Sensitive moisture response to Holocene millennial-scale climate variations in the Mid-Atlantic region, USA

Abstract

Millennial-scale climate variability has been increasingly recognized as one of the most prominent features of the Holocene. However, regional responses, especially in terms of moisture conditions, are poorly documented and understood. Here we present lithologic and magnetic evidence from White Lake in northern New Jersey, USA, to show that low lake levels occurred at about 1.3, 3.0, 4.4 and 6.1 ka (1 ka0/1000 cal. yr BP). The low lake levels are indicated by heterogeneous coarse calcareous sediment layers showing strong magnetic intensities. These detrital layers were likely formed during low stands when shallow-water marls were exposed, oxidized, transported and redeposited. This model is supported by laboratory experiments showing that oxidation of marls can enhance magnetic intensities. The dry periods inferred from the low lake levels of White Lake appear to occur concurrently with the cold periods recorded in the North Atlantic sediments. The correlation between millennial-scale dry/wet cycles inferred from lake-level fluctuations of White Lake and cold/warm cycles in North Atlantic sediments suggests sensitive moisture responses to Holocene millennial-scale climate variability. The dry-cold (or wetwarm) association is supported by instrumental records of the last century showing that the Mid-Atlantic region was dominated by wet conditions, while most parts of the conterminous USA experienced droughts, when the North Atlantic Ocean was warm. The consistent moisture responses of the Mid-Atlantic region to temperature changes of the North Atlantic Ocean may have persisted for the past 6000 years.

Repeated century-scale droughts over the past 13,000 yr near the Hudson River watershed, USA

“…In addition to the long-term trend, the eleven low stand units (many containing multiple individual event layers) indicate the regional importance of multi-century hydroclimatic variability consistent with that inferred from an emerging group of recent studies (Li et al, 2007;Newby et al, 2009) Unit IX (before 3.5 cal ka BP) corresponds to a New Long Pond low stand at 4.1-3.6 cal ka BP, Davis Pond Unit X (3.0-2.3 cal ka BP; likely two events before and after 2.7 cal ka BP) overlaps to two New Long Pond low stands at 3.6-2.7 and 2.5-1.9 cal ka BP, and Davis Pond Unit XI (1.6-0.6 cal ka BP) correlates with one at New Long Pond at 1.9-1.2 cal ka BP . Further afield, the four low-stand intervals at White Lake in New Jersey (Li et al, 2007) cal ka BP events .…”

“…Further afield, the four low-stand intervals at White Lake in New Jersey (Li et al, 2007) cal ka BP events . As noted by Li et al (Li et al, 2007), the influence of the North Atlantic Ocean may have continued to play an important role in forcing prolonged regional droughts during the remainder of the Holocene, just as it did in the most severe historic drought in AD 1962-1966(Namias, 1966. For example, the coincident low stands at Davis Pond (esp.…”

“…The closest study to the Hudson River watershed indicates four (ca. 1.3, 3.0, 4.4, 6.1 cal ka BP) centennial-scale droughts in New Jersey (Li et al, 2007), and two lakes in Massachusetts contain evidence of repeated century to multi-century droughts throughout the past 14.0 cal ka BP ).…”

“…Jersey (Li et al, 2007) and on the Plymouth-Carver Sand Plain of Massachusetts Shuman et al, 2009). Despite numerous local paleoevironmental studies in the region (Kirby et al, 2002;Maenza-Gmelch, 1997;Peteet et al, 1990), no other paleohydrologic studies have been conducted at century-scale resolution within 350 km.…”

Paired oxygen isotope records reveal modern North American atmospheric dynamics during the Holocene

“…We suggest that the inversely correlated component of isotopic change in the western and eastern sites may reflect long-term variability of the mean state of PNA through the Holocene based on the documented association of anti-phase precipitation isotopic variation in these regions with PNA. During the MH, relatively low d 18 ARTICLE across North America [19][20][21] , and corresponds temporally with the 4.2-3.9 kyr before present (BP) abrupt climate event documented globally 22 . Our result is supported by independent proxy evidence from a range of sites across the continent.…”