Tuesday, July 06, 2010
2:30pm, More showers over Haryana, Madhyapradesh, Chatisgarh, Orissa and Central U.P... http://ow.ly/i/2rQ2
Kerala - Kakkayam dam
One of the rainiest place in Kerala - Kakkayam dam
---------------------------
Kakkayam dam site has been experiencing more than 5000 mm of annual rainfall since 2000. It has been noticed that rainfall displays an increasing trend.
Annual rainfall (mm) received at Kakkayam Dam
2000 - 5248
2001 - 6177
2002 - 5078
2003 - 4656
2004 - 6515
posted by Pradeep
---------------------------
Kakkayam dam site has been experiencing more than 5000 mm of annual rainfall since 2000. It has been noticed that rainfall displays an increasing trend.
Annual rainfall (mm) received at Kakkayam Dam
2000 - 5248
2001 - 6177
2002 - 5078
2003 - 4656
2004 - 6515
posted by Pradeep
Global wind shifts ended last Ice Age?
Scientists have claimed that global wind shifts many have ushered in a warmer climate and the birth of human civilisation at the end of the last Ice Age about 20,000 years ago.
An international team has looked to a global shift in winds and propose a chain of events that began with melting of the large northern hemisphere ice sheets about 20,000 years ago, the 'Science' journal reported.
The melting ice sheets reconfigured the planet's wind belts, pushing warm air and seawater south, and pulling carbon dioxide from the deep ocean into the atmosphere, allowing the planet to heat even further. Their hypothesis makes use of climate data preserved in cave formations, polar ice cores and deep-sea sediments to describe how Earth finally thawed out.
"Finally, we have a clear picture of the global teleconnection in Earth's climate system that are active across many time scales.
"These same linkages that brought the earth out of the last ice age are active today, and they will almost certainly play a role in future climate change as well," Bob Anderson at Columbia University, who led the team.
Earth regularly goes into an ice age every 100,000 years or so, as its orientation toward the sun shifts in what are called Milankovitch cycles.
At the peak of the last ice age, about 20,000 years ago, with New York City and large parts of Europe and Asia buried under thick sheets of ice, Earth's orbit shifted.
posted by Anonymous
An international team has looked to a global shift in winds and propose a chain of events that began with melting of the large northern hemisphere ice sheets about 20,000 years ago, the 'Science' journal reported.
The melting ice sheets reconfigured the planet's wind belts, pushing warm air and seawater south, and pulling carbon dioxide from the deep ocean into the atmosphere, allowing the planet to heat even further. Their hypothesis makes use of climate data preserved in cave formations, polar ice cores and deep-sea sediments to describe how Earth finally thawed out.
"Finally, we have a clear picture of the global teleconnection in Earth's climate system that are active across many time scales.
"These same linkages that brought the earth out of the last ice age are active today, and they will almost certainly play a role in future climate change as well," Bob Anderson at Columbia University, who led the team.
Earth regularly goes into an ice age every 100,000 years or so, as its orientation toward the sun shifts in what are called Milankovitch cycles.
At the peak of the last ice age, about 20,000 years ago, with New York City and large parts of Europe and Asia buried under thick sheets of ice, Earth's orbit shifted.
posted by Anonymous
Monsoon break looms even as rains break into north-west India
The monsoon has been declared as having broken over north-west India, but at the cost of a largely dry Uttar Pradesh upstream to the east.
As if this is not enough, international agencies also point to the probability of monsoon entering into yet another brief lull phase from July 11.
‘CONVERGENCE' RAIN
The pattern of the ongoing heavy to very heavy rain over parts of the rest of northwest India suggests they are borne out of ‘convergence' between easterlies and a prevailing western disturbance.
One view is that these rains may last only for as long as the western disturbance is active in the region.
Meanwhile, a decisive change in ambient wind conditions helped monsoon easterlies establish themselves over large parts of northwest India.
They have also managed to bring the rains, though not in a pattern or quantum identified with normal monsoon.
The good times may not last beyond the next six days since flows over the Arabian Sea may once again weaken from July 11 onwards, says Dr Akhilesh Gupta, leading operational forecaster and Advisor to the Department of Science and Technology.
The lull phase is likely to hold until July 14, subsequent to which they are expected to revive gradually.
MONSOON ADVANCES
On Monday, the India Meteorological Department (IMD) said that monsoon has further advanced into Madhya Pradesh, Bihar, Uttar Pradesh, most parts of east Rajasthan and entire Haryana, Delhi, Punjab, Uttarakhand, Himachal Pradesh and Jammu and Kashmir. The IMD, too, conceded that the advance of monsoon over east Uttar Pradesh was feeble at best.
The northern limit of monsoon passed through Jawai Dam, Ajmer, Churu and Sriganganagar — all in Rajasthan.
Conditions are favourable for its further advance into the remaining parts of Rajasthan during next two days.
At no time in the recent past have monsoon flows been subjected to as many frequent ‘stops' as have happened this year, Dr Gupta told Business Line.
This requires a careful examination of conditions prevailing in the upstream domains, especially the southern hemisphere from where the flows originate.
According to him, the quick turnaround in the northwest over the past day or two was facilitated by the re-orientation of flows over North Arabian Sea.
QUIET BAY
That it draws little from an ‘attitudinal change' in the Bay of Bengal climes helps expose the weak link in the monsoon chain.
Explaining the change in the welcome wind pattern, Dr Gupta said the winds over North Arabian Sea changed from being south-southwesterly (heading straight into northwest India) to southwesterly-to-westerly.
This opened up a crucial sluice valve towards the east of the country, allowing easterlies to rush in to the plains in the north.
Had the re-oriented flows sustained for a longer time than is forecast, they would have initiated a proper low-pressure area in the North Bay and piloted the monsoon in.
Given this, it is likely that Uttar Pradesh would continue to a pose a stumbling block for the IMD even as monsoon finds its way in fits and starts to the rest of the north-west.
An IMD warning valid for the next two days said that isolated heavy to very heavy rainfall would occur over Konkan in Goa, coastal Karnataka, Telangana, coastal Andhra Pradesh, Madhya Maharashtra, Vidarbha, Gujarat, East Rajasthan, West Madhya Pradesh, Punjab, Haryana, West Uttar Pradesh, Uttarkhand and Himachal Pradesh.
Outlook until Thursday suggested that widespread rain/thundershowers would occur over west coast.
Fairly widespread rain/thundershowers would occur over Andaman and Nicobar Islands, the Northeastern States, sub-Himalayan West Bengal, Sikkim, Orissa, north Andhra Pradesh, Gujarat, Vidarbha, Chhattisgarh, Madhya Pradesh and
Lakshadweep.
Fairly widespread rain/thundershowers are likely over Haryana, Punjab, Chandigarh, Delhi, Rajasthan, Jammu and Kashmir, West Uttar Pradesh, Uttarakhand and Himachal Pradesh during the next two days and decrease thereafter.
Extended outlook until Saturday said that only scattered rainfall activity is likely over the plains of northwest India. But rains may scale up over Uttar Pradesh, Bihar, Sub-Himalayan West Bengal, Sikkim and the Northeastern States.
Monsoon likely to mimic 2006 pattern
Will this monsoon be a repeat of 2006 (normal) pattern or will it end up in a disaster like last year?
Going by the quantum of rainfall received so far and the India Meteorological Department's (IMD) optimistic prognosis for July and August, there is reason to believe that the current south-west monsoon season (June-September) will be on the lines of 2006.
SLOW START
In 2006, the monsoon got off to a slow start, with the country getting only an average of 141.8 mm of rains during June, as against the normal long period average (LPA) of 162.4 mm for the month.
But July turned out to be good and August-September even better, so that the season, as a whole, returned a near-normal monsoon.
This time, too, June has registered an area-weighted average precipitation of just 137.5 mm.
This, even being deficient relative to the normal, is still a considerable improvement over last June's 85.7 mm, which was the worst-ever recorded June.
The IMD, in its updated forecast issued on June 25, has predicted rainfall at 98 per cent of the LPA in July and 101 per cent in August (subject to a plus or minus 9 per cent model error).
These would work out to an estimated 287 mm and 265 mm respectively, which more or less conform to the pattern in 2006. But the most disastrous scenario would be a repeat of last year, when the monsoon staged a smart recovery in July and then completely fizzled out in August and September.
Farmers, in the process, faced a double setback: The rains did not come when they sowed the first time. When the rains finally arrived, they sowed afresh only to encounter a second dry phase.
This time, farmers have been more cautious, not resorting to aggressive planting and waiting for the monsoon to advance. If July and August turn out good, it would probably be worth the wait.
Subscribe to:
Posts (Atom)