[COLOR=#333333 !important]of extreme temperatures have primarily focused on atmospheric temperatures. Using 18 years of the latest version of the Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) data, we globally investigate the spatial patterns of hot and cold extremes as well as diurnal temperature range (DTR). We show that the world’s highest LST of 80.8°C, observed in the Lut Desert in Iran and the Sonoran Desert in Mexico, is over 10°C above the previous global record of 70.7°C observed in 2005. The coldest place on Earth is Antarctica with the record low temperature of ?110.9°C. The world’s maximum DTR of 81.8°C is observed in a desert environment in China. We see strong latitudinal patterns in hot and cold extremes as well as DTR. Biomes worldwide are faced with different levels of temperature extremes and DTR: we observe the highest zonal average maximum LST of 61.1° ± 5.3°C in the deserts and xeric shrublands; the lowest zonal average minimum LST of ?66.6° ± 14.8°C in the tundra; and the highest zonal average maximum DTR of 43.5° ± 9.9°C in the montane grasslands and shrublands. This global exploration of extreme LST and DTR across different biomes sheds light on the type of extremes different ecosystems are faced with.Alkujaan tämän lähetti Jouko_T
Corresponding author: Yunxia Zhao, yunxiaz1@uci.edu
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Keywords: Climate change; Climate variability; Surface temperature; Diurnal effects
While the Earth has warmed by around 1°C on average above the preindustrial level, much higher record hot extremes have been observed around the world in the past decades (IPCC 2018). Ecoregions worldwide are showing signs of thermal stress, leading to changes in their structure, composition, functioning, and significant ecological pressure (Hughes et al. 2018; Peng et al. 2013; Xie et al. 2018). Between 1980 and 2018, over 2,000 extreme events including heatwaves, droughts, wildfires, and winter storms have occurred, killing over 180,000 people and leading to nearly $700 billion in damage (Munich RE 2019). Most previous studies on temperature variability have focused on extreme air temperatures (e.g., heatwaves) (Schwartz 2005; Oudin Åström et al. 2013; Kretschmer et al. 2018; Papritz 2020; Luo et al. 2019; Johnson et al. 2018; Kodra et al. 2011; Tang et al. 2013) and relatively little attention has been paid to extreme high and low temperatures across the Earth’s skin (Azarderakhsh, et al. 2020; Nie et al. 2020).
Studies of extreme hot land surface temperatures (LSTs), also known as skin temperature, have mainly focused on the city or subcity scale where the urban heat island is a major hazard (Benz et al. 2021). However, the most extreme hot and cold LSTs usually occur in deserts and polar regions, respectively. Warming rates in arid areas are higher than the global average (Zhou et al. 2015; Zhou and Wang 2016), and the Arctic region is warming at a rate more than twice the global mean (Cohen et al. 2014).
Locations of the hottest and coldest places on Earth’s have always been of interest to a broad range of scientists including meteorologists, ecologists, and biologists. A global understanding of extreme hot and cold LSTs and diurnal temperature ranges (DTRs, daily maximum LST minus daily minimum LST) across different environments and biomes could shed light on the type of extremes different ecosystems are faced with. This is increasingly more important as the atmosphere warms in response to anthropogenic emissions. However, there are limited temperature observations in the polar regions and desert environments where the most extreme temperatures occur.
According to the World Meteorological Organization (WMO) Commission of Climatology (CCl) World Archive of Weather and Climate Extremes, the record high atmospheric temperature is 56.7°C observed in Death Valley on 10 July 1913, and the record low temperature is ?89.2°C observed in Antarctica on 21 July 1983 (Arizona State University 2020). However, the limited coverage of ground-based observations indicates that the hottest and coldest spots reported by WMO are likely not the actual hottest and coldest places on Earth. Further, the land surface temperature is expected to be warmer than atmospheric temperature (Mildrexler et al. 2011a; Good 2016). The Moderate Resolution Imaging Spectroradiometer (MODIS) provides LST data with global coverage at high resolution collected twice daily, which can be used to identify the global hot and cold spots. The quality of V5 MODIS LST data has been widely validated in literature (Coll et al. 2005, 2009; Wan 2008; Wan et al. 2004; Wan and Li 2008; Wang and Liang 2009; Li et al. 2013; Wang et al. 2007), with an accuracy of within ±2 K (±1
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