Earth  ID: 3850

Extreme Russian Fires and Pakistan Floods Linked Meteorologically

In the summer of 2010, months of record-breaking drought and temperatures culminated with a rash of fires that ravaged western Russia for weeks. Temperatures in Moscow soared to an average of 104 °F (40 °C) during late July and early August — more than 18 °F (10 °C) above normal. Hundreds of fires broke out producing some $15 million in damages. The heat and smoke killed about 56,000 people, making the Russian wildfires fires one of the most lethal natural disasters of the year.

Meanwhile, some 930 kilometers (1,500 miles) away, relentless rainfall was simultaneously pounding Pakistan and generating intense flooding. The Pakistan Meteorological Department reported nationwide rain totals 70 percent above normal in July and 102 percent above normal in August.

New research conducted by William Lau, an atmospheric scientist at NASA's Goddard Space Flight Center in Greenbelt, Md., suggests the two seemingly disconnected events were actually closely linked.

Under normal circumstances, the jet stream pushes weather fronts through Eurasia in four or five days, but something unusual happened in July of 2010. A large-scale, stagnant weather pattern — known as an Omega blocking event — slowed the Rossby wave over Russia and prevented the normal progression of weather systems from west to east.

As a result, a large region of high-pressure formed over Russia trapping a hot, dry air mass over the area. As the high lingered, the land surface dried and the normal transfer of moisture from the soil to the atmosphere slowed. Precipitation ceased, vegetation dried out, and the region became a taiga tinderbox.

Meanwhile, the blocking pattern created unusual downstream wind patterns over Pakistan. Areas of low pressure on the leading edge of the Rossby wave formed in response to the high, pulling cold, dry Siberian air into lower latitudes.

This cold air from Siberia clashed with warm, moist air arriving over Pakistan from the Bay of Bengal as part of the monsoon. There's nothing unusual about moisture moving north over India toward the Himalayas. It's a normal part of the monsoon. However, in this case, the unusual wind patterns associated with the blocking high brought upper level air disturbances farther south than typical, which in effect helped shifted the entire monsoon system north and west.

This brought heavy monsoon rains — centered over parts of India — squarely over the northern part of Pakistan, a region ill-prepared to handle large amounts of rain.

 

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Visualization Credits

Trent L. Schindler (USRA): Lead Animator
Adam P Voiland (Wyle Information Systems): Producer
William K. Lau (NASA/GSFC): Scientist
Kyu-Myong Kim (Morgan State University): Scientist
Adam P Voiland (Wyle Information Systems): Writer
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NASA/Goddard Space Flight Center Scientific Visualization Studio

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Missions:
Terra
Tropical Rainfall Measuring Mission - TRMM

Data Used:
Aqua/AIRS
Aqua/MODIS
Terra/MODIS
TRMM and DMSP/SSM/I and TMI/3B4XRT
MERRA
Note: While we identify the data sets used in these visualizations, we do not store any further details nor the data sets themselves on our site.

This item is part of these series:
Fires
Floods

Keywords:
SVS >> Drought
SVS >> HDTV
SVS >> Weather
GCMD >> Earth Science >> Atmosphere >> Precipitation >> Rain
GCMD >> Earth Science >> Human Dimensions >> Natural Hazards >> Fires
GCMD >> Earth Science >> Hydrosphere >> Surface Water >> Floods
SVS >> Hyperwall
NASA Science >> Earth

GCMD keywords can be found on the Internet with the following citation: Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 8.0.0.0.0