Understanding and predicting the state of North Atlantic Oscillation (NAO) is key to forecasting weather in United Kingdom (UK). It has been shown that particular phases Madden–Julian (MJO) act as precursors either NAO+ or NAO? events. We assess ability UK Met Office coupled climate model (HadGEM3-GC3.1-MM) simulate these NAO responses at lead times 1–2 weeks show improvements are needed modell...

Abstract Based on the database of Subseasonal to Seasonal (S2S) Prediction project World Weather Research Programme (WWRP) / Climate (WCRP), influence North Atlantic Oscillation (NAO) Madden- Julian (MJO) and its forecast skill is investigated. It found that most models can capture MJO phase changes following positive negative NAO events. About 20 days after initialized with a (negative) NAO, a...

The North Atlantic Oscillation (NAO) is the leading mode of variability across sector and a key metric extratropical forecast performance. Skilful predictions NAO are possible at medium-range (1–2 weeks) seasonal time scales. However, in dynamical prediction system, we find that sub-seasonal (1 month with lead 20–30 days) not statistically significant represent gap skill. In this study, have in...

The Pacific–North American (PNA) teleconnection is a major mode of Northern Hemisphere wintertime climate variability, with well-known impacts on North American temperature and precipitation. To assess whether the PNA teleconnection has extended predictability, comprehensive data analysis is conducted to elucidate PNA evolution, with an emphasis on patterns of PNA development and decay. These p...

Abstract Radiosonde data are important for understanding and monitoring the upper troposphere lower stratosphere (UTLS) region. Over much of Africa, however, such lacking; consequently, African UTLS is understudied, potential proxies as climate models reanalysis products fail to fully capture behavior UTLS. This study pioneers use Global Navigation Satellite System‐Radio Occultation (GNSS‐RO) f...

Boreal winter (December–February) 2020/2021 in the North Atlantic/European region was characterised by a negative Atlantic Oscillation (NAO) index. Although this captured within ensemble spread of predictions from Met Office Global Seasonal forecast system (GloSea5), with 17% members predicting an NAO less than zero, mean shifted towards positive phase. The observed monthly anomalies were parti...

شور و داوم اه : ،یبرجت همین قیقحت نیا رد 28 نیماتیو ،نیرمت ،لرتنک هورگ راهچ هب یفداصت روط هب و باختنا قاچ رتخد C یبیکرت و دندش میسقت . نیرمت تدش اب يزاوه 50 ات 70 ،رثکادح بلق نابرض دصرد 3 تدم هب و هتفه رد هسلج 8 هتفه دش ماجنا . هورگ ياه نیماتیو C و صرق یبیکرت 500 یلیم نیماتیو یمرگ C ار 3 فرصم هتفه رد راب دندومن . هنومن و لبق اتشان ینوخ ياه 48 هلخادم نیرخآ زا سپ تعاس اه عم...

تاسياقلما فلتخم ىلع ءوضلا ضعب ءاقلإ تم ةعجارلما هذه يف دضتسلماب دضلا تلاعافت ىلع دمتعت يتلا ةموسولما ةيعانلما ةيعانلما و ،ةيقلأتلا ةيعانلما تاسايقلما لمشت يتلاو Ag-Ab هذه فيرعت تم .)EIA, ELISA( ةييمزنلإا ةيعانلما و ،ةيعاعشلا و تلاعافتلا أدبلم رصتخم فصو عم لًاوأ ةثلاثلا تاسياقلما اهروطت حيضوتل يخيراتلا جردتلا بسح تشقون مث ،تاقيبطتلا امك .لماك لكشب ةيلآ ةينقت ىلإ ةياهنلا يف داق يذلا يجيردتلا ةخطلل...