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مباحث عمومی هواشناسی تابستان 1393
- شروع کننده موضوع heaven1
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اوه 768 ساعت بعد
تا اون موقع کی مرده و کی زنده
راستی این کدام سایت هست که تا اون موقع رو می زنه ؟
Amir Mohsen
متخصص بخش هواشناسی
در راستای تاثیرات امواج کلوین و راسبی بر شکل گیری و تشدید پدیده های النینو و لانینا
Amir Mohsen
متخصص بخش هواشناسی
این خروجی مدلهای اسمبل ECMWF موسوم به eps هست و بنظر باید از دقت بالایی برخوردار باشه.
این از شاهکارهای weatherbell هست
Amir Mohsen
متخصص بخش هواشناسی
what’s an El Niño Modokai?
But before we can understand El Niño Modokai variant we need to have to understand El Niño itself. It is part of the El Niño-Southern Oscillation (ENSO) that alternately gives us warm El Niños and cool La Niñas.
An ENSO is a physical oscillation of ocean waters from side to side of the tropical Pacific Ocean. It is kept going by trade winds that push the water westwards along the north and south equatorial currents. Between these two currents is the equatorial counter current and the water piled up in the western Pacific eventually comes back east via that counter current. It does so periodically as a massive wave, observable as a Kelvin wave, because the oscillation is caused by wave resonance and the resonance period is determined by the dimensions of the ocean basin.
As and when an El Niño wave reaches South America at the equator it splashes ashore and spreads out. This creates a large area of warm water, the air above gets warm, an updraft forms that interferes with trade winds, and global temperature rises by half a degree Celsius. But any wave that runs ashore must also pull back. As the El Niño wave retreats water level behind it drops half a meter or more, cold water from below wells up to fill the space, and a La Niña gets started.
But in the case of Modokai, only 20% of the time a La Niña emerges. More often, the Niño dips below the La Niña threshold, but do not remain there long enough to be considered an official La Niña. So if an El Niño Modokai is indeed confirmed this year, it is most likely next year we should be having an ENSO neutral year, rather than a La Niña year. This means, if the El Niño factor is considered as the prime one, we can expect 2013 monsoon season to be within the normal-above average range.
Modokai is but a chaotic variation of a typical El Niño pattern, absent the current gyres that usually form at the eastern terminus. This unique warming in the central equatorial Pacific associated with a horse-shoe pattern is flanked by a colder sea surface temperature anomaly (SSTA) on both sides along the equator. This year, as seen in the above graph, there is a lot of cold water circulating from Alaska down the west coast of Canada, the US and Mexico. This cold water is mixing with equatorial Pacific waters and keeping SSTs in equatorial Pacific down.
The real difference between the normal El Niño and El Niño Modokai isn’t their locale within the Pacific, it is the mode of energy release and it’s spreading out. The former is predominantly a localised event at the sea surface, because a huge spike in humidity which traps emerging energy and spreads it globally via the resulting winds.
Whereas El Niño Modokai is more a global emission of energy from the ocean, resulting in a general humidity increase worldwide rather than a localised blanket of water vapour around a localised emission event, followed by rapid heat loss to space once the warm air is spread out. That is why lower tropospheric temperatures can be expected to remain high as long as 4-6 months after the Pacific event petered out.
So from this month to maybe first quarter next year, global temperatures maybe expected to spike moderately and maybe the last hurrah for global warmists. Once the event is over, global lower tropospheric temperatures can be expected to fall very fast, particularly once the NH winter kicks in. Due to the loss of humidity over the cold land masses; the 2014 northern hemisphere winter could be expected to be extremely cold.
But before we can understand El Niño Modokai variant we need to have to understand El Niño itself. It is part of the El Niño-Southern Oscillation (ENSO) that alternately gives us warm El Niños and cool La Niñas.
An ENSO is a physical oscillation of ocean waters from side to side of the tropical Pacific Ocean. It is kept going by trade winds that push the water westwards along the north and south equatorial currents. Between these two currents is the equatorial counter current and the water piled up in the western Pacific eventually comes back east via that counter current. It does so periodically as a massive wave, observable as a Kelvin wave, because the oscillation is caused by wave resonance and the resonance period is determined by the dimensions of the ocean basin.
As and when an El Niño wave reaches South America at the equator it splashes ashore and spreads out. This creates a large area of warm water, the air above gets warm, an updraft forms that interferes with trade winds, and global temperature rises by half a degree Celsius. But any wave that runs ashore must also pull back. As the El Niño wave retreats water level behind it drops half a meter or more, cold water from below wells up to fill the space, and a La Niña gets started.
But in the case of Modokai, only 20% of the time a La Niña emerges. More often, the Niño dips below the La Niña threshold, but do not remain there long enough to be considered an official La Niña. So if an El Niño Modokai is indeed confirmed this year, it is most likely next year we should be having an ENSO neutral year, rather than a La Niña year. This means, if the El Niño factor is considered as the prime one, we can expect 2013 monsoon season to be within the normal-above average range.
Modokai is but a chaotic variation of a typical El Niño pattern, absent the current gyres that usually form at the eastern terminus. This unique warming in the central equatorial Pacific associated with a horse-shoe pattern is flanked by a colder sea surface temperature anomaly (SSTA) on both sides along the equator. This year, as seen in the above graph, there is a lot of cold water circulating from Alaska down the west coast of Canada, the US and Mexico. This cold water is mixing with equatorial Pacific waters and keeping SSTs in equatorial Pacific down.
The real difference between the normal El Niño and El Niño Modokai isn’t their locale within the Pacific, it is the mode of energy release and it’s spreading out. The former is predominantly a localised event at the sea surface, because a huge spike in humidity which traps emerging energy and spreads it globally via the resulting winds.
Whereas El Niño Modokai is more a global emission of energy from the ocean, resulting in a general humidity increase worldwide rather than a localised blanket of water vapour around a localised emission event, followed by rapid heat loss to space once the warm air is spread out. That is why lower tropospheric temperatures can be expected to remain high as long as 4-6 months after the Pacific event petered out.
So from this month to maybe first quarter next year, global temperatures maybe expected to spike moderately and maybe the last hurrah for global warmists. Once the event is over, global lower tropospheric temperatures can be expected to fall very fast, particularly once the NH winter kicks in. Due to the loss of humidity over the cold land masses; the 2014 northern hemisphere winter could be expected to be extremely cold.
Amir Mohsen
متخصص بخش هواشناسی
الگوی سالهای النینو مودوکی رو برای ایران در ماههای دسامبر- ژانویه و فوریه شبیه سازی کردم و نتایج خیلی جالب بود
Amir Mohsen
متخصص بخش هواشناسی
ماشاء الله به این النینوی مودوکی که دوره های پر بارش ایران دقیقا در طی سالهای النینو مودوکی بوقوع پیوسته پس میشه نتیجه گرفته که استمرار پدیده النینوی مودوکی منجر به وقوع ترسالی میشه!
Amir Mohsen
متخصص بخش هواشناسی
لانینای مودوکی هم خیلی موثر بر اقلیم کشور مون هست
Amir Mohsen
متخصص بخش هواشناسی
In fact, out of the three major El Ni Niño events
o after 1977, only the 1982 1982-83 period fits the
hypothesis stipulated by Trenberth and Stepaniak
(2001).
Even during 1997 when a strong El Ni Niño event
o occurred, it was preceded by a very weak El Ni Niño o
Modoki event. Importantly, it can also be seen
that that the condition suggested by Trenberth Trenberthand and Stepaniak (2001) is not valid for the so so-called
protracted El Ni Niño period of 1990 o 1990-94.
o after 1977, only the 1982 1982-83 period fits the
hypothesis stipulated by Trenberth and Stepaniak
(2001).
Even during 1997 when a strong El Ni Niño event
o occurred, it was preceded by a very weak El Ni Niño o
Modoki event. Importantly, it can also be seen
that that the condition suggested by Trenberth Trenberthand and Stepaniak (2001) is not valid for the so so-called
protracted El Ni Niño period of 1990 o 1990-94.
Amir Mohsen
متخصص بخش هواشناسی
Concluding Remarks
Concluding Remarks
4. The Nino3.4 index is not proper to define El Niño phenomena, because
it picks up the warming in either eastern or central equatorial Pacific.
Thus, the El Niño events defined by this index mixes up both the
canonical El Niño events and El Niño Modoki events.The teleconnection
patterns related to Nino3.4 index is a residual of those related to two
different phenomena: El Nino Modoki and El Nino.
1.El Niño Modoki is a phenomenon in the tropical Pacific, has different
spatial and temporal characteristics from those of canonical El Niño.
2.The extratropical response to the tropical SST distribution in El Niño
Modoki, and the location where the largest moisture transport from the
tropical Pacific to the subtropical and extratropical regions are very
different from those during El Niño events.
3.The large decadal background provide background of persistent
droughts in some region, such as the West of the United States in
the beginning of the 21stcentury.
Concluding Remarks
4. The Nino3.4 index is not proper to define El Niño phenomena, because
it picks up the warming in either eastern or central equatorial Pacific.
Thus, the El Niño events defined by this index mixes up both the
canonical El Niño events and El Niño Modoki events.The teleconnection
patterns related to Nino3.4 index is a residual of those related to two
different phenomena: El Nino Modoki and El Nino.
1.El Niño Modoki is a phenomenon in the tropical Pacific, has different
spatial and temporal characteristics from those of canonical El Niño.
2.The extratropical response to the tropical SST distribution in El Niño
Modoki, and the location where the largest moisture transport from the
tropical Pacific to the subtropical and extratropical regions are very
different from those during El Niño events.
3.The large decadal background provide background of persistent
droughts in some region, such as the West of the United States in
the beginning of the 21stcentury.
Amir Mohsen
متخصص بخش هواشناسی
شهاب از بوشهر
کاربر ويژه
درود امیر جان.
این نقشه در کدام قسمت از سایت ودر بل هست که من ندارم.
بی زحمت لینک دسترسی رو پ.خ کنید.
مرسی.
Amir Mohsen
متخصص بخش هواشناسی
درود
با اکانت موقتی که شما دارید بعید میدونم امکان دیدن این نقشه رو داشته باشید!
Amir Mohsen
متخصص بخش هواشناسی
Amir Mohsen
متخصص بخش هواشناسی
قویترین النینوی مودوکی - نقشه بارش
Amir Mohsen
متخصص بخش هواشناسی
Sardinia, Italy, Thunderstorm Creates Spectacular Light Show (PHOTOS)
By Sean Breslin Published: Jul 23, 2014, 7:04 AM EDT weather.com
1 / 6
Lightning Over Sardinia
All images courtesy of the Caters News Agency.
http://www.weather.com/safety/thund...derstorm-photos-20140722?cm_ven=FB_JK_72414_2
By Sean Breslin Published: Jul 23, 2014, 7:04 AM EDT weather.com
1 / 6
Lightning Over Sardinia
All images courtesy of the Caters News Agency.
http://www.weather.com/safety/thund...derstorm-photos-20140722?cm_ven=FB_JK_72414_2
شهاب از بوشهر
کاربر ويژه
شهاب از بوشهر
کاربر ويژه
امیر کوروش عزیز لطفا پیام خصوصی خودتون رو چک کنید.
تشکر.:گل:
تشکر.:گل:
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