DOI: 10.1594/pangaea.841057
title: Heat index at 2 m above ground: A globally gridded dataset based on reanalysis data from 1979-2013, links to GeoTIFFs

description: The increase in global mean temperatures resulting from climate change has wide reaching consequences for the earth's ecosystems and other natural systems. Many studies have been devoted to evaluating the distribution and effects of these changes. We go a step further and evaluate global changes to the heat index, a measure of temperature as perceived by humans. Heat index, which is computed from temperature and relative humidity, is more important than temperature for the health of humans and other animals. Even in cases where the heat index does not reach dangerous levels from a health perspective, it has been shown to be an important factor in worker productivity and thus in economic productivity.We compute heat index from dewpoint temperature and absolute temperature 2 m above ground from the ERA-Interim reanalysis dataset for the years 1979-2013. The data is provided aggregated to daily minima, means and maxima. Furthermore, the data is temporally aggregated to monthly and yearly values and spatially aggregated to the level of countries after being weighted by population density in order to demonstrate its usefulness for the analysis of its impact on human health and productivity. The resulting data deliver insights into the spatiotemporal development of near-ground heat index during the course of the past 3 decades. It is shown that the impact of changing heat index is unevenly distributed through space and time, affecting some areas differently than others. The likelihood of dangerous heat index events has increased globally. Also, heat index climate groups that would formerly be expected closer to the tropics have spread latitudinally to include areas closer to the poles. The data can serve in future studies as a basis for evaluating and understanding the evolution of heat index in the course of climate change, as well as its impact on human health and productivity.
description: Our data is based on ECMWF reanalyses of 2 m temperature and humidity. It contains the daily minimum, mean and maximum heat index value for every point on a 0.75x0.75° grid for every day from 1 Jan 1979 - 31 Dec 2013. The minimum, mean and maximum were chosen in order to make a given file comparable in meaning for the entire globe without having to account for time zones. Additionally, we provide the heat index deciles for each of these metrics for each month for the periods 1979-1999 and 2000-2013. This data should be useful for further studies in the areas of human health, climate change and climatology. It is made available as GeoTIFFs, a common format for gridded, georeferenced data. The data is structured as follows: - quantiles.zip - Contains GeoTIFFs named after the following convention: hi_{century}xx_{month}_{metric}_{decile}.tif (e.g., hi_20xx_08_average_0.5.tif - 50% percentile of average heat index for the years 20??, month 08)- Zipfiles named as {year}.zip. Each zipfile contains GeoTIFFs named after the following convention: hi_{year}{month}{day}_{metric}.tif (e.g. hi_20131224_maximum.tif - maximum heat index for 24 Dec 2013)The total size of the zipfiles is 32 GB
description: Supplement to: Lee, Daniel; Brenner, Thomas (2015): Perceived temperature in the course of climate change: an analysis of global heat index from 1979 to 2013. Earth System Science Data, 7(2), 193-202