{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,26]],"date-time":"2025-10-26T15:12:14Z","timestamp":1761491534356,"version":"build-2065373602"},"reference-count":47,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2023,2,21]],"date-time":"2023-02-21T00:00:00Z","timestamp":1676937600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"The National Natural Science Foundation of China","award":["42230611","41875020","20JR10RA804","20JR10RA446"],"award-info":[{"award-number":["42230611","41875020","20JR10RA804","20JR10RA446"]}]},{"name":"Natural Science Foundation of Gansu Province","award":["42230611","41875020","20JR10RA804","20JR10RA446"],"award-info":[{"award-number":["42230611","41875020","20JR10RA804","20JR10RA446"]}]},{"name":"Ten-talent Plan of Gansu Meteorological Bureau","award":["42230611","41875020","20JR10RA804","20JR10RA446"],"award-info":[{"award-number":["42230611","41875020","20JR10RA804","20JR10RA446"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The summer monsoon transition zone (SMTZ) in China represents an unusual land type with an agro-pasture ecotone, and it is a climate-sensitive region. Changes in climate aridity and changes in meteorological drought are mutually related yet fundamentally different. In this study, potential evapotranspiration (ETO) is calculated using Penman\u2013Monteith, based on China\u2019s national meteorological stations data from 1961 to 2013. An ETO-based climate aridity index (IAI) and ETO-based standardized precipitation evapotranspiration index (SPEI) are used as the metrics for climate aridity and meteorological drought, respectively. The result shows a significant difference between climate aridity and meteorological drought in the SMTZ, compared with the monsoon and non-monsoon zone. This difference varies on different time scales (1\u201348 months), and the greatest differences between IAI and SPEI are on seasonal and monthly scales (1\u201312 months), but lower at longer time scales (&gt;12 months). The first reason for the difference is the desynchronicity of meteorological drought and the background climate. After the background climate becomes a relatively arid state (such as 0.96 &lt; IAI &lt; 1) from a semi-arid state (0.50 &lt; IAI &lt; 0.80), the continued arid state with weak IAI fluctuations eventually results in increasingly severe meteorological droughts, or the recurrence of equally severe droughts with drastic reduction. Consequently, the onset of the most severe climate aridity is two to seven months (mostly three to four months) ahead of the onset of the most severe drought events, until the climate returns to a semi-arid state. Second, climate aridity represents the average state of the background climate over a long time period and changes gently, while meteorological droughts are stochastic climate events and change drastically. These findings indicate that IAI can serve as a predictor of the onset of meteorological drought events, especially in the SMTZ, but it fails to characterize the progression of meteorological drought events well. Therefore, this result is of great significance for drought prediction and early warning.<\/jats:p>","DOI":"10.3390\/rs15051175","type":"journal-article","created":{"date-parts":[[2023,2,22]],"date-time":"2023-02-22T01:39:47Z","timestamp":1677029987000},"page":"1175","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Analysis of the Difference between Climate Aridity Index and Meteorological Drought Index in the Summer Monsoon Transition Zone"],"prefix":"10.3390","volume":"15","author":[{"given":"Hongli","family":"Zhang","sequence":"first","affiliation":[{"name":"College of Resources and Environmental Engineering, Tianshui Normal University, Tianshui 741001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Liang","family":"Zhang","sequence":"additional","affiliation":[{"name":"Institute of Arid Meteorology, CMA, Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province, Key Laboratory of Arid Climatic Change and Disaster Reduction of CMA, Lanzhou 730020, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qiang","family":"Zhang","sequence":"additional","affiliation":[{"name":"Institute of Arid Meteorology, CMA, Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province, Key Laboratory of Arid Climatic Change and Disaster Reduction of CMA, Lanzhou 730020, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6595-2369","authenticated-orcid":false,"given":"Qian","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Atmospheric Sciences, Sun Yat-sen University, Zhuhai 519082, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaoni","family":"You","sequence":"additional","affiliation":[{"name":"College of Resources and Environmental Engineering, Tianshui Normal University, Tianshui 741001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lixia","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Resources and Environmental Engineering, Tianshui Normal University, Tianshui 741001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,2,21]]},"reference":[{"key":"ref_1","first-page":"1339","article-title":"Analysis on variation characteristics and differences of the climate drying degree between south and north of China","volume":"35","author":"Zhang","year":"2016","journal-title":"Plateau Meteor."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2130","DOI":"10.1007\/s11434-007-0284-z","article-title":"The inter-decadal trend and shift of dry\/wet over the central part of North China and their relationship to the Pacific Decadal Oscillation (PDO)","volume":"52","author":"Ma","year":"2007","journal-title":"Chin. 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