Wednesday, September 02, 2009
Tuesday, September 01, 2009
Global warming behind reduced monsoon activity
The below normal rains this monsoon may be a consequence of Global warming as a new research warned there is a steady increase in temperature of Arabian sea compared to landmass thus weakening the monsoon activity over the country.
The difference between the temperature of sea, which is normally lesser than land, and land-mass around it is known as Temperature Gradient responsible to bring monsoon winds, called westerlies, to India.Researchers from Indian Institute of Tropical Meteorology,Pune found that sea temperature is rising at a higher rate than land--meaning crucial temperature difference is narrowing resulting in weakening of rain causing westerlies.
Dr S M Bawiskar who led the study stated that in the long term the reduction in temperature gradient, induced by global warming, will mean monsoon current over Arabian sea would become weak.The decreasing trend is highly significant and in another 150 years or so it may go down to zero.This will lead to reduced rainfall activity over Indian Peninsula. The break like circulation will prevail for a longer period of time which we are already experiencing during this monsoon, he said in an interview.
Chennai:: It's not yet monsoon, but it's raining diseases
Monsoon is not yet here, but the city and suburbs are seeing an increase in diseases associated with the rainy season. Water-borne and
vector-borne diseases such as acute diarrhoeal disorders, malaria, dengue, Chikunguniya and leptospirosis have raised their heads. The directorate of public health has urged doctors to be on the look out for differential diagnosis when these diseases come along with the present epidemic, A H1N1.
"It's too early to predict how serious the combined illnesses would affect people," says director of public health Dr S Elango. "We have told doctors to be careful while diagnosing and treating patients. With rains and cold weather, there will be a large number of people, particularly children and the elderly, down with several viral infections. Sometimes it can be combination of A H1N1 with another disease. Doctors should look out for trends to make the right diagnosis," he added.
The monsoon, he said, also marks the beginning of festive days. "While we are in the peak of winter in December, we would have expats and NRIs coming home for the Marghazi festival. That would obviously increase risks at the time when the weather is friendly," he adds.
While entomologists predict dengue and chikunguniya will be higher this monsoon, laboratories including the Tamil Nadu University of Veterinary Sciences (Tanuvas) have already seen an increase in the number of leptospirosis, commonly called rat fever. Private hospitals such as St Antony Hospital in Madhavaram have already begun admitting patients for leptospirosis and doctors say they see at least two new cases every day from areas like Manali and Madhavaram.
Tanuvas vice chancellor Dr P Thangaraju says he sees at least 25 cases every day. "Of the 50 samples we test everyday, at least 25 of them are positive. We expect it to go up to 100 a day by November," said Thangaraju. In July alone, the directorate of public health recorded 37 cases of dengue and 114 cases of chikunguniya across the state. The directorate of public health says it has been holding workshops and training for doctors and paramedical staff to look for people with symptoms. "We hold seminars and coordinate with civic agencies for chlorination of water and vector control measures.