Details:

Journal Title:
Journal of Climate
Personal Author:
Barnston, Anthony G. ; Lyon, Bradfield
Barnston, Anthony G. ; Lyon, Bradfield Less -
NOAA Program & Office:
OAR (Oceanic and Atmospheric Research) ; CPO (Climate Program Office)
OAR (Oceanic and Atmospheric Research) ; CPO (Climate Program Office) Less -
Description:
A global-scale decadal climate shift, beginning in 1998/99 and enduring through 2013, has been documented in recent studies, with associated precipitation shifts in key regions throughout the world. These precipitation shifts are most easily detected during March–May when ENSO effects are weak. Analyses have linked this climate shift to a shift in the Pacific decadal variability (PDV) pattern to its negative phase. Here the authors evaluate the predictive skill of the North American Multimodel Ensemble (NMME), and the CFSv2 model alone, in maintaining the observed precipitation shifts in seasonal forecasts, emphasizing the southwestern United States where deficient precipitation has tended to prevail since the late 1990s.

The NMME hindcasts out to 6 months lead are found to maintain the observed decadal precipitation shifts in key locations qualitatively correctly, but with increasingly underestimated amplitude with increasing lead time. This finding holds in the separate CFSv2 model hindcasts. The decadal precipitation shift is relatively well reproduced in the southwestern United States. The general underestimation of the precipitation shift is suggested to be related to a muted reproduction of the observed shift in Pacific sea surface temperature (SST). This conclusion is supported by runs from a different (but overlapping) set of atmospheric models, which when forced with observed SST reproduce the decadal shifts quite well. Overall, the capability of the NMME model hindcasts to reflect the observed decadal rainfall pattern shift, but with weakened amplitude (especially at longer leads), underscores the broader challenge of retaining decadal signals in predictions of droughts and pluvials at seasonal-to-interannual time scales.


Keywords:
[+]
Climate Prediction Drought Modeling Sea Surface Temperature NOAA Modeling, Analysis, Prediction and Projections (MAPP)
Source:
Journal of Climate, 29(2), 561-581.
DOI:
https://doi.org/10.1175/JCLI-D-15-0311.1
Document Type:
Journal Article
Funding:
Grantn no. NA12OAR4310088
Place as Subject:
Southwestern states
Rights Information:
Other
Compliance:
Submitted
Main Document Checksum:
[+]
urn:sha256:90768e61a36056ec0536a895b3147438d5e87beea9a52608535e2b8fb2ac9e11
Download URL:
https://repository.library.noaa.gov/view/noaa/28962/noaa_28962_DS1.pdf
File Type:

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