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Archive for Image of the day

Climate Change in the Barents Sea – June 21st, 2013

70.2N 50.8E

June 21st, 2013 Category: Climate Change, Image of the day VIIRSSuomi-NPP

Russia – June 21st, 2013

Visible on the right side of this image is the Novaya Zemlya archipelago, part of Russia, between the Barents and Kara Seas. Recent data over the last decade show an Arctic wide temperature increase consistent with model projections of global warming rather than showing regional warming patterns which would have been caused by natural variability as occurred in previous Arctic warming episodes such as the 1930s.

While a major surprise was the nearly 40% loss of September sea ice extent in 2007, the major change is that in every year since then sea ice has been below 30% and that much old, thick sea ice has disappeared. Extensive forest fires are another major Arctic change. These shifts seem to be rapid and occurring 20-30 years earlier than expected by steady processes in climate forecast models.

The Arctic is normally dominated a very stable “Polar Vortex” of counter-clockwise circulating winds surrounding the North Pole which traps the cold Arctic air mass at high latitudes. However, during early winter of 2009-2010 the Polar Vortex weakened due to higher geopotential heights over the Arctic, allowing cold air to spill southwards and be replaced by warm air moving poleward, a warm Arctic –cold continent climate pattern. One
indicator of a weak Polar Vortex is the North Atlantic Oscillation (NAO) index which in December 2009 through February 2010 had its most negative value (weak vortex) in 145 years of record.

Meteorological attribution to these sub-Arctic events is difficult. Certainly random chaos in the development of weather patterns can produce such extreme events. There is a potential impact, however, from Arctic regions where heat stored in the ocean in sea-ice-free and thin ice areas has been released to the lower atmosphere during autumn. One would not expect a sub-Arctic impact in every year or the in the same locations every year. The Barents Sea seems to be part of the Arctic wide warming pattern, while northern Europe is in the subArctic high climate variability zone (click here for more information).

Kármán Vortex Streets Trailing Off Cape Verde and Canary Islands – June 20th, 2013

21.8N 18.5W

June 20th, 2013 Category: Clouds, Image of the day VIIRSSuomi-NPP

West Africa – June 19th, 2013

West of Western Sahara, Mauritania and Senegal, off the coast of West Africa, is an atmospheric phenomenon known as Kármán Vortex Streets. These parallel rows of oppositely spinning vortices, caused by the unsteady separation of flow of a fluid around blunt bodies, can be seen trailing off the Canary Islands (above) and off the Cape Verde islands (below). Some dust can also be seen spreading off the coast of Mauritania.

Fire in Sierra Nevada Foothills, California, USA – June 18th, 2013

37.3N 119.7W

June 18th, 2013 Category: Fires, Image of the day MODISTerra

USA – June 17th, 2013

A plume of smoke from a wildfire burning in the wooded foothills of the Sierra Nevada, east of California’s Great Central Valley, can be seen just to the right of the center of this image. The smoke from the fire is blowing towards the south-southeast, trailing over the valley.

Fires in Australia’s Northern Territory – June 17th, 2013

13.4S 130.8E

June 17th, 2013 Category: Fires, Image of the day MODISTerra

Australia – June 17th, 2013

Fires in the northern part of Australia’s Northern Territory, between the Van Diemen Gulf and King Sound, release plumes of smoke that blow towards the west. The coastline is framed by sediments, with a greenish phytoplankton bloom visible further offshore in the upper left quadrant.

Environmental Issues for Volga River, Russia – June 16th, 2013

46.0N 49.2E

June 16th, 2013 Category: Image of the day, Rivers MODISAqua

Russia – June 16th, 2013

Draining most of western Russian, the Volga is the largest river in Europe. From its source in the Valdai Hills north east of Moscow the river flows east and south east to the Caspian Sea. This thumbnail images focuses on its delta at the shores of the Caspian Sea, while a larger portion of the river’s meanderings can be seen to the north upon opening the full image.

A large number of tributaries make up the Volga river system the delta where the river enters the Caspian is composed of hundreds of channels and lies 28 m below sea level. For three months of the year the river is frozen for most of its length, the presence of a large number of dams has improved navigation but has reduced the river’s flow.

Consequently the river is suffering from pollution compounded by the fact that it flows through some of the most populated area of the country and includes an important agricultural area. Half of all river freight in Russia uses the Volga, which is connected to the Black sea via the Don river and canals (click here for more information).