Sea saltiness predicts extreme rain in a landlocked region

Sea–surface salinity levels in the Pacific and Atlantic oceans can presage heavy rains in the Midwestern United States.

 Thunder clouds build over a farm in the Midwestern United States, where the likelihood of extreme storms can be predicted from sea-surface salinity. Credit: Getty
 From Nature.com

RESEARCH HIGHLIGHT 

Image: Thunder clouds build over a farm in the Midwestern United States, where the likelihood of extreme storms can be predicted from sea-surface salinity. Credit: Getty 

Salinity measurements in far-flung oceans can be used to better predict damaging rainfall across the Great Plains of the United States1.

So far, seasonal forecasts for the country’s Midwestern region have relied mainly on surface-temperature trends in the tropical Pacific Ocean and North Atlantic oceans. These trends have been linked with weather patterns across the whole of the the continental United States and beyond.

Seeking to bolster forecasts for the agriculturally significant Midwest, Laifang Li at Pennsylvania State University in University Park and her colleagues analysed seven decades of rainfall data for the region, alongside records of sea-surface temperature and salinity in both oceans.

The authors found that ocean salinity in the western Pacific, as well as along the east coast of North America, were a more reliable predictor of summer weather patterns across the United States than were ocean temperatures. By including ocean salinity in their models, the authors were able to double the accuracy of their forecasts of extreme rainfall across the Midwest.

Nature 607, 425 (2022)

doi: https://doi.org/10.1038/d41586-022-01913-7

References

  1. Li, L., Schmitt, R. W. & Ummenhofer, C. C. Geophys. Res. Lett. 49, e2022GL098554 (2022).

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