UTCI—Why another thermal index?

Abstract

19The existing assessment procedures of the thermal environment in the fields of public weather 20 services, public health systems, precautionary planning, urban design, tourism & recreation 21and climate impact research show significant shortcomings. This is most evident for simple 22 (mostly two-parameter) indices, when comparing them to complete heat budget models 23 developed since the 1960s. ISB Commission 6 took up the idea to develop a Universal 24 Thermal Climate Index (UTCI) which was to be based on the most advanced multi-node 25 model of thermoregulation representing the progress in science within the last 3 to 4 decades, 26 both in thermo-physiological and heat exchange theory. (FPC) was adopted for this study. The model was extensively validated applying as yet 5 unused data from other research groups, and extended for purposes of the project. This model 6 was coupled with a state-of-the-art clothing model considering the behavioural adaptation of 7 clothing insulation by the general urban population to actual environmental temperature. 8 UTCI was then derived conceptually as an Equivalent Temperature (ET). Thus, for any 9 combination of air temperature, wind, radiation, and humidity (stress), UTCI is defined as the 10 air temperature of the reference condition which would elicit the same dynamic response 11 (strain) of the physiological model as the actual conditions. As UTCI is based on 12 contemporary science its use will standardize applications in the major fields of human 13 biometeorology thus making research results comparable and physiologically relevant. 14 15

The evolutionary adaptation of the C282Y mutation to culture and climate during the European Neolithic

“…Therefore, we created a climate index to test the predictions set out in our hypothesis. Since more than one climate factor ultimately impacts human physiology, indices based on multiple climate variables have long been used to predict human physiological outcomes (Jendritzky et al, 2012). To create our climate index, the following climate data were transformed to Z ‐scores: mean of mean daily temperature, mean maximum daily temperature, and mean wet days.…”

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“…In order to evaluate the thermal comfort, the Universal Thermal Climate Index (UTCI) (Jendritzky et al 2012, Bröde et al 2012b, Bröde et al 2012a, Fiala et al 2012) has been used. The UTCI is developed by the research activities compiled by COST Action 730, with the main objective of developing one internationally recognized model.…”

“…It is based on physiological model that can describe thermal comfort condition in outdoor spaces and it can be available for different types of applications such as: urban planning, climate therapy, warning systems, tourists information, etc. (Jendritzky et al 2012). …”

“…The UTCI equivalent temperature for a given combination of wind, radiation, humidity and air temperature is then defined as the air temperature of the reference environment that produces the same strain index value. As calculating the UTCI equivalent temperatures by repeatedly running the thermoregulation model could be too time-consuming for climate simulations and numerical weather forecasts, a fast calculation procedure has been developed and made available in the COST Action 730 web-page (http://www.utci.org/) (Jendritzky et al 2012). The use of a numerical indicator makes the evaluation more objective.…”

“…The selection of the index has influenced the choice of the calculation system too, because it should be able to provide the output required for the index calculation. A review of the state of the art on outdoor thermal comforts indexes was done, and after conducting an empirical study of different systems; the Universal Thermal Climate Index (UTCI) (Jendritzky et al 2012, Bröde et al 2012b, Bröde et al 2012a, Fiala et al 2012) was chosen for this study.…”