Virtual Climate Station data and products
Virtual climate station estimates are produced every day, based on the spatial interpolation of actual data observations made at climate stations located around the country.
Virtual Climate station Network (VCSN) data are estimates of daily rainfall, potential evapotranspiration, air and vapour pressure, maximum and minimum air temperature, soil temperature, relative humidity, solar radiation, wind speed and soil moisture on a regular (~5km) grid covering the whole of New Zealand. The estimates are produced every day, based on the spatial interpolation of actual data observations made at climate stations located around the country.
A thin-plate smoothing spline model is used for the spatial interpolations. This model incorporates two location variables (latitude and longitude) and a third "pattern" variable. For example, for rainfall the 1951–80 mean annual rainfall digitised from an expert-guided contour map is used to aid the interpolation (Tait et al. 2006; Tait et al. 2012). The software used for the interpolations is ANUSPLIN (Hutchinson 2012).
A similar interpolation procedure is used by the Australian Bureau of Meteorology to deliver estimated weather data at similar resolution over all Australia (Jeffrey et al. 2001).
VCSN Data for indivisdual virtual stations can be obtained through the NIWAData interface at https://data.niwa.co.nz
Cichota R, Snow V, Tait A 2008. A functional evaluation of virtual climate station rainfall data. New Zealand Journal of Agricultural Research, 51(3), 317–329.
Clark M, Hreinsson E, Martinez G, Tait A, Slater A, Hendrikx J, Owens I, Gupta H, Schmidt J, Woods R, 2009. Simulations of seasonal snow for the South Island, New Zealand. Journal of Hydrology (NZ), 48(2), 41-58.
Hutchinson M, 2012. ANUSPLIN version 4.3. https://researchers.anu.edu.au/publications/38018
Jeffrey SJ, Carter JO, Moodie KB, Beswick AR 2001. Using spatial interpolation to construct a comprehensive archive of Australian climate data. Environmental Modelling & Software 16(4): 309–330.
Romera A, Beukes P, Clark C, Clark D, Levy H, Tait A, 2010. Use of a pasture growth model to estimate herbage mass at a paddock scale and assist management on dairy farms. Computers and Electronics in Agriculture, 74(1), 66–72.
Tait A, Turner R 2005. Generating multiyear gridded daily rainfall over New Zealand. Journal of Applied Meteorology 44(9): 1315–1323.
Tait A, Henderson R, Turner R, Zheng XG 2006. Thin plate smoothing spline interpolation of daily rainfall for New Zealand using a climatological rainfall surface. International Journal of Climatology 26(14): 2097–2115.
Tait A., Woods R 2007. Spatial interpolation of daily potential evapotranspiration for New Zealand using a spline model. Journal of Hydrometeorology, 8, pp 430–438.
Tait A, 2008. Future projections of growing degree days and frost in New Zealand and some implications for grape growing. Weather and Climate 28, 17-36.
Tait A, Liley B, 2009. Interpolation of daily solar radiation for New Zealand using a satellite data-derived cloud cover surface. Weather and Climate, 29, 70-88.
Tait A, Sturman J, Clark M, 2012. An assessment of the accuracy of interpolated daily rainfall for New Zealand. Journal of Hydrology (NZ), 51(1), 25-44.