{"title":"基于 CRU 和 ERA5 再分析的印度东北部及毗邻地区地表温度长期趋势分析","authors":"Rohit Gautam, Binita Pathak, Pradip Kumar Bhuyan, Arup Borgohain, Shyam Sundar Kundu","doi":"10.1007/s12040-024-02346-8","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This study investigated the annual and seasonal mean temperature trends of North-East Indian region and surrounding territories over the period 1901–2020 with special emphasis on the trends from the recent past (1979–2020) utilising Climatic Research Unit (CRU) and ECMWF Reanalysis version-5 (ERA5) data. Spatio-temporal distribution of surface temperature across different seasons and associated biases between 1901 and 2020 were examined. The long-term trend of temperature was evaluated by linear regression for each month from the entire 120-yr period over the whole study domain. Further, Mann–Kendall and Sen’s slope test was employed to assess the magnitude of the trend at 11 selected locations of varying altitudes. Areas around Bangladesh, which are notably polluted, as well as Myanmar and the Indian states of West Bengal, Jharkhand, Bihar and Chhattisgarh exhibited notable mean temperatures than the rest of the region. Both near-surface and 2m-temperature displayed positive trends for the period 1901–1950, 1979–2020, and during the whole duration 1901–2020, despite negative trends during 1951–1978. It has been observed that the regions with relatively higher elevations have experienced a larger warming rate than the low-elevation zones.</p><h3 data-test=\"abstract-sub-heading\">Highlights</h3><ul>\n<li>\n<p>Annual and seasonal temperature trends for North-East India and surrounding territories were studied.</p>\n</li>\n<li>\n<p>Mann-Kendall and Sen’s slope test was carried out for 11 selected locations.</p>\n</li>\n<li>\n<p>Post-monsoon season experienced greatest rise in mean temperatures between 1901 and 2020.</p>\n</li>\n<li>\n<p>Temperature data revealed increasing trends for periods 1901–1950, 1979–2020, but decreasing trends for 1951-1978.</p>\n</li>\n<li>\n<p>Warming rates were higher for higher elevation zones, particularly during the postmonsoon and winter months.</p>\n</li>\n</ul>","PeriodicalId":15609,"journal":{"name":"Journal of Earth System Science","volume":"67 1","pages":""},"PeriodicalIF":1.3000,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Long-term trend analysis of surface temperature over North-East India and adjoining regions based on CRU and ERA5 reanalysis\",\"authors\":\"Rohit Gautam, Binita Pathak, Pradip Kumar Bhuyan, Arup Borgohain, Shyam Sundar Kundu\",\"doi\":\"10.1007/s12040-024-02346-8\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<h3 data-test=\\\"abstract-sub-heading\\\">Abstract</h3><p>This study investigated the annual and seasonal mean temperature trends of North-East Indian region and surrounding territories over the period 1901–2020 with special emphasis on the trends from the recent past (1979–2020) utilising Climatic Research Unit (CRU) and ECMWF Reanalysis version-5 (ERA5) data. Spatio-temporal distribution of surface temperature across different seasons and associated biases between 1901 and 2020 were examined. The long-term trend of temperature was evaluated by linear regression for each month from the entire 120-yr period over the whole study domain. Further, Mann–Kendall and Sen’s slope test was employed to assess the magnitude of the trend at 11 selected locations of varying altitudes. Areas around Bangladesh, which are notably polluted, as well as Myanmar and the Indian states of West Bengal, Jharkhand, Bihar and Chhattisgarh exhibited notable mean temperatures than the rest of the region. Both near-surface and 2m-temperature displayed positive trends for the period 1901–1950, 1979–2020, and during the whole duration 1901–2020, despite negative trends during 1951–1978. It has been observed that the regions with relatively higher elevations have experienced a larger warming rate than the low-elevation zones.</p><h3 data-test=\\\"abstract-sub-heading\\\">Highlights</h3><ul>\\n<li>\\n<p>Annual and seasonal temperature trends for North-East India and surrounding territories were studied.</p>\\n</li>\\n<li>\\n<p>Mann-Kendall and Sen’s slope test was carried out for 11 selected locations.</p>\\n</li>\\n<li>\\n<p>Post-monsoon season experienced greatest rise in mean temperatures between 1901 and 2020.</p>\\n</li>\\n<li>\\n<p>Temperature data revealed increasing trends for periods 1901–1950, 1979–2020, but decreasing trends for 1951-1978.</p>\\n</li>\\n<li>\\n<p>Warming rates were higher for higher elevation zones, particularly during the postmonsoon and winter months.</p>\\n</li>\\n</ul>\",\"PeriodicalId\":15609,\"journal\":{\"name\":\"Journal of Earth System Science\",\"volume\":\"67 1\",\"pages\":\"\"},\"PeriodicalIF\":1.3000,\"publicationDate\":\"2024-07-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Earth System Science\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.1007/s12040-024-02346-8\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"GEOSCIENCES, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Earth System Science","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1007/s12040-024-02346-8","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
Long-term trend analysis of surface temperature over North-East India and adjoining regions based on CRU and ERA5 reanalysis
Abstract
This study investigated the annual and seasonal mean temperature trends of North-East Indian region and surrounding territories over the period 1901–2020 with special emphasis on the trends from the recent past (1979–2020) utilising Climatic Research Unit (CRU) and ECMWF Reanalysis version-5 (ERA5) data. Spatio-temporal distribution of surface temperature across different seasons and associated biases between 1901 and 2020 were examined. The long-term trend of temperature was evaluated by linear regression for each month from the entire 120-yr period over the whole study domain. Further, Mann–Kendall and Sen’s slope test was employed to assess the magnitude of the trend at 11 selected locations of varying altitudes. Areas around Bangladesh, which are notably polluted, as well as Myanmar and the Indian states of West Bengal, Jharkhand, Bihar and Chhattisgarh exhibited notable mean temperatures than the rest of the region. Both near-surface and 2m-temperature displayed positive trends for the period 1901–1950, 1979–2020, and during the whole duration 1901–2020, despite negative trends during 1951–1978. It has been observed that the regions with relatively higher elevations have experienced a larger warming rate than the low-elevation zones.
Highlights
Annual and seasonal temperature trends for North-East India and surrounding territories were studied.
Mann-Kendall and Sen’s slope test was carried out for 11 selected locations.
Post-monsoon season experienced greatest rise in mean temperatures between 1901 and 2020.
Temperature data revealed increasing trends for periods 1901–1950, 1979–2020, but decreasing trends for 1951-1978.
Warming rates were higher for higher elevation zones, particularly during the postmonsoon and winter months.
期刊介绍:
The Journal of Earth System Science, an International Journal, was earlier a part of the Proceedings of the Indian Academy of Sciences – Section A begun in 1934, and later split in 1978 into theme journals. This journal was published as Proceedings – Earth and Planetary Sciences since 1978, and in 2005 was renamed ‘Journal of Earth System Science’.
The journal is highly inter-disciplinary and publishes scholarly research – new data, ideas, and conceptual advances – in Earth System Science. The focus is on the evolution of the Earth as a system: manuscripts describing changes of anthropogenic origin in a limited region are not considered unless they go beyond describing the changes to include an analysis of earth-system processes. The journal''s scope includes the solid earth (geosphere), the atmosphere, the hydrosphere (including cryosphere), and the biosphere; it also addresses related aspects of planetary and space sciences. Contributions pertaining to the Indian sub- continent and the surrounding Indian-Ocean region are particularly welcome. Given that a large number of manuscripts report either observations or model results for a limited domain, manuscripts intended for publication in JESS are expected to fulfill at least one of the following three criteria.
The data should be of relevance and should be of statistically significant size and from a region from where such data are sparse. If the data are from a well-sampled region, the data size should be considerable and advance our knowledge of the region.
A model study is carried out to explain observations reported either in the same manuscript or in the literature.
The analysis, whether of data or with models, is novel and the inferences advance the current knowledge.