A 250-year periodicity in Southern Hemisphere westerly winds over the last 2600 years
Data(s) |
03/02/2016
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Resumo |
Southern Hemisphere westerly airflow has a significant influence on the ocean–atmosphere system of the mid- to high latitudes with potentially global climate implications. Unfortunately, historic observations only extend back to the late 19th century, limiting our understanding of multi-decadal to centennial change. Here we present a highly resolved (30-year) record of past westerly wind strength from a Falkland Islands peat sequence spanning the last 2600 years. Situated within the core latitude of Southern Hemisphere westerly airflow (the so-called furious fifties), we identify highly variable changes in exotic pollen and charcoal derived from South America which can be used to inform on past westerly air strength. We find a period of high charcoal content between 2000 and 1000 cal. years BP, associated with increased burning in Patagonia, most probably as a result of higher temperatures and stronger westerly airflow. Spectral analysis of the charcoal record identifies a pervasive ca. 250-year periodicity that is coherent with radiocarbon production rates, suggesting that solar variability has a modulating influence on Southern Hemisphere westerly airflow. Our results have important implications for understanding global climate change through the late Holocene. |
Formato |
application/pdf |
Identificador | |
Idioma(s) |
eng |
Direitos |
info:eu-repo/semantics/openAccess |
Fonte |
Turney , C S M , Jones , R T , Fogwell , C , Hatton , J , Williams , A N , Hogg , A , Thomas , Z A , Palmer , J , Mooney , S & Reimer , R W 2016 , ' A 250-year periodicity in Southern Hemisphere westerly winds over the last 2600 years ' Climate of the Past , vol 12 , no. 2 , pp. 189-200 . DOI: 10.5194/cp-12-189-2016 |
Tipo |
article |