Have you felt the full force of monsoon rains?

Monsoon

A monsoon is a climatic pattern which consists of a seasonal wind and the sometimes extremely heavy rain that comes with it. In summer the land heats up more quickly than the ocean. The warm air rises, creating an area of low pressure which steadily draws in the moist air from over the ocean. As the moist air reaches the mountains it is diverted upwards, becoming cooler and the moisture condenses. In winter the land cools more than the ocean. The warm air over the ocean rises. The resultant low pressure draws air away from the land, though the temperature difference is not so great that the wind is constant.

The monsoon affects a swath of countries including the countries bordering the Indian Ocean, much of China, Indonesia, the northern edge of Australia, northern Madagascar, and most of Africa north of the Equator but not as far north as the Mediterranean coast. It blows from the southwest along the shores of the Indian Ocean (especially in the Arabian Sea) for half of the year, and from the northeast for the other half. The monsoon is also influenced by the jet stream. Australia and southeast Asia experience a lot of rainfall during the Northeast Winter Monsoon (December to early March), and India and neighbouring countries during the Southwest Summer Monsoon (June to September).

The monsoons even affect the currents in the Indian Ocean; for example the Somali Current only occurs from June through September, the South Equatorial Current is stronger during the southwest monsoon, and the North Equatorial Current reverses direction during the northeast monsoon.

The North American monsoon from mid July to September affects inland and mostly desert Arizona, California, Colorado, Mexico, Nevada, New Mexico, and Utah.

The African monsoon is essential for survival in the Sahel, but in the 1970s and 1980s it failed to reach that far north, leading to extreme drought and the pictures of starvation in Ethiopia that shocked the world in 1984. A climate model has since shown that some kinds of pollution from Europe and North America can affect the clouds, causing them to reflect more sunlight back out into space, and so cooling the oceans of the northern hemisphere. As a result the clouds stayed further south, as less warmth from the sun got through to draw the monsoon rains north. The phenomenon causing this is called global dimming. It is caused by particulate matter and dust polluting the air, rather than by the gases that cause global warming. Since Europe has reduced this kind of pollution, the droughts in the Sahel have not been as bad most years.

There are other reasons why there may be good (average rainfall) or poor (drought) monsoon years. They are connected with the fluctuations of the El Niño Southern Oscillation (ENSO), which happens every 2 to 8 years. A large pool of warm water near South America caused by a change in the pattern of winds in the southwest Pacific Ocean causes a knock on effect elsewhere in the world, bringing droughts to Africa, Australia, India and the former Soviet Union and unusually heavy rain to the Mediterranean and the South American coast. ENSO and the monsoons are not in step; the abnormal weather occurs when their peaks and troughs coincide. For example, there were strong ENSO events in 1877, 1884, 1891, 1911, 1918, 1925, 1941, 1957, 1972 and 1982. In only 4 of those years was the Asian monsoon in step - in 1877, 1899, 1918 and 1972 - and there were major droughts.

Records show that the monsoons have grown stronger over the past few centuries, which climatologists believe could be a result of global warming. This week's record rains in India are a sign that this could well be the case. The trend could continue, but it is possible that a sudden change such as a cooling of the North Atlantic Ocean (see Ocean Conveyor Belt) could weaken future monsoons. If the North Atlantic continues to get warmer, the monsoons will likely get stronger.

The Asian monsoon brings the rains needed for survival by more than half of the world's population. If they should fail, or gain significantly in strength, the result could be massive human misery. We are at the mercy of a powerful and complex natural system, but it would appear that we have found ways to influence it which will return to haunt us.

Indians Recover 200 Bodies From Monsoon, Floods kill dozens in India as Bombay under water

Bombay has felt the heaviest monsoon rainfall ever recorded there, with many people marooned and 200 already found dead in the region. Some were killed by landslides. Bombay, the airport and railway stations were closed down. Troops have been brought in to help and food and water are being distributed. The rain peaked at 37.1 inches (94 cm) in one day.

Please see the following message for the remaining stories.

Livestock Not Immune From Heat Stress

It's not just humans who are suffering in the heat that most of the USA is sweltering under; livestock is too. Farmers are doing what they can, but over 1,200 head of cattle in Nebraska have died. Plenty of water is essential.

Bones Found in Texas Likely a Mammoth

The bones unearthed near Brownwood, Texas last month were probably of a Columbian mammoth from 9,000 to 40,000 years ago. They weighed up to 9 tons with 16-foot tusks.

Federal Agents Target Two Wolves in Idaho

The U.S. Fish and Wildlife Service has ordered 2 wolves from the Chesimia wolf pack in north central Idaho to be killed. They are suspected of having killed two cows and six dogs. If that doesn't work the whole pack may need to be taken out.

Skunk Beats the N.Y. Heat in Drug Store

A skunk sought respite from the hot weather in a drug store in Chenango, N.Y. Customers were turned away. It was eventually taken away by a pest control expert without having been upset.

More Rare Hummingbirds Spotted in Texas

White-eared hummingbirds are extremely rare in Texas, but more than usual have been spotted recently, making ornithologists wonder if they are extending their range.

Brown Bear Photo courtesy of US F&WS

Witnesses Say Bears Back in Switzerland

Switzerland had opened up a wildlife corridor to allow some of the expanding population of brown bears in northern Italy to move into eastern Switzerland's Ofenpass National Park. Witnesses now believe they have seen one which, if confirmed, would be the fist bear in Switzerland since 1904.

Dead Anchovies Leave Putrid Stink in Ore.

Millions of anchovies have washed up dead on the northern Oregon Coast and the Neawanna River. This is a normal occurrence, probably because there were too many of them. Authorities have warned people to keep away until the tide removes them, but it seems likely that the stench will ensure that.

Environmental Report Names Top Polluters

One third of the Northeast USA's carbon dioxide emissions were produced by just ten power plants last year. A coalition of environmental groups has named the ten worst, with Brayton Point Station, Somerset coming in first.

Pesticides May Be Sickening School Kids

More than 500 children and school employees a year have been taken ill as a result of pesticides in or around their schools over the past 5 years. Most illnesses were mild.

Aftershocks Shake Southwestern Montana

Eight aftershocks of between magnitude 2.8 and 3.8 have shaken Montana in the wake of the recent magnitude-5.6 earthquake.

Have you felt the full force of monsoon rains?

[Views expressed are those of the author(s) and do not necessarily reflect those of CompuServe, Netscape, any government, agency, or news organization. External Websites are "At Your Own Risk," and no endorsement is expressed or implied.]