مباحث عمومی هواشناسی

[Amir Mohsen]

سلام دوستان عزیز

امروز بعدازظهر باز به سرم زد که برای ورزش برم پارک وکیل آباد و همه جا و همه چی حسابی منجمد بود به عکسهای زیر توجه کنید:

حدودهای ساعت 5 بعدازظهر بعد از اتمام ورزش جهت صرف چای و استراحت روی یکی از تختهای ضلع شرقی پارک اتراق کردیم یعنی اینجا:

و خوب طبق معمول من هم ضمن صرف چای به اینکاری که خیلی علاقه دارم پرداختم و اونهم چیزی نبود جز ثبت وضعیت جوی و ایستگاه هواشناسی موبایل رو روشن کردم تا ببینم واقعا دما اونجا چند درجه است که ما اینقدر می لرزیدیم!!!!!!!!!!

خودتون ببیند و قضاوت کنید:

وضعیت فعلی ایستگاه هواشناسی رسمی مشهد:

 

[Miss zahra]

سلام خدمت برادران عزیز:54::احترام:
عصر زمستونیتون بخیر:7:




​

 

[ali_kermanshah]

سلام
دوستان به نظرتون وقتی این کمفشار وارد فلات ایران بشه وضعیت پرفشار چه تغییری می کنه و خط سرما چقدر عقب نشینی می کنه ؟؟

 

[Amir Mohsen]

 

[Amir Mohsen]

:گل::گل::گل::گل::شاد::شاد::شاد::شاد2::شاد2::شاد2::گل::گل::گل::گل:

 

[Amir Mohsen]

 

[Amir Mohsen]

آخرین تجزیه و تحلیل اقیانوس هند:

آنومالی بارش




بارش:



ورتیسیتی:

 

[ali_kermanshah]

:گل::گل::گل::گل::شاد::شاد::شاد::شاد2::شاد2::شاد2::گل::گل::گل::گل:

امیر محسن عزیز

نظرتون در مورد اون نقشه ای که گذاشتم چیه ؟؟

 

[Amir Mohsen]

امیر محسن عزیز

نظرتون در مورد اون نقشه ای که گذاشتم چیه ؟؟

سلام علی عزیز

اون کم فشاری که در نقشه مشخص کردید رو من چند وقته که در حال رصدش هست . در واقع این یک ناوه ای هست که از جریانات اصلی storm track از نواحی شمالی اروپا به روی مدیترانه عمیق میشه بعد متاسفانه از جریانات اصلی Storm track جدا میشه و به شکل یک cut off low در میاد که تو ایران بهش میگن بند دال!!!!!!!

حالا این اصطلاح رو از کجا در آوردن و به فارسی میگن بندال من نمیدونم و با ترجمه تحت الفظی این اصطلاحات هم کاملا مخالفم و بنظرم این اصطلاحات اصلا نباید ترجمه بشه!

بگذریم..........

کلیمتالوژی cut off ها طوری هست که به شکل یک سلول بسته واحد در میان و با سرعت خیلی کمی حرکت میکنند تا اینکه کاملا مضمحل بشن!!

در واقع یکی از دلایل وقوع بارشهای شدید و غیر مترقبه و شرایط نامساعد جوی طولانی مدت همین سامانه های کات هستند که در محدوده فعالیتشون برای چندین روز میتونند مسبب بارشهای سنگین به شکل باران و یا برف بشن.

این سامانه ها معمولا سرعت خیلی خیلی کم دارند و بعید میدونم که بتونه با اطلاعات فعلی به مناطق بیشتری از ایران نفوذ کنه.

برای آشنایی بیشتر شما دوست خوبم انواع سامانه های cut off low رو در ادامه این پست قرار میدم که با کات آف هایی با بارش سنگین - بارش ضعیف و یا بدون بارش بیشتر آشنا بشید.

خیلی جالبه که بصورت همزمان ما دو تا کات آف با دو تا کلیماتولوژی متفاوت در روزهای پیشرو یکی در جنوب غرب و یکی در شمال شرق ایران داریم:



Heavy Precipitation Cutoff Cyclone Days:

Negative Tilt

Neutral Tilt

Positive Tilt

Low Precipitation Cutoff Cyclone Days:

Negative Tilt

Neutral Tilt

Positive Tilt

No Precipitation Cutoff Cyclone Days:
Note: Since there were so few no precipitation cutoff cyclone days, these days were not subdivided into cutoffs and troughs.

Negative Tilt

Neutral Tilt

Positive Tilt

 

[سیبری]

18:30
سقز18-
سراب17-
بستان اباد 16-
خیراباد 15-
ملکان15-
بناب14-
ماکو14-
قره ضیاالدین 14-
همدان13-
نقده13-
سلماس 13-
زرینه13-
مراغه13-
اشونیه13-
تبریز12-
بوکان12-
شبستر12-
چالدران12-
آوج11-
رزن11-
همدان نوژه11-
قروه11-
مهاباد11-
ارومیه11-
خوی11-
فیروزاباد کوثر11-
اردبیل11-
ورزقان11-
پیرانشهر10-
پلدشت 10-
جلفا10-
خلخال10-
عجب شیر10-
خدابنده10-
اسداباد10-

 

[Amir Mohsen]

حالا کی میدونه دو تا سامانه ای که قرار هست در کشور ما در شمال شرق و جنوبغرب فعالیت کنه ، کدوم یک از سامانه های بالاست؟؟؟؟؟؟؟؟؟

 

[سیبری]

حقیقتا باید به مردم سقز لقب جان سخت داد!
حدود دو هفته تمام شبها زیر تیغ 20- قرار دارن !
سرمای 20- رو درست پس از غروب آفتاب و در همین ابتدای شب و در حالیکه مردم به امور روزمره و رفت و آمد در محیط باز و خیابانها مشغولن تجربه میکنن!
20- کم دمایی نیستا!

 

[heaven1]

حالا کی میدونه دو تا سامانه ای که قرار هست در کشور ما در شمال شرق و جنوبغرب فعالیت کنه ، کدوم یک از سامانه های بالاست؟؟؟؟؟؟؟؟؟

واسه شمال شرق اینه

 

[Amir Mohsen]

آخرین وضعیت نوسانات MJO سپتامبر 2013 الی 23 دسامبر 2013



خوب ببینم این مولفه اتمسفری پارسال از 9 نوامبر تا 6 فوریه در چه فازهایی سر کرده !!!! بعد دوستان میتونند با فلش بک به گذشته فازهای مناسب منطقه محل سکونت شون رو در سال پیش معلوم کنند

شایان ذکر است که پارسال هم انسو در فاز خنثی بوده ولی فاز ها در هر ماه با توجه به وضعیت انسو متفاوت خواهد بود:

 

[Amir Mohsen]

ممنون از مشارکت در بحث!

نقشه مشابه تراز 500 سامانه شمال شرق رو استخراج کنید و بعد بگید به چه دلیلی همچین استنباطی کردید هادی جان:گل:

واسه شمال شرق اینه

 

[heaven1]

آخرین وضعیت نوسانات MJO سپتامبر 2013 الی 23 دسامبر 2013

مشاهده پیوست 49278

خوب ببینم این مولفه اتمسفری پارسال از 9 نوامبر تا 6 فوریه در چه فازهایی سر کرده !!!! بعد دوستان میتونند با فلش بک به گذشته فازهای مناسب منطقه محل سکونت شون رو در سال پیش معلوم کنند

شایان ذکر است که پارسال هم انسو در فاز خنثی بوده ولی فاز ها در هر ماه با توجه به وضعیت انسو متفاوت خواهد بود:


مشاهده پیوست 49279

آنومالی دمای ناحیه NINO 3.4 هم تقریبن به صفر رسیده و الان 0.06 - هست!

 

[heaven1]

ممنون از مشارکت در بحث!

نقشه مشابه تراز 500 سامانه شمال شرق رو استخراج کنید و بعد بگید به چه دلیلی همچین استنباطی کردید هادی جان:گل:

کارهای سخت سخت از ما نخواه دیگه:خنده1:

 

[heaven1]

ممنون از مشارکت در بحث!

نقشه مشابه تراز 500 سامانه شمال شرق رو استخراج کنید و بعد بگید به چه دلیلی همچین استنباطی کردید هادی جان:گل:

استدلال ما اشتباه بود بفرمایید

 

[Amir Mohsen]

استدلال ما اشتباه بود بفرمایید

یک راهنمایی:

JET STREAK ON LEFT SIDE OF TROUGH

METEOROLOGIST JEFF HABY
Embedded within the jet stream are jet streaks. The high momentum air associated with a jet streak helps build troughs and ridges. When a stream of air on a straight-line path moves into a region where it must follow a curved path, a centrifugal force results. The centrifugal force is an outward fleeing force. It is synonymous to a car turning a sharp corner. The car remains on a curved path due to friction, however, your body and separate items in the car want to remain on a straight-line path. The driver will feel their body wanting to go through the side of the car. Air in the atmosphere works in a similar fashion, except air does not turn corners as easily as a car on the road due to a low value of friction in the upper atmosphere. A jet streak of air on the left side of the trough will tend to amplify the trough. The diagram below shows a time series of a jet streak amplifying a trough.

Another perspective in looking at how a jet streak on the left side of a trough amplifies a trough is by studying the left front divergence quadrant of a jet streak. Mass is evacuated from the left front quadrant of a jet streak. As the left front quadrant moves south, the trough will build to the south. The diagram below shows the left front quadrant of a jet streak that begins to enter the base of a trough.

As a jet streak turns into the base of a trough, the left front quadrant remains just to the south of the axis of rotation associated with the trough. Because divergence is greater to the south of the axis of rotation as compared to the north, the trough builds to the south. Strong upper level divergence lowers heights and surface pressure. The diagram below shows the position of the left front quadrant with respect to the position of the axis of rotation.

It is the left front quadrant and the production of PVA that are responsible for divergence to the north of a jet streak axis in the base of a trough. The diagram below shows the positions of a vort max and the left front quadrant within the base of a trough. The divergence from PVA and the left front Quadrant being south of the axis of rotation allows the trough to build south and amplify.

Haby sez: The momentum of a jet streak and divergence created from the left front quadrant and PVA allow a jet streak on the left side of the trough, which is entering into the base of the trough, to deepen and amplify toward the south.


------------------------------------------------------------

JET STREAK ON RIGHT SIDE OF TROUGH

METEOROLOGIST JEFF HABY
When a jet streak is on the right side of a trough, the momentum of the jet streak has the opposite effect as it had on the left side of a trough. The diagram below shows a time series of a jet streak on the right side of a trough and trough lifting. Lifting of a trough means the amplitude of the trough becomes less and the axis of rotation moves to the north or northeast.

A perspective in understanding how a jet streak on the right side of a trough lifts a trough is by studying the left rear convergence quadrant of a jet streak. Mass is added to the left rear quadrant of a jet streak. As the left rear quadrant moves north, the trough will lift because convergence in the base of a trough causes height rises (due to addition of mass) and a subsequent weakening of the trough. The diagram below shows the left rear quadrant of a jet streak that is exiting the base of a trough.

LEFT REAR QUAD
As a jet streak leaves the base of a trough, the left rear quadrant overlaps the base of the trough. Because convergence is occurring within the axis of rotation the trough weakens. Strong upper level convergence raises heights and surface pressure. The diagram below shows the position of the left rear quadrant with respect to the position of the axis of rotation.

LEFT REAR QUAD W.R.T. ROTATIONAL AXIS
Adding to the convergence created by the left rear quadrant is NVA. The PVA and divergence from the left front quadrant will be to the northeast (approximate direction) of the axis of rotation. This will promote a northeast lifting of the trough. The diagram below shows the two mechanisms of convergence (left rear quad and NVA) within the base of the trough and the two mechanisms of divergence (left front quad and PVA) to the northeast of the axis of rotation.

NVA AND JET STREAK CONVERGENCE WITHIN TROUGH BASE
Haby sez: The momentum of a jet streak and convergence created from the left rear quadrant and NVA allow a jet streak on the right side of the trough, which is exiting the base of the trough, to weaken and lift the trough to the northeast.
​

 

[heaven1]

یک راهنمایی:

JET STREAK ON LEFT SIDE OF TROUGH

METEOROLOGIST JEFF HABY
Embedded within the jet stream are jet streaks. The high momentum air associated with a jet streak helps build troughs and ridges. When a stream of air on a straight-line path moves into a region where it must follow a curved path, a centrifugal force results. The centrifugal force is an outward fleeing force. It is synonymous to a car turning a sharp corner. The car remains on a curved path due to friction, however, your body and separate items in the car want to remain on a straight-line path. The driver will feel their body wanting to go through the side of the car. Air in the atmosphere works in a similar fashion, except air does not turn corners as easily as a car on the road due to a low value of friction in the upper atmosphere. A jet streak of air on the left side of the trough will tend to amplify the trough. The diagram below shows a time series of a jet streak amplifying a trough.

Another perspective in looking at how a jet streak on the left side of a trough amplifies a trough is by studying the left front divergence quadrant of a jet streak. Mass is evacuated from the left front quadrant of a jet streak. As the left front quadrant moves south, the trough will build to the south. The diagram below shows the left front quadrant of a jet streak that begins to enter the base of a trough.

As a jet streak turns into the base of a trough, the left front quadrant remains just to the south of the axis of rotation associated with the trough. Because divergence is greater to the south of the axis of rotation as compared to the north, the trough builds to the south. Strong upper level divergence lowers heights and surface pressure. The diagram below shows the position of the left front quadrant with respect to the position of the axis of rotation.

It is the left front quadrant and the production of PVA that are responsible for divergence to the north of a jet streak axis in the base of a trough. The diagram below shows the positions of a vort max and the left front quadrant within the base of a trough. The divergence from PVA and the left front Quadrant being south of the axis of rotation allows the trough to build south and amplify.

Haby sez: The momentum of a jet streak and divergence created from the left front quadrant and PVA allow a jet streak on the left side of the trough, which is entering into the base of the trough, to deepen and amplify toward the south.


------------------------------------------------------------

JET STREAK ON RIGHT SIDE OF TROUGH

METEOROLOGIST JEFF HABY
When a jet streak is on the right side of a trough, the momentum of the jet streak has the opposite effect as it had on the left side of a trough. The diagram below shows a time series of a jet streak on the right side of a trough and trough lifting. Lifting of a trough means the amplitude of the trough becomes less and the axis of rotation moves to the north or northeast.

A perspective in understanding how a jet streak on the right side of a trough lifts a trough is by studying the left rear convergence quadrant of a jet streak. Mass is added to the left rear quadrant of a jet streak. As the left rear quadrant moves north, the trough will lift because convergence in the base of a trough causes height rises (due to addition of mass) and a subsequent weakening of the trough. The diagram below shows the left rear quadrant of a jet streak that is exiting the base of a trough.

LEFT REAR QUAD
As a jet streak leaves the base of a trough, the left rear quadrant overlaps the base of the trough. Because convergence is occurring within the axis of rotation the trough weakens. Strong upper level convergence raises heights and surface pressure. The diagram below shows the position of the left rear quadrant with respect to the position of the axis of rotation.

LEFT REAR QUAD W.R.T. ROTATIONAL AXIS
Adding to the convergence created by the left rear quadrant is NVA. The PVA and divergence from the left front quadrant will be to the northeast (approximate direction) of the axis of rotation. This will promote a northeast lifting of the trough. The diagram below shows the two mechanisms of convergence (left rear quad and NVA) within the base of the trough and the two mechanisms of divergence (left front quad and PVA) to the northeast of the axis of rotation.

NVA AND JET STREAK CONVERGENCE WITHIN TROUGH BASE
Haby sez: The momentum of a jet streak and convergence created from the left rear quadrant and NVA allow a jet streak on the right side of the trough, which is exiting the base of the trough, to weaken and lift the trough to the northeast.
​

شماره 15