scholarly journals Correlation of Late-Pleistocene Lake-Level Oscillations in Mono Lake, California, with North Atlantic Climate Events

1998 ◽  
Vol 49 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Larry V. Benson ◽  
Steve P. Lund ◽  
James W. Burdett ◽  
Michaele Kashgarian ◽  
Timothy P. Rose ◽  
...  
Keyword(s):  
North Atlantic ◽  
Inorganic Carbon ◽  
Mono Lake ◽  
Total Inorganic Carbon ◽  
Lake Levels ◽  
Owens Lake ◽  
North Atlantic Climate ◽  
The Mean ◽  
Climate Events ◽  
Wilson Creek Formation

Oxygen-18 (18O) values of sediment from the Wilson Creek Formation, Mono Basin, California, indicate three scales of temporal variation (Dansgaard–Oeschger, Heinrich, and Milankovitch) in the hydrologic balance of Mono Lake between 35,400 and 12,900 14C yr B.P. During this interval, Mono Lake experienced four lowstands each lasting from 1000 to 2000 yr. The youngest lowstand, which occurred between 15,500 and 14,000 14C yr B.P., was nearly synchronous with a desiccation of Owens Lake, California. Paleomagnetic secular variation (PSV) data indicate that three of four persistent lowstands occurred at the same times as Heinrich events H1, H2, and H4.18O data indicate the two highest lake levels occurred ∼18,000 and ∼13,100 14C yr B.P., corresponding to passages of the mean position of the polar jet stream over the Mono Basin. Extremely low values of total inorganic carbon between 26,000 and 14,000 14C yr B.P. indicate glacial activity, corresponding to a time when summer insolation was much reduced.

scholarly journals Transports and budgets of total inorganic carbon in the subpolar and temperate North Atlantic

2003 ◽  
Vol 17 (1) ◽  
pp. 2-1-2-21 ◽  
Author(s):  
Marta Álvarez ◽  
Aida F. Ríos ◽  
Fiz F. Pérez ◽  
Harry L. Bryden ◽  
Gabriel Rosón
Keyword(s):  
North Atlantic ◽  
Inorganic Carbon ◽  
Total Inorganic Carbon

scholarly journals Revisiting the absolute calibration of the Greenland ice-core age-scales

2008 ◽  
Vol 4 (3) ◽  
pp. 791-807 ◽  
Author(s):  
L. Skinner
Keyword(s):  
North Atlantic ◽  
Ice Core ◽  
Ice Cores ◽  
Absolute Calibration ◽  
North Atlantic Climate ◽  
The Absolute ◽  
Absolute Age ◽  
Surface Reservoir ◽  
Climate Events ◽  
Age Constraints

Abstract. Recently, an absolute "calibration" was proposed for the GRIP and GISP2 Greenland ice-core time scales (Shackleton et al., 2004). This calibration attempted to reconcile the stratigraphic integration of ice-core, marine and speleothem archives with the absolute age constraints that marine and speleothem records incorporate. Here we revisit this calibration in light of the new layer-counted chronology of the NGRIP ice-core (GICC05). The GICC05 age-scale differs from the proposed absolute calibration by up to 1200 years late in the last glaciation, with implications both for radiocarbon cycling and the inferred timing of North Atlantic climate events relative to absolutely dated archives (e.g. relative sea-level). By precisely aligning the stratigraphy of Iberian Margin marine cores with that of the Greenland ice-cores, it appears that either: 1) the radiocarbon content of mid-latitude Atlantic surface-waters was extremely depleted (resulting in average surface reservoir ages up to 1700 years prior to ~22 ka BP); or 2) the GICC05 age-scale includes too few years (is up to 1200 years too young). It is shown here that both of these possibilities are in fact correct to some degree. Northeast Atlantic surface reservoir ages should be revised upward by ~350 years, while the NGRIP age-scale appears to be "missing" time. These findings illustrate the importance of integrated stratigraphy as a test for our chronologies, which are rarely truly "absolute". This is an important point, since probably the worst error that we can make is to entrench and generalise a precise stratigraphical relationship on the basis of erroneous absolute age assignations.

scholarly journals Revisiting the absolute calibration of the Greenland ice-core age-scales*

2008 ◽  
Vol 4 (4) ◽  
pp. 295-302 ◽  
Author(s):  
L. C. Skinner
Keyword(s):  
North Atlantic ◽  
Ice Core ◽  
Ice Cores ◽  
Absolute Calibration ◽  
North Atlantic Climate ◽  
The Absolute ◽  
Absolute Age ◽  
Surface Reservoir ◽  
Climate Events ◽  
Age Constraints

Abstract. Recently, an absolute "calibration" was proposed for the GRIP and GISP2 Greenland ice-core time scales (Shackleton et al., 2004). This calibration attempted to reconcile the stratigraphic integration of ice-core, marine and speleothem archives with the absolute age constraints that marine and speleothem records incorporate. Here we revisit this calibration in light of the new layer-counted chronology of the NGRIP ice-core (GICC05). The GICC05 age-scale differs from the proposed absolute calibration by up to 1200 years late in the last glaciation, with implications both for radiocarbon cycling and the inferred timing of North Atlantic climate events relative to radiometrically dated archives (e.g. relative sea-level). By aligning the stratigraphy of Iberian Margin marine cores with that of the Greenland ice-cores, it can be shown that either: 1) the radiocarbon content of mid-latitude Atlantic surface-waters was extremely depleted (resulting in average surface reservoir ages up to 1700 years prior to ~22 ka BP); or 2) the GICC05 age-scale includes too few years (is up to 1200 years too young). It is shown here that both of these possibilities are probably correct to some degree. Based on the assumed accuracy of coral and speleothem U-Th ages, Northeast Atlantic surface reservoir ages should be revised upward by ~350 years, while the NGRIP age-scale appears to be "missing" time. These findings illustrate the utility of integrated stratigraphy as a test for our chronologies, which are rarely truly "absolute". This is an important point, since probably the worst error that we can make is to entrench and generalise a precise stratigraphical relationship on the basis of erroneous absolute age assignations.

North Atlantic climate II Addendum

2005 ◽  
Author(s):  
T. Kanamatsu ◽  
R. Stein ◽  
C.A. and Alvarez Zarikian
Keyword(s):  
North Atlantic ◽  
North Atlantic Climate

scholarly journals Carbonate system distribution, anthropogenic carbon and acidification in the western tropical South Pacific (OUTPACE 2015 transect)

2018 ◽  
Vol 15 (16) ◽  
pp. 5221-5236 ◽  
Author(s):  
Thibaut Wagener ◽  
Nicolas Metzl ◽  
Mathieu Caffin ◽  
Jonathan Fin ◽  
Sandra Helias Nunige ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
South Pacific ◽  
Total Alkalinity ◽  
Total Inorganic Carbon ◽  
Saturation State ◽  
Anthropogenic Carbon ◽  
Subsurface Waters ◽  
Derived Properties ◽  
Intermediate Waters ◽  
South Pacific Gyre

Abstract. The western tropical South Pacific was sampled along a longitudinal 4000 km transect (OUTPACE cruise, 18 February, 3 April 2015) for the measurement of carbonate parameters (total alkalinity and total inorganic carbon) between the Melanesian Archipelago (MA) and the western part of the South Pacific gyre (WGY). This paper reports this new dataset and derived properties: pH on the total scale (pHT) and the CaCO3 saturation state with respect to aragonite (Ωara). We also estimate anthropogenic carbon (CANT) distribution in the water column using the TrOCA method (Tracer combining Oxygen, inorganic Carbon and total Alkalinity). Along the OUTPACE transect a deeper penetration of CANT in the intermediate waters was observed in the MA, whereas highest CANT concentrations were detected in the subsurface waters of the WGY. By combining our OUTPACE dataset with data available in GLODAPv2 (1974–2009), temporal changes in oceanic inorganic carbon were evaluated. An increase of 1.3 to 1.6 µmol kg−1 a−1 for total inorganic carbon in the upper thermocline waters is estimated, whereas CANT increases by 1.1 to 1.2 µmol kg−1 a−1. In the MA intermediate waters (27 kg m−3 <σθ<27.2 kg m−3) an increase of 0.4 µmol kg−1 a−1 CANT is detected. Our results suggest a clear progression of ocean acidification in the western tropical South Pacific with a decrease in the oceanic pHT of up to −0.0027 a−1 and a shoaling of the saturation depth for aragonite of up to 200 m since the pre-industrial period.

scholarly journals Patterns of millennial variability over the last 500 ka

2010 ◽  
Vol 6 (3) ◽  
pp. 295-303 ◽  
Author(s):  
M. Siddall ◽  
E. J. Rohling ◽  
T. Blunier ◽  
R. Spahni
Keyword(s):  
Atmospheric Circulation ◽  
North Atlantic ◽  
Glacial Cycles ◽  
The North ◽  
The North Atlantic ◽  
Paleoclimate Records ◽  
Temperature Proxy ◽  
Freshwater Release ◽  
Glacial Periods ◽  
Climate Events

Abstract. Millennial variability is a robust feature of many paleoclimate records, at least throughout the last several glacial cycles. Here we use the mean signal from Antarctic climate events 1 to 4 to probe the EPICA Dome C temperature proxy reconstruction through the last 500 ka for similar millennial-scale events. We find that clusters of millennial events occurred in a regular fashion over half of the time during this with a mean recurrence interval of 21 kyr. We find that there is no consistent link between ice-rafted debris deposition and millennial variability. Instead we speculate that changes in the zonality of atmospheric circulation over the North Atlantic form a viable alternative to freshwater release from icebergs as a trigger for millennial variability. We suggest that millennial changes in the zonality of atmospheric circulation over the North Atlantic are linked to precession via sea-ice feedbacks and that this relationship is modified by the presence of the large, Northern Hemisphere ice sheets during glacial periods.

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