Publication Abstracts

Bishop et al. 2021

Bishop, D.A., A.P. Williams, R. Seager, E. Cook, D. Peteet, B.I. Cook, M.P. Rao, and D.W. Stahle, 2021: Placing the east-west North American aridity gradient in a multi-century context. Environ. Res. Lett., 16, 114043, doi:10.1088/1748-9326/ac2f63.

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 CMIP6 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.

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BibTeX Citation

  author={Bishop, D. A. and Williams, A. P. and Seager, R. and Cook, E. and Peteet, D. and Cook, B. I. and Rao, M. P. and Stahle, D. W.},
  title={Placing the east-west North American aridity gradient in a multi-century context},
  journal={Environ. Res. Lett.},

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RIS Citation

ID  - bi07100r
AU  - Bishop, D. A.
AU  - Williams, A. P.
AU  - Seager, R.
AU  - Cook, E.
AU  - Peteet, D.
AU  - Cook, B. I.
AU  - Rao, M. P.
AU  - Stahle, D. W.
PY  - 2021
TI  - Placing the east-west North American aridity gradient in a multi-century context
JA  - Environ. Res. Lett.
VL  - 16
SP  - 114043
DO  - 10.1088/1748-9326/ac2f63
ER  -

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