Lucas R. Vargas Zeppetello, Lily N. Zhang, David S. Battisti, Marysa M. Laguë
{"title":"陆地-大气耦合对美国西部夏季气温变化的影响有多大?","authors":"Lucas R. Vargas Zeppetello, Lily N. Zhang, David S. Battisti, Marysa M. Laguë","doi":"10.1175/jcli-d-23-0716.1","DOIUrl":null,"url":null,"abstract":"Abstract Interannual fluctuations in average summertime temperatures across the western United States are captured by a leading EOF that explains over 50% of the total observed variance. In this paper, we explain the origins of this pattern of interannual temperature variability by examining soil moisture-temperature coupling that acts across seasons in observations and climate models. We find that a characteristic pattern of coupled temperature-soil moisture climate variability accounts for 34% of the total observed variance in summertime temperature across the region. This pattern is reproduced in state-of-the-art global climate models, where experiments that eliminate soil moisture variability reduce summertime average temperature variance by a factor of three on average. We use an idealized model of the coupled atmospheric boundary layer and underlying land surface to demonstrate that feedbacks between soil moisture, boundary layer relative humidity, and precipitation can explain the observed relations between springtime soil moisture and summertime temperature. Our results suggest that antecedent soil moisture conditions and subsequent land-atmosphere interactions play an important role in interannual summertime temperature variability in the western U.S.; soil moisture variations cause distal temperature anomalies and impart predictability at timescales longer than one season. Our results indicate that 40% of the observed warming trend across the western U.S. since 1981 has been driven by wintertime precipitation trends in the U.S. southwest.","PeriodicalId":15472,"journal":{"name":"Journal of Climate","volume":"57 1","pages":""},"PeriodicalIF":4.8000,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"How Much Does Land-Atmosphere Coupling Influence Summertime Temperature Variability in the Western United States?\",\"authors\":\"Lucas R. Vargas Zeppetello, Lily N. Zhang, David S. Battisti, Marysa M. Laguë\",\"doi\":\"10.1175/jcli-d-23-0716.1\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract Interannual fluctuations in average summertime temperatures across the western United States are captured by a leading EOF that explains over 50% of the total observed variance. In this paper, we explain the origins of this pattern of interannual temperature variability by examining soil moisture-temperature coupling that acts across seasons in observations and climate models. We find that a characteristic pattern of coupled temperature-soil moisture climate variability accounts for 34% of the total observed variance in summertime temperature across the region. This pattern is reproduced in state-of-the-art global climate models, where experiments that eliminate soil moisture variability reduce summertime average temperature variance by a factor of three on average. We use an idealized model of the coupled atmospheric boundary layer and underlying land surface to demonstrate that feedbacks between soil moisture, boundary layer relative humidity, and precipitation can explain the observed relations between springtime soil moisture and summertime temperature. Our results suggest that antecedent soil moisture conditions and subsequent land-atmosphere interactions play an important role in interannual summertime temperature variability in the western U.S.; soil moisture variations cause distal temperature anomalies and impart predictability at timescales longer than one season. Our results indicate that 40% of the observed warming trend across the western U.S. since 1981 has been driven by wintertime precipitation trends in the U.S. southwest.\",\"PeriodicalId\":15472,\"journal\":{\"name\":\"Journal of Climate\",\"volume\":\"57 1\",\"pages\":\"\"},\"PeriodicalIF\":4.8000,\"publicationDate\":\"2024-03-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Climate\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.1175/jcli-d-23-0716.1\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"METEOROLOGY & ATMOSPHERIC SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Climate","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1175/jcli-d-23-0716.1","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"METEOROLOGY & ATMOSPHERIC SCIENCES","Score":null,"Total":0}
How Much Does Land-Atmosphere Coupling Influence Summertime Temperature Variability in the Western United States?
Abstract Interannual fluctuations in average summertime temperatures across the western United States are captured by a leading EOF that explains over 50% of the total observed variance. In this paper, we explain the origins of this pattern of interannual temperature variability by examining soil moisture-temperature coupling that acts across seasons in observations and climate models. We find that a characteristic pattern of coupled temperature-soil moisture climate variability accounts for 34% of the total observed variance in summertime temperature across the region. This pattern is reproduced in state-of-the-art global climate models, where experiments that eliminate soil moisture variability reduce summertime average temperature variance by a factor of three on average. We use an idealized model of the coupled atmospheric boundary layer and underlying land surface to demonstrate that feedbacks between soil moisture, boundary layer relative humidity, and precipitation can explain the observed relations between springtime soil moisture and summertime temperature. Our results suggest that antecedent soil moisture conditions and subsequent land-atmosphere interactions play an important role in interannual summertime temperature variability in the western U.S.; soil moisture variations cause distal temperature anomalies and impart predictability at timescales longer than one season. Our results indicate that 40% of the observed warming trend across the western U.S. since 1981 has been driven by wintertime precipitation trends in the U.S. southwest.
期刊介绍:
The Journal of Climate (JCLI) (ISSN: 0894-8755; eISSN: 1520-0442) publishes research that advances basic understanding of the dynamics and physics of the climate system on large spatial scales, including variability of the atmosphere, oceans, land surface, and cryosphere; past, present, and projected future changes in the climate system; and climate simulation and prediction.