آره داداش همین پارسال روز اول تیر بود که مشهد بارون میبارید و بخار از دهان بیرون میومد!!!
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مباحث عمومی هواشناسی
- شروع کننده موضوع Amir Mohsen
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آره داداش همین پارسال روز اول تیر بود که مشهد بارون میبارید و بخار از دهان بیرون میومد!!!
خدا صبر بده بهتون:فرار2::فرار2:
راستش چند سال پیش همین قم یه روز توی اوایل شهریور بود که حداکثر دما به 22 درجه رسید!
Amir Mohsen
متخصص بخش هواشناسی
درود دوستان
در ارتباط با اینکه چرا سایت هواشناسی خراسان رضوی دمای مشهد رو 3 درجه خنکتر از نرمال اعلام کرده ، حتما یکسری فاکتورهایی رو لحاظ کرده که ما خبری ازش نداریم و باید از خودشون بپرسیم ولی تا اینجای کار اونچیزی که بدن ما حس میکنه این هست که دمای هوای خنکتر از نرمال بوده هم در روز و هم در شب!!!!
اما ببینید که اینروزها گرم شدن هوا فقط در غالب نقاط ایران نیست و اون چیزیکه در آنسوی اقیانوسها داره اتفاق میافته هم دست کمی از خاورمیانه نداره:
در ارتباط با اینکه چرا سایت هواشناسی خراسان رضوی دمای مشهد رو 3 درجه خنکتر از نرمال اعلام کرده ، حتما یکسری فاکتورهایی رو لحاظ کرده که ما خبری ازش نداریم و باید از خودشون بپرسیم ولی تا اینجای کار اونچیزی که بدن ما حس میکنه این هست که دمای هوای خنکتر از نرمال بوده هم در روز و هم در شب!!!!
اما ببینید که اینروزها گرم شدن هوا فقط در غالب نقاط ایران نیست و اون چیزیکه در آنسوی اقیانوسها داره اتفاق میافته هم دست کمی از خاورمیانه نداره:
Amir Mohsen
متخصص بخش هواشناسی
Today, 12:53 PM
I happened upon a correlation between the June-July-August Arctic Oscillation and the December-January-February 500mb heights in the winter after the JJA period. As the image below shows, there is a negative correlation between JJA AO values and what would appear to be DJF AO and NAO values?? Regardless of which indices it affects, the negative correlation is certainly present in the Arctic Circle.
Because we are only in the middle of July, the only value we have access to is the June AO index. The June AO value was observed to be at 0.549. Going by this negative correlation, we could be expecting a trend towards a negative AO come winter.
However, recall that a study I presented last week on this thread favored a positive AO this winter, adding to the confusion that can be caused if we take into account all of these studies/correlations. Just take each one for what it's worth. It is important to note there is a positive correlation between June AO values and December 500mb anomalies (though the positive correlation is rather weak), and the only month which defines this negative correlation is February.
I happened upon a correlation between the June-July-August Arctic Oscillation and the December-January-February 500mb heights in the winter after the JJA period. As the image below shows, there is a negative correlation between JJA AO values and what would appear to be DJF AO and NAO values?? Regardless of which indices it affects, the negative correlation is certainly present in the Arctic Circle.
Because we are only in the middle of July, the only value we have access to is the June AO index. The June AO value was observed to be at 0.549. Going by this negative correlation, we could be expecting a trend towards a negative AO come winter.
However, recall that a study I presented last week on this thread favored a positive AO this winter, adding to the confusion that can be caused if we take into account all of these studies/correlations. Just take each one for what it's worth. It is important to note there is a positive correlation between June AO values and December 500mb anomalies (though the positive correlation is rather weak), and the only month which defines this negative correlation is February.
از دست تو!!!
:قاطی::مجروح::تنبیه::ذوق زده::هنگ::51::نمیدونم:
کلن از جهت باد جنوبی بدم میاد باد باید از شمال بوزه به قول قدیمیا "باید شمال بیه":خنده2:
شب خوش دوستان
navid-mashhad
کاربر ويژه
اگه خونمون حیاط داشت امشب حال می داد برای لحاف دوشک پهن کردن
برو پشت بوم
Amir Mohsen
متخصص بخش هواشناسی
نقشه های امشب ناهنجاری دمایی یعنی دمای سردتر از نرمال رو فقط برای ماههای اکتبر و فوریه نشون میدن!!!!!! و در الباقی ماههای پیشرو دمای هوا یا نرمال یا بین 2 الی 4 درجه گرمتر از نرمال خواهد بود.
بنظرم من میشه روی ماه فوریه هم از لحاظ سرد بودن و هم از لحاظ پر بارش بودن حساب ویژه ای باز کرد:
منتهای این نقشه ها بازهم نفوذ هوای سرد رو از سمت شمال شرق نشون میدن که تا نواحی مرکزی پیشروی میکنه ولی به شمال غرب ایران نمیرسه!!!!!!!
بنظرم من میشه روی ماه فوریه هم از لحاظ سرد بودن و هم از لحاظ پر بارش بودن حساب ویژه ای باز کرد:
منتهای این نقشه ها بازهم نفوذ هوای سرد رو از سمت شمال شرق نشون میدن که تا نواحی مرکزی پیشروی میکنه ولی به شمال غرب ایران نمیرسه!!!!!!!
آخرین ویرایش:
Amir Mohsen
متخصص بخش هواشناسی
Alaska's Redoubt Volcano 'Screamed' Before Exploding
By Megan Gannon, News Editor | July 16, 2013 02:56pm ET
Earthquakes can often signal an impending volcanic eruption, and sometimes before a mountain blows its lid, seismologists detect a continuous, rhythmic series of quakes known as a harmonic tremor.
One after the other, tiny temblors originate beneath a volcano, typically accompanied by a rumble that's at such a low frequency, humans would not be able to hear it. But the harmonic tremor that preceded the March 2009 eruption of Alaska's Mount Redoubt made the volcano "scream," the frequency got so high, researchers say.
A swarm of earthquakes — up to 30 per second — produced an unusually high-pitched racket at Redoubtand then an eerie silence before the peak was rocked by a series of six explosions, according to a pair of new studies.
"If you were on the volcano, you might hear a very soft, low bass rumble (just barely at the limit of human hearing) followed by about 30 seconds of silence and then the roar of the explosion," study researcher Alicia Hotovec-Ellis, a University of Washington doctoral student, explained in an email. [50 Amazing Volcano Facts]
Volcano monitoring stations around the mountain — located southwest of Anchorage in the Aleutian Islands — recorded low frequencies starting out around 1-to-5 hertz that built up to 30 hertz before the initial blast in 2009, according to the study. Anything lower than 20 hertz is considered infrasound, beyond the limits of normal human hearing.
This phenomenon has been documented at other volcanoes, but the building tectonic growl had always remained in the inaudible range. The Soufriere Hills volcano on the Caribbean island of Montserrat, for example, had a similar "scream" in the 1990s, though it only got up to 3 hertz, said Hotovec-Ellis. That's even lower than the lowest infrasonic moans of elephants and blue whales.
Hotovec-Ellis and colleagues think that at Redoubt an unusually high number of little earthquakes caused the volcano's noisy hum. Their version of events looks like this: Magma was being pushed through a narrow, high-pressure channel into the heart of the mountain. The molten rock probably got stuck and then forced through this conduit in spurts. This friction between the channel walls and the magma resulted in small earthquakes (ranging in magnitude from about 0.5 to 1.5). As pressure built, the earthquakes occurred in a quickening sequence, up to a rate of 30 per second, and blended into a harmonic tremor. After a pause, the volcano finally blew its lid, with all that pressure is released in an eruption.
This new model is dubbed "frictional-faulting" in a study detailed in the journal Nature Geoscience. Redoubt's strange harmonic tremor is also described in the Journal of Volcanology and Geothermal Research.
While understanding this process doesn't offer much promise for forecasting volcanic eruptions, it could give scientists a valuable glimpse inside active volcanoes, Hotovec-Ellis said.
"It might be able to give a few minutes to hours of warning before the next explosion," Hotovec-Ellis wrote in an email. "I think the main utility at this point is in better understanding what's going on inside volcanoes when they erupt."
By Megan Gannon, News Editor | July 16, 2013 02:56pm ET
|
Alaska's Redoubt volcano during its 2009 eruption, with ash visible against the new snow and a cloud of volcanic gas and steam drifting to the northn.Credit: Scott Lawrence/Alaska Volcano Observatory View full size image |
One after the other, tiny temblors originate beneath a volcano, typically accompanied by a rumble that's at such a low frequency, humans would not be able to hear it. But the harmonic tremor that preceded the March 2009 eruption of Alaska's Mount Redoubt made the volcano "scream," the frequency got so high, researchers say.
A swarm of earthquakes — up to 30 per second — produced an unusually high-pitched racket at Redoubtand then an eerie silence before the peak was rocked by a series of six explosions, according to a pair of new studies.
"If you were on the volcano, you might hear a very soft, low bass rumble (just barely at the limit of human hearing) followed by about 30 seconds of silence and then the roar of the explosion," study researcher Alicia Hotovec-Ellis, a University of Washington doctoral student, explained in an email. [50 Amazing Volcano Facts]
Volcano monitoring stations around the mountain — located southwest of Anchorage in the Aleutian Islands — recorded low frequencies starting out around 1-to-5 hertz that built up to 30 hertz before the initial blast in 2009, according to the study. Anything lower than 20 hertz is considered infrasound, beyond the limits of normal human hearing.
This phenomenon has been documented at other volcanoes, but the building tectonic growl had always remained in the inaudible range. The Soufriere Hills volcano on the Caribbean island of Montserrat, for example, had a similar "scream" in the 1990s, though it only got up to 3 hertz, said Hotovec-Ellis. That's even lower than the lowest infrasonic moans of elephants and blue whales.
Hotovec-Ellis and colleagues think that at Redoubt an unusually high number of little earthquakes caused the volcano's noisy hum. Their version of events looks like this: Magma was being pushed through a narrow, high-pressure channel into the heart of the mountain. The molten rock probably got stuck and then forced through this conduit in spurts. This friction between the channel walls and the magma resulted in small earthquakes (ranging in magnitude from about 0.5 to 1.5). As pressure built, the earthquakes occurred in a quickening sequence, up to a rate of 30 per second, and blended into a harmonic tremor. After a pause, the volcano finally blew its lid, with all that pressure is released in an eruption.
This new model is dubbed "frictional-faulting" in a study detailed in the journal Nature Geoscience. Redoubt's strange harmonic tremor is also described in the Journal of Volcanology and Geothermal Research.
While understanding this process doesn't offer much promise for forecasting volcanic eruptions, it could give scientists a valuable glimpse inside active volcanoes, Hotovec-Ellis said.
"It might be able to give a few minutes to hours of warning before the next explosion," Hotovec-Ellis wrote in an email. "I think the main utility at this point is in better understanding what's going on inside volcanoes when they erupt."
aria_tehran
کاربر ويژه
درود
این عکس تهرانه
این عکس تهرانه
محمدمنکه گفتم اقلیم این مناطقی که گفتی تا نابودی فاصله ای نداره الان شمال شرق کشور داره یه تنه ابروداری میکنه فکنم !!
aria_tehran
کاربر ويژه
شمال تهران
aria_tehran
کاربر ويژه
شبی برفی و مه آلود در شمال تهران
به به
به به
- وضعیت