Climate and weather have major effects on human comfort and health. Meteorological variables such as air temperature, relative humidity, solar radiation, and wind speed influence both the physical and mental health and state. Occasionally, harsh climatic conditions affect certain activity patterns, causing body and mind pain, disrupting the sleeping cycle, and, in the worst-case scenario, causing serious health consequences. Because of climate change and increased heat stress in cities, interest in measuring thermal comfort has risen in the last decade. The main aim of this research is to investigate the spatial and temporal distribution of human discomfort index (HDI) for summer seasons and its climatic trends in different regions of the CONUS (Continental US), and the Meso-America for the period of last thirty years (1990-2019). This is a relatively new index based on population real thermal feeling and is applicable for different climate regions. Positive HDI represents cooling state conditions, while negative HDI represents warming state conditions. &nbsp;The HDI is estimated using the difference between a reference comfort and outdoor heat index (HI) which is a combination of air temperature and relative humidity, a measure of how people “feel” when exposed to warm and humid environments. Evidently, HI and the HDI are changing variables with geography and with climate seasons and change. Hourly air temperature and relative humidity data were collected from the National Center for Atmospheric Research (NCEP) North American Regional Reanalysis (NARR). NARR has a spatial resolution of approximately 0.3 degrees (32km) resolution at the lowest latitude, and a temporal coverage of 8-times daily values. The Algorithm used in our study to determine the HI is similar to the one used by the National Weather Service (NWS) measuring air temperature in degrees Fahrenheit (T) and relative humidity in percent (RH).&nbsp;The variation of average HDI was observed to be above 0.35 in southeast states along the gulf coast and Greater Antilles and in some regions along the gulf of California. Eastern states tend to have positive values of HDI for summer months while the western states demonstrate the negative values within the range of -0.2 to -0.38. The summer mean HDI climatology exhibits the largest values in Southwest of the CONUS along Gulf of Mexico coast, Greater Antilles and some areas along the Gulf of California Coast. The variation of summer mean HDI values vary from 0.01 to 0.4 for these regions. The trend of HDI indicates a notable increasing pattern of 0.001 per year, and the trends are more prominent in Midwest and Eastern states than in Western states. The southeast, the Midwest, and some regions along gulf coast have seen HDI increase the most with the trends range of 0.0005 to 0.001 per year, while Western regions have experienced little change. Caribbean countries can be seen to have observed decreasing trends of 0.009 per year.&nbsp; Future studies will focus on relating HDI trends to energy demands for all regions studied.&nbsp;

Climatology and Trends of Heat Index, Human Discomfort Index and Energy per Capita for CONUS and Meso-America

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

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