the effective patterns and mechanisms of synoptic systems during the wet and dry spells in midwest of iran(mwi) analyzed and discussed on seasonal scales from 1974 to 2003. synoptic analysis is based on synoptic chartson sea level pressure (slp), 850 and 500 hpa levels. the results of synoptic analysis show that dry spells in mwiare mostly corresponded to azores high (azh) intensifying and its ...

Abstract Medicanes are tropical‐like cyclones that develop in the Mediterranean Sea. Due to their harmful potential, study of medicanes has captured great attention from scientific community. In context a changing climate, future climatological characterization can only be achieved using climate model output. A frequently used method characterize thermal structure is cyclone phase space (CPS) d...

Deep learning artificial intelligence technology, which has the advantages of nonlinear mapping ability, massive information extraction spatial-temporal modeling and so on, provides new ideas methods for further improving accuracy weather climate extreme event prediction. A transfer CNN (Convolutional Neural Networks) classification model is established to classify circulation patterns, along w...

The Mediterranean region is strongly affected by extreme precipitation events (EPEs), sometimes leading to severe negative impacts on society, economy, and the environment. Understanding such natural hazards their drivers essential mitigate related risks. Here, EPEs over between 1979 2019 are analysed, using ERA5, latest reanalysis dataset from ECMWF. determined based 99th percentile of daily d...

[1] We find that the North Annular Mode (NAM) of the wintertime geopotential height anomalies between 10 and 1000 hPa is influenced by solar changes and that the effect is statistically significant. This evidence suggests that a mechanism of solar influence on climate operates through the excitation of this mode. The influence depends on the phase of the quasi-biennial oscillation (QBO). In ear...

The Botswana High is an important component of the regional atmospheric circulation during austral spring, summer and autumn. While high tends to be stronger El Niño weaker La Niña, its direct response Southern Oscillation (ENSO) remains unknown. To that end, a variable resolution global climate model (Model Prediction Across Scales version 7, hereafter MPAS) applied with relatively (48-km grid...

Abstract. Surface ozone (O3) pollution during summer (June–August) over eastern China has become more severe in recent years, resulting a co-occurrence of surface O3 and PM2.5 (particulate matter with aerodynamic diameters ? 2.5 µm the air) pollution. However, mechanisms regarding how synoptic weather pattern (SWP) might influence this compound remain unclear. In study, we applied T-mode princi...

Based on 40 years of daily precipitation, 272 extreme precipitation days in the Northern Xinjiang region are defined. Using data these days, four spatial patterns were obtained through principal component analysis. Then, daily-averaged reanalysis used to analyze variations synoptic systems and two before after. The rainfall centers shifted with influential at 500 hPa. Water vapor western Tiansh...

the aim of this research is investigating the relations between climatic large scale signals and spring rainfall of khorasan-e razavi province. in this research, we have analyzed 38 years of rainfall data in khorasan-e razavi province, located in northeastern iran. we attempted to train artificial neural network based upon climatic large scale signals with 38 years of rainfall data. for perform...