the moisture flux convergence (mfc) and relative humidity in dusty days at different times and levels over the alvand mountain was investigated. the required basic data for the years 2009-2012, including relative humidity, visibility and synoptic codes, were gathered from hamadan synoptic station, while sea level pressure, uwind, vwind and specific humidity data were gathered from ncer/ncar sit...

The ability of altimetry to detect extreme low pressure events and the relationship between sea level pressure and sea level anomalies during extra-tropical depressions have been investigated. Specific altimeter treatments have been developed for tropical cyclones and applied to obtain a relevant along-track sea surface height (SSH) signal: the case of tropical cyclone Isabel is presented here....

in this research, the correlation between precipitation change in southern coasts of caspian sea and variability of sea level pressure have been analyzed by using environmental to circulation approach at time period 1339- 1383. in this respect, we make use of daily precipitation data of the 12 synoptic stations of studied area at surface data base section and prepare the time series matrix of p...

The Pacific Walker circulation is a large overturning cell that spans the tropical Pacific Ocean, characterized by rising motion (lower sea-level pressure) over Indonesia and sinking motion (higher sea level-pressure) over the eastern Pacific1,2. Fluctuations in the Walker circulation reflect changes in the location and strength of tropical heating, so related circulation anomalies have global ...

weather process prediction is the tool for managers to planning the future political for maximum operation. the aim of this research is relation investigation of large scale synoptically patterns with seasonal rainfall of khorasan province. in this research, we have analyzed 37 years of rainfall data in khorasan province that is located the northeastern part of iran .we attempted to train adapt...

A nonlinear projection of the tropical Pacific sea surface temperature anomalies (SSTA) onto the Northern Hemisphere winter sea level pressure (SLP) anomalies by neural networks (NN) was performed to investigate the nonlinear association between ENSO and the Euro-Atlantic winter climate. While the linear impact of ENSO on the Euro-Atlantic winter SLP is weak, the NN projection reveals statistic...

[1] Previous analyses of sea level pressure (SLP) trends have often focused on boreal winter trends. Here we demonstrate that externally-forced SLP trends are observed in all four seasons, with simulated and observed decreases in SLP at high latitudes and increases elsewhere. We find that the observed pattern of seasonal mean zonal mean SLP changes is inconsistent with simulated internal variab...

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...

Recent advances in neural network modeling have led to the nonlinear generalization of classical multivariate analysis techniques such as principal component analysis and canonical correlation analysis (CCA). The nonlinear canonical correlation analysis (NLCCA) method is used to study the relationship between the tropical Pacific sea level pressure (SLP) and sea surface temperature (SST) fields...

We present the construction of a continuous, daily (09:00 UTC), station-based (Azores-Iceland) North Atlantic Oscillation (NAO) Index back to 1871 which is extended back to 1850 with additional daily mean data. The constructed index more than doubles the length of previously existing, widely available, daily NAO time series. The index is created using entirely observational sea-level pressure (...