Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India.
Centre for Hydrology & Remote Sensing (CHRS), Department of Civil & Environmental Engineering, University of California, Irvine, California, USA.
Sci Rep. 2017 Aug 4;7(1):7350. doi: 10.1038/s41598-017-07627-5.
Understanding the evolution of Diurnal Temperature Range (DTR), which has contradicting global and regional trends, is crucial because it influences environmental and human health. Here, we analyse the regional evolution of DTR trend over different climatic zones in India using a non-stationary approach known as the Multidimensional Ensemble Empirical Mode Decomposition (MEEMD) method, to explore the generalized influence of regional climate on DTR, if any. We report a 0.36 °C increase in overall mean of DTR till 1980, however, the rate has declined since then. Further, arid deserts and warm-temperate grasslands exhibit negative DTR trends, while the west coast and sub-tropical forest in the north-east show positive trends. This transition predominantly begins with a 0.5 °C increase from the west coast and spreads with an increase of 0.25 °C per decade. These changes are more pronounced during winter and post-monsoon, especially in the arid desert and warm-temperate grasslands, the DTR decreased up to 2 °C, where the rate of increase in minimum temperature is higher than the maximum temperature. We conclude that both maximum and minimum temperature increase in response to the global climate change, however, their rates of increase are highly local and depend on the underlying climatic zone.
了解昼夜温度范围（DTR）的演变至关重要，因为它影响环境和人类健康。尽管昼夜温度范围在全球和区域呈现相反的趋势，但我们仍采用非平稳方法，即多维集合经验模态分解（MEEMD）方法，分析印度不同气候带昼夜温度范围趋势的区域演变，以探索区域气候对昼夜温度范围的普遍影响。结果表明，截至 1980 年，昼夜温度范围的整体平均值增加了 0.36°C，但此后这一速率有所下降。此外，干旱荒漠和温暖草原地区的昼夜温度范围呈负趋势，而西海岸和东北部的亚热带森林地区呈正趋势。这种转变主要始于西海岸的 0.5°C 的增加，并以每十年增加 0.25°C 的速度扩散。这些变化在冬季和后季风期更为明显，尤其是在干旱荒漠和温暖草原地区，昼夜温度范围下降了 2°C，最低温度的增长率高于最高温度。我们得出结论，全球气候变化导致最高和最低温度均升高，但它们的增长率在很大程度上是局部的，并且取决于基础气候带。
