بارون شروع شده. باد سرد میاد. دما رو دماسنج من حدود 12 درجه نشون میده. از ظهر تا حالا حدود 13 درجه کاهش دما داشتیم. 12 تا دیگه می خوایما! :شاد:
سلام دکتر
استاد میره جینی کارشناس هواشناسی گیلان تو رادیو یک ساعت پیش گفت خط ساحل هم دماش فردا اوایل صبح به صفر رسیده وبرای مناطق مستعد مثل رشت و لاهیجان احتمال ایپچه سفید شدن هم هست!!:83::83:
سلام علی.
واقعا؟!
ایپچه سفید شدن هم عالیه arastu: :شاد::ذوق زده:arastu:
Figure 6. The mean sea surface pressure distribution pattern for winter (December-January-February) period of 1963-1964. The NAO dipole system is characterized by the Iceland low (L) and Azore high (H) pressure centers over the North Atlantic. The EAWR dipole system is characterized by the high pressure cell (H) over the northwestern Europe and a low pressure cell (L) over the Caspian region. The region in red colour near the eastern boundary of the plot represent Siberian high pressure system.
Examining 41-year (1958-1998) December-January-February mean precipitation patterns of the Eastern Mediterranean, Krichak et al. (2002) noted modulation of the NAO-based climatic teleconnection patterns by the so-called East Atlantic/West Russia (EAWR) quasi-persistent atmospheric system. They concluded that the NAO system alone can not adequately describe climate variability of the Eastern Mediterranean.
The EAWR system is characterized by two poles with either negative or positive surface pressure anomaly centers located over the northwestern Europe and the Caspian region. The positive winter EAWR pattern involves decreasing surface pressures from west to east with a low pressure anomaly center over the Caspian Sea region and a high pressure anomaly center over the northwestern Europe. The Black Sea-Eastern Mediterranean system is then affected by arctic air masses providing colder and drier than normal conditions, similar to those observed in the positive NAO years. The alternative EAWR winter pattern involves a positive surface pressure anomaly center over the Caspian region and a negative anomaly center in the northwestern Europe. The Black Sea is then accompanied by warmer and wetter than normal conditions as in the case of the negative NAO index.
The cooling cycle defined by decreasing ATI values during the first half of the 1960s fits into EAWR >0 phase as shown in Fig. 6, and quantified by the positive EAWR index values provided at the URL site http://www.cpc.ncep.noaa.gov/data/teledoc/eawruss.html. If the original NAO index is modified by replacing its values with those of the EAWR index for this period, the “modified NAO index” time series (shown by yellow line in Fig. 5) reveal more synchronous variations with the ATI time series. Their correlation (significant at 99.9% confidence level) then increases from 0.45 to 0.59 (Fig. 3b).