Sunday, January 31, 2016

Overhead or underfoot Moon affects rainfall, says a new study.

At a time I am engaged in experimentation with Rainfall astrology in terms of "Garbottam", the findings of a research based on 15 years data compiled by NASA and Rainfall measuring Mission satellite of Japan adds strength to the views of ancient Hindu astrology on the influence of Moon on rainfall. The researchers at the New University of Washington have just followed the path of the Moon in the sky on each day and have seen that Moon at zenith or nadir is capable exerting a pull on the atmosphere of the earth and thus on air pressure at that place. This reduces the amount of rainfall at that time, though very slightly.

I am happy to note that they are planning to conduct more experiments on connection between Moon and rainfall. I would like them to check specifically two features told by the ancient sages of India and supposed to have been successfully checked and followed by the people of India for hundreds of generations.

But before spelling those out I have a doubt on whether they checked a related feature / phase of the Moon. The news report on their experiments says that rainfall was affected when Moon was overhead or underfoot in a place at that time. I would like to know whether they checked specifically the days of 8th and 9th phase of Moon in a place. It is because Moon will be directly overhead when it is passing these 2 phases. These two days would also see the Moon at right angles to the Sun.

My questions are (1) does Moon at over head position at the time of nightfall during the 8th and 9th phase cause any change in the air pressure / atmosphere? (1a) Anyway Moon in these 2 phases would rise 6 hours before sunset. Does that have any impact on the rainfall right from the time it rises in the day time at a place?

 (2) From another perspective, is the influence of Moon (tidal force) the least on rainfall on those 2 days owing to the fact that the combined force of the Moon and the Sun on the earth must be the least on those 2 days as they are 90 degrees apart?

Now the two features that I wish the researchers and whoever else interested in this kind of research, to take up: (These are based on rainfall astrological concepts of Vedic sages. Let modern science test and verify them.)

1. What is the status of influence on rainfall on Full Moon and New Moon days? The concept is that if it rains on a New Moon day in a place, it would not rain in the waning phase that comes after a fortnight.

2.  If it rains when the moon is within 8 to 15 degrees from the sun after conjunction (New Moon) or opposition (Full moon), then it will rain for a month till moon reaches the same position again. This can be tested using the data.

There are numerous other features related to Moon’s position across the sky (sidereal based) that have a bearing on rainfall. The above mentioned two are related to the phase of the Moon which the researchers are concentrating on. (This article is being mailed to the researchers)



Phases of the moon affect amount of rainfall

When the moon is high in the sky, it creates bulges in the planet’s atmosphere that creates imperceptible changes in the amount of rain that falls below.

New University of Washington research to be published in Geophysical Research Letters shows that the lunar forces affect the amount of rain – though very slightly.

“As far as I know, this is the first study to convincingly connect the tidal force of the moon with rainfall,” said corresponding author Tsubasa Kohyama, a UW doctoral student in atmospheric sciences.

Kohyama was studying atmospheric waves when he noticed a slight oscillation in the air pressure. He and co-author John (Michael) Wallace, a UW professor of atmospheric sciences, spent two years tracking down the phenomenon.

Satellite data over the tropics, between 10 degrees S and 10 degrees N, shows a slight dip in rainfall when the moon is directly overhead or underfoot. The top panel shows the air pressure, the middle shows the rate of change in air pressure, and the bottom shows the rainfall difference from the average. The change is 0.78 micrometers, or less than one ten thousandth of an inch, per hour. University of Washington

Air pressure changes linked to the phases of the moon were first detected in 1847, and temperature in 1932, in ground-based observations. An earlier paper by the UW researchers used a global grid of data to confirm that air pressure on the surface definitely varies with the phases of the moon.

“When the moon is overhead or underfoot, the air pressure is higher,” Kohyama said.

Their new paper is the first to show that the moon’s gravitational tug also puts a slight damper on the rain.

When the moon is overhead, its gravity causes Earth’s atmosphere to bulge toward it, so the pressure or weight of the atmosphere on that side of the planet goes up. Higher pressure increases the temperature of air parcels below. Since warmer air can hold more moisture, the same air parcels are now farther from their moisture capacity.

“It’s like the container becomes larger at higher pressure,” Kohyama said. The relative humidity affects rain, he said, because “lower humidity is less favorable for precipitation.”

Kohyama and Wallace used 15 years of data collected by NASA and the Japan Aerospace Exploration Agency’s Tropical Rainfall Measuring Mission satellite from 1998 to 2012 to show that the rain is indeed slightly lighter when the moon is high. The change is only about 1 percent of the total rainfall variation, though, so not enough to affect other aspects of the weather or for people to notice the difference.

“No one should carry an umbrella just because the moon is rising,” Kohyama said.

Instead, this effect could be used to test climate models, he said, to check if their physics is good enough to reproduce how the pull of the moon eventually leads to less rain.

Wallace plans to continue exploring the topic to see whether certain categories of rain, like heavy downpours, are more susceptible to the phases of the moon, and whether the frequency of rainstorms shows any lunar connection.

The research was funded by the National Science Foundation, the Tanaka Ikueikai Scholarship Society, and the Iizuka Takeshi Scholarship Foundation.

For more information, contact Kohyama at Wallace is traveling out of the country through March.


Srikanth said...

I wanted to share this with you. Interesting to see this analysis from the perspective of how ancient Indian astronomy used similar knowledge to put out expected rain forecasts.

Jayasree Saranathan said...

Thanks Mr Srikanth. I happened to read the news report on this research in Dinamalar (Tamil daily). Wonder what the reporters have understood of the research.

They have written

நிலவின் வடிவம், சற்று பெரிதாகும் போது, காற்று மண்டலத்தில் அழுத்தம் அதிகரித்து, பூமியில் பெய்யும் மழையின் அளவு, சற்று குறைவதாக, புதிய ஆராய்ச்சி ஒன்று தெரிவித்துள்ளது.

வாஷிங்டன் பல்கலைக்கழக ஆராய்ச்சியாளரான சுபாசா கொயமா இதுகுறித்து கூறியதாவது: பல்வேறு காரணங்களால், நிலவின் வெளிவட்ட சுற்று, அவ்வப்போது விரிவடைந்தும், சுருங்கியும் காணப்படுகிறது. இதுபோன்ற சமயங்களில், காற்று மண்டலத்தில், காற்றின் அழுத்தம் அதிகரிக்கிறது. இதனால், வெப்பக்காற்று குளிர்வதில் பிரச்னை ஏற்படுகிறது. ஈரப்பதம் குறைவதால், மழை பொழிவு, சற்று குறையும், எனினும், பெரிய அளவில் பாதிப்பு ஏற்படாது.
1998 - 2012 ஆண்டுகளில், அமெரிக்க விண்வெளி ஆய்வு மைய புள்ளி விவரங்களை வைத்து, இதை உறுதி செய்துள்ளோம். இவ்வாறு அவர் கூறினார்.

What do they mean by 'பல்வேறு காரணங்களால், நிலவின் வெளிவட்ட சுற்று, அவ்வப்போது விரிவடைந்தும், சுருங்கியும் காணப்படுகிறது'?
Is this what the researchers have said?

I pity the Tamil readers.

Unknown said...

Madam. I would like to understand about avani avittam. Why it's not common and why is it not celebrated in avani. Can you help educate my sefl

Jayasree Saranathan said...

@ Swamynathan Sekar,

The answers for your questions are available on internet. Check this link: