Climate Reanalysis


Using historical global patterns and satellites to create a "reanalysis" product for regional weather

     Ideally it would be possible to develop a detailed description of the patterns over time of the surface climate (temperature, rainfall) from local meteorological records. But records aren't sufficient for this. To provide a robust descriptor of past weather patterns, the process of "re-analysis" was used, as follows.

     A global half-degree gridded meteorological forcing dataset as described in Adam et al. (2006) was used to generate daily historical gridded forcings of temperature minima and maxima, precipitation, and wind speed at one-sixteenth degree latitude-longitude resolution from observed station data using methods described in Maurer et al. (2002). This dataset is from hereon referred to as the UW dataset. The dataset can be downloaded in its entirety here: UW Global 1/2 Degree. Daily values of precipitation and temperature were then disaggregated into 3-hourly time steps according to methods outlined in Nijssen et al. (2001) and Wang et al. (2009). Similar to Maurer (2002), other meteorological and radiation variables are calculated from established relationships, for example downward solar and longwave radiation and dew point were derived from the daily temperature and temperature range using methods described in Nijssen et al. (2001).

     The following spatial plots show the are the average annual gridded 1/8 degree climatology used in VIC over Espírito Santo. The data are available to be queried in greater detail, as desired.

     Evaporation is computed from the VIC model, using precipitation and temperature to drive the model.