A scPDSI-based global data set of dry and wet spells for 1901–2009

摘要: [1] Global maps of monthly self-calibrating Palmer Drought Severity Index (scPDSI) have been calculated for the period 1901–2009 based on CRU TS 3.10.01 data sets. This work addresses some concerns with regard to monitoring global drought conditions using traditional Index. First, scPDSI has a similar range variability in diverse climates making it more suitable metric comparing relative availability moisture different regions. Second, physically Penman-Monteith parameterization potential evapotranspiration is used, actual vegetation cover rather than reference crop. Third, seasonal snowpack dynamics are considered water balance model. The leading mode new set represents trend towards drying parts globe between 1950 and 1985 but accounts less 9% total variability. Increasing temperature explain part trend. However, local trends most regions not significant. Previously published evidence unusually strong or widespread supported by this work. A fundamental aspect calculation selection calibration period. When does include recent record, extreme amplified. It shown that principal reason interpretations scale not, as recently claimed, use simplified forcing data.