Past and future trends of diurnal temperature range and their correlation with vegetation assessed by MODIS and CMIP6

You-Ren Wang; Bjørn H Samset; Frode Stordal; Anders Bryn; Dag O Hessen

doi:10.1016/j.scitotenv.2023.166727

Past and future trends of diurnal temperature range and their correlation with vegetation assessed by MODIS and CMIP6

Sci Total Environ. 2023 Dec 15:904:166727. doi: 10.1016/j.scitotenv.2023.166727. Epub 2023 Sep 4.

Authors

You-Ren Wang¹, Bjørn H Samset², Frode Stordal³, Anders Bryn⁴, Dag O Hessen⁵

Affiliations

¹ Dept. Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung 80424, Taiwan; Graduate Institute of Marine Affairs, National Sun Yat-sen University, Kaohsiung 80424, Taiwan; Dept. Biosciences and Centre for Biogeochemistry in the Anthropocene, University of Oslo, Oslo 0316, Norway. Electronic address: yrwang@mail.nsysu.edu.tw.
² CICERO Center for International Climate Research, Oslo 0349, Norway.
³ Dept. Geosciences and Centre for Biogeochemistry in the Anthropocene, University of Oslo, Oslo 0316, Norway.
⁴ Natural History Museum and Centre for Biogeochemistry in the Anthropocene, University of Oslo, Oslo 0316, Norway.
⁵ Dept. Biosciences and Centre for Biogeochemistry in the Anthropocene, University of Oslo, Oslo 0316, Norway.

PMID: 37673261
DOI: 10.1016/j.scitotenv.2023.166727

Abstract

Temperature anomalies and changes in the diurnal temperature range (DTR) are expected to pose physiological challenges to biota; hence, both spatial and temporal variations in DTR provide important insights into temperature-induced stress in humans, animals, and vegetation. Furthermore, vegetation could dampen temperature variability. Here, we use the Moderate Resolution Imaging Spectroradiometer (MODIS) remote sensing data of Land Surface Temperature (LST) to evaluate the global variation in DTR and its rate of change in spatial and temporal scales for the two decades spanning from 2001 to 2020. We show that North America, Africa, and Antarctica, as well as the global mean, experienced statistically significant DTR rates of change over the last 20 years in either summer, winter, or the annual mean. The rates were all negative, indicating the day-night temperature differences are decreasing in those regions because night temperatures are increasing at a faster rate than day temperatures. MODIS data of the Normalized Difference Vegetation Index (NDVI) revealed a strongly negative correlation with DTR, with a spatial correlation coefficient of -0.61. This correlation demonstrates a prominent dampening effect of vegetation on diurnal temperature oscillations. For future DTR projections, we used 19 models in the Coupled Model Intercomparison Project 6 (CMIP6) to predict global DTR trends from 2021 to 2050 with low and high CO₂ concentration scenarios. The high CO₂ emission scenario projects significant decreases in DTR in circumpolar regions, central Africa, and India compared to the low CO₂ scenario. This difference in the two scenarios underscores the substantial influence of increased global temperatures and elevated CO₂ concentration on DTR and, consequently, on the ecosystems in certain regions.

Keywords: Climate change; DTR; NDVI; Remote sensing; Temperature impact on biota; Vegetation-climate effect.