 degrees Fahrenheit over the last three decades, over 10 times more than the global annual average 0.7 degree Fahrenheit,” says Shindell. “Warmer winters will also include more wet weather in Europe and western North America, with parts of western Europe the worst hit by storms coming off the Atlantic.”

Year-to-year changes in the polar winds are quite large, according to Shindell. But over the past 30 years, we have tended to see stronger winds and warming, indicative of continually increasing greenhouse gases.

Shindell looked at volcanic activity from 1959 to 2000 and identified volcanically active and non-active years. The researchers concluded that because volcanic forcing is intermittent and decays rapidly, it seems unlikely to have contributed greatly to the long-term observed warming trend. Large volcanic eruptions such as Mount Pinatubo in 1991 inject aerosols into the atmosphere and have a global cooling effect during the years following an eruption.

Also included in the model were the 11-year solar cycle and the effects of solar radiation on stratospheric ozone. Schmidt noted that long-term changes in solar irradiance have influenced the upper atmosphere. “However, it is unlikely that solar variability has been responsible for much of the observed trend in increasing the polar winds,” Schmidt said.

Because the upper polar atmosphere becomes colder when ozone is depleted, the winds circling the pole are slightly enhanced. “However,” Shindell noted, “greenhouse gases have the biggest impact on the strengthening of the polar winds, and in turn, the warming of the northern hemisphere during winter months.”

Shindell said that the warming trend would likely continue over the next 30 years as greenhouse gases continue to increase in the atmosphere.


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. "Greenhouse Gases Main Reason For Quicker Northern Winter Warming." ScienceDaily. ScienceDaily, 24 April 2001. <www.sciencedaily.com/releases/2001/04/010424073849.htm>.
NASA/Goddard Space Flight Center. (2001, April 24). Greenhouse Gases Main Reason For Quicker Northern Winter Warming. ScienceDaily. Retrieved November 20, 2014 from www.sciencedaily.com/releases/2001/04/010424073849.htm
NASA/Goddard Space Flight Center. "Greenhouse Gases Main Reason For Quicker Northern Winter Warming." ScienceDaily. www.sciencedaily.com/releases/2001/04/010424073849.htm (accessed November 20, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Thursday, November 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nations Pledge $9.3 Bn for Green Climate Fund

Nations Pledge $9.3 Bn for Green Climate Fund

AFP (Nov. 20, 2014) Nations meeting in Berlin pledge $9.3 billion (7.4 bn euros) for a climate fund to help poor countries cut emissions and prepare for global warming, just shy of a $10bn target. Duration: 00:46 Video provided by AFP
Powered by NewsLook.com
What's The Point Of Climate Conferences?

What's The Point Of Climate Conferences?

Newsy (Nov. 20, 2014) There's optimism about the U.N.'s climate conference in Paris next year, and if climate conferences past are anything to go off, that's notable. Video provided by Newsy
Powered by NewsLook.com
Giant Panda at Toronto Zoo Loves Somersaulting in the Snow

Giant Panda at Toronto Zoo Loves Somersaulting in the Snow

Buzz60 (Nov. 19, 2014) A giant panda at the Toronto Zoo named Da Mao is celebrating the northeast snowfall by playing and tumbling in the snow in his outdoor enclosure. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Scientists Find Out What's Been Killing Millions Of Starfish

Scientists Find Out What's Been Killing Millions Of Starfish

Newsy (Nov. 18, 2014) Scientists have found the cause of the biggest marine epidemic in history: the virus behind starfish wasting disease. 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