Details:

Journal Title:
Journal of Climate
Personal Author:
Hoerling, Martin ; Eischeid, Jon ; Perlwitz, Judith ; Quan, Xiao-Wei ; Wolter, Klaus ; ... More +
Hoerling, Martin ; Eischeid, Jon ; Perlwitz, Judith ; Quan, Xiao-Wei ; Wolter, Klaus ; Cheng, Linyin Less -
NOAA Program & Office:
OAR (Oceanic and Atmospheric Research) ; CPO (Climate Program Office) ; ESRL (Earth System Research Laboratory) ; CIRES (Cooperative Institute for Research in Environmental Sciences)
OAR (Oceanic and Atmospheric Research) ; CPO (Climate Program Office) ; ESRL (Earth System Research Laboratory) ; CIRES (Cooperative Institute for Research in Environmental Sciences) Less -
Description:
Time series of U.S. daily heavy precipitation (95th percentile) are analyzed to determine factors responsible for regionality and seasonality in their 1979-2013 trends. For annual conditions, contiguous U.S. trends have been characterized by increases in precipitation associated with heavy daily events across the northern United States and decreases across the southern United States. Diagnosis of climate simulations (CCSM4 and CAM4) reveals that the evolution of observed sea surface temperatures (SSTs) was a more important factor influencing these trends than boundary condition changes linked to external radiative forcing alone. Since 1979, the latter induces widespread, but mostly weak, increases in precipitation associated with heavy daily events. The former induces a meridional pattern of northern U.S. increases and southern U.S. decreases as observed, the magnitude of which closely aligns with observed changes, especially over the south and far west. Analysis of model ensemble spread reveals that appreciable 35-yr trends in heavy daily precipitation can occur in the absence of forcing, thereby limiting detection of the weak anthropogenic influence at regional scales. Analysis of the seasonality in heavy daily precipitation trends supports physical arguments that their changes during 1979-2013 have been intimately linked to internal decadal ocean variability and less so to human-induced climate change. Most of the southern U.S. decrease has occurred during the cold season that has been dynamically driven by an atmospheric circulation reminiscent of teleconnections linked to cold tropical eastern Pacific SSTs. Most of the northeastern U.S. increase has been a warm season phenomenon, the immediate cause for which remains unresolved.
Source:
Journal of Climate, 29(7), 2313-2332.
DOI:
https://doi.org/10.1175/JCLI-D-15-0441.1
Document Type:
Journal Article
Rights Information:
Other
Compliance:
Submitted
Main Document Checksum:
[+]
urn:sha256:9a511eb85957f615fcce68186a5963a7106f6155843bd291a8f9c414a9a9082a
Download URL:
https://repository.library.noaa.gov/view/noaa/14555/noaa_14555_DS1.pdf
File Type:

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