Homogenization of daily temperature data of the five principal stations in the Netherlands (version 1.0)

Ministry of Infrastructure and the Environment, Royal Netherlands Meteorological Institute (KNMI), T. Brandsma
De Bilt : KNMI

Problem description
Meteorological time series may become inhomogeneous for reasons such as relocations of stations and/or instruments, slow or abrupt changes in the environment and changes in instruments and measurement practices. For climate change and variability studies, it is important to deal with these potential sources of inhomogeneities and obtain homogenized datasets.
The daily temperature series of the five principal station in the Netherlands have known inhomogeneities due to relocations. De Bilt, also experienced a change from a large pagoda screen, open at the bottom, to a Stevenson screen. In most cases parallel observations have been made that facilitate correction of the series for the inhomogeneities.
Nowadays, many studies are being undertaken that homogenize time series before calculating trends and variability (Venema et al., 2012). Homogenization is then mostly done in a statistical way by calculating corrections from mutual comparisons of stations. This report deals with the homogenization of the daily minimum, maximum and mean temperatures (Tn, Tx, Tmean) in the Netherlands using parallel measurements. An existing technique called percentile matching will be used to obtain a baseline version 1.0 of the homogenized daily temperatures for The Netherlands.

40 p.
Fig., tab.
(Technical report = Technisch rapport ; TR-356)
With ref.