Climatic water balance and velocity of climate change data for the contiguous US during the 20th century 

This page provides links to climatic water balance data for the continental United States (CONUS). The data are derived from the Parameter Regression of Independent Slopes Model (PRISM) data for the period 1900-2010, soils data from SSTATSGO, and atmospheric data from NLDAS-2 and NARR.

Climatic water balance characterizes the concurrent availability of energy and water for biota and is represented here by actual evapotranspiration (AET) and climatic water deficit (deficit). AET (a proxy for productivity) and deficit (a proxy for drought) represent the supply and unmet atmospheric demand components of the climatic water balance respectively. A water-balance model was developed to calculate annual estimates of AET and deficit between 1900 and 2010 at the 30 arc-second resolution (~800m). The model operates on a monthly time-step and accounts for atmospheric demand (potential evapotranspiration-PET), soil water storage, and includes the effect of temperature and radiation on snow hydrology via a snow melt model. PET was calculated using the Penman-Monteith equation and includes (i) terrain and cloud-corrected monthly average climatological downward shortwave radiation derived from NLDAS-2, (ii) monthly average 10 m wind velocity from the North American Regional Reanalysis, and (iii) monthly average dew-point temperature derived from PRISM data.

Using the water balance data we assess the climate change velocity for AET, deficit, and minimum temperature over the CONUS during the 20th century (1916–2005). Climate change velocity at a location is calculated by dividing the rate of climate change through time (e.g. °C yr ^-1) by the spatial gradient in climate at that location (e.g. °C km ^-1) yielding an estimate of the velocity (km yr ^-1) and direction of climate displacement. Climate change velocity describes the rate and direction which an organism would need to migrate to maintain an isocline of a given climate variable.

This dataset has been prepared for the AdaptWest project and was funded by the National Science Foundation and the USFS Rocky Mountain Research Station.

For further details see: Dobrowski, S.Z., J. Abatzoglou, A.K. Swanson, J.A. Greenberg, A.R. Mynsberge, Z.A. Holden, M.K. Schwartz (2013) The climate velocity of the contiguous United States during the 20^th century. Global Change Biology 19: 241-251. (link)

Click on the thumbnails below to see high resolution images