گرد و غبار بر فراز ایران ، افغانستان و پاکستان Dust over Iran, Afghanistan, and Pakistan

Dust plumes blew over southwestern Asia at the end of May 2011. On May 31, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image of dust plumes blowing over the borders of Iran, Afghanistan, and Pakistan.
The thickest plume originates in eastern Iran. The opaque plume blows toward the south-southeast, passing over parts of Afghanistan and Pakistan. To the east, another plume blows in the same direction. Farther east (upper right quadrant of the image), a camel-colored, unevenly shaped plume appears to float over Afghanistan.
Dust plumes in this region often originate from dry lakebed sediments along the Iran-Afghanistan border, and from sandy deserts in Afghanistan and Pakistan.

گرد و غبار بر فراز جنوب باختر آسیا Dust over Southwestern Asia

Dust storms spread over southwestern Asia on June 1, 2011. As the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite passed overhead, dust-storm activity extended from the Iran-Afghanistan border across Pakistan and into India. Dust also blew over the Gulf of Oman and the Arabian Sea.
Dust plumes often arise from the dry lakebed sediments along the border between Iran and Afghanistan. Thick plumes blow from that region toward the southeast in this natural-color image. Dust also arises from the sand seas occurring over much of western Pakistan, and the sandy desert that stretches for hundreds of kilometers along the Pakistan-India border.
Although thinner than the plumes to the north and east, dust also occurs over Oman. Sandy deserts in Oman could be the source of the dust in that region, but the dust might have arisen in and around Pakistan, and been carried across the Arabian Sea and Gulf of Oman.

توفان بر فراز عراق Dust Storm over Iraq

A thick dust plume blew over Iraq on June 2, 2011, stopping just short of Iran and Kuwait. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image the same day.

The dust forms a giant beige arc that obscures most of Iraq. At least some of the dust storm appears to originate in Syria, where sandy desert sprawls over the landscape on either side of the Euphrates River. Dust also arises east of the Syria-Iraq border.

Fine sediments of river basins in Iraq make this area one of the world’s leading dust-producing regions. Rising temperatures in the summertime increase the likelihood of dust storms. High temperatures make the air near the ground unstable, increasing the chance that even a light breeze will loft dust into the air.

1. References
2. University Corporation for Atmospheric Research. Forecasting Dust Storms. (Registration required.) Accessed June 2, 20

آتش سوزی در خاور روسیه Fires in Eastern Russia

Fires in Eastern Russia

Several large, smoky fires burned in the forests of southeastern Russia when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired this image. The fires are marked in red.
The image includes parts of two Russian provinces, the Irkutsk Region in the east and the Krasnoyarsk Territory in the west. On June 1, 59 fires burned in the Irkutsk Region, affecting 1,214.3 hectares, said EMERCOM of Russia. 33 fires burned in Krasnoyarsk Territory, affecting 1,834.8 hectares. Most of the fires burned in forest, producing the thick smoke shown in the image.
The two regions were among the areas that posed the greatest challenge to firefighters in early June because of the difficult, remote terrain and warm, fire-friendly weather. So far in 2011, 425,186.16 hectares of land have burned, compared to 187,391.39 hectares for the same period in 2010
Thick smoke blanketed eastern Russia on May 26, 2011, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this image. The smoke is rising from clusters of intense wildfires, which are marked in red.
The fires are burning in the forests around the Aldan and Lena rivers in the Sakha Republic (Yakutiya). According to Rusian Tsalikov, the first deputy minister of EMERCOM on Russia, the fires in the Russian Far East are more extreme than usual, requiring federal firefighting assitance. Most of the fires, said Tsalikov, were started by people burning grasses and undergrowth. Hot, dry, and windy weather helped the fires expand to the forests.

1. References

2. BBC News. Fears of repeat disaster as fires rage in Russian east. Accessed June 2, 2011.
3. Tsalikov, R. (2011, May 25). About the fire situation in Russia. EMERCOM of Russia, the Ministry of the Russian Federation for Civil Defense, Emergencies, and Elimination of Consequences of Natural Disasters. Accessed June 2, 2011

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نگاه نو به کهکشا ن ها A New Look at Galaxies

“A new, colorful collection of galaxy specimens has been released by NASA’s Wide-field Infrared Survey Explorer, or WISE, mission.” Quoted from the NASA news release

توفا ن خورشیدی Global Eruption Rocks the Sun

Global Solar Storm“On August 1, 2010, an entire hemisphere of the sun erupted. Filaments of magnetism snapped and exploded, shock waves raced across the stellar surface, billion-ton clouds of hot gas billowed into space. Astronomers knew they had witnessed something big. It was so big, it may have shattered old ideas about solar activity.” Quoted from the NASA press release.

پهنه ی تلماسه –دریای شن – " برخان " در عما ن Ar Rub’ al Khali Sand Sea, Arabian

The Ar Rub’ al Khali, also called the “Empty Quarter,” is a large region of sand dunes and interdune flats known as a sand sea or erg. This astronaut photograph highlights a part of the Ar Rub’ al Khali near its southeastern margin, in the Sultanate of Oman.
Large, linear reddish-brown sand dunes alternate with interdune salt flats, or sabkhas. The orientation of the linear dunes lies at a right angle to northwesterly trade winds that originate in Iraq, known as the Shamal winds.
Secondary barchan (crescent-shaped) dunes and star dunes—with crests originating from a single point and stretching in several directions—can form atop the linear dunes when southwesterly winds blow during the monsoon season (Kharif winds). The long, linear dunes begin to break up into isolated large star dunes to the northeast and east (image right). This is likely the result of wind pattern interactions and of changes in the sand supply.
The Empty Quarter covers much of the south-central portion of the Arabian Peninsula, and with an area of approximately 660,000 square kilometers, it is the largest continuous sand desert on Earth. The Empty Quarter was so named because the hyperarid climate and difficulty of travel through the dunes has long discouraged permanent settlement within the region. There is geological and archeological evidence of cooler and wetter climates and human settlements in the region in the past. This evidence includes exposed lakebed sediments, scattered stone tools, and the fossils of hippopotamus, water buffalo, and long-horned cattle.