Amir Mohsen
متخصص بخش هواشناسی
سلام و درود برشما دوست خوبم
خوب بالون رادیو سوند هم از شرق تبریز به آسمان فرستاده شده
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مباحث عمومی هواشناسی
- شروع کننده موضوع Amir Mohsen
- تاریخ شروع
- وضعیت
سلام و درود برشما دوست خوبم
خوب بالون رادیو سوند هم از شرق تبریز به آسمان فرستاده شده
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havashenas
کاربر ويژه
havashenas
کاربر ويژه
طبق اظهارات دوستان تبریزی کوه سهند تبریز تا 3/4 بر اثر شدت تگرگ سفید شده است!!!!!
Amir Mohsen
متخصص بخش هواشناسی
از این بابت بسیار متاثر و اندوهگینم. خدا به خونواده هاشون صبر بده
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شهاب از بوشهر
کاربر ويژه
درود.
طبق صحبتی که دوستان در ملکان داشتم ، امروز صبح بارش های بارزی را در این شهرستان داشته ایم.
بارش روزهای قبل نیز شدید گزارش شد.
در برخی مناطق تگرگ هم باریده.
من هم کم کم دارم مهیای سفر به ملکان و شمال غرب میشم.
طبق صحبتی که دوستان در ملکان داشتم ، امروز صبح بارش های بارزی را در این شهرستان داشته ایم.
بارش روزهای قبل نیز شدید گزارش شد.
در برخی مناطق تگرگ هم باریده.
من هم کم کم دارم مهیای سفر به ملکان و شمال غرب میشم.
شهاب از بوشهر
کاربر ويژه
اقای هواشناس از تکاب میخوام بهتون پیام بدم ولی میگه ظرفیت پیام های شما پر شده.
لطفا خالی کنید تا پیام بدم.
تشکر.
لطفا خالی کنید تا پیام بدم.
تشکر.
شهاب از بوشهر
کاربر ويژه
من در هواشناسی باران برای شما پیام دادم.:گل:
Amir Mohsen
متخصص بخش هواشناسی
World is unprepared for major El Niño later this year
THE weather is preparing to go wild, and will wreak havoc and death around the globe later this year. An El Niño, a splurge of warm water in the Pacific Ocean, is coming. It will unleash floods in the Americas, while South-East Asia and Australia face drought. Yet little is being done to address these consequences.
"The tropical climate system is primed for a big El Niño," says Axel Timmermann of the University of Hawaii in Honolulu (see diagram).
An El Niño begins when warm water near Indonesia spreads eastwards and rises to the surface of the Pacific. The warm water carries rain with it, so El Niño takes rain from Asia and Australia and dumps it on the Americas (see "Rising waters").
The effects can be deadly. A big El Niño in 1997-98 killed 20,000 people and caused almost $97 billion of damage.
Meteorologists contacted by New Scientist all expect an El Niño at the end of this year. And it looks like a big one, says Wenju Cai of CSIRO, Australia's national research agency, in Melbourne. The more heat in the Pacific, the bigger the El Niño, and right now, 150 metres below the surface, a ball of warm water is crossing that ocean. "It's huge," says Cai.
Yet official forecasts remain cautious. As recently as 5 May, the US National Oceanic and Atmospheric Administration only said the odds of an El Niño would exceed 50 per cent this year.
Most El Niño researchers say forecasters are being too conservative. "One thing I hear over and over again is 'we do not want to create a panic'," says Timmermann. There is a reason: forecasting a big El Niño would cause a spike in food prices. "But it may be better to have this reaction at an early stage, when farmers can still adapt, rather than later."
The good news is that El Niño is a known quantity. "We already know what happens when a big El Niño hits," says Zafar Adeel of the United Nations University in Hamilton, Canada. That means vulnerable populations can be identified and emergency plans put in place. But not everywhere has a plan.
California, which faces floods, is well prepared for emergencies and has water rescue teams, says David McEntire of the University of North Texas in Denton. But Central and South America are more vulnerable (see "In the firing line") and it is unclear what will happen in Asia and Australia (see "Monsoon disruption"). India has invested in water storage in case of drought.
Local forecasts are crucial, says Zafar, because large-scale predictions can get the fine detail wrong. In 1997, after a coarse-grained forecast, Costa Rica moved thousands of cattle away from an area where drought was expected. But they moved into an area of worse drought and died.
A big El Niño does not have to be a disaster. Impacts like shifting fish stocks and changes in rainfall can be handled, or even turned into benefits, if people are prepared for them. "But you need that trigger saying 'yes it's going to be a big one'," says Zafar.
Leader: "El Niño forecasters must not repeat mistakes of 1997"
This article appeared in print under the headline "Sitting ducks in coming storm"
[h=3]Monsoon disruption Asia and Australia will see less rainfall as a result of El Niño, leading to drought and wildfires. But many impacts depend on how El Niño affects the monsoons, which is hard to predict.
"There is no other phenomenon that can influence the monsoons like El Niño," says Krishna Kumar of the Indian Institute of Tropical Meteorology in Pune. If it weakens the Asian monsoons, it will threaten the food supply of billions of people.
Most El Niños weaken east Asian monsoons, but the Indian monsoon may survive. El Niños have caused the Indian monsoon to fail, however the 1997-98 El Niño didn't, despite being the biggest on record (Science, doi.org/fj7cbx). Kumar says the coming El Niño looks similar to the 1997-98 event, so India might be lucky.
[h=3]Rising waters The western US faces storms and floods from an approaching El Niño.
The sea level along California's coast may rise 30 centimetres, and then be pushed even higher by storm surges, says Kevin Trenberth of the National Center for Atmospheric Research in Boulder, Colorado. Extra water may sound good, because California has been hit by a severe drought. But the raised seas may combine with heavy El Niño rains to cause devastating floods, as happened to the San Francisco area in 1997-98.
El Niño also brings warmer weather, which melts ice. In 1997, extra river water in North Dakota and Minnesota may have contributed to the worst flood of the Red river since 1826.
[h=3]In the firing line When El Niño arrives, Central and South America face a mix of storms, floods and droughts.
These countries are more vulnerable to the effects of El Niño than the US, partly because they have less money. "Poverty is a major cause of vulnerability," says David McEntire of the University of North Texas in Denton.
However, more-developed regions are not always better off, says McEntire. Development causes its own problems, such as greater use of dangerous chemicals that can escape during disasters. And wealthier regions produce less of their own food, so can run short quickly.
As a result of all these issues, most countries in Latin America have become more vulnerable to El Niño, says Rodney Martínez of the International Research Centre on El Niño in Guayaquil, Ecuador. Even though many have El Niño response plans, the risks have grown thanks to population increases and crops being planted in high-risk zones. Such countries can also struggle to give each area a warning that is local enough.
- 07 May 2014 by Michael Slezak
- Magazine issue 2968. Subscribe and save
- For similar stories, visit the Climate Change Topic Guide
THE weather is preparing to go wild, and will wreak havoc and death around the globe later this year. An El Niño, a splurge of warm water in the Pacific Ocean, is coming. It will unleash floods in the Americas, while South-East Asia and Australia face drought. Yet little is being done to address these consequences.
"The tropical climate system is primed for a big El Niño," says Axel Timmermann of the University of Hawaii in Honolulu (see diagram).
An El Niño begins when warm water near Indonesia spreads eastwards and rises to the surface of the Pacific. The warm water carries rain with it, so El Niño takes rain from Asia and Australia and dumps it on the Americas (see "Rising waters").
The effects can be deadly. A big El Niño in 1997-98 killed 20,000 people and caused almost $97 billion of damage.
Meteorologists contacted by New Scientist all expect an El Niño at the end of this year. And it looks like a big one, says Wenju Cai of CSIRO, Australia's national research agency, in Melbourne. The more heat in the Pacific, the bigger the El Niño, and right now, 150 metres below the surface, a ball of warm water is crossing that ocean. "It's huge," says Cai.
Yet official forecasts remain cautious. As recently as 5 May, the US National Oceanic and Atmospheric Administration only said the odds of an El Niño would exceed 50 per cent this year.
Most El Niño researchers say forecasters are being too conservative. "One thing I hear over and over again is 'we do not want to create a panic'," says Timmermann. There is a reason: forecasting a big El Niño would cause a spike in food prices. "But it may be better to have this reaction at an early stage, when farmers can still adapt, rather than later."
The good news is that El Niño is a known quantity. "We already know what happens when a big El Niño hits," says Zafar Adeel of the United Nations University in Hamilton, Canada. That means vulnerable populations can be identified and emergency plans put in place. But not everywhere has a plan.
California, which faces floods, is well prepared for emergencies and has water rescue teams, says David McEntire of the University of North Texas in Denton. But Central and South America are more vulnerable (see "In the firing line") and it is unclear what will happen in Asia and Australia (see "Monsoon disruption"). India has invested in water storage in case of drought.
Local forecasts are crucial, says Zafar, because large-scale predictions can get the fine detail wrong. In 1997, after a coarse-grained forecast, Costa Rica moved thousands of cattle away from an area where drought was expected. But they moved into an area of worse drought and died.
A big El Niño does not have to be a disaster. Impacts like shifting fish stocks and changes in rainfall can be handled, or even turned into benefits, if people are prepared for them. "But you need that trigger saying 'yes it's going to be a big one'," says Zafar.
Leader: "El Niño forecasters must not repeat mistakes of 1997"
This article appeared in print under the headline "Sitting ducks in coming storm"
[h=3]Monsoon disruption Asia and Australia will see less rainfall as a result of El Niño, leading to drought and wildfires. But many impacts depend on how El Niño affects the monsoons, which is hard to predict.
"There is no other phenomenon that can influence the monsoons like El Niño," says Krishna Kumar of the Indian Institute of Tropical Meteorology in Pune. If it weakens the Asian monsoons, it will threaten the food supply of billions of people.
Most El Niños weaken east Asian monsoons, but the Indian monsoon may survive. El Niños have caused the Indian monsoon to fail, however the 1997-98 El Niño didn't, despite being the biggest on record (Science, doi.org/fj7cbx). Kumar says the coming El Niño looks similar to the 1997-98 event, so India might be lucky.
[h=3]Rising waters The western US faces storms and floods from an approaching El Niño.
The sea level along California's coast may rise 30 centimetres, and then be pushed even higher by storm surges, says Kevin Trenberth of the National Center for Atmospheric Research in Boulder, Colorado. Extra water may sound good, because California has been hit by a severe drought. But the raised seas may combine with heavy El Niño rains to cause devastating floods, as happened to the San Francisco area in 1997-98.
El Niño also brings warmer weather, which melts ice. In 1997, extra river water in North Dakota and Minnesota may have contributed to the worst flood of the Red river since 1826.
[h=3]In the firing line When El Niño arrives, Central and South America face a mix of storms, floods and droughts.
These countries are more vulnerable to the effects of El Niño than the US, partly because they have less money. "Poverty is a major cause of vulnerability," says David McEntire of the University of North Texas in Denton.
However, more-developed regions are not always better off, says McEntire. Development causes its own problems, such as greater use of dangerous chemicals that can escape during disasters. And wealthier regions produce less of their own food, so can run short quickly.
As a result of all these issues, most countries in Latin America have become more vulnerable to El Niño, says Rodney Martínez of the International Research Centre on El Niño in Guayaquil, Ecuador. Even though many have El Niño response plans, the risks have grown thanks to population increases and crops being planted in high-risk zones. Such countries can also struggle to give each area a warning that is local enough.
Amir Mohsen
متخصص بخش هواشناسی
Pacific Ocean hot spot causing warming in the Arctic, scientists say Posted Mon 12 May 2014, 2:21pm AEST
Photo: Scientists say the area over Greenland is warming rapidly due, in part, to natural variations in the Pacific Ocean. (ABC News: Phoebe McDonald)
Map: Papua New Guinea
An international team of scientists has discovered a hot spot in the Pacific Ocean is partly responsible for global warming in the Arctic.
The area, east of Papua New Guinea, is an unusually warm part of the ocean and is causing atmospheric changes, researchers say.
Professor John Wallace from the University of Washington says the climate pattern is similar to that of El Nino.
"What it's doing is producing a very large scale wave pattern in the atmosphere, with warming in some places and a little bit of cooling in other places," he told Pacific Beat.
Audio: Pacific Ocean hot spot causing warming in Arctic (ABC News)
"But that region of warming happens to be sitting over northern Greenland and the Canadian archipelago, that's a region we're seeing a lot of effects from global warming anyway.
"This pattern is exacerbating it, making the warming larger than it would otherwise be."
The scientists say while carbon dioxide emissions are still the major cause of global warming, their discovery shows that natural climate variations can still play a significant role.
"I think when we talk about climate change at a particular place on earth ... there are always confounding factors, it's not just a simple picture of the globe warming and the same warming taking place," Professor Wallace said.
"Some places are warming faster than the earth as a whole, others are warming more slowly.
"It is a complicated picture and this is just one example of it."
Ailie Gallant from Monash University, part of the research team, said the findings shows the Pacific hot spot is affecting the Arctic significantly.
"What we found was, in fact, about half of that observed warming over Greenland since 1979 can be attributed to natural variations actually stemming from the Pacific Ocean."
Photo: Scientists say the area over Greenland is warming rapidly due, in part, to natural variations in the Pacific Ocean. (ABC News: Phoebe McDonald) Map: Papua New Guinea
An international team of scientists has discovered a hot spot in the Pacific Ocean is partly responsible for global warming in the Arctic.
The area, east of Papua New Guinea, is an unusually warm part of the ocean and is causing atmospheric changes, researchers say.
Professor John Wallace from the University of Washington says the climate pattern is similar to that of El Nino.
"What it's doing is producing a very large scale wave pattern in the atmosphere, with warming in some places and a little bit of cooling in other places," he told Pacific Beat.
Audio: Pacific Ocean hot spot causing warming in Arctic (ABC News)
"But that region of warming happens to be sitting over northern Greenland and the Canadian archipelago, that's a region we're seeing a lot of effects from global warming anyway.
"This pattern is exacerbating it, making the warming larger than it would otherwise be."
The scientists say while carbon dioxide emissions are still the major cause of global warming, their discovery shows that natural climate variations can still play a significant role.
"I think when we talk about climate change at a particular place on earth ... there are always confounding factors, it's not just a simple picture of the globe warming and the same warming taking place," Professor Wallace said.
"Some places are warming faster than the earth as a whole, others are warming more slowly.
"It is a complicated picture and this is just one example of it."
Ailie Gallant from Monash University, part of the research team, said the findings shows the Pacific hot spot is affecting the Arctic significantly.
"What we found was, in fact, about half of that observed warming over Greenland since 1979 can be attributed to natural variations actually stemming from the Pacific Ocean."
Amir Mohsen
متخصص بخش هواشناسی
Predicted El Niño means warm, dry summer for Metro Vancouver By Jeff Clowers | 1 day ago | Speak Up
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Lately, it’s been hard to forecast Vancouver weather. From torrential downpours to blazing heatwaves, we’ve seen it all. But it seems our trusty meteorologists have come to an agreement: this summer will be hot and dry.
The prediction comes at the same time that the Climate Prediction Center (CPC) released a report, saying the chances of an El Niño developing have reached 65 percent – a 15 percent increase in the past month.
[h=4]What is an El Niño? Normally, trade winds blow from east to west, which propels warm surface waters away from South America and allows cool water to well up to the surface from the depths of the ocean. But as an El Niño develops, those trade winds tend to ease up, sometimes going in reverse. This allows warm water to slosh back from the western side of the Pacific toward the eastern side, triggering a chain reaction of weather effects.
Image: Cross Section of El Nino via Shutterstock
When the average monthly sea surface temperature in the eastern Pacific Ocean is 0.5° Celsius or more above average, the CPC will declare that an El Niño is in progress.
[h=4]What does this mean for Metro Vancouver? Simply put, it’s going to be hot out. According to AccuWeather, high pressure combined with above average sea surface temperatures in the northeast Pacific will lead to a warmer summer than normal with a reduced chance for rain.
“We have above-average confidence that the summer will be very warm compared to normal with less rainfall over much of British Columbia [...] as high pressure reigns,” notes AccuWeather’s Brett Anderson.
It remains to be seen whether we’ll hit the record highs we reached during the summer of 2009, when Environment Canada recorded a high of 33.8° Celcius in Vancouver on July 29, breaking the previous record of 33.3° set in 1960.
Because of the combination of warm, dry weather, as well as the continuing problems with the Pine Bark Beetle, there will be also be an increased threat for large wildfires later this summer.
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Lately, it’s been hard to forecast Vancouver weather. From torrential downpours to blazing heatwaves, we’ve seen it all. But it seems our trusty meteorologists have come to an agreement: this summer will be hot and dry.
The prediction comes at the same time that the Climate Prediction Center (CPC) released a report, saying the chances of an El Niño developing have reached 65 percent – a 15 percent increase in the past month.
[h=4]What is an El Niño? Normally, trade winds blow from east to west, which propels warm surface waters away from South America and allows cool water to well up to the surface from the depths of the ocean. But as an El Niño develops, those trade winds tend to ease up, sometimes going in reverse. This allows warm water to slosh back from the western side of the Pacific toward the eastern side, triggering a chain reaction of weather effects.
Image: Cross Section of El Nino via Shutterstock
When the average monthly sea surface temperature in the eastern Pacific Ocean is 0.5° Celsius or more above average, the CPC will declare that an El Niño is in progress.
[h=4]What does this mean for Metro Vancouver? Simply put, it’s going to be hot out. According to AccuWeather, high pressure combined with above average sea surface temperatures in the northeast Pacific will lead to a warmer summer than normal with a reduced chance for rain.
“We have above-average confidence that the summer will be very warm compared to normal with less rainfall over much of British Columbia [...] as high pressure reigns,” notes AccuWeather’s Brett Anderson.
Because of the combination of warm, dry weather, as well as the continuing problems with the Pine Bark Beetle, there will be also be an increased threat for large wildfires later this summer.
Amir Mohsen
متخصص بخش هواشناسی
Amir Mohsen
متخصص بخش هواشناسی
تهران/واحدمرکزی‌خبر/علمی و فرهنگی 1393/02/23
دانشمندان درباره سرعت گرفتن روند ذوب یخهای قطب جنوب هشدار دادند.
به گزارش شبکه تلویزیونی پرس تی وی، گرم شدن کره زمین آثار زیست محیطی زیادی بر جا گذاشته است. یکی از آثار جدی این مسئله در قطب مشهود است. تحقیقات جدیدی که درباره وضع یخهای قطب جنوب انجام شده است نشان می دهد یخهای این منطقه با سرعت متوقف نشدنی در حال ذوب شدن است. براساس نتایج این تحقیقات، یکی از عواقب ذوب شدن یخهای قطب جنوب این است که دردهه های آینده، سطح آب دریاها بالاتر خواهد آمد. به گفته کارشناسان، باتوجه به نتایج تحقیقات اخیر باید پیش بینی های قبلی درباره میزان بالاآمدن سطح آب دریاها تغییر کند زیرا این روند سرعت بیشتری پیدا کرده است. دانشمندان دانشگاه کالیفرنیا با تحقیقات خود و با کمک تصاویر ماهواره ای سازمان هوا-فضای آمریکا(ناسا) هشدار دادند ، صفحات بزرگی از یخهای واقع در غرب منطقه قطب جنوب به عقب نشینی غیرقابل بازگشت رسیده است به این معنا که یخهای آن با سرعتی غیرقابل توقف در حال ذوب شدن است.
درود
استاد اميرمحسن تاثير ذوب شدن يخ هاى قطب جنوب بر وضعيت دما و بارش ايران چيه ؟ و اينكه آيا ذوب شدن يخ هاى قطب جنوب باعث تضعيف النينو ميشود ؟ ممنون
دانشمندان درباره سرعت گرفتن روند ذوب یخهای قطب جنوب هشدار دادند.
به گزارش شبکه تلویزیونی پرس تی وی، گرم شدن کره زمین آثار زیست محیطی زیادی بر جا گذاشته است. یکی از آثار جدی این مسئله در قطب مشهود است. تحقیقات جدیدی که درباره وضع یخهای قطب جنوب انجام شده است نشان می دهد یخهای این منطقه با سرعت متوقف نشدنی در حال ذوب شدن است. براساس نتایج این تحقیقات، یکی از عواقب ذوب شدن یخهای قطب جنوب این است که دردهه های آینده، سطح آب دریاها بالاتر خواهد آمد. به گفته کارشناسان، باتوجه به نتایج تحقیقات اخیر باید پیش بینی های قبلی درباره میزان بالاآمدن سطح آب دریاها تغییر کند زیرا این روند سرعت بیشتری پیدا کرده است. دانشمندان دانشگاه کالیفرنیا با تحقیقات خود و با کمک تصاویر ماهواره ای سازمان هوا-فضای آمریکا(ناسا) هشدار دادند ، صفحات بزرگی از یخهای واقع در غرب منطقه قطب جنوب به عقب نشینی غیرقابل بازگشت رسیده است به این معنا که یخهای آن با سرعتی غیرقابل توقف در حال ذوب شدن است.
درود
استاد اميرمحسن تاثير ذوب شدن يخ هاى قطب جنوب بر وضعيت دما و بارش ايران چيه ؟ و اينكه آيا ذوب شدن يخ هاى قطب جنوب باعث تضعيف النينو ميشود ؟ ممنون
Amir Mohsen
متخصص بخش هواشناسی
درود امیر کوروش عزیز
ممنون از سوال خوبی که پرسیدید.
عرض کنم خدمت تون که بر اساس مدل سازیهای کامپیوتری ، قطعا ذوب شدن یخ های کره زمین بر رژیم بارش دنیا و منطقه ما تاثیر گذار هست ولی خوب در این مدل سازی ها ذوب شدن یخ های قطب شمال و جنوب از همدیگه تفکیک نشده و من هم خروجی کلی این مدل رو برای سه ماه دسامبر- ژانویه و فوریه تقدیم حضورتون میکنم که بر پایه دوره آماری 1979-2013 هست:
آخرین ویرایش:
Amir Mohsen
متخصص بخش هواشناسی
مدتی بسیار طولانیست که ما شاهد مثبت بودن پیاپی نوسان قطبی موسوم به AO بودیم که این موضوع باعث شده بود در روند کلی چرخش اقلیم نیمکره شمالی اخلال ایجاد بشه و شاهد شکلگیری الگوهای رکس بلاکینگ پی در پی در عرضهای مختلف نیمکره شمالی باشیم.
مثل همون چیزیکه اینروزها شاهدش هستیم!
بهرحال پش بینی شده از اواخر این ماه میلادی که در اون قرار گرفته ایم با تضعیف فاز مثبت نوسان قطبی شرایط به حالت نرمال این موقع از سال در نیمکره شمالی برگرده!
بر اساس مشاهداتی که داشتیم و از مثبت بودن نوسان قطبی در این برهه زمانی از سال این درس رو گرفتیم که فاز مثبت این شاخص از لحاظ تاثیرات دمایی با اونچیزی که در فصل زمستون از اون بیاد داریم تفاوتهایی کلی داره.
مثل همون چیزیکه اینروزها شاهدش هستیم!
بهرحال پش بینی شده از اواخر این ماه میلادی که در اون قرار گرفته ایم با تضعیف فاز مثبت نوسان قطبی شرایط به حالت نرمال این موقع از سال در نیمکره شمالی برگرده!
بر اساس مشاهداتی که داشتیم و از مثبت بودن نوسان قطبی در این برهه زمانی از سال این درس رو گرفتیم که فاز مثبت این شاخص از لحاظ تاثیرات دمایی با اونچیزی که در فصل زمستون از اون بیاد داریم تفاوتهایی کلی داره.
Amir Mohsen
متخصص بخش هواشناسی
اینهم نمایه ای از الگوی رکس بلاکینگ:
Amir Mohsen
متخصص بخش هواشناسی
Amir Mohsen
متخصص بخش هواشناسی
هواشناسی کانادا تا 234 ساعت آینده:
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