Placing the east-west North American aridity gradient in a multi-century context
Instrumental records indicate a century-long trend towards drying over western North America and wetting over eastern North America. A continuation of these trends into the future would have significant hydroclimatic and socioeconomic consequences in both the semi-arid Southwest and humid East. Usin...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2021-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ac2f63 |
| _version_ | 1797747445255372800 |
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| author | Daniel A Bishop A Park Williams Richard Seager Edward R Cook Dorothy M Peteet Benjamin I Cook Mukund P Rao David W Stahle |
| author_facet | Daniel A Bishop A Park Williams Richard Seager Edward R Cook Dorothy M Peteet Benjamin I Cook Mukund P Rao David W Stahle |
| author_sort | Daniel A Bishop |
| collection | DOAJ |
| description | Instrumental records indicate a century-long trend towards drying over western North America and wetting over eastern North America. A continuation of these trends into the future would have significant hydroclimatic and socioeconomic consequences in both the semi-arid Southwest and humid East. Using tree-ring reconstructions and hydrologic simulations of summer soil moisture, we evaluate and contextualize the modern summer aridity gradient within its natural range of variability established over the past 600 years and evaluate the effects of observed and anthropogenic precipitation, temperature, and humidity trends. The 2001–2020 positive (wet east-dry west) aridity gradient was larger than any 20 year period since 1400 CE, preceded by the most negative (wet west-dry east) aridity gradient during 1976–1995, leading to a strong multi-decade reversal in aridity gradient anomalies that was rivaled only by a similar event in the late-16th century. The 2001–2020 aridity gradient was dominated by long-term summer precipitation increases in the Midwest and Northeast, with smaller contributions from more warming in the West than the East and spring precipitation decreases in the Southwest. Multi-model mean climate simulations from Coupled Model Intercomparison Project 6 experiments suggest anthropogenic climate trends should not have strongly affected the aridity gradient thus far. However, there is high uncertainty due to inter-model disagreement on anthropogenic precipitation trends. The recent strengthening of the observed aridity gradient, its increasing dependence on precipitation variability, and disagreement in modeled anthropogenic precipitation trends reveal significant uncertainties in how water resource availability will change across North America in the coming decades. |
| first_indexed | 2024-03-12T15:51:36Z |
| format | Article |
| id | doaj.art-35be1ad93b7b4ece94256fda346e1cbb |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:51:36Z |
| publishDate | 2021-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-35be1ad93b7b4ece94256fda346e1cbb2023-08-09T15:07:14ZengIOP PublishingEnvironmental Research Letters1748-93262021-01-01161111404310.1088/1748-9326/ac2f63Placing the east-west North American aridity gradient in a multi-century contextDaniel A Bishop0https://orcid.org/0000-0002-0394-5996A Park Williams1https://orcid.org/0000-0001-8176-8166Richard Seager2https://orcid.org/0000-0003-4772-9707Edward R Cook3https://orcid.org/0000-0001-7478-4176Dorothy M Peteet4https://orcid.org/0000-0003-3029-7506Benjamin I Cook5https://orcid.org/0000-0002-4501-9229Mukund P Rao6https://orcid.org/0000-0003-3398-2453David W Stahle7https://orcid.org/0000-0002-8943-2541Tree Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University , Palisades, NY 10964, United States of America; Department of Earth and Environmental Sciences, Columbia University , New York, NY 10027, United States of AmericaTree Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University , Palisades, NY 10964, United States of America; Department of Geography, University of California , Los Angeles, CA 90095, United States of AmericaLamont-Doherty Earth Observatory of Columbia University , Palisades, NY, 10964, United States of AmericaTree Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University , Palisades, NY 10964, United States of AmericaLamont-Doherty Earth Observatory of Columbia University , Palisades, NY, 10964, United States of America; NASA Goddard Institute for Space Studies , New York, NY 10025, United States of AmericaTree Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University , Palisades, NY 10964, United States of America; NASA Goddard Institute for Space Studies , New York, NY 10025, United States of AmericaTree Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University , Palisades, NY 10964, United States of America; Cooperative Programs for the Advancement of Earth System Science, University Corporation for Atmospheric Research , Boulder, CO 80301, United States of America; Department of Plant Science, University of California , Davis, CA 95616, United States of AmericaUniversity of Arkansas , Fayetteville, AR 72701, United States of AmericaInstrumental records indicate a century-long trend towards drying over western North America and wetting over eastern North America. A continuation of these trends into the future would have significant hydroclimatic and socioeconomic consequences in both the semi-arid Southwest and humid East. Using tree-ring reconstructions and hydrologic simulations of summer soil moisture, we evaluate and contextualize the modern summer aridity gradient within its natural range of variability established over the past 600 years and evaluate the effects of observed and anthropogenic precipitation, temperature, and humidity trends. The 2001–2020 positive (wet east-dry west) aridity gradient was larger than any 20 year period since 1400 CE, preceded by the most negative (wet west-dry east) aridity gradient during 1976–1995, leading to a strong multi-decade reversal in aridity gradient anomalies that was rivaled only by a similar event in the late-16th century. The 2001–2020 aridity gradient was dominated by long-term summer precipitation increases in the Midwest and Northeast, with smaller contributions from more warming in the West than the East and spring precipitation decreases in the Southwest. Multi-model mean climate simulations from Coupled Model Intercomparison Project 6 experiments suggest anthropogenic climate trends should not have strongly affected the aridity gradient thus far. However, there is high uncertainty due to inter-model disagreement on anthropogenic precipitation trends. The recent strengthening of the observed aridity gradient, its increasing dependence on precipitation variability, and disagreement in modeled anthropogenic precipitation trends reveal significant uncertainties in how water resource availability will change across North America in the coming decades.https://doi.org/10.1088/1748-9326/ac2f63droughtsoil moistureprecipitationaridity gradientNorth Americatree-ring reconstruction |
| spellingShingle | Daniel A Bishop A Park Williams Richard Seager Edward R Cook Dorothy M Peteet Benjamin I Cook Mukund P Rao David W Stahle Placing the east-west North American aridity gradient in a multi-century context Environmental Research Letters drought soil moisture precipitation aridity gradient North America tree-ring reconstruction |
| title | Placing the east-west North American aridity gradient in a multi-century context |
| title_full | Placing the east-west North American aridity gradient in a multi-century context |
| title_fullStr | Placing the east-west North American aridity gradient in a multi-century context |
| title_full_unstemmed | Placing the east-west North American aridity gradient in a multi-century context |
| title_short | Placing the east-west North American aridity gradient in a multi-century context |
| title_sort | placing the east west north american aridity gradient in a multi century context |
| topic | drought soil moisture precipitation aridity gradient North America tree-ring reconstruction |
| url | https://doi.org/10.1088/1748-9326/ac2f63 |
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