Saturday, 27 February 2016


Clouds are fascinating things, which we pay no attention to, even when we fly in airplanes, and can observe them first hand. They play an absolutely vital role in our daily lives, but we tend to pay so little attention to them, in science studies. Poets, though, love them and cannot resist writing about them or using them as metaphors.

Cloud over Texas - from SFO to ATL

Cloud over the Arctic - Dubai to LAX

The Institute of Mathematical Sciences, Madras organized a set of lectures at the Music Academy on February 14, 2016. There was an excellent turnout. The first lecture was about Clouds, by Dr Rama Govindarajan. Her actual title was "A Future in the Clouds." She is the first woman to get the Government of India's S. S. Bhatnagar award, the highest award for science! The following is my summary of her lecture.

--- Begin summary ---

Let us understand the value of green house gases Carbon dioxide, Methane and water vapor. Life on earth is possible ONLY because of green house gases. Oxygen and nitrogen, which together constitute nearly 99% of the atmosphere, do nothing for warming the planet or keeping it at optimal temperature for life. Without an atmosphere, the surface temperature of the earth would be -18 degrees Celsius. It would be as barren of life as the other planets in the solar system.

Sunlight and ultraviolet light from the sun are shortwave radiation coming into the atmosphere. When reflected, it becomes long wave outgoing radiation (heat, infrared). 

India gets high concentration of rain during four monsoon months - 85cm annual average. In contrast, Paris, France, for example, gets 6cm every month and this barely changes across 12 months. There is an On and Off pattern to the clouds moving over the Indian subcontinent. The monsoon, a special feature of Indian geography, has rain clouds going north bearing water. Kalidasa's epic poem Meghadootham and Sangam Literature in Tamil discuss this northern traversal of clouds. Tamilnadu is an outlier from most of India, because here the monsoon is mostly in October and November. The onset of the monsoon in India is preceded by scorching heat and parched earth, and the rains are greeted with great celebration.

Most clouds are white, highly reflective. Fifty to seventy percent of Earth is covered by clouds.  Low clouds and high clouds act very differently in terms of allowing reflecting or radiating heat. Low thick clouds act as a reflector, they keep the surface under them cool. High thin clouds are transparet, and act like a blanket they preserve the heat that they let in.

Weather is very chaotic (mathematically speaking) . Extreme events of weather are not as statistically rare as they would be on normal distributions. Industrial greenhouse gases have pushed weather towards more extreme events at higher temperature.

Life has adapted to climate change when change happens gradually. Biggest extinction event was 640 million years ago, when temperatures rose very fast and 75% of life perished. Now because of global warming (i.e., industrial pollution) which is really fast, life doesn't have time to adapt.

Scientist Roddam Narasimha has hypothesised a model of clouds. He has built clouds in his lab in Bangalore.

We don't understand why a cloud forms. We can't answer the most trivial questions about clouds. But we know they are very turbulent. Full of Eddies. Why do they go that high? We dont know. Clouds are obviously different from chimney smoke, which doesn't rise one km high.

-----End Summary----

These are from quick notes, so naturally not even an attempt to be comprehensive.

Gopu's comments

What struck me was the she had a hazy idea of biology, and of the history of Life. Sadly even most biologists may have limited understanding of history of life. She thinks there was one large extinction event 640 MYA (Million Years Ago). There have actually been five major extinction events in just the last 540MYA (and more before that). The biggest was the Permian extinction, which happened about 250 MYA. There are also Snowball earth events, that happened two billion years ago. Most biologists seem to ignore all geological events and even life before 540MYA!

I was struck by her remark that scientists don't know the most trivial things about clouds. The Climate Change alarmists tend to speak about Global Warming as uncontested indisputable Absolute Truth. 

It was a wonderful lecture, opening up a world of information on clouds, a topic rarely discussed.

1. Video of Dr Rama Govindarajan's Lecture

2. Botanical Gardens 
3. Floating among the clouds - How to numb your senses

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