This analysis was conducted on 31 synoptic stations in Iran. Initially, the Mann-Kendall test was administered in order to analyse the trend of alterations of these two components over time and the results suggest that 16% of the stations show significant relationship with annual precipitation (positive and negative). More stations showed significant relationships between sunspots and minimum a...

The Standardized Precipitation Index (SPI) has become a popular measure of drought across the globe. In this study, Standardized Precipitation Index (SPI) was used in annual period of time to survey on drought. Also, in order to zonation frequency of drought, geographic information system (GIS) software and Kriging method used for extracting dry areas. The zoning maps show most severe drought i...

[1] The forecast atmospheric hydrologic cycle of the Polar version 3.1.1 of the Weather Research and Forecasting model (WRF) is examined for December 2006 – November 2007. The domain is similar to the Arctic System Reanalysis (ASR), an assimilation of model fields and Arctic observations being conducted partly by the Byrd Polar Research Center. Simulations are performed in 48 h increments initi...

We studied discharges of organic carbon from eight contiguous small watersheds on the Atlantic Coastal Plain in Maryland for up to 24 yr. Six of these watersheds were second or third order with mixed-land-use, while two were first order (one completely forested and one highly dominated by cropland). These watersheds have perched aquifers, so all groundwater discharges as well as surface runoff ...

Six rainfall datasets are compared over the Amazon basin, Northeast Brazil, and the Congo basin. These datasets include three gauge-only precipitation products from the Climate Prediction Center (CPC), Global Precipitation Climatology Center (GPCC), and Brazilian Weather Forecast and Climate Studies Center (CLMNLS), and three combined gauge and satellite precipitation datasets from the CPC Merg...

abstract this research evaluates climate change effects on drought severity in the region of gharesou, iran. the standardized precipitation index (spi) has been used for estimation of drought severity. a geographical information system is applied for calculating the mean areal precipitation time series from 11 meteorological stations, in and out of the area for the hydrological period jan 1971-...

The Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR4) presents twenty-two global climate models (GCMs). In this paper, we evaluate the ability of 22 GCMs to reproduce temperature and precipitation over the Tibetan Plateau by comparing with ground observations for 1961~1900. The results suggest that all the GCMs underestimate surface air temperature and most mo...

Precipitation over Lake Victoria in East Africa greatly influences its water balance. Over 30 million people rely on Lake Victoria for food, potable water, hydropower and transport. Projecting precipitation changes over the lake is vital in dealing with climate change impacts. The past and future precipitation over the lake were assessed using 42 model runs obtained from 26 General Circulation ...

W ether – M ay 215, ol. 0, o. 5 adjustment for the variation in the vertical profile of reflectivity, to produce an estimate of the reflectivity at the Earth’s surface (Kitchen et al., 1994; Smyth and Illingworth, 1998). This radar reflectivity is converted into precipitation rate (R) by a constant Z–R power law relationship of Z = 200R1.6 (Marshall and Palmer, 1948; Marshall et al., 1955). Thi...