Patterns of Centennial-to-Millennial Holocene Climate Variation in the North American Mid-Latitudes
Noise in Holocene paleoclimate reconstructions can hamper detection of centennial-to-millennial climate variations and diagnoses of the dynamics involved. This paper uses multiple ensembles of reconstructions to separate signal and noise and determine what, if any, centennial-to-millennial variation...
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ftcopernicus:oai:publications.copernicus.org:cpd107801 2023-05-15T17:34:02+02:00 Patterns of Centennial-to-Millennial Holocene Climate Variation in the North American Mid-Latitudes Shuman, Bryan N. 2022-11-28 application/pdf https://doi.org/10.5194/cp-2022-89 https://cp.copernicus.org/preprints/cp-2022-89/ eng eng doi:10.5194/cp-2022-89 https://cp.copernicus.org/preprints/cp-2022-89/ eISSN: 1814-9332 Text 2022 ftcopernicus https://doi.org/10.5194/cp-2022-89 2022-12-05T17:22:43Z Noise in Holocene paleoclimate reconstructions can hamper detection of centennial-to-millennial climate variations and diagnoses of the dynamics involved. This paper uses multiple ensembles of reconstructions to separate signal and noise and determine what, if any, centennial-to-millennial variations influenced North America during the past 7000 yr. To do so, ensembles of temperature and moisture reconstructions were compared across four different spatial scales: continental, regional, sub-regional, and local scales. At each scale, two independent multi-record ensembles were compared to detect any centennial-to-millennial departures from the long Holocene trends, which correlate more than expected from random patterns. In all cases, the potential centennial-to-millennial variations had small magnitudes. However, at least two patterns of centennial-to-millennial variability appear evident. First, large-scale variations included a prominent Mid-Holocene anomaly from 5600–4500 YBP that increased mean effective moisture and produced temperature anomalies of different signs in different regions. The changes steepened the north-south temperature gradient in mid-latitude North America with a pattern similar to the positive mode of the North Atlantic Oscillation (NAO). Second, correlated multi-century (~500 yr) variations produce a distinct spectral signature in temperature and hydroclimate records along the western Atlantic margin. Both patterns differ from random autocorrelated variations but expressed distinct spatiotemporal characteristics consistent with separate controlling dynamics. Text North Atlantic North Atlantic oscillation Copernicus Publications: E-Journals |
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Copernicus Publications: E-Journals |
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English |
description |
Noise in Holocene paleoclimate reconstructions can hamper detection of centennial-to-millennial climate variations and diagnoses of the dynamics involved. This paper uses multiple ensembles of reconstructions to separate signal and noise and determine what, if any, centennial-to-millennial variations influenced North America during the past 7000 yr. To do so, ensembles of temperature and moisture reconstructions were compared across four different spatial scales: continental, regional, sub-regional, and local scales. At each scale, two independent multi-record ensembles were compared to detect any centennial-to-millennial departures from the long Holocene trends, which correlate more than expected from random patterns. In all cases, the potential centennial-to-millennial variations had small magnitudes. However, at least two patterns of centennial-to-millennial variability appear evident. First, large-scale variations included a prominent Mid-Holocene anomaly from 5600–4500 YBP that increased mean effective moisture and produced temperature anomalies of different signs in different regions. The changes steepened the north-south temperature gradient in mid-latitude North America with a pattern similar to the positive mode of the North Atlantic Oscillation (NAO). Second, correlated multi-century (~500 yr) variations produce a distinct spectral signature in temperature and hydroclimate records along the western Atlantic margin. Both patterns differ from random autocorrelated variations but expressed distinct spatiotemporal characteristics consistent with separate controlling dynamics. |
format |
Text |
author |
Shuman, Bryan N. |
spellingShingle |
Shuman, Bryan N. Patterns of Centennial-to-Millennial Holocene Climate Variation in the North American Mid-Latitudes |
author_facet |
Shuman, Bryan N. |
author_sort |
Shuman, Bryan N. |
title |
Patterns of Centennial-to-Millennial Holocene Climate Variation in the North American Mid-Latitudes |
title_short |
Patterns of Centennial-to-Millennial Holocene Climate Variation in the North American Mid-Latitudes |
title_full |
Patterns of Centennial-to-Millennial Holocene Climate Variation in the North American Mid-Latitudes |
title_fullStr |
Patterns of Centennial-to-Millennial Holocene Climate Variation in the North American Mid-Latitudes |
title_full_unstemmed |
Patterns of Centennial-to-Millennial Holocene Climate Variation in the North American Mid-Latitudes |
title_sort |
patterns of centennial-to-millennial holocene climate variation in the north american mid-latitudes |
publishDate |
2022 |
url |
https://doi.org/10.5194/cp-2022-89 https://cp.copernicus.org/preprints/cp-2022-89/ |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-2022-89 https://cp.copernicus.org/preprints/cp-2022-89/ |
op_doi |
https://doi.org/10.5194/cp-2022-89 |
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1766132731998109696 |