Scientists verify predictive model for winter weather

August 20, 2007

Scientists have verified the accuracy of a model that uses October snow cover in Siberia to predict upcoming winter temperatures and snowfall for the high- and mid-latitudes of the Northern Hemisphere.

The model is called sCast, short for seasonal forecast model. Atmospheric scientist Judah Cohen of AER, Inc., in Lexington, Mass., and colleagues analyzed seven real-time winter forecasts and 33 winter hindcasts (simulations of winters going back to 1972) to verify sCast.

"sCast works well in accurately predicting winter conditions over much of the eastern United States and Northern Eurasia," said Jay Fein, program director in the National Science Foundation (NSF)'s Division of Atmospheric Sciences, which funded the research. "Dynamical model prediction of winter climate remains a formidable challenge, and statistical approaches such as Cohen's continue to be a valuable alternative."

The results are published this week in the Journal of Climate.

Cohen and colleagues outline the link between October snow cover in Siberia and the Northern Hemisphere's winter temperatures, and snowfall.

October is the month when snow begins to pile up across Siberia. October is also the month that the Siberian high, one of three dominant weather centers across the Northern Hemisphere, forms.

In years when Siberian snow cover is above normal, a strengthened Siberian high and colder surface temperatures across Northern Eurasia develop in the fall.

"The result is a warming in Earth's stratosphere that occurs in January," said Cohen. "This eventually descends from the stratosphere to Earth's surface over a week or two in January, making for a warmer winter in Northern Hemisphere high latitudes. However, in mid-latitudes it turns colder, so winters in the northeastern U.S. and eastern Europe are likely to be colder and snowier than normal. The skill of the sCast model takes us the next step beyond current seasonal forecast models employed worldwide."
-end-


National Science Foundation

Related Stratosphere Articles from Brightsurf:

International team tracks record-setting smoke cloud from Australian wildfires
Researchers with the University of Saskatchewan's Institute of Space and Atmospheric Studies are part of a global team that has found that the smoke cloud pushed into the stratosphere by last winter's Australian wildfires was three times larger than anything previously recorded.

Iodine may slow ozone layer recovery
Air pollution and iodine from the ocean contribute to damage of Earth's ozone layer.

Snowmageddon warnings in North America come from tropics more than Arctic stratosphere
Scientists conducted the first ever study to identify how the four main winter weather patterns in the US and Canada behave depending on the strength of the stratospheric polar vortex.

Reevaluating the impacts of smoke plumes aloft, based on the 2017 Pacific Northwest wildfires
Extensive wildfires in the Pacific Northwest in the summer of 2017 unleashed a vast plume of smoke that ascended high into the stratosphere, persisted for more than eight months and provided researchers a rare opportunity to evaluate current models of smoke ascent.

Persistent plume
Thunderstorms generated by a group of giant wildfires in 2017 injected a small volcano's worth of aerosol into the stratosphere, creating a smoke plume that lasted for almost nine months.

Super volcanic eruptions interrupt ozone recovery
Strong volcanic eruptions, especially when a super volcano erupts, will have a strong impact on ozone, and might interrupt the ozone recovery processes.

2018's biggest volcanic eruption of sulfur dioxide
The Manaro Voui volcano on the island of Ambae in the nation of Vanuatu in the South Pacific Ocean made the 2018 record books.

Extratropical volcanoes influence climate more than assumed
The eruption of Mount Pinatubo in 1991 had a significant impact on climate, decreasing global mean temperature by about 0.5°C.

The ozone layer continues to thin
The vital ozone layer has continued to deplete in recent years over the densely populated mid-latitudes and tropics, while it is recovering at the poles.

Ozone at lower latitudes is not recovering, despite Antarctic ozone hole healing
The ozone layer -- which protects us from harmful ultraviolet radiation -- is recovering at the poles, but unexpected decreases in part of the atmosphere may be preventing recovery at lower latitudes.

Read More: Stratosphere News and Stratosphere Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.