Saturday 31 May 2014

Monsoon disrupted in India

Monsoon Disrupted By El Nino + Climate Change as India Suffers Deaths, Crop Losses from Extreme Heat.



Robertscribbler,

30 May, 2014


May is the month when the massive rainstorm that is the Asian Monsoon begins to gather and advance. This year, as in many other years, the monsoon gradually formed along the coast of Myanmar early in the month. It sprang forward with gusto reaching the Bay of Bengal by last week.


And there it has stalled ever since.
On May 25-27, an outburst of moisture from this stalled monsoonal flow splashed over the coasts of India. But by the 29th and 30th, these coastal storms and even the ones gathering over the Bengali waters had all been snuffed out. The most prominent feature in the MODIS shot of India today isn’t the rainfall that should be now arriving along the southeast coast, but the thick and steely-gray pallor of coal-ash smog trapped under a persistent and oppressive dome of intense heat.
Monsoon Disrupted
(MODIS shot of India on May 30th. See the open stretch of blue water in the lower right frame? That’s the Bay of Bengal which borders coastal India. During a normal year at this time, that entire ocean zone should be filled with the storm clouds of a building monsoon that is already encroaching on coastal India. Today, there is nothing but a smattering of small and dispersed cloud through a mostly clear sky. Image source: LANCE-MODIS.)

Monsoon Described as Feeble

Official forecasts had already announced as of May 27th that the annual monsoon was likely to be delayed by at least a week for southeast regions of India. Meanwhile, expected monsoonal rainfall for western and northern sections of India for 2014 fell increasingly into doubt.
The monsoon is likely to be delayed by 10 days, according to scientists at the Indian Institute of Tropical Meteorology (IITM) here. The IITM’s third experimental real-time forecast says that a feeble monsoon will reach central India after June 20 as against the usual June 15. Last year, the monsoon had covered the entire country by June 15.
The annual monsoon is key to India’s agriculture. The substantial rains nurture crops even as they tamp down a powerful heating that typically builds throughout the sub-continent into early summer. Without these rains, both heat and drought tend to run rampant, bringing down crop yields and resulting in severe human losses due to excessive heat.
But, this year, heat and drought are already at extreme levels.
Major Heatwave Already Results in Loss of Life for 2014
As early as late March, the heatwave began to build over the Indian subcontinent. The heat surged throughout the state, setting off fires, resulting in a growing list of heat casualties, shutting down the power grid and spurring unrest. Meanwhile, impacts to India’s agriculture were already growing as the Lychee fruit crop was reported to have suffered a 40% loss.
By late May, temperatures across a broad region had surged above 105 degrees shattering records as the oppressive and deadly heat continued to tighten its grip.
In a country surrounded on three sides by oceans, it is a combination of heat, humidity and persistently high night-time temperatures that can be a killer. Wet bulb temperatures surge into a high-risk range for human mortality during the day even as night-time provides little respite for already stressed human bodies. Such extreme and long-duration heat doesn’t come without a sad toll. As of today, early reports indicated a loss of more than 56 lives due to heat stroke (In 2012 and 2013, total Indian heat deaths were near 1,000 each year). That said, final figures on heat losses are still pending awaiting complete reports from all of India’s provinces.
Climatologically, we know that heatwaves are increasing in frequency and the number of days exceeding 45ÂșC temperatures is increasing. The frequency will increase further with global warming, hence this is a good example of a situation where science and disaster management can come together and avert damage,” a spokesman for India’s National Disaster Management Authority noted on Friday.

Hot Dust
(Hot Dust. A dust storm rolls through New Delhi on Friday amidst furnace-like 113 degree heat snarling traffic and resulting in the tragic loss of 9 more lives. Image source: Gaurav Karoliwal/YouTube Screenshot.)

Today the heatwave continued to gain ground, with Kota and Rajasthan reaching an all-time record of 116 degree F (46.5 C) as New Delhi’s mercury hit 113 degrees F in the midst of a drought-induced dust storm. Dust shrouding the city spurred traffic chaos and in the heat, darkness, and confusion nine more souls were lost.

After two months of growing disruption due to heat and drought, the lands and peoples of India cry out for a Monsoon that is running later and later with each new weather report.
Climate Change + El Nino: Adding Heat and Beating Back the Monsoon
As systems approach tipping points, they are more likely to tilt toward the extremes.
For India this year, its seasonally warmest period from April to May found severe heat amplification from a number of global factors. First, climate change seeded the ground for the current Indian heatwave by adding general heat and evaporation to already hot conditions. With global average heating of +0.8 C above 1880s levels amplifying in the hot zones, early moisture loss due to higher-than-normal temperatures produces a kind of snowball effect for still more warming. Essentially, the cooling effect of water evaporation is baked out early allowing for heat to hit harder just as typical seasonal maximums are reached.
Equatorial Pacific Ocean Temperatures May 30
(Equatorial Pacific Ocean temperatures warmed to +0.63 C positive anomaly on May 30th, extending further into El Nino Range. Image source: University of Maine.)

In addition, this year saw rapid progress toward an El Nino event in the Pacific Ocean with sea surface temperatures warming into the El Nino range by mid-May and continuing to ramp higher. By today, Equatorial Pacific anomalies had hit +0.63 C according to GFS analysis, extending a run into El Nino conditions.


El Nino events typically allow for the formation of hot, drier air over India. These air masses tend to engender extreme heatwaves like the one we are seeing now even as they delay the onset of cooling monsoonal rains. In essence, the monsoon is confronted with a heavy and entrenched wall of hot air that doggedly resists being shoved aside. And this is the very situation we observe now over India — a sputtering monsoon to the east getting bullied by a brutally hot and thick air mass that just won’t give ground. Climate change only exaggerates the problem by increasing the intensity and inertia of the hot air mass.
Major monsoonal disruptions typically occur during years following an El Nino’s peak heating impact. For example, in 1998, during a period following an extreme El Nino in the Pacific Ocean, India suffered one of its most severe droughts and monsoonal delays on record. But during recent years preceding El Nino, such as 2009, India also saw severe heat, drying, and crop damage due to a weakening of the annual summer rains. So an early monsoonal enfeeblement and coincident strong heatwaves and droughts over India with El Nino still forming is cause for some concern and bears further monitoring.
Currently, temperatures over India are surging to between 5 and 12 degrees Celsius above already hot averages. With heat and drought firmly in place, forecasts are calling for a 1 to 2 week delay in the cooling and moisture-bringing monsoon as India continues to swelter.
Links:
(Hat Tip to Colorado Bob RE Tipping Points)
(Hat Tip to Mark from New England for Excellent Clarifying Questions)

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