navid-mashhad
کاربر ويژه
ای بابا چرا حیوونکی ها رو درآوردی؟برار:خجالت2:
-
توجه: در صورتی که از کاربران قدیمی ایران انجمن هستید و امکان ورود به سایت را ندارید، میتوانید با آیدی altin_admin@ در تلگرام تماس حاصل نمایید.
مباحث عمومی هواشناسی
- شروع کننده موضوع Amir Mohsen
- تاریخ شروع
- وضعیت
Amir Mohsen
متخصص بخش هواشناسی
وضعیت جوی مشهد در همین لحظه:
خب کسی که اینجارو خریده میخواد همچیزو نابود کنه و چند طبقه بسازه.باخودم گفتم بدست خودم برداشت بشن بهتر تره:گریه:
شهاب از بوشهر
کاربر ويژه
گراف دمایی و نقطه شبنم ایستگاه مشهد الرضا از روز 24 الی 30 ژوئن 2013 میلادی:
navid-mashhad
کاربر ويژه
اگه داخل باغچه گل و گیاهی که قابلیت جابه جایی داره با ریشه در بیار ببر
البته اگر منزل جدید باغچه داره
البته اگر منزل جدید باغچه داره
aria_tehran
کاربر ويژه
غرب تهران
پاراگلایدر سوار هم تو آسمون معلومه
پاراگلایدر سوار هم تو آسمون معلومه
aria_tehran
کاربر ويژه
غرب تهران
وقتی از سمت غرب به تهران بریم اول کوه علوم تحقیقات معلوم میشه بعدش کلکچال و در صورت تمیز بودن هوا دماوند سرافراز
وقتی از سمت غرب به تهران بریم اول کوه علوم تحقیقات معلوم میشه بعدش کلکچال و در صورت تمیز بودن هوا دماوند سرافراز
Cumulonimbus
متخصص هواشناسی
U.S. weather forecaster sees neutral conditions into Northern winter
NEW YORK, July 5 | Fri Jul 5, 2013 12:00pm EDT
Reuters - The U.S. government weather forecaster said on Friday that neutral conditions will last longer than previously expected, reducing the chance that the La Nina or El Nino patterns that play havoc with global weather will materialize this year.
In its monthly report based on conditions over the past four weeks, the Climate Prediction Center (CPC) said extreme weather would be unlikely to occur heading into the Northern Hemisphere winter.
Neutral conditions mean neither La Nina nor El Nino patterns will occur.
In June, sea surface temperatures in the eastern Pacific were below average and near average across the rest of the equatorial Pacific, it said.
Last month, the CPC, an office under the National Oceanic Atmospheric Administration, had said extreme conditions were unlikely into the Northern Hemisphere summer.
In 2011, La Nina, an abnormal cooling of waters in the equatorial Pacific that wreaks havoc on weather in Asia and the Americas, was blamed for crippling droughts in Texas and severe dry spells in South America that killed crops.
Its infamous counterpart, El Nino, heats up tropical oceans in East Asia, sending warm air into the United States and South America, often causing flooding and heavy rains.
It can also trigger drought conditions in Southeast Asia and Australia, regions that produce some of the world's major food staples, such as sugar cane and grains. (Reporting by Josephine Mason; Editing by Steve Orlofsky)
NEW YORK, July 5 | Fri Jul 5, 2013 12:00pm EDT
Reuters - The U.S. government weather forecaster said on Friday that neutral conditions will last longer than previously expected, reducing the chance that the La Nina or El Nino patterns that play havoc with global weather will materialize this year.
In its monthly report based on conditions over the past four weeks, the Climate Prediction Center (CPC) said extreme weather would be unlikely to occur heading into the Northern Hemisphere winter.
Neutral conditions mean neither La Nina nor El Nino patterns will occur.
In June, sea surface temperatures in the eastern Pacific were below average and near average across the rest of the equatorial Pacific, it said.
Last month, the CPC, an office under the National Oceanic Atmospheric Administration, had said extreme conditions were unlikely into the Northern Hemisphere summer.
In 2011, La Nina, an abnormal cooling of waters in the equatorial Pacific that wreaks havoc on weather in Asia and the Americas, was blamed for crippling droughts in Texas and severe dry spells in South America that killed crops.
Its infamous counterpart, El Nino, heats up tropical oceans in East Asia, sending warm air into the United States and South America, often causing flooding and heavy rains.
It can also trigger drought conditions in Southeast Asia and Australia, regions that produce some of the world's major food staples, such as sugar cane and grains. (Reporting by Josephine Mason; Editing by Steve Orlofsky)
aria_tehran
کاربر ويژه
و قله داراباد هم معلومه سمت راست کلکچال در این عکس
aria_tehran
کاربر ويژه
محمد همشو دیدم
آخرین ویرایش:
aria_tehran
کاربر ويژه
میشه مشخص کنی
Amir Mohsen
متخصص بخش هواشناسی
Astronomers detect strange radio signals from deep space
By Scott Sutherland | Geekquinox – 2 hours 35 minutes ago
The Parkes radio telescope in Australia.The Earth is under constant barrage by radio signals from space. Typically they just come from mundane sources like our own satellites, garden variety stars, and even more exotic things like 'rotating neutron stars'. However, astronomers have found one type of signal whose source has, so far, remained a mystery. No, I'm not talking about the 'Wow! signal' (although that's a great one).
For us, this story starts in 2007, when a team of astronomers reported finding an incredibly powerful and incredibly short radio burst, from a sky survey done back in 2001. It had flashed very 'bright' to their radio telescope for about 5 milliseconds and then it was gone. The pulse itself wasn't the first thing that struck them as odd, though; it was that the pulse didn't repeat. Looking at it a bit closer, they found that it got even stranger, because it came from a point in the sky that suggested it originated from outside our galaxy. In fact, they found that whatever sent forth this blast of radio waves was roughly 3 billion light years away, so not even in our galactic neighbourhood (for comparison, the Andromeda Galaxy is 'only' 2.5 million light years away).
[ Related: Pluto’s newest moons now called Kerberos and Styx ]
This mysterious radio signal became known as the 'Lorimer burst', named after National Radio Astronomy Observatory astrophysicist Duncan Lorimer, who led the team that discovered and studied the burst.
Now, fast-forward to today, and astronomers have published another study that examines four more of these signals they detected over the last four years. That's not the only ones they've seen, though. According to ABC Science, the astronomers set up a permanent detector that sees one of these bursts every 10 days or so. Their research only covers four of them because the radio telescope can only cover a very small area of the sky at any given time.
These bursts are all from single events (as opposed to the same object emitting repeated bursts), that happened billions of light years away (so billions of years ago), but their source is still a mystery.
They're definitely caused by some kind of cataclysmic astronomical event — maybe a massive supernova that forms a black hole or two neutron stars colliding, but the leading contender is something that may be even more strange — a magnetic neutron star, or 'magnestar'.
Magnetar SGR 1900+14 isn't visible in this Spizter Space Telescope image, but evidence of its power can be seen …A neutron star is what's left over when a star that's many times bigger than our Sun dies. This stellar 'remnant' is typically about 20 kilometres in diameter, and so dense that a mere thimble-full of its matter would weigh over 100 million tons. Some neutron stars rotate very quickly (on the order of milliseconds per rotation) and put off beams of radiation from their poles, a bit like a lighthouse shining a beacon across space. These are called 'pulsars'.
A magnestar is a neutron star that rotates much slower ('only' once every few seconds) and has incredibly powerful magnetic fields. For comparison, the strength of our own Sun's magnetic field is measured in micro-Teslas — thousandths of a unit of magnetic field strength. A magnestar's magnetic field strength is measured in hundreds of millions to hundreds of billions of Telsas.
"These are the most magnetic stars in the universe, and every now and then they have very large explosions on them, which may be a good candidate for the origin of these things," said Prof. Matthew Bailes, the director of the Swinburne Centre for Astrophysics and Supercomputing, in Melbourne, Australia, according to ABC Science.
"They can give off as much energy as the Sun does for 300,000 years, in just a millisecond."
It's this potential for such incredibly powerful bursts of energy that puts them at the top of the list of suspects. Anything weaker and the signal wouldn't survive crossing intergalactic space to reach us.
Another exceptional thing about these bursts is that they carry information along with them about the universe.
"Every time the radio waves go past an electron, the electron's presence gets encoded in the burst of photons," Bailes told ABC Science.
"We can use this to count how many electrons there are between us and half way across the universe, which is incredibly exciting because almost all of the normal atoms are actually not in galaxies, they're just sitting around in the intergalactic medium."
[ More Geekquinox: DNA study ties B.C. First Nations groups to ancient ancestors ]
Astronomers have used the beams of pulsars to tell us about what lies between the pulsar and us, but in this case, it may be one mystery helping us to solve another mystery. We may not know where these bursts are coming from, but the bursts themselves will be able to tell us a lot about the universe we live in.
"We are still not sure about what makes up the space between galaxies, so we will be able to use these radio bursts like probes in order to understand more about some of the missing matter in the Universe," said study co-author Dr. Ben Stappers, from Manchester’s School of Physics and Astronomy, according to a news release. "We are now starting to use Parkes and other telescopes, like the Lovell Telescope of the University of Manchester, to look for these bursts in real time."
By Scott Sutherland | Geekquinox – 2 hours 35 minutes ago
For us, this story starts in 2007, when a team of astronomers reported finding an incredibly powerful and incredibly short radio burst, from a sky survey done back in 2001. It had flashed very 'bright' to their radio telescope for about 5 milliseconds and then it was gone. The pulse itself wasn't the first thing that struck them as odd, though; it was that the pulse didn't repeat. Looking at it a bit closer, they found that it got even stranger, because it came from a point in the sky that suggested it originated from outside our galaxy. In fact, they found that whatever sent forth this blast of radio waves was roughly 3 billion light years away, so not even in our galactic neighbourhood (for comparison, the Andromeda Galaxy is 'only' 2.5 million light years away).
[ Related: Pluto’s newest moons now called Kerberos and Styx ]
This mysterious radio signal became known as the 'Lorimer burst', named after National Radio Astronomy Observatory astrophysicist Duncan Lorimer, who led the team that discovered and studied the burst.
Now, fast-forward to today, and astronomers have published another study that examines four more of these signals they detected over the last four years. That's not the only ones they've seen, though. According to ABC Science, the astronomers set up a permanent detector that sees one of these bursts every 10 days or so. Their research only covers four of them because the radio telescope can only cover a very small area of the sky at any given time.
These bursts are all from single events (as opposed to the same object emitting repeated bursts), that happened billions of light years away (so billions of years ago), but their source is still a mystery.
They're definitely caused by some kind of cataclysmic astronomical event — maybe a massive supernova that forms a black hole or two neutron stars colliding, but the leading contender is something that may be even more strange — a magnetic neutron star, or 'magnestar'.
Magnetar SGR 1900+14 isn't visible in this Spizter Space Telescope image, but evidence of its power can be seen …A neutron star is what's left over when a star that's many times bigger than our Sun dies. This stellar 'remnant' is typically about 20 kilometres in diameter, and so dense that a mere thimble-full of its matter would weigh over 100 million tons. Some neutron stars rotate very quickly (on the order of milliseconds per rotation) and put off beams of radiation from their poles, a bit like a lighthouse shining a beacon across space. These are called 'pulsars'.A magnestar is a neutron star that rotates much slower ('only' once every few seconds) and has incredibly powerful magnetic fields. For comparison, the strength of our own Sun's magnetic field is measured in micro-Teslas — thousandths of a unit of magnetic field strength. A magnestar's magnetic field strength is measured in hundreds of millions to hundreds of billions of Telsas.
"These are the most magnetic stars in the universe, and every now and then they have very large explosions on them, which may be a good candidate for the origin of these things," said Prof. Matthew Bailes, the director of the Swinburne Centre for Astrophysics and Supercomputing, in Melbourne, Australia, according to ABC Science.
"They can give off as much energy as the Sun does for 300,000 years, in just a millisecond."
It's this potential for such incredibly powerful bursts of energy that puts them at the top of the list of suspects. Anything weaker and the signal wouldn't survive crossing intergalactic space to reach us.
Another exceptional thing about these bursts is that they carry information along with them about the universe.
"Every time the radio waves go past an electron, the electron's presence gets encoded in the burst of photons," Bailes told ABC Science.
"We can use this to count how many electrons there are between us and half way across the universe, which is incredibly exciting because almost all of the normal atoms are actually not in galaxies, they're just sitting around in the intergalactic medium."
[ More Geekquinox: DNA study ties B.C. First Nations groups to ancient ancestors ]
Astronomers have used the beams of pulsars to tell us about what lies between the pulsar and us, but in this case, it may be one mystery helping us to solve another mystery. We may not know where these bursts are coming from, but the bursts themselves will be able to tell us a lot about the universe we live in.
"We are still not sure about what makes up the space between galaxies, so we will be able to use these radio bursts like probes in order to understand more about some of the missing matter in the Universe," said study co-author Dr. Ben Stappers, from Manchester’s School of Physics and Astronomy, according to a news release. "We are now starting to use Parkes and other telescopes, like the Lovell Telescope of the University of Manchester, to look for these bursts in real time."
navid-mashhad
کاربر ويژه
اگه تابستون بیشینه ها در حد همین 32-33 یاشه خوبه و قابل تحمل
ولی متاسفانه همیشه اینطور نیست
ولی متاسفانه همیشه اینطور نیست
navid-mashhad
کاربر ويژه
ذغال اخته قزوینی فرد اعلا آیا ؟:خجالت2:
aria_tehran
کاربر ويژه
سهند 2013 هنوزم با گوشی هستی یا رفتی کافی نت؟:سوت:
- وضعیت