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مباحث عمومی هواشناسی
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Amir Mohsen
متخصص بخش هواشناسی
نقشه دما و ارتفاع استراتوسفر- آپدیت جدید
امروز:
144 ساعت آینده:
180 ساعت آینده:
192 ساعت آینده:
204 ساعت آینده:
28 ژانویه:
امروز:
144 ساعت آینده:
180 ساعت آینده:
192 ساعت آینده:
204 ساعت آینده:
28 ژانویه:
Amir Mohsen
متخصص بخش هواشناسی
The Stratosphere And How It Affects The Weather
When we are outside and experiencing the full onslaught of winter, we know that what we receive comes from above. Little do we realize, often this weather is controlled by conditions a lot higher than we think! In fact, there is increasing research showing the stratosphere can have a strong influence on the weather patterns we experience at the surface.
The stratosphere is the second layer of the earth's atmosphere, situated above the lowest layer 'the troposphere'. The stratosphere starts at an altitude of ~6 miles (10km) and extends up to ~30 miles (50km). It is so named because the stratified layers within it have a temperature profile that increases with altitude. The stratosphere holds the ozone that absorbs harmful UV radiation and prevents it from reaching the surface.
Image courtesy of Windows to the Universe
So how does this layer affect our weather?
Every winter the stratosphere over the North Pole cools, this begins when the sunlight can no longer provide the energy to heat the ozone. Without this energy, the stratosphere cools rapidly, creating a thermal imbalance with the warmer stratosphere further south. This imbalance creates a large pressure difference and combined with the Coriolis effect, creates a large strong jet stream, circumnavigating the globe in the stratosphere in an eastwards direction. This system is known as the polar night jet, and contained within it is a strong vortex - known as the polar vortex.
The polar vortex increases and decreases in strength depending upon how cold the polar stratospheric atmosphere becomes during winter. The colder the polar stratosphere becomes, the stronger the polar vortex - and vice versa. The strength of the stratospheric polar vortex influences the atmosphere below it in the troposphere.
The troposphere also has a strong vortex over the North Pole during winter, this occurs due to tropospheric temperature and pressure differences. The strength of the stratospheric vortex helps govern the strength of the tropospheric vortex and this directly affects the strength of the jet stream.
In colder stratospheric conditions the jet stream becomes stronger; the stronger the jet stream, the straighter it flows and during winter, this normally keeps it on a collision course with the UK. A powerful jet stream is associated with unsettled and milder air, often with periods of heavy rain and windy conditions as one depression after another charges in from the Atlantic.
In warmer stratospheric conditions the jet stream takes a more meandering path due to a weaker polar vortex. This allows cold air to spill further south. If the UK is in the firing line of the cold air then this will lead to colder (often more settled) and possibly snowier weather.
Looking back at the last two years one can match the preceding stratospheric conditions to the November and December weather experienced. The warmer stratospheric conditions in 2010 led to a very cold start to winter. However, the colder stratospheric conditions seen in the early winter of 2011 have led to a far more unsettled start to winter, with gales being a prominent feature.
Sudden Stratospheric Warming
There is one further dramatic stratospheric phenomenon that can occur occasionally during the polar winter, this is known as a Sudden Stratospheric Warming. A Sudden Stratospheric Warming occurs when there is an abrupt warming of air, which is introduced into the vortex. The reasons behind this are complex and the results are dramatic. The stratospheric polar vortex can completely disintegrate and the winds flow in the opposite direction. This can have an amplified effect on the weather patterns seen in the troposphere, with a higher increase in .blocking patterns. that inhibit the normal flow of the jet stream. These disruptive patterns can last up to two months and once again colder weather can be experienced at latitudes further south.
One example of a Sudden Stratospheric Warming occurred in late January 2009 - the effects were felt very quickly, in early February 2009. The winds came in from the East, bringing snow and below average temperatures. This warming, and the effect on the polar vortex in 2009 can be viewed on the following striking NASA animation.
Video courtesy of NASA
So, next time it snows or you observe gales, remember that the weather you experience may be dictated by the polar vortex pattern, tens of miles above us in the stratosphere over the North Pole!
When we are outside and experiencing the full onslaught of winter, we know that what we receive comes from above. Little do we realize, often this weather is controlled by conditions a lot higher than we think! In fact, there is increasing research showing the stratosphere can have a strong influence on the weather patterns we experience at the surface.
The stratosphere is the second layer of the earth's atmosphere, situated above the lowest layer 'the troposphere'. The stratosphere starts at an altitude of ~6 miles (10km) and extends up to ~30 miles (50km). It is so named because the stratified layers within it have a temperature profile that increases with altitude. The stratosphere holds the ozone that absorbs harmful UV radiation and prevents it from reaching the surface.
Image courtesy of Windows to the Universe
So how does this layer affect our weather?
Every winter the stratosphere over the North Pole cools, this begins when the sunlight can no longer provide the energy to heat the ozone. Without this energy, the stratosphere cools rapidly, creating a thermal imbalance with the warmer stratosphere further south. This imbalance creates a large pressure difference and combined with the Coriolis effect, creates a large strong jet stream, circumnavigating the globe in the stratosphere in an eastwards direction. This system is known as the polar night jet, and contained within it is a strong vortex - known as the polar vortex.
The polar vortex increases and decreases in strength depending upon how cold the polar stratospheric atmosphere becomes during winter. The colder the polar stratosphere becomes, the stronger the polar vortex - and vice versa. The strength of the stratospheric polar vortex influences the atmosphere below it in the troposphere.
The troposphere also has a strong vortex over the North Pole during winter, this occurs due to tropospheric temperature and pressure differences. The strength of the stratospheric vortex helps govern the strength of the tropospheric vortex and this directly affects the strength of the jet stream.
In colder stratospheric conditions the jet stream becomes stronger; the stronger the jet stream, the straighter it flows and during winter, this normally keeps it on a collision course with the UK. A powerful jet stream is associated with unsettled and milder air, often with periods of heavy rain and windy conditions as one depression after another charges in from the Atlantic.
In warmer stratospheric conditions the jet stream takes a more meandering path due to a weaker polar vortex. This allows cold air to spill further south. If the UK is in the firing line of the cold air then this will lead to colder (often more settled) and possibly snowier weather.
Looking back at the last two years one can match the preceding stratospheric conditions to the November and December weather experienced. The warmer stratospheric conditions in 2010 led to a very cold start to winter. However, the colder stratospheric conditions seen in the early winter of 2011 have led to a far more unsettled start to winter, with gales being a prominent feature.
Sudden Stratospheric Warming
There is one further dramatic stratospheric phenomenon that can occur occasionally during the polar winter, this is known as a Sudden Stratospheric Warming. A Sudden Stratospheric Warming occurs when there is an abrupt warming of air, which is introduced into the vortex. The reasons behind this are complex and the results are dramatic. The stratospheric polar vortex can completely disintegrate and the winds flow in the opposite direction. This can have an amplified effect on the weather patterns seen in the troposphere, with a higher increase in .blocking patterns. that inhibit the normal flow of the jet stream. These disruptive patterns can last up to two months and once again colder weather can be experienced at latitudes further south.
One example of a Sudden Stratospheric Warming occurred in late January 2009 - the effects were felt very quickly, in early February 2009. The winds came in from the East, bringing snow and below average temperatures. This warming, and the effect on the polar vortex in 2009 can be viewed on the following striking NASA animation.
Video courtesy of NASA
So, next time it snows or you observe gales, remember that the weather you experience may be dictated by the polar vortex pattern, tens of miles above us in the stratosphere over the North Pole!
mehrdad_teh
متخصص بخش هواشناسی
بارش های خفیف تهران به دلیل جریانات جنوبی ضعیف بوده الان با تمام وجود اهمیت رطوبت جنوبی رو درک می کنم.
Amir Mohsen
متخصص بخش هواشناسی
دوستان این نقشه ها رو میذارم ولی باید برم
اگه این نقشه ها محقق بشه روزهای خوبی در انتظار کشورمون خواهد بود:
اگه این نقشه ها محقق بشه روزهای خوبی در انتظار کشورمون خواهد بود:
Cumulonimbus
متخصص هواشناسی
سلام
متاسفانه متن كامل مقالات در دسترس نيست و من هم فقط چكيده اش رو مطالعه كردم.
آخرین ویرایش:
عجب بارشی هفته دوم داریم
صبح بخیر عرض میکنم خدمت همه دوستان عزیز:گل:
بنظر میاد بلاخره از این دوران بی بارشی درحال تمام شدن هست و بارش های بسیار خوبی رو در پیش رو خواهیم داشت.
دیشب آقای حامد از مشهد گفته بودن برف برای تهران و خیلی نقاط ایران در نیمه بهمن غیر محتمل هست . در حالی که این حرف خیلی خنده داره . دقیقا برعکسش درسته .سنگین ترین برف سالای اخیر تهرتن در نیمه دوم بهمن بوده 1 متر . چیزی که شاید برای شما دوست عزیز که اینقدر راحت اظهار نظر میکنید قابل تصور نباشهتهران تا اخر اسفند احتمال بررف داره مهرداد جان . اتفاقا در بهمن احتمال برف سنگین از دی بیشتر هست . پستای دیشب و خوندم جوری بود که همه فکر کردند تهران در نزدیک زاهدان واقع شده !
دقیقا یادمه زمانی که خشایار شاه مستوفی : دی زیر اسمان شهر نشون میداد فک کنم سال 81 یا 82 بود از اول اسفند هوا به قدری گرم شد همه وسایل گرمایشی جم کردن تنها یک هفته به عید بود که با غافلگیری تمام تهران و قم برف خوبی امد.برف تهران بالای 40 سانت بود.
حتی یادمه دو سه سال قبلش حتی قم تو عید برف امد
تنها نکته ای که برف های اسفند داره زمان ماندگاریش کمه
سلام خدمت دوستان عزیز :گل:
محمد جان منم که هرچی برف سنگین دیدم تو مشهد بهمن بوده: برف نیم متری 20 بهمن 76، برف نیم متری هفته اول بهمن 74 و البته سال 50 هم رکورد سرما و برف درکشور و البته در مشهد 14 بهمن بوده!
سامیار هواشناس
کاربر ويژه
انقدر حرس نخور محمد حدود سال 76 بود 1 هفته قبل از عید ما ملاصدرا زندگی میکردیم 20 تا 25 سانت برف خشک ت اومد که مهراباد1- بود و اون روز به همه میگفتم دیدین زمین نفس کشیده یه حرف بی اساس و اشتباه هست و حتی در تابستانم اگر دما مناسب باشه برف میاد و میشینه
به هر حال اون روزو کاملا یادمه برفش خیلی خشک بود و در اخرین روزهای زمستان خیلی همرو بهت زده کرد
آخرین ویرایش:
درود:گل:
لحظاتی پیش اینجا هم ی رگبار زد
درود سجاد جان
نمیدونم برای رگبارم میشه تبریک گفت : دی
خدای عکسای قشنگی میگیری پیشنهاد میکنم یه مسابقه عکاسی در بخش اب و هوا و زیبایی های طبیعت راه بندازیم رقابت جالبی میشه
هر ماه هم برنده مشخص بشه
زیاد نگران گذشت زمان و نباریدن برف نباشید
اینم برف 29 فروردین 82 مشهد!
لینک:http://www.wunderground.com/history/airport/OIMM/2003/4/18/DailyHistory.html
Hourly Observations
اینم برف 29 فروردین 82 مشهد!
لینک:http://www.wunderground.com/history/airport/OIMM/2003/4/18/DailyHistory.html
Hourly Observations
| Time (IRDT) | Temp. | Windchill | Dew Point | Humidity | Pressure | Visibility | Wind Dir | Wind Speed | Gust Speed | Precip | Events | Conditions |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 12:20 AM | 2.0 °C | -1.8 °C | 2.0 °C | 100% | 1018 hPa | 5.0 km | SSW | 14.4 km/h / 4.0 m/s | - | N/A | Light Drizzle | |
| 1:20 AM | 2.0 °C | -2.4 °C | 2.0 °C | 100% | 1018 hPa | 4.0 km | South | 18.0 km/h / 5.0 m/s | - | N/A | Light Drizzle | |
| 2:20 AM | 1.0 °C | -2.3 °C | 0.0 °C | 93% | 1017 hPa | 4.0 km | SSW | 10.8 km/h / 3.0 m/s | - | N/A | Light Drizzle | |
| 3:20 AM | 0.0 °C | -2.5 °C | 0.0 °C | 100% | 1017 hPa | 1.5 km | South | 7.2 km/h / 2.0 m/s | - | N/A | Snow | Snow |
| 4:20 AM | 0.0 °C | -4.3 °C | 0.0 °C | 100% | 1017 hPa | 1.0 km | South | 14.4 km/h / 4.0 m/s | - | N/A | Snow | Snow |
| 5:20 AM | 0.0 °C | -3.5 °C | 0.0 °C | 100% | 1017 hPa | 1.0 km | SSE | 10.8 km/h / 3.0 m/s | - | N/A | Snow | Heavy Snow |
| 6:00 AM | - | - | - | N/A% | 1018.2 hPa | - | North | - | - | N/A | Unknown | |
| 6:20 AM | -1.0 °C | -3.6 °C | -1.0 °C | 100% | 1018 hPa | 0.5 km | South | 7.2 km/h / 2.0 m/s | - | N/A | Snow | Heavy Snow |
| 7:20 AM | -1.0 °C | -4.7 °C | -1.0 °C | 100% | 1018 hPa | 0.5 km | SW | 10.8 km/h / 3.0 m/s | - | N/A | Snow | Heavy Snow |
| 8:20 AM | 0.0 °C | -3.5 °C | 0.0 °C | 100% | 1018 hPa | 1.0 km | SW | 10.8 km/h / 3.0 m/s | - | N/A | Snow | Snow |
| 9:20 AM | 0.0 °C | -4.3 °C | 0.0 °C | 100% | 1019 hPa | 0.3 km | South | 14.4 km/h / 4.0 m/s | - | N/A | Snow | Heavy Snow |
| 10:20 AM | 0.0 °C | -3.5 °C | 0.0 °C | 100% | 1020 hPa | 0.5 km | South | 10.8 km/h / 3.0 m/s | - | N/A | Snow | Heavy Snow |
| 11:20 AM | 0.0 °C | -3.5 °C | 0.0 °C | 100% | 1018 hPa | 0.8 km | South | 10.8 km/h / 3.0 m/s | - | N/A | Snow | Heavy Snow |
| 12:20 PM | 1.0 °C | -2.3 °C | -1.0 °C | 87% | 1019 hPa | 1.5 km | SSW | 10.8 km/h / 3.0 m/s | - | N/A | Snow | Snow |
| 1:20 PM | 1.0 °C | -3.0 °C | -1.0 °C | 87% | 1020 hPa | 4.0 km | South | 14.4 km/h / 4.0 m/s | - | N/A | Snow | Light Snow |
| 2:20 PM | 1.0 °C | -2.3 °C | -1.0 °C | 87% | 1020 hPa | 4.0 km | South | 10.8 km/h / 3.0 m/s | - | N/A | Snow | Light Snow |
| 3:20 PM | 1.0 °C | -3.7 °C | -1.0 °C | 87% | 1020 hPa | 2.5 km | South | 18.0 km/h / 5.0 m/s | - | N/A | Snow | Snow |
| 4:20 PM | 1.0 °C | -3.0 °C | -1.0 °C | 87% | 1020 hPa | 4.0 km | SSE | 14.4 km/h / 4.0 m/s | - | N/A | Snow | Light Snow |
| 5:30 PM | 0.0 °C | -3.5 °C | 0.0 °C | 100% | 1021 hPa | 1.5 km | SSE | 10.8 km/h / 3.0 m/s | - | N/A | Snow | Snow |
| 6:20 PM | 0.0 °C | -4.9 °C | 0.0 °C | 100% | 1021 hPa | 2.0 km | SSE | 18.0 km/h / 5.0 m/s | - | N/A | Snow | Snow |
| 7:20 PM | - | - | - | N/A% | 1022 hPa | 2.0 km | South | 14.4 km/h / 4.0 m/s | - | N/A | Unknown | |
| 8:20 PM | -1.0 °C | -3.6 °C | -1.0 °C | 100% | 1022 hPa | 2.0 km | South | 7.2 km/h / 2.0 m/s | - | N/A | Snow | Light Snow |
| 10:20 PM | -1.0 °C | -3.6 °C | -1.0 °C | 100% | 1022 hPa | 4.0 km | SSE | 7.2 km/h / 2.0 m/s | - | N/A | Mostly Cloudy |
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