{"674610":{"#nid":"674610","#data":{"type":"news","title":"Tropical Revelations: Unearthing the Impacts of Hydrological Sensitivity on Global Rainfall","body":[{"value":"\u003Cp\u003EGeorgia Tech researcher \u003Ca href=\u0022https:\/\/eas.gatech.edu\/people\/he-dr-jie\u0022\u003EJie He\u003C\/a\u003E set out to predict how rainfall will change as Earth\u2019s atmosphere continues to heat up. In the process, he made some unexpected discoveries that might explain how greenhouse gas emissions will impact tropical oceans, affecting climate on a global scale.\u003C\/p\u003E\u003Cp\u003E\u201cThis is not a story with just one punch line,\u201d said He, assistant professor in Georgia Tech\u2019s \u003Ca href=\u0022https:\/\/eas.gatech.edu\/\u0022\u003ESchool of Earth and Atmospheric Sciences\u003C\/a\u003E, whose most recent work appeared in the journal \u003Ca href=\u0022https:\/\/www.nature.com\/articles\/s41558-024-01982-8\u0022\u003E\u003Cem\u003ENature Climate Change\u003C\/em\u003E\u003C\/a\u003E. \u201cI didn\u2019t really expect to find anything this interesting\u2014there were a few surprises.\u201d\u003C\/p\u003E\u003Cp\u003EHe is principal investigator of the \u003Ca href=\u0022https:\/\/he.eas.gatech.edu\/\u0022\u003EClimate Modeling and Dynamics Group\u003C\/a\u003E, which combines expertise in physics, mathematics, and computer science to study climate change. The team\u2019s latest study, a collaboration with Mississippi State University and Princeton University, examines hydrological sensitivity in the planet\u2019s three tropical basins: the central portions of both the Pacific and Atlantic oceans and most of the Indian Ocean, an equatorial belt girding the Earth between the Tropic of Cancer (north) and Tropic of Capricorn (south).\u003C\/p\u003E\u003Cp\u003EHydrological sensitivity (HS) refers to the precipitation change per degree of surface warming. Hydrological sensitivity is a key metric researchers use in evaluating or predicting how rainfall will respond to future climate change. Positive HS indicates a wetter climate, while negative HS indicates a drier climate.\u003C\/p\u003E\u003Cp\u003E\u201cThe projection of hydrological sensitivity and future precipitation has been widely investigated, but most studies look at global averages \u2014 nobody had yet looked closely at each individual basin,\u201d He said. \u201cAnd the real impact on global climate change will come from the regional scale.\u201d\u003C\/p\u003E\u003Cp\u003EIn other words, what happens in tropical waters has far-reaching effects.\u003C\/p\u003E\u003Ch4\u003E\u003Cstrong\u003ELong Reach of the Tropics\u003C\/strong\u003E\u003C\/h4\u003E\u003Cp\u003EHe wanted to specifically examine the tropical basins because they already have a well-known influence on remote locations: El Ni\u00f1os and La Ni\u00f1as. These weather patterns that shift every couple of years are examples of tropical oceanic precipitation changes that have a global impact.\u003C\/p\u003E\u003Cp\u003E\u201cThese precipitation changes create heating and cooling in the atmosphere that set off atmospheric waves affecting remote climates across the globe,\u201d He said. During El Ni\u00f1o winters, for example, the southeastern U.S. typically gets more precipitation than usual.\u003C\/p\u003E\u003Cp\u003EBut El Ni\u00f1os and La Ni\u00f1as are naturally occurring, whereas the tropical precipitation changes He identified are projected as outcomes of human-induced global warming \u2014 a simulation, part of a climate model.\u003C\/p\u003E\u003Cp\u003EClimate models are an essential tool for He and other researchers, who use them to simulate possible future scenarios. These are computer programs that rely on complex math equations to project the atmospheric interactions of energy and matter likely to occur across the planet.\u003C\/p\u003E\u003Cp\u003EWhat surprised He was the substantial difference in HS between tropical basins. Essentially, in He\u2019s model the Pacific tropical basin has an HS more than twice as large as the Indian basin, with the Atlantic basin projected as a negative value.\u003C\/p\u003E\u003Cp\u003E\u201cIt was surprising because these differences can\u2019t be explained by the mainstream theories on tropical precipitation changes,\u201d He said. \u201cIn other words, none of the theories we knew would have predicted it.\u201d\u003C\/p\u003E\u003Ch4\u003E\u003Cstrong\u003EModeling the Sensitive Future\u003C\/strong\u003E\u003C\/h4\u003E\u003Cp\u003EThe effects of such diverging hydrological sensitivity would be widespread, according to He. For example, his experiments suggest that the continental U.S. will get wetter, and the Amazon will become drier.\u003C\/p\u003E\u003Cp\u003E\u201cIf these model projections are true, these effects will materialize as the climate continues to warm,\u201d said He, who can\u2019t predict exactly how long it will be before these effects can be detected in actual observations of our three-dimensional world.\u003C\/p\u003E\u003Cp\u003EThat\u2019s because they only have reliable observations of oceanic tropical precipitation since 1979. Precipitation changes over decades are strongly affected by internal climate variability \u2014 that is, climate change that isn\u2019t caused by humans. When human-induced precipitation changes are significantly greater than internal climate variability, we should be able to detect the wide-ranging effects of diverging hydrological sensitivity.\u003C\/p\u003E\u003Cp\u003EBut the challenges of continuing climate change do not allow the luxury of waiting until every aspect of climate projection becomes a reality, He noted, adding, \u201cWe are relying on climate projections to some extent to guide our adaptation and mitigation plans. Therefore, it is important to study and understand the climate projections.\u201d\u003C\/p\u003E\u003Cp\u003EBased on the scenario projected by climate models used in He\u2019s research, the effects of El Ni\u00f1os and La Ni\u00f1as on remote climates will become stronger.\u003C\/p\u003E\u003Cp\u003E\u201cWhat we can imply is that this strengthening would be partly due to the diverging HS among tropical basins,\u201d He concluded.\u003C\/p\u003E\u003Cp\u003EWhile the future effects of HS on El Ni\u00f1os and La Ni\u00f1as weren\u2019t discussed in this study, He believes it would make a very interesting research subject going forward.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EGeorgia Tech researcher Jie He investigated how rainfall will change as Earth\u2019s atmosphere heats up, leading to unexpected discoveries about hydrological sensitivity in tropical basins.\u0026nbsp;\u003C\/p\u003E\r\n","format":"limited_html"}],"field_summary_sentence":[{"value":"Georgia Tech researcher investigates how rainfall will change as Earth\u2019s atmosphere heats up."}],"uid":"28153","created_gmt":"2024-05-09 03:38:08","changed_gmt":"2024-08-30 16:55:02","author":"Jerry Grillo","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2024-05-08T00:00:00-04:00","iso_date":"2024-05-08T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"673964":{"id":"673964","type":"image","title":"Jie He","body":"\u003Cp\u003EJie He, assistant professor in the School of Earth and Atmospheric Sciences, wants to predict how rainfall will change in the presence of continuing climate change. \u0026nbsp;\u2014 Photo by Jerry Grillo\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n","created":"1715224311","gmt_created":"2024-05-09 03:11:51","changed":"1715225596","gmt_changed":"2024-05-09 03:33:16","alt":"Jie He","file":{"fid":"257425","name":"JieHe.jpg","image_path":"\/sites\/default\/files\/2024\/05\/08\/JieHe.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2024\/05\/08\/JieHe.jpg","mime":"image\/jpeg","size":4217463,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2024\/05\/08\/JieHe.jpg?itok=nbSrN8EX"}}},"media_ids":["673964"],"groups":[{"id":"1278","name":"College of Sciences"},{"id":"1188","name":"Research Horizons"},{"id":"364801","name":"School of Earth and Atmospheric Sciences (EAS)"}],"categories":[{"id":"154","name":"Environment"},{"id":"135","name":"Research"}],"keywords":[{"id":"187915","name":"go-researchnews"},{"id":"831","name":"climate change"},{"id":"188259","name":"rainfall"},{"id":"182531","name":"Global Warming And The Environment"},{"id":"192254","name":"cos-climate"},{"id":"193266","name":"cos-research"}],"core_research_areas":[],"news_room_topics":[{"id":"71911","name":"Earth and Environment"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Ca href=\u0022jerry.grillo@ibb.gatech.edu\u0022\u003EJerry Grillo\u003C\/a\u003E\u003C\/p\u003E","format":"limited_html"}],"email":["jerry.grillo@gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}