Multidecadal Drought and Holocene Climate Instability in the Rocky Mountains


Autoria(s): Stone, Jeffery R; Fritz, Sherilyn C
Data(s)

01/01/2006

Resumo

Time series analysis of a diatom-inferred drought record suggests that Holocene hydroclimate of the northern Rocky Mountains has been characterized by oscillation between two mean climate states. The dominant climate state was initiated at the onset of the Holocene (ca. 11 ka); under this climate state, drought was strongly cyclic, recurring at frequencies that are similar to twentieth century multidecadal phase changes of the Pacific Decadal Oscillation. This pattern remained consistent throughout much of the mid- Holocene, continuing until ca. 4.5 ka. After this time the mean climate state changed, and drought recurrence became unstable; periods of cyclic drought alternated with periods of less predictable drought. The timing of this shift in climate was coincident with widespread severe drought in the mid-continent of North America. Overall, the strongest periodicity in severe drought occurred during the mid-Holocene, when temperatures in the northern Rocky Mountains were warmer than today.

Identificador

http://digitalcommons.unl.edu/geosciencefacpub/118

http://geology.gsapubs.org/content/34/5/409.full.pdf+html

Publicador

DigitalCommons@University of Nebraska - Lincoln

Fonte

Papers in the Earth and Atmospheric Sciences

Palavras-Chave #drought #diatoms #Holocene #climate variability #Pacific Decadal Oscillation #Earth Sciences #Geology
Tipo

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