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 ...

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 ...

the wet and dry spells can be defined as a number of consecutive months with rain amount greater or less than the truncation level, respectively.analysis of the wet and dry spell properties of monthly rainfall series at 40 meteorology stations in the golestan province is carried out for an extended period of 34 years (1974–2007). the results proved that the patterns of wet and dry spell duratio...

Extreme precipitation events in the Peruvian Andes have significant socioeconomic impacts, yet their atmospheric dynamics are poorly understood. Here austral summer (December–March) wet and dry spells and their continentaland large-scale teleconnections are analyzed using reanalysis, gridded, and in situ precipitation data. Dry and wet spells in the Peruvian Andes show a pervasive dipole patter...

A lengthening of dry spells (DSLs) has been reported by some regional studies, but its linkage with heatwaves via the feedback between soil moisture and air temperature is still not clear on global continental scales. Here we examine increases in length DSLs during summer over continents using situ precipitation records. Globally, average DSL increased 0.46 day/decade since 1970s along high-pre...

This study set out to investigate the trends of agriculturally-relevant rainfall characteristics among small-scale farmers in the rainfall-sensitive dry savanna agro-ecological zone of northern Ghana. Interviews are used to identify characteristics of rainfall which are deemed by the farmers as important in their food production. Time series daily rainfall data from 1960-2007 is then used to id...

With a growing world population and a trend towards more resource-intensive diets, pressure on land and water resources for food production will continue to increase in the coming decades. Large parts of the world rely on rainfed agriculture for their food security. In Africa, 90 % of the food production is from rainfed agriculture, generally with low yields and a high risk of crop failure. One...