Thursday, December 31, 2009
NCMRWF:: Still predicts a Huge low pressure system Just east -south-east of Srilanka on 7-Jan.. http://yfrog.com/1yv0xj
Heavy isolated afternoon showers along North Kerala & South Coastal Karnataka .. http://ping.fm/jbMKt
After 1741, 2010 to witness lunar eclipse on NEW year day.
On a full blue moon day on Thursday, skywatchers will have a bonanza when they find the lunar radiance, rather dim, as the country witnesses a partial lunar eclipse. The phenomenon, according to astrophysicists, is only the second time since 1741 when the world saw a lunar eclipse on a New Year’s day.
A partial lunar eclipse occurs when only part of the Moon passes through the darkest part of the Earth’s shadow.
The eclipse is scheduled to begin when the Moon enters the Earth’s shadow at 10:47 pm, and it ends at 02:58:11 am. The start of the partial eclipse will be at 00:22:43 am on January 1, 2010. It will end at 01:22:41 am.
“Although the partial phase of the eclipse lasts for an hour, only 7 per cent of the diameter of the Moon is covered by the umbral shadow of the Earth, which is too negligible to be easily visible,” said N Rathnashree, director of Nehru Planetarium.
When a second full moon in a calendar month appears in the night sky, the occurrence is known as a blue moon. There are 12 full moons most years, but every two or three years there is an extra full moon which is called a blue moon.
“Such an eclipse of the Moon will be difficult to discern with naked eye—although an astrophotograph of the Moon might just show a hint of darkening over a very tiny region of the Moon,” Rathnasree said.
According to scientists, the astronomical event can be seen all over Asia and Europe, major parts of Africa and a small portion of southwestern Australia.
“The beginning, the middle and the ending of the eclipse will be visible from all parts of India,” Science Popularisation Association of Communicators and Educators (SPACE) Director C B Devgun said.
The beginning of the umbral phase will be visible from the extreme southeastern part of Australia, middle of South and North Pacific Ocean and extreme Solomon Island. The ending of the umbral phase will be visible from North and South Atlantic Ocean and Greenland.
A partial lunar eclipse occurs when only part of the Moon passes through the darkest part of the Earth’s shadow.
The eclipse is scheduled to begin when the Moon enters the Earth’s shadow at 10:47 pm, and it ends at 02:58:11 am. The start of the partial eclipse will be at 00:22:43 am on January 1, 2010. It will end at 01:22:41 am.
“Although the partial phase of the eclipse lasts for an hour, only 7 per cent of the diameter of the Moon is covered by the umbral shadow of the Earth, which is too negligible to be easily visible,” said N Rathnashree, director of Nehru Planetarium.
When a second full moon in a calendar month appears in the night sky, the occurrence is known as a blue moon. There are 12 full moons most years, but every two or three years there is an extra full moon which is called a blue moon.
“Such an eclipse of the Moon will be difficult to discern with naked eye—although an astrophotograph of the Moon might just show a hint of darkening over a very tiny region of the Moon,” Rathnasree said.
According to scientists, the astronomical event can be seen all over Asia and Europe, major parts of Africa and a small portion of southwestern Australia.
“The beginning, the middle and the ending of the eclipse will be visible from all parts of India,” Science Popularisation Association of Communicators and Educators (SPACE) Director C B Devgun said.
The beginning of the umbral phase will be visible from the extreme southeastern part of Australia, middle of South and North Pacific Ocean and extreme Solomon Island. The ending of the umbral phase will be visible from North and South Atlantic Ocean and Greenland.
Till 5-Jan-10, heavy showers for West, and North-west India and till 15-Jan-10, showers for South-East India ..??? http://is.gd/5HnBD
"Blue Moon" to Shine on New Year's Eve
For the first time in almost 20 years, a bright "blue moon" will grace New Year's Eve celebrations worldwide. (Take a moon myths quiz.)
If the skies are clear, revelers looking up at midnight will get an eyeful of the second full moon of the month—commonly called a blue moon. The last time a blue moon appeared on New Year's Eve was in 1990, and it won't happen again until 2028.
With this New Year's Eve blue moon, "there is nothing scientific about it, and it has no astronomical significance," said Mark Hammergren, a staff astronomer at the Adler Planetarium in Chicago, Illinois.
"But I believe it does give us some insight into history and makes us think of how our calendar system has derived from motions of objects in the sky."
Blue Moon Error
The popular definition of a blue moon isn't the only one—and it's one that's based on an editorial error, astronomers contend.
The widespread definition of the second full moon in a month stems from errors made in an astronomy magazine, when a writer misinterpreted how the term was used in the Maine Farmer's Almanac.
Later studies of almanacs published from 1819 to 1962 revealed that the term "blue moon" actually refers to the "extra" full moon that can occur in a year due to differences between the calendar year and the astronomical year.
(Related: "Leap Year—How the World Makes Up for Lost Time.")
Most years on average have 12 full moons, with 1 appearing each month.
That's because the lunar month—the time it takes the moon to cycle through its phases—corresponds closely to the calendar month.
But the calendar year is actually based on the solar cycle, or the time it takes Earth to make one trip around the sun. This means a year is not evenly divisible by lunar months, so every three years or so there are 13 full moons.
The farmer's almanac further divided the year into four seasons, with each season lasting three months. When a given season saw four full moons, the almanac dubbed the third moon as a blue moon.
Ultimately, a blue moon as defined by the calendar isn't that rare, added Hammergren. The term's significance instead lies in the way it links people to the motions of the cosmos.
"Just being able to recognize that we can have a full moon twice in a month and have [folklore] attached really highlights the fact that humans have been astronomers their entire existence," he said.
"True" Blue Moon
Before the editorial error, the term "blue moon" more often referred to the rare instances when the moon actually seemed to turn blue, as can happen under certain atmospheric conditions.
"After a forest fire or volcanic eruption, there may be enough particulate matter in the air so that the moon can take on a bluish tinge," Hammergren said.
For instance, a "true" blue moon occurred in 1950 after a large forest fire in Canada blew smoke across most of the Northern Hemisphere.
Another appeared in 1980 after the last major eruption of Mount St. Helens, which sent tons of ash into the upper atmosphere.
Although rumblings at the Mayon Volcano in the Philippines seem to signal a major eruption is imminent, experts don't think Mayon's current output will make this New Year's Eve full moon turn blue.
Howling at the Blue Moon
Even if the 2009 New Year's Eve blue moon has astronomers scoffing, nighttime partygoers may still get moonstruck.
Rising in the east at sunset, the New Year's Eve full moon will reach its highest point at midnight, noted Jack Horkheimer, director of the Miami Space-Transit Planetarium and host of PBS television's long-running show Star Gazer.
"Full moons around winter solstice rise their highest for the entire year," Horkheimer added.
"Even if you are downtown in a large city, if it is clear at the stroke of midnight the moon will be very visible if you look up."
In any location, the high, silvery orb will seem like a floodlight cast on the landscape, added Horkheimer, who is organizing a national moon-howling contest around this year's blue moon.
"This is especially true where the ground is covered with a blanket of snow. There is nothing quite so spectacular as a snow-covered scene under a December full moon at midnight."
From National Geographic
If the skies are clear, revelers looking up at midnight will get an eyeful of the second full moon of the month—commonly called a blue moon. The last time a blue moon appeared on New Year's Eve was in 1990, and it won't happen again until 2028.
With this New Year's Eve blue moon, "there is nothing scientific about it, and it has no astronomical significance," said Mark Hammergren, a staff astronomer at the Adler Planetarium in Chicago, Illinois.
"But I believe it does give us some insight into history and makes us think of how our calendar system has derived from motions of objects in the sky."
Blue Moon Error
The popular definition of a blue moon isn't the only one—and it's one that's based on an editorial error, astronomers contend.
The widespread definition of the second full moon in a month stems from errors made in an astronomy magazine, when a writer misinterpreted how the term was used in the Maine Farmer's Almanac.
Later studies of almanacs published from 1819 to 1962 revealed that the term "blue moon" actually refers to the "extra" full moon that can occur in a year due to differences between the calendar year and the astronomical year.
(Related: "Leap Year—How the World Makes Up for Lost Time.")
Most years on average have 12 full moons, with 1 appearing each month.
That's because the lunar month—the time it takes the moon to cycle through its phases—corresponds closely to the calendar month.
But the calendar year is actually based on the solar cycle, or the time it takes Earth to make one trip around the sun. This means a year is not evenly divisible by lunar months, so every three years or so there are 13 full moons.
The farmer's almanac further divided the year into four seasons, with each season lasting three months. When a given season saw four full moons, the almanac dubbed the third moon as a blue moon.
Ultimately, a blue moon as defined by the calendar isn't that rare, added Hammergren. The term's significance instead lies in the way it links people to the motions of the cosmos.
"Just being able to recognize that we can have a full moon twice in a month and have [folklore] attached really highlights the fact that humans have been astronomers their entire existence," he said.
"True" Blue Moon
Before the editorial error, the term "blue moon" more often referred to the rare instances when the moon actually seemed to turn blue, as can happen under certain atmospheric conditions.
"After a forest fire or volcanic eruption, there may be enough particulate matter in the air so that the moon can take on a bluish tinge," Hammergren said.
For instance, a "true" blue moon occurred in 1950 after a large forest fire in Canada blew smoke across most of the Northern Hemisphere.
Another appeared in 1980 after the last major eruption of Mount St. Helens, which sent tons of ash into the upper atmosphere.
Although rumblings at the Mayon Volcano in the Philippines seem to signal a major eruption is imminent, experts don't think Mayon's current output will make this New Year's Eve full moon turn blue.
Howling at the Blue Moon
Even if the 2009 New Year's Eve blue moon has astronomers scoffing, nighttime partygoers may still get moonstruck.
Rising in the east at sunset, the New Year's Eve full moon will reach its highest point at midnight, noted Jack Horkheimer, director of the Miami Space-Transit Planetarium and host of PBS television's long-running show Star Gazer.
"Full moons around winter solstice rise their highest for the entire year," Horkheimer added.
"Even if you are downtown in a large city, if it is clear at the stroke of midnight the moon will be very visible if you look up."
In any location, the high, silvery orb will seem like a floodlight cast on the landscape, added Horkheimer, who is organizing a national moon-howling contest around this year's blue moon.
"This is especially true where the ground is covered with a blanket of snow. There is nothing quite so spectacular as a snow-covered scene under a December full moon at midnight."
From National Geographic
Unusually Late Rain in India
Taken from Jim's Blog, www.accuweather.com
Rain has broken out along the southern Deccan and neighboring west coast of southern India during the last few days. Rainfall of 23 mm was observed as of Monday at Bangalore whereas sea-side Mangalore picked up about 6 cm since Sunday. This would be unusually late in the season for rain this far north.
If the lateness of the south India rain were not enough, there is more of it on the way. For help in understanding this, the reader may wish to go here to look at the IMD infrared satellite imagery.
The COLA site compiles GFS forecast rainfall ("QPF") in a fortnightly outlook:
During the first forecast week, forecast rainfall is shown for most of the west coast/Western Ghats,
even reaching into northern India and Nepal. The underlying trigger for this forecast of rain would be two separate troughs in the Westerlies forecast to cross the Subcontinent from the west.
First of these western disturbances will swing quickly across the Subcontinent during the next 24-48 hours, triggering showers and thunderstorms in the recurving stream of tropical moisture. The idea that a few spots will get heavy falls--say, 10 cm or so--seems valid to me.
Look for another western disturbance to dip through the Khaleej of South West Asia before transiting the Subcontinent at week`s end. It is this second western disturbance that could trigger a little New Year`s Day rain at Mumbai.
I do not yet know what to make of it, but the second week of the forecast is shown to be unusually wet over eastern India. It is something to watch during the coming days.
Rain has broken out along the southern Deccan and neighboring west coast of southern India during the last few days. Rainfall of 23 mm was observed as of Monday at Bangalore whereas sea-side Mangalore picked up about 6 cm since Sunday. This would be unusually late in the season for rain this far north.
If the lateness of the south India rain were not enough, there is more of it on the way. For help in understanding this, the reader may wish to go here to look at the IMD infrared satellite imagery.
The COLA site compiles GFS forecast rainfall ("QPF") in a fortnightly outlook:
During the first forecast week, forecast rainfall is shown for most of the west coast/Western Ghats,
even reaching into northern India and Nepal. The underlying trigger for this forecast of rain would be two separate troughs in the Westerlies forecast to cross the Subcontinent from the west.
First of these western disturbances will swing quickly across the Subcontinent during the next 24-48 hours, triggering showers and thunderstorms in the recurving stream of tropical moisture. The idea that a few spots will get heavy falls--say, 10 cm or so--seems valid to me.
Look for another western disturbance to dip through the Khaleej of South West Asia before transiting the Subcontinent at week`s end. It is this second western disturbance that could trigger a little New Year`s Day rain at Mumbai.
I do not yet know what to make of it, but the second week of the forecast is shown to be unusually wet over eastern India. It is something to watch during the coming days.
Subscribe to:
Posts (Atom)