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Dr. Jeff Masters’ WunderBlog : Over 500 Killed in India’s Monsoon Floods | Weather Underground

Over 500 Killed in India’s Monsoon Floods

By Dr. Jeff Masters

Published: 4:25 PM GMT on June 21, 2013
Earth’s deadliest natural disaster so far in 2013 is the deadly flooding in India’s Himalayan Uttarakhand region, where torrential monsoon rains have killed at least 556 people, with hundreds more feared dead. At least 5,000 people are missing. According to the Indian Meteorological Department, Uttarakhand received more than three times (329%) of its normal June rainfall from June 1 – 21, and rainfall was 847% of normal during the week June 13 – 19. Satellite estimates indicate that more than 20″ (508 mm) or rain fell in a 7-day period from June 11 – 17 over some regions of Uttarakhand, which lies just to the west of Nepal in the Himalayas. Dehradun, the capital of Uttarakhand, received 14.57″ (370 mm) of rain in 24 hours June 16 – 17. This was the highest 24-hour rainfall in city history, according to an official from the India Meteorological Department. Dr. Dave Petley’s Landslide Blog details that the torrential rains triggered a massive landslide that hit Uttarakhand’s Hindu shrine in Kedarnath, which lies just a short distance from the snout of two mountain glaciers. The shrine is an important pilgrimage destination this time of year, and was packed with visitors celebrating the char-dham yatra: a pilgrimage to the four holy sites of Gangotri, Kedarnath, Yamnotri and Badrinath. Apparently, heavy rainfall triggered a collapse event on the mountain above Kedarnath, which turned into a debris flow downstream that struck the town. The main temple was heavily damaged, and numerous buildings in the town were demolished. It was Earth’s deadliest landslide since the August 2010 Zhouqu landslide in China.

According to Aon Benfield’s May Catastrophe Report, Earth’s deadliest natural disasters of 2013 so far:

Winter weather, India, Banglaadesh, Nepal, 1/1 – 1/20, 329 deaths
Earthquake, China, 4/20, 196 deaths
Flooding, Southern Africa, 1/10 – 2/28, 175 deaths
Flooding, Argentina, 4/2 – 4/4, 70 deaths
Flooding, Kenya, 3/10 – 4/30, 66 deaths

Figure 1. Indo-Tibetan Border Police (ITBP) arrive to rescue stranded Sikh devotees from Hemkunt Sahib Gurudwara, a religious Sikh temple, to a safe place in Chamoli district, in northern Indian state of Uttarakhand, India, Monday, June 17, 2013. AP photo.

Figure 2. Satellite-estimated rainfall for the 7-day period June 11 – 17, 2013, from NASA’s TRMM satellite exceeded 20 inches (508 mm) over portions of India’s Uttarakhand province, leading to catastrophic floods. Image credit: NASA.

A record early arrival of the monsoon
The June 2013 monsoon rains in Uttarakhand were highly unusual, as the monsoon came to the region two weeks earlier than normal. The monsoon started in South India near the normal June 1 arrival date, but then advanced across India in unusually rapid fashion, arriving in Pakistan along the western border of India on June 16, a full month earlier than normal. This was the fastest progression of the monsoon on record. The previous record for fastest monsoon progression occurred in 1961, when all of India was under monsoon conditions by June 21. Reliable monsoon records go back to 1961, and are patchy before then. Fortunately, no more heavy rain is expected in Uttarakhand over the next few days, as the monsoon will be active only in eastern India. Heavy rains are expected again in the region beginning on June 24. Wunderblogger Lee Grenci’s post, Summer Monsoon Advances Rapidly across India: Massive Flooding Ensues, has more detail on the meteorology of this year’s monsoon. There is criticism from some that the devastating floods were not entirely a natural disaster–human-caused deforestation, dam building, and mining may have contributed. “Large-scale construction of dams and absence of environmental regulations has led to the floods,” said Sunita Narian, director general of Delhi based advocacy group Centre for Science and Environment (CSE).

(please follow link at bottom to Jeff Master’s blog to see this image-unable to copy image)
Figure 3. The summer monsoon arrived in southwest India right on schedule (June 1) in South India, but it spread northward much faster than usual, reaching Pakistan a full month earlier than normal. Solid green contours indicate the progress of the 2013 summer monsoon (each contour is labeled with a date). You can compare this year’s rapid advance to a “normal” progression, which is represented by the dashed, red contours (also labeled with dates).

Monsoons in India: a primer
Disastrous monsoon floods are common in India and surrounding nations, and 60,000 people–an average of 500 people per year–died in India due to monsoon floods between 1900 – 2012, according to EM-DAT, the International Disaster Database. EM-DAT lists sixteen flood disasters which killed 1,000 or more people in India since records began in 1950. Here are the number of people killed in these events, along with the month and year of occurrence and locales affected:

4892, Jul 1968, Rajasthan, Gujara
3800, Jul 1978, North, Northeast
2001, May – Oct, 1994, Assam, Arunachal Pradesh
2000, Jul 1961, North
1811, Aug 1998, Assam, Arunachal, Bihar
1600, Aug 1980, Uttar Pradesh, Bihar
1591, Jul 28, 1989, Maharashtra, Andhra Prade
1479, Sep 1995, Bihar, Haryana, Punjab
1442, Aug 1997, Andhra Pradesh, Arunachal
1200, Jul 24 – Aug 5, 2005 Gujarat, Madhya Pradesh
1200, Aug 1987, Assam, Bihar, West Bengal
1103, Jul 3 – Sep 22, 2007, Bihar, Uttar Pradesh
1063, Jun 11 – Jul 21, 2008 West Bengal, Orissa
1023, Jun 1971, North
1000, Sep 22 – OCt 9, 1988, Punjab, Himachal Pradesh
1000, Oct 1961

The monsoon occurs in summer, when the sun warms up land areas more strongly than ocean areas. This happens because wind and ocean turbulence mix the ocean’s absorbed heat into a “mixed layer” approximately 50 meters deep, whereas on land, the sun’s heat penetrates at a slow rate to a limited depth. Furthermore, due to its molecular properties, water has the ability to absorb more heat than the solid materials that make up land. As a result of this summertime differential heating of land and ocean, a low pressure region featuring rising air develops over land areas. Moisture-laden ocean winds blow towards the low pressure region and are drawn upwards once over land. The rising air expands and cools, condensing its moisture into some of the heaviest rains on Earth–the monsoon. Monsoons operate via the same principle as the familiar summer afternoon sea breeze, but on a grand scale. Each summer, monsoons affect every continent on Earth except Antarctica, and are responsible for life-giving rains that sustain the lives of billions of people. In India, home for over 1.1 billion people, the monsoon provides 80% of the annual rainfall. The most deadly flooding events usually come from monsoon depressions (also known as monsoon lows.) A monsoon depression is similar to (but larger than) a tropical depression. Both are spinning storms hundreds of kilometers in diameter with sustained winds of 50 – 55 kph (30 – 35 mph), nearly calm winds at their center, and generate very heavy rains. Typically, 6 – 7 monsoon depressions form each summer over the Bay of Bengal and track westwards across India.

The future of monsoons in India
A warming climate loads the dice in favor of heavier extreme precipitation events. This occurs because more water vapor can evaporate into a warmer atmosphere, increasing the chances of record heavy downpours. In a study published in Science in 2006, Goswami et al. found that the level of heavy rainfall activity in the monsoon over India had more than doubled in the 50 years since the 1950s, leading to an increased disaster potential from heavy flooding. Moderate and weak rain events decreased during those 50 years, leaving the total amount of rain deposited by the monsoon roughly constant. The authors commented, “These findings are in tune with model projections and some observations that indicate an increase in heavy rain events and a decrease in weak events under global warming scenarios.” We should expect to see an increased number of disastrous monsoon floods in coming decades if the climate continues to warm as expected. Since the population continues to increase at a rapid rate in the region, death tolls from monsoon flooding disasters are likely to climb dramatically in coming decades. However, my greater concern for India is drought. The monsoon rains often fail during El Niño years, and more than 4.2 million people died in India due to droughts between 1900 – 2012. Up until the late 1960s, it was common for the failure of the monsoon rains to kill millions of people in India. The drought of 1965 – 1967 killed at least 1.5 million people. However, since the Green Revolution of the late 1960s–a government initiative to improve food self-sufficiency using new technology and high-yield grains–failure of the monsoon rains has not led to mass starvation in India. It is uncertain whether of not the Green Revolution can keep up with India’s booming population, and the potential that climate change might bring more severe droughts. Climate models show a wide range of possibilities for the future of the Indian monsoon, and it is unclear at present what the future might hold. However, the fact that one of the worst droughts in India’s history occurred in 2009 shows that serious droughts have to be a major concern for the future. The five worst Indian monsoons along with the rainfall deficits for the nation:

1) 1877, -33%
2) 1899, -29%
3) 1918, -25%
4) 1972, -24%
5) 2009, -22%

Goswami, et al., 2006, ” Increasing Trend of Extreme Rain Events Over India in a Warming Environment”, Science, 1 December 2006:Vol. 314. no. 5804, pp. 1442 – 1445 DOI: 10.1126/science.1132027

Wunderground’s climate change blogger Dr. Ricky Rood wrote a nice 3-part series about the challenges India faces due to climate change after he completed a 2009 trip there.

(read the rest of this article, with all images and links intact here-

http://www.wunderground.com/blog/JeffMasters/article.html )

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Unusually cold spring in Europe and the Southeast U.S. due to the Arctic Oscillation | Weather Underground

For those still wondering why when it is snowing in May where they live we can call it “Global Warming”, this post may help make things much clearer.

The snow in unusual locations in May comes in tandem with things like roadways and railroads in the Arctic and Tibet buckling and crumbling due to loss of permafrost (melting of long term frozen ground on which they were built). So even tho it is unusually cold in some places,at some times, it is still warmer over the planet as a whole.

Dr. Jeff Masters’ WunderBlog

Unusually cold spring in Europe and the Southeast U.S. due to the Arctic Oscillation

Posted by: Dr. Jeff Masters, 2:52 PM GMT on April 25, 2013 +39

During March 2013, residents of Europe and the Southeast U.S. must have wondered what happened to global warming. Repeated bitter blasts of bitter cold air invaded from the Arctic, bringing one of the coldest and snowiest Marches on record for much of northern Europe. In the U.K., only one March since 1910 was colder (1962), and parts of Eastern Europe had their coldest March since 1952. A series of exceptional snowstorms struck many European locations, including the remarkable blizzard of March 11 – 12, which dumped up to 25 cm (10) of snow on the Channel Islands of Guernsey and Jersey in the U.K., and in the northern French provinces of Manche and Calvados. The entire Southeast U.S. experienced a top-ten coldest March on record, with several states experiencing a colder month than in January 2013. Despite all these remarkable cold weather events, global temperatures during March 2013 were the 9th warmest since 1880, said NASA. How, then, did such cold extremes occur in a month that was in the top 8% of warmest Marches in Earth’s recorded history? The answer lies in the behavior of the jet stream. This band of strong high-altitude winds marks the boundary between cold, polar air and warm, subtropical air. The jet stream, on average, blows west to east. But there are always large ripples in the jet, called planetary waves (or Rossby waves.) In the Northern Hemisphere, cold air from the polar regions spills southward into the U-shaped troughs of these ripples, and warm air is drawn northwards into the upside-down U-shaped ridges. If these ripples attain unusually high amplitude, a large amount of cold polar air will spill southwards into the mid-latitudes, causing unusual cold extremes. This was the case in Europe and the Eastern U.S. in March 2013. These cold extremes were offset by unusually warm conditions where the jet stream bulged northwards–over the Atlantic, the Western U.S., and in China during March 2013. In fact, the amplitude of the ripples in the jet stream reached their most extreme value ever recorded in any March during 2013, as measured by an index called the Arctic Oscillation (AO).

Figure 1. The monthly Arctic Oscillation (AO) index from 1950 – March 2013 shows that three of the six most extreme negative cases have occurred since 2009. Note that all of the six most negative AO indices on record were associated with historic cold waves and blizzards over Europe or the Eastern U.S. Image created using data from NOAA’s Climate Prediction Center.

Measuring the jet stream’s contortions: the Arctic Oscillation (AO)
One measure of how extreme the ripples in the jet stream are is by measuring the difference in pressure between the Icelandic Low and the Azores High. An index based in this pressure difference is called the North Atlantic Oscillation (NAO). When this index is strongly negative, it means that the pressure difference between the Icelandic Low and the Azores High is low. This results in a weaker jet stream, allowing it to take large, meandering loops. These loops allow cold air to spill far to the south from the Arctic into the mid-latitudes. A more general index that looks at pressure patterns over the entire Arctic, not just the North Atlantic, is called the Arctic Oscillation (AO). The AO and NAO are closely related about 90% of the time. According to a 2010 paper by L’Heureux et al., a strongly negative AO pattern that allows cold air to spill southwards into the mid-latitudes does nothing to the average temperature of the planet. Fluctuations in the jet stream as measured by the AO simply act to redistribute heat. It’s kind of like turning off your refrigerator and leaving the refrigerator door open–the cold air from the refrigerator spills out into the room, but is replaced inside the refrigerator by warm room air. No net change in heat occurs. During March 2013, the AO index hit -3.2. Not only was this the most extreme negative March value of the AO since record keeping began in 1950, it was also the sixth lowest AO index ever measured. It was also the first time the AO index had been that extremely negative in a non-winter month (because the circulation patterns are stronger in the winter, we tend to see more extreme values of the AO index in December, January, and February.) This unusual contortion of the jet stream in March 2013 allowed Europe to have exceptional cold weather in a month when the global average temperature was among the warmest 8% of Marches on record. Why did the AO index get so extreme in March 2013? Part of the blame goes to the sudden stratospheric warming event that began in January (wunderblogger Lee Grenci has a detailed post on this event.) Sudden stratospheric warming events tend to push the atmosphere into a more negative AO configuration. Another major factor was the very active Madden Julian Oscillation (MJO), a pattern of increased thunderstorm activity near the Equator that moves around the globe in 30 – 60 days. When the area of increased thunderstorms associated with the MJO is located in the Pacific Ocean, as occurred during much of March 2013, this tends to create negative AO conditions. Finally, wintertime Arctic sea ice loss has been tied to more negative AO patterns, and sea ice was well blow average again during March.

Figure 2. The Arctic Oscillation (AO) is a pattern of varying pressure and winds over the Northern Hemisphere that can strongly influence mid-latitude weather patterns. When the AO is in its positive phase, jet stream winds are strong and the jet stream tends to blow mostly west to east, with low-amplitude waves (troughs and ridges.) Since the jet stream marks the boundary between cold Arctic air to the north and warm subtropical air to the south, cold air stays bottled up in the Arctic. When the AO is in its negative phase, the winds of the jet stream slow down, allowing the jet to take on more wavy pattern with high-amplitude troughs and ridges. High amplitude troughs typically set up over the Eastern U.S. and Western Europe during negative AO episodes, allowing cold air to spill southwards in those regions and create unusally cold weather.

Are jet stream patterns getting more extreme?
We’ve had some wildly variable jet stream patterns in recent years in the Northern Hemisphere. Just last year, we had a strongly positive AO in March, when our ridiculous “Summer in March” heat wave brought the warmest March on record to the U.S. The first day of spring in Chicago, IL on March 20, 2013 had a high temperature of just 25°F–a 60 degree difference from last year’s high of 85°F on March 20! During the past five years, we’ve set new monthly records for extreme negative AO index for six of the twelve months of the year:

-4.3: February 2010
-3.4: December 2009
-3.2: March 2013
-1.5: October 2009, 2012
-1.4: June 2009
-1.4: July 2009

Note that four of these months with an extremely negative AO occurred in one year–2009. This unusual event was “unprecedented in the 60-year record”, according to L’Heureux et al. (2010.) Despite the unusually large negative AO in 2009, the authors found that the AO index between 1950 – 2009 had actually trended to be more positive, in both the winter and annual mean. This is in agreement with what many climate models predict: the AO index should get increasingly positive, due to increasing levels of CO2 in the atmosphere, since this tends to make the stratosphere cool and increase the strength of high altitude winds over the Arctic. However, a number of papers have been published since 2009 theorizing that the record loss of Arctic sea ice in recent years may be significantly altering Northern Hemisphere jet stream patterns (I list eleven of these papers below.) Many of these studies show a link between Arctic sea ice loss and an increasingly negative AO and NAO index in winter. Dr. Jennifer Francis of Rutgers has authored several of these papers, and wrote a very readable explanation of the theory linking Arctic sea ice loss to extreme weather in the mid-latitudes for our Earth Day 2013 microsite. Her post was called, “The Changing Face of Mother Nature.” The most recent technical paper connecting Arctic sea ice loss to extreme weather was a March 2013 paper by Tang et al., “Cold winter extremes in northern continents linked to Arctic sea ice loss”. The paper argued that unusual jet stream contortions in winter have become increasingly common in recent years. The scientists found a mathematical relationship between wintertime Arctic sea ice loss and the increase in unusual jet stream patterns capable of bringing cold, snowy weather to the Eastern U.S., Western Europe, and East Asia, typical of what one sees during a strongly negative Arctic Oscillation. They theorized that sea ice loss in the Arctic promotes more evaporation, resulting in earlier snowfall in Siberia and other Arctic lands. The earlier snow insulates the soil, allowing the land to cool more rapidly. This results in a southwards shift of the jet stream and builds higher atmospheric pressures farther to the south, which increases the odds of cold spells and blocking high pressure systems that can cause extended periods of unusually cold and snowy weather in the mid-latitudes. The research linking climate change impacts in the Arctic to more extreme jet stream patterns is still very new, and we need several more years of data and additional research before we can be confident that this is occurring. But if the new research is correct, the crazy winter weather we’ve been seeing since 2009 may be the new normal in a world with rapid warming occurring in the Arctic.

Related posts
“The Changing Face of Mother Nature” by Dr. Jennifer Francis of Rutgers, April 22, 2013.
Why was the start to spring 2013 so cold? by the UK Met Office, April 2013.
Extreme jet stream causing record warmth in the east, record cold in the west (January 2013)
Arctic sea ice loss tied to unusual jet stream patterns (April 2012)
Our extreme weather: Arctic changes to blame? (December 2011)
Florida shivers; Hot Arctic-Cold Continents pattern is back (December 2010)
Jet stream moved northwards 270 miles in 22 years; climate change to blame? (June 2008)
Linking Weird Weather to Rapid Warming of the Arctic by Dr. Jennifer Francis of Rutgers University (March 2012)
From Heat Wave to Snowstorms, March Goes to Extremes by Andrew Freedman of Climate Central (March 2013)

L’Heureux, M., A. Butler, B. Jha, A. Kumar, and W. Wang (2010), Unusual extremes in the negative phase of the Arctic Oscillation during 2009, Geophys. Res. Lett., 37, L10704, doi:10.1029/2010GL043338.

Papers published since 2009 that link Arctic sea ice loss to an increase in negative AO or NAO conditions
Deser, C., R. Tomas, M. Alexander, and D. Lawrence (2010), “The seasonal atmospheric response to projected Arctic sea ice loss in the late 21st century,” J. Clim., 23, 333351, doi:10.1175/2009JCLI3053.1.

Francis, J.A., and S.J. Vavrus (2012), “Evidence linking Arctic amplification to extreme weather in mid-latitudes,” Geophysical Research Letters, 21 February, 2012.

Francis, J. A., W. Chan, D. J. Leathers, J. R. Miller, and D. E. Veron, 2009, “Winter northern hemisphere weather patterns remember summer Arctic sea-ice extent,” Geophys. Res. Lett., 36, L07503, doi:10.1029/2009GL037274.

Honda, M., J. Inoue, and S. Yamane, 2009, “Influence of low Arctic sea-ice minima on anomalously cold Eurasian winters,” Geophys. Res. Lett., 36, L08707, doi:10.1029/2008GL037079.

Jaiser, R., K. Dethloff, D. Handorf, A. Rinke, J. Cohen (2012), “Impact of sea ice cover changes on the Northern Hemisphere atmospheric winter circulation”, Tellus A 2012, 64, 11595, DOI: 10.3402/tellusa.v64i0.11595

Liu et al. (2012), “Impact of declining Arctic sea ice on winter snowfall”, Proc. Natl. Academy of Sciences, Published online before print February 27, 2012, doi: 10.1073/pnas.1114910109

Overland, J. E., and M. Wang, 2010, “Large-scale atmospheric circulation changes associated with the recent loss of Arctic sea ice,” Tellus, 62A, 1.9.

Petoukhov, V., and V. Semenov, 2010, “A link between reduced Barents-Kara sea ice and cold winter extremes over northern continents,” J. Geophys. Res.-Atmos., ISSN 0148-0227.

Seager, R., Y. Kushnir, J. Nakamura, M. Ting, and N. Naik (2010), “Northern Hemisphere winter snow anomalies: ENSO, NAO and the winter of 2009/10,” Geophys. Res. Lett., 37, L14703, doi:10.1029/2010GL043830.

Seierstad, I. A., and J. Bader (2009), “Impact of a projected future Arctic Sea Ice reduction on extratropical storminess and the NAO,” Clim. Dyn., 33, 937-943, doi:10.1007/s00382-008-0463-x.

Tang et al., “Cold winter extremes in northern continents linked to Arctic sea ice loss,” Environ. Res. Lett. 8 014036 doi:10.1088/1748-9326/8/1/014036

Jeff Masters