Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Disentangling contributions to past and future trends in US surface soil moisture

Abstract

Climate model simulations and various aridity indices generally indicate that summertime surface soil moisture will decrease in the continental USA as a consequence of anthropogenic climate change. However, soil moisture observations from ground probes and satellites from 2011 to 2020 indicate positive summertime trends across 57% of the continental USA. To evaluate the mechanisms driving these trends, we have developed a two-layer land surface model that predicts surface temperature and soil moisture on the basis of observed variations in precipitation, solar radiation, vapour pressure and snowmelt. Of these four model forcings, we found that internal precipitation variability explains the largest fraction of the observed soil moisture trends from 2011 to 2020. Surface air warming and the response of plants to increasing atmospheric CO2 also influence the soil moisture trends, but these effects are small at decadal timescales and partly compensate for one another. Looking forwards, our results indicate that internal precipitation variability will dictate decadal soil moisture trends and that centennial soil moisture trends will primarily depend on changes in precipitation that are currently highly uncertain.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Observed and modelled soil moisture trends for the period 2011–2020.
Fig. 2: Contributions of three forcings to soil moisture trends.
Fig. 3: Soil moisture trends induced by warming and stomatal closure.
Fig. 4: Influence of precipitation on future soil moisture trends.
Fig. 5: Coupling between temperature, VPD and soil moisture trends.

Similar content being viewed by others

Data availability

All of the data used in this study are publicly available.

Code availability

The python code for the EMBM is available at https://github.com/Lvargaszeppetello/Two_Layer.

References

  1. Wasko, C., Nathan, R. & Peel, M. C. Changes in antecedent soil moisture modulate flood seasonality in a changing climate. Water Resour. Res. 56, e2019WR026300 (2020).

    Article  ADS  Google Scholar 

  2. Sazib, N., Bolten, J. D. & Mladenova, I. E. Leveraging NASA Soil Moisture Active Passive for assessing fire susceptibility and potential impacts over Australia and California. IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens. 15, 779–787 (2021).

    Article  ADS  Google Scholar 

  3. Rigden, A., Mueller, N., Holbrook, N., Pillai, N. & Huybers, P. Combined influence of soil moisture and atmospheric evaporative demand is important for accurately predicting US maize yields. Nat. Food 1, 127–133 (2020).

    Article  CAS  PubMed  Google Scholar 

  4. Vargas Zeppetello, L. R., Battisti, D. S. & Baker, M. B. The physics of heat waves: what causes extremely high summertime temperatures? J. Clim. 35, 2231–2251 (2022).

    Article  ADS  Google Scholar 

  5. McColl, K. A., He, Q., Lu, H. & Entekhabi, D. Short-term and long-term surface soil moisture memory time scales are spatially anticorrelated at global scales. J. Hydrometeorol. 20, 1165–1182 (2019).

    Article  ADS  Google Scholar 

  6. Stahl, M. O. & McColl, K. A. The seasonal cycle of surface soil moisture. J. Clim. 35, 4997–5012 (2022).

    Article  ADS  Google Scholar 

  7. Berg, A., Sheffield, J. & Milly, P. C. Divergent surface and total soil moisture projections under global warming. Geophys. Res. Lett. 44, 236–244 (2017).

    Article  ADS  Google Scholar 

  8. Cook, B. I. et al. Twenty-first century drought projections in the CMIP6 forcing scenarios. Earths Future 8, e2019EF001461 (2020).

    Article  ADS  Google Scholar 

  9. Western, A. W., Grayson, R. B. & Blöschl, G. Scaling of soil moisture: a hydrologic perspective. Annu. Rev. Earth Planet. Sci. 30, 149–180 (2002).

    Article  ADS  CAS  Google Scholar 

  10. Famiglietti, J. S., Ryu, D., Berg, A. A., Rodell, M. & Jackson, T. J. Field observations of soil moisture variability across scales. Water Resour. Res. 44, W01423 (2008).

  11. Montzka, C. et al. Validation of spaceborne and modelled surface soil moisture products with cosmic-ray neutron probes. Remote Sens. 9, 103 (2017).

    Article  ADS  Google Scholar 

  12. Short Gianotti, D. J. et al. Landscape water storage and subsurface correlation from satellite surface soil moisture and precipitation observations. Water Resour. Res. 55, 9111–9132 (2019).

    Article  ADS  Google Scholar 

  13. Feldman, A. et al. Remotely sensed soil moisture can capture dynamics relevant to plant water uptake. Water Resour. Res. 59, e2022WR033814 (2022).

    Article  ADS  Google Scholar 

  14. Feng, H. & Zhang, M. Global land moisture trends: drier in dry and wetter in wet over land. Sci. Rep. 5, 18018 (2015).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  15. Dorigo, W. et al. Evaluating global trends (1988–2010) in harmonized multi-satellite surface soil moisture. Geophys. Res. Lett. 39, L18405 (2012).

    Article  ADS  Google Scholar 

  16. Proctor, J., Rigden, A., Chan, D. & Huybers, P. More accurate specification of water supply shows its importance for global crop production. Nat. Food 3, 753–763 (2022).

    Article  PubMed  Google Scholar 

  17. Yuan, S., Quiring, S. M. & Leasor, Z. T. Historical changes in surface soil moisture over the contiguous United States: an assessment of CMIP6. Geophys. Res. Lett. 48, e2020GL089991 (2021).

    Article  ADS  Google Scholar 

  18. Koster, R. D. et al. On the nature of soil moisture in land surface models. J. Clim. 22, 4322–4335 (2009).

    Article  ADS  Google Scholar 

  19. Qiao, L., Zuo, Z. & Xiao, D. Evaluation of soil moisture in CMIP6 simulations. J. Clim. 35, 779–800 (2022).

    Article  ADS  Google Scholar 

  20. Trugman, A., Medvigy, D., Mankin, J. & Anderegg, W. Soil moisture stress as a major driver of carbon cycle uncertainty. Geophys. Res. Lett. 45, 6495–6503 (2018).

    Article  ADS  Google Scholar 

  21. Lian, X. et al. Multifaceted characteristics of dryland aridity changes in a warming world. Nat. Rev. Earth Environ. 2, 232–250 (2021).

    Article  ADS  Google Scholar 

  22. Scheff, J. & Frierson, D. M. Terrestrial aridity and its response to greenhouse warming across CMIP5 climate models. J. Clim. 28, 5583–5600 (2015).

    Article  ADS  Google Scholar 

  23. Huang, J., Yu, H., Guan, X., Wang, G. & Guo, R. Accelerated dryland expansion under climate change. Nat. Clim. Change 6, 166–171 (2016).

    Article  ADS  Google Scholar 

  24. Dai, A., Zhao, T. & Chen, J. Climate change and drought: a precipitation and evaporation perspective. Curr. Clim. Change Rep. 4, 301–312 (2018).

    Article  Google Scholar 

  25. Denissen, J. et al. Widespread shift from ecosystem energy to water limitation with climate change. Nat. Clim. Change 12, 677–684 (2022).

    Article  ADS  Google Scholar 

  26. Swann, A. L., Hoffman, F. M., Koven, C. D. & Randerson, J. T. Plant responses to increasing CO2 reduce estimates of climate impacts on drought severity. Proc. Natl Acad. Sci. USA 113, 10019–10024 (2016).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  27. Berg, A. & McColl, K. A. No projected global drylands expansion under greenhouse warming. Nat. Clim. Change 11, 331–337 (2021).

    Article  ADS  Google Scholar 

  28. IPCC. in Climate Change 2021: The Physical Science Basis (eds Masson-Delmotte, V. et al.) (Cambridge Univ. Press, 2021).

  29. Al-Yaari, A. et al. Assessment and inter-comparison of recently developed/reprocessed microwave satellite soil moisture products using ISMN ground-based measurements. Remote Sens. Environ. 224, 289–303 (2019).

    Article  ADS  Google Scholar 

  30. Dorigo, W. et al. ESA CCI soil moisture for improved Earth system understanding: state-of-the art and future directions. Remote Sens. Environ. 203, 185–215 (2017).

    Article  ADS  Google Scholar 

  31. Harris, I., Osborn, T. J., Jones, P. & Lister, D. Version 4 of the CRU TS monthly high-resolution gridded multivariate climate dataset. Sci. Data 7 109 (2000).

  32. Loeb, N. G. et al. Clouds and the Earth’s Radiant Energy System (CERES) Energy Balanced and Filled (EBAF) top-of-atmosphere (TOA) edition-4.0 data product. J. Clim. 31, 895–918 (2018).

    Article  ADS  Google Scholar 

  33. Hersbach, H. et al. The ERA5 global reanalysis. Q. J. R. Meteorol. Soc. 146, 1999–2049 (2020).

    Article  ADS  Google Scholar 

  34. Xie, Y., Gibbs, H. K. & Lark, T. J. Landsat-based Irrigation Dataset (LANID): 30 m resolution maps of irrigation distribution, frequency, and change for the US, 1997–2017. Earth Syst. Sci. Data 13, 5689–5710 (2021).

    Article  ADS  Google Scholar 

  35. Grossiord, C. et al. Plant responses to rising vapor pressure deficit. New Phytol. 226, 1550–1566 (2020).

    Article  PubMed  Google Scholar 

  36. Kovenock, M., Koven, C. D., Knox, R. G., Fisher, R. A. & Swann, A. L. Leaf trait plasticity alters competitive ability and functioning of simulated tropical trees in response to elevated carbon dioxide. Global Biogeochem. Cycles 35, e2020GB006807 (2021).

    Article  ADS  CAS  Google Scholar 

  37. Zhang, Y. et al. Increasing sensitivity of dryland vegetation greenness to precipitation due to rising atmospheric CO2. Nat. Commun. 13, 4875 (2022).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  38. Rasmusson, E. M. & Arkin, P. A. A global view of large-scale precipitation variability. J. Clim. 6, 1495–1522 (1993).

    Article  ADS  Google Scholar 

  39. McKinnon, K. A. & Deser, C. The inherent uncertainty of precipitation variability, trends, and extremes due to internal variability, with implications for western US water resources. J. Clim. 34, 9605–9622 (2021).

    Google Scholar 

  40. Ainsworth, E. A. & Rogers, A. The response of photosynthesis and stomatal conductance to rising CO2: mechanisms and environmental interactions. Plant Cell Environ. 30, 258–270 (2007).

    Article  CAS  PubMed  Google Scholar 

  41. Meinshausen, M. et al. The shared socio-economic pathway (SSP) greenhouse gas concentrations and their extensions to 2500. Geosci. Model Dev. 13, 3571–3605 (2020).

    Article  ADS  CAS  Google Scholar 

  42. Yang, Y., Roderick, M. L., Zhang, S., McVicar, T. R. & Donohue, R. J. Hydrologic implications of vegetation response to elevated CO2 in climate projections. Nat. Clim. Change 9, 44–48 (2019).

    Article  ADS  Google Scholar 

  43. Held, I. M. & Soden, B. J. Robust responses of the hydrological cycle to global warming. J. Clim. 19, 5686–5699 (2006).

    Article  ADS  Google Scholar 

  44. Tsonis, A. Widespread increases in low-frequency variability of precipitation over the past century. Nature 382, 700–702 (1996).

    Article  ADS  CAS  Google Scholar 

  45. Higgins, S. I., Buitenwerf, R. & Moncrieff, G. R. Defining functional biomes and monitoring their change globally. Global Change Biol. 22, 3583–3593 (2016).

    Article  ADS  Google Scholar 

  46. Deser, C. et al. Isolating the evolving contributions of anthropogenic aerosols and greenhouse gases: a new CESM1 large ensemble community resource. J. Clim. 33, 7835–7858 (2020).

    Article  ADS  Google Scholar 

  47. Yuan, W. et al. Increased atmospheric vapor pressure deficit reduces global vegetation growth. Sci. Adv. 5, 1396 (2019).

    Article  ADS  Google Scholar 

  48. Chen, X. et al. Detecting significant decreasing trends of land surface soil moisture in eastern China during the past three decades (1979–2010). J. Geophys. Res. Atmos. 121, 5177–5192 (2016).

    Article  Google Scholar 

  49. Emori, S. & Brown, S. Dynamic and thermodynamic changes in mean and extreme precipitation under changed climate. Geophys. Res. Lett. 32, L17706 (2005).

    Article  ADS  Google Scholar 

  50. Shiogama, H., Watanabe, M., Kim, H. & Hirota, N. Emergent constraints on future precipitation changes. Nature 602, 612–616 (2022).

    Article  ADS  CAS  PubMed  Google Scholar 

  51. Vargas Zeppetello, L. R., Battisti, D. S. & Baker, M. B. The origin of soil moisture evaporation ‘regimes’. J. Clim. 32, 6939–6960 (2019).

    Article  ADS  Google Scholar 

  52. Abatzoglou, J. T. & Williams, A. P. Impact of anthropogenic climate change on wildfire across western US forests. Proc. Natl Acad. Sci. USA 113, 11770–11775 (2016).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  53. Ellis, T. M., Bowman, D. M., Jain, P., Flannigan, M. D. & Williamson, G. J. Global increase in wildfire risk due to climate-driven declines in fuel moisture. Global Change Biol. 28, 1544–1559 (2022).

    Article  CAS  Google Scholar 

  54. Staley, D. & Jurica, G. Effective atmospheric emissivity under clear skies. J. Appl. Meteorol. Climatol. 11, 349–356 (1972).

    Article  ADS  CAS  Google Scholar 

  55. Vargas Zeppetello, L. R., Donohoe, A. & Battisti, D. Does surface temperature respond to or determine downwelling longwave radiation? Geophys. Res. Lett. 46, 2781–2789 (2019).

    Article  ADS  Google Scholar 

  56. Manabe, S. Climate and the ocean circulation: I. The atmospheric circulation and the hydrology of the Earth’s surface. Mon. Weather Rev. 97, 739–774 (1969).

    Article  ADS  Google Scholar 

  57. Neumann, R. B. & Cardon, Z. G. The magnitude of hydraulic redistribution by plant roots: a review and synthesis of empirical and modeling studies. New Phytol. 194, 337–352 (2012).

    Article  PubMed  Google Scholar 

  58. Jackson, R. B. et al. A global analysis of root distributions for terrestrial biomes. Oecologia 108, 389–411 (1996).

    Article  ADS  CAS  PubMed  Google Scholar 

  59. Raupach, M. Vegetation–atmosphere interaction and surface conductance at leaf, canopy and regional scales. Agric. For. Meteorol. 73, 151–179 (1995).

    Article  ADS  Google Scholar 

  60. Guswa, A. J., Celia, M. A. & Rodriguez-Iturbe, I. Models of soil moisture dynamics in ecohydrology: a comparative study. Water Resour. Res. 38, 1166 (2002).

    Article  ADS  Google Scholar 

  61. Vrettas, M. D. & Fung, I. Y. Sensitivity of transpiration to subsurface properties: exploration with a 1-D model. J. Adv. Model. Earth Syst. 9, 1030–1045 (2017).

    Article  ADS  Google Scholar 

  62. Cueto-Felgueroso, L., Suarez-Navarro, M. J., Fu, X. & Juanes, R. Interplay between fingering instabilities and initial soil moisture in solute transport through the vadose zone. Water 12, 917 (2020).

    Article  Google Scholar 

  63. Oren, R. et al. Survey and synthesis of intra- and interspecific variation in stomatal sensitivity to vapour pressure deficit. Plant Cell Environ. 22, 1515–1526 (1999).

    Article  Google Scholar 

  64. Vargas Zeppetello, L. R. et al. Apparent surface conductance sensitivity to vapour pressure deficit in the absence of plants. Nat. Water 1, 941–951 (2023).

  65. Novick, K. A. et al. The increasing importance of atmospheric demand for ecosystem water and carbon fluxes. Nat. Clim. Change 6, 1023–1027 (2016).

    Article  ADS  CAS  Google Scholar 

  66. Wang, M., Chen, J. M. & Wang, S. Reconstructing the seasonality and trend in global leaf area index during 2001–2017 for prognostic modeling. J. Geophys. Res. Biogeosci. 125, 2020–005698 (2020).

    Article  Google Scholar 

  67. Verger, A., Baret, F., Weiss, M., Filella, I. & Peñuelas, J. Geoclim: a global climatology of LAI, FAPAR, and FCOVER from VEGETATION observations for 1999–2010. Remote Sens. Environ. 166, 126–137 (2015).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

L.R.V.Z. thanks the James S. McDonnell Foundation and the Harvard University Center for the Environment. A.M.T. thanks CONACyT, Fundación México en Harvard, and the Instituto de Inovación y Transferencia de Tecnología. P.H. thanks the Sahara Project.

Author information

Authors and Affiliations

Authors

Contributions

L.R.V.Z. designed the EMBM, performed the analysis and wrote the first draft of the paper, and all authors contributed to the revisions. A.M.T. provided quality control validation for the soil moisture datasets and proposed measures to ensure statistical robustness. P.H. proposed the project, helped to write the paper and gave important suggestions to the section of the paper that concerns uncertainty in precipitation projections under climate change.

Corresponding author

Correspondence to Lucas R. Vargas Zeppetello.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Water thanks the anonymous reviewers for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figs. 1–16 and Tables 1 and 2.

Reporting Summary

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Vargas Zeppetello, L.R., Trevino, A.M. & Huybers, P. Disentangling contributions to past and future trends in US surface soil moisture. Nat Water 2, 127–138 (2024). https://doi.org/10.1038/s44221-024-00193-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s44221-024-00193-x

Search

Quick links

Nature Briefing Anthropocene

Sign up for the Nature Briefing: Anthropocene newsletter — what matters in anthropocene research, free to your inbox weekly.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing: Anthropocene