Class

Article

College

College of Science

Department

Plants, Soils, and Climate Department

Faculty Mentor

Wei Zhang

Presentation Type

Poster Presentation

Abstract

Historically, the precipitation trend over the past few decades in the Contiguous United States (CONUS) exhibits a "Dry-West Wet-East" pattern; this is manifested by recent droughts/floods in the western/eastern US. However, it remains elusive what atmospheric phenomenon has potentially driven such a remarkable, and impactful precipitation pattern. Here we found that a coupled climate mode—the Pacific Meridional Mode (PMM) exerted strong impacts on the precipitation pattern over the CONUS during the summer season. We discovered a significant association between the PMM index and precipitation across the CONUS; this was manifested as a zonal dipole pattern—negative correlations in the western U.S. along with positive correlations in the eastern and central U.S. Overall, the physical mechanisms based on observations were supported by using AMIP simulations available CMIP6.

Location

Logan, UT

Start Date

4-8-2025 1:30 PM

End Date

4-8-2025 2:20 PM

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Apr 8th, 1:30 PM Apr 8th, 2:20 PM

Modulation of the Pacific Meridional Mode on the Dipole Pattern of the CONUS Summertime Precipitation

Logan, UT

Historically, the precipitation trend over the past few decades in the Contiguous United States (CONUS) exhibits a "Dry-West Wet-East" pattern; this is manifested by recent droughts/floods in the western/eastern US. However, it remains elusive what atmospheric phenomenon has potentially driven such a remarkable, and impactful precipitation pattern. Here we found that a coupled climate mode—the Pacific Meridional Mode (PMM) exerted strong impacts on the precipitation pattern over the CONUS during the summer season. We discovered a significant association between the PMM index and precipitation across the CONUS; this was manifested as a zonal dipole pattern—negative correlations in the western U.S. along with positive correlations in the eastern and central U.S. Overall, the physical mechanisms based on observations were supported by using AMIP simulations available CMIP6.