Thursday, 17 November 2011

Monsoon Skyscapes

Right now, the Northeast or winter monsoons are sweeping through Tamil Nadu. While we felt the first few thundershowers around Diwali last month, more squally weather is anticipated till the end of this year. The sky often changes colours swiftly from dark grey to clear blue. Here are a few pictures of the sky, taken in the past few days.

Looming Dark Thunderclouds
Next Morning: Clear Skies and A Rainbow
The term "Monsoon" is derived from the Arabic "Mausam", meaning season. While there are monsoons experienced in other parts of the world, the Indian Monsoons are the most spectacular, providing the country with most of its rain. Here's a layman's perspective of the workings of the monsoon. We have two monsoon seasons: the Southwest monsoon or the summer monsoon and the Northeast monsoon or the winter monsoon.

In summer, while the Asian continent is steadily getting heated, the surrounding giant ocean does not get similarly heated. Reason: land heats up and cools down much faster than water. The difference in heat between the land and water bodies is huge, since on the one hand we have the large Asian continent and on the other, we have an equally vast Indian ocean. As the hot air above the land rises, a low pressure is created. The cooler air from above the ocean rushes in to fill the void. Laden with moisture from the oceans, winds (blowing from the south west to the north east) hit the Indian coast by the end of summer. The date of arrival is around June 1st. This is the summer or Southwest monsoons.

Later in the year when the sun retreats, the land cools rapidly, while the ocean still holds its heat. The result is a high pressure zone over the land, which causes the wind from the Himalayas to sweep down towards the Indian Ocean. These winds pick up moisture from the Bay of Bengal and bring rain to Tamil Nadu and other parts; these are known as the Northeast monsoon or the retreating monsoon.

Southern Sky at 11 a.m.: Cloudy Turmoil

Western Sky at 11 a.m.: Azure Blue Skies
Above are pictures from yesterday, taken at exactly the same time. While parts of the sky seemed to be in turmoil, when I turned around, the scene was much calmer.

Evening Sky at 6 p.m.: A Beautiful Sunset
By evening, the sky had cleared up a bit and was a brilliant crimson. There was little hint of the torrential rain that was to follow at night.
Soft Pink Glow
The monsoons are rather erratic and highly unpredictable.  In fact, I read here, in this rather informative article, how the only predictability about the monsoon is its unpredictability. Indian farmers are hugely dependent on the monsoons. Yet, our meteorologists give us little and sometimes misleading information about this annual mega weather event. The monsoons are poorly understood and need to be studied more. With more research and better technology in the future, I hope India will have improved weather forecasts. Until then, many Indians may be more content relying on astrological predictions rather than predictions from the met department.

Linked to Skywatch 


  1. vasanti said:

    Lovely pictures! Espcially the one with the flying eagle and the rainbow.

  2. That rainbow brightened up my day. I'm afraid those aren't eagles. They were most probably pigeons.

  3. Brilliant photos - very dramatic! I like the idea of "predictable unpredictability". It sounds like the word our weather-forecasters use when they have no idea what is going to happen: "changeable".

  4. Brilliant photos! I did not realize that there were different types of monsoons. Great post!

  5. excellent pictures. why not add it to Skywatch Friday

  6. Thank you Arati! Have linked to Skywatch.

  7. Those overcast skies remind me of the time that I was there. Your sunset shots are stunning!!