Observed changes in climate of the U.S. Pacific Northwest since the early twentieth century were examined using four different datasets. Annual mean temperature increased by approximately 0.68–0.88C from 1901 to 2012, with corroborating indicators including a lengthened freeze-free season, increased temperature of the coldest night of the year, and increased growing-season potential evapotransp...

Drought is a complex phenomenon which can be characterised mainly by its severity, duration and areal extent. Among these three dimensions, drought severity is the key factor which can be used for drought analysis. Drought indices are typically used to assess drought severity in a meaningful way. DrinC (Drought Indices Calculator) is a software package which was developed for providing a simple...

Stochastic weather generators (SWGs) are statistically-based point-scale models of meteorological data that are driven by random number generators. Commonly taking observational data or lowresolution global climate model data as input, they are useful tools for generating many realizations of possible climate scenarios for use in impacts studies. This dissertation presents the stochastic harmon...

Dryland plant ecosystems tend to exhibit bistable dynamics with two preferential configurations of bare and vegetated soils. Climate fluctuations are usually believed to act as a source of disturbance on these ecosystems and to reduce their stability and resilience. In contrast, this work shows that random interannual fluctuations of precipitation may lead to the emergence of an intermediate st...

In order to provide consistent weather warnings it is essential to estimate the probabilities for certain weather events occurring. There are a number of operational numerical and statistical methods for estimating the probability that precipitation occurs at a fixed location (a point probability). However, there is a growing interest in the computation of probabilities for precipitation occurr...

in order to determine the synoptic pattern of heavy and extreme precipitations on the southern coast of the caspian sea, precipitation characteristics of the caspian region were investigated by the use of eight synoptic stations data. considering the percentage thresholds, the days with heavy and extreme precipitations were determined for a 10 year period (1994-2003). since more than 75% of day...

Simulated global changes, including warming, increased precipitation, and nitrogen deposition, alone and in concert, increased net primary production (NPP) in the third year of ecosystem-scale manipulations in a California annual grassland. Elevated carbon dioxide also increased NPP, but only as a single-factor treatment. Across all multifactor manipulations, elevated carbon dioxide suppressed ...

introduction selection of the clear and transparent index for the precipitation using long-term homogeneous data is an important point for the researchers. several investigations have led to different indices for heavy rainfall. in some cases the specific amount of precipitation was used for heavy rainfall (rahimzadeh, 2005; masoodian, 2008; kamiguchi et al., 2006), e.g. alijani (2002) has sugg...