Interhemispheric gradient of atmospheric radiocarbon reveals natural  variability of Southern Ocean winds

Rodgers, Keith B.; Fletcher, S. E. Mikaloff; Bianchi, Daniele; Beaulieu, Claudie; Galbraith, Eric D.; Gnanadesikan, Anand; Hogg, Alan G.; Iudicone, Daniele; Lintner, Benjamin R.; Naegler, Tobias; Reimer, Paula J.; Sarmiento, Jorge L.; Slater, Richard D.

doi:10.5194/cp-7-1123-2011

Cited by 39 publications

(42 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This age difference is known as the interhemispheric (or North-South) offset and varies periodically (~130 yr periodicity, with amplitudes ranging from -2 to 83 14 C yr for the time interval 200 BC-AD 1850 . The relatively older ages in the SH are considered due to a higher sea-air 14 CO 2 flux from the larger expanse of SH oceans, with temporal perturbations resulting from variable Southern Ocean wind strength (Rodgers et al 2011).…”

Section: Introductionmentioning

confidence: 99%

SHCal13 Southern Hemisphere Calibration, 0–50,000 Years cal BP

et al. 2013

View full text Add to dashboard Cite

ABSTRACT. The Southern Hemisphere SHCal04 radiocarbon calibration curve has been updated with the addition of new data sets extending measurements to 2145 cal BP and including the ANSTO Younger Dryas Huon pine data set. Outside the range of measured data, the curve is based upon the ern Hemisphere data sets as presented in IntCal13, with an interhemispheric offset averaging 43 ± 23 yr modeled by an autoregressive process to represent the short-term correlations in the offset.

show abstract

Section: Introductionmentioning

confidence: 99%

SHCal13 Southern Hemisphere Calibration, 0–50,000 Years cal BP

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Between 1850 and 1952, atmospheric 14 C decreased from approximately −4 ‰ to a minimum value around −25 ‰ as emissions from fossil fuel combustion increased after the Industrial Revolution. In the preindustrial and early industrial period to 1915, 14 C was 3-6 ‰ lower in the Southern Hemisphere than the Northern Hemisphere due to the negative influence of CO 2 exchange with aged, 14 C-depleted waters upwelling in the Southern Ocean (Braziunas et al, 1995;Rodgers et al, 2011;Lerman et al, 1970;Levin et al, 1987). Between 1915 and 1955, the interhemispheric gradient decreased due to the growth in fossil fuel emissions, which are concentrated in the Northern Hemisphere (McCormac et al, 1998).…”

Section: Historical Simulations Of Carbon Isotopes In Cmip6mentioning

confidence: 99%

Compiled records of carbon isotopes in atmospheric CO<sub>2</sub> for historical simulations in CMIP6

et al. 2017

View full text Add to dashboard Cite

Abstract. The isotopic composition of carbon ( 14 C and δ 13 C) in atmospheric CO 2 and in oceanic and terrestrial carbon reservoirs is influenced by anthropogenic emissions and by natural carbon exchanges, which can respond to and drive changes in climate. Simulations of 14 C and 13 C in the ocean and terrestrial components of Earth system models (ESMs) present opportunities for model evaluation and for investigation of carbon cycling, including anthropogenic CO 2 emissions and uptake. The use of carbon isotopes in novel evaluation of the ESMs' component ocean and terrestrial biosphere models and in new analyses of historical changes may improve predictions of future changes in the carbon cycle and climate system. We compile existing data to produce records of 14 C and δ 13 C in atmospheric CO 2 for the historical period 1850-2015. The primary motivation for this compilation is to provide the atmospheric boundary condition for historical simulations in the Coupled Model Intercomparison Project 6 (CMIP6) for models simulating carbon isotopes in the ocean or terrestrial biosphere. The data may also be useful for other carbon cycle modelling activities.

show abstract

“…Gouramanis et al, 2010). Fluctuations in atmospheric 14 C through time may result from aperiodic changes in ocean-atmosphere-terrestrial radiocarbon partitioning, upper-atmosphere radiocarbon production, and oceanic upwelling dynamics (Rodgers et al, 2011) that lead to "wiggles" in the radiocarbon calibration curve. When this is pared with the measurement uncertainty of radiocarbon samples, it leads to a range of possible calendar dates (Blaauw, 2010).…”

Section: Caveats On Resolving Changes From Low-resolution Sedimentarymentioning

confidence: 99%

Low-resolution Australasian palaeoclimate records of the last 2000 years

et al. 2017

View full text Add to dashboard Cite

Abstract. Non-annually resolved palaeoclimate records in the Australasian region were compiled to facilitate investigations of decadal to centennial climate variability over the past 2000 years. A total of 675 lake and wetland, geomorphic, marine, and speleothem records were identified. The majority of records are located near population centres in southeast Australia, in New Zealand, and across the maritime continent, and there are few records from the arid regions of central and western Australia. Each record was assessed against a set of a priori criteria based on temporal resolution, record length, dating methods, and confidence in the proxy-climate relationship over the Common Era. A subset of 22 records met the criteria and were endorsed for subsequent analyses. Chronological uncertainty was the primary reason why records did not meet the selection criteria. New chronologies based on Bayesian techniques were constructed for the high-quality subset to ensure a consistent approach to age modelling and quantification of age uncertainties. The primary reasons for differences between published and reconstructed age-depth models were the consideration of the non-singular distribution of ages in calibrated 14 C dates and the use of estimated autocorrelation between sampled depths as a constraint for changes in accumulation rate. Existing proxies and reconstruction techniques that successfully capture climate variability in the region show potential to address spatial gaps and expand the range of climate variables covering the last 2000 years in the Australasian region. Future palaeoclimate research and records in Australasia could be greatly improved through three main actions: (i) greater data availability through the public archiving of published records; (ii) thorough characterisation of proxy-climate relationships through site monitoring and climate sensitivity tests; and (iii) improvement of chronologies through coretop dating, inclusion of tephra layers where possible, and increased date density during the Common Era.

show abstract

Interhemispheric gradient of atmospheric radiocarbon reveals natural variability of Southern Ocean winds

Abstract: Abstract.Tree ring 14 C data McCormac et al., 2004) indicate that atmospheric 14 C varied on multi-decadal to centennial timescales, in both hemispheres, over the period between AD 950 and 1830.

Cited by 39 publications

References 61 publications

SHCal13 Southern Hemisphere Calibration, 0–50,000 Years cal BP

SHCal13 Southern Hemisphere Calibration, 0–50,000 Years cal BP

Compiled records of carbon isotopes in atmospheric CO<sub>2</sub> for historical simulations in CMIP6

Low-resolution Australasian palaeoclimate records of the last 2000 years

Contact Info

Product

Resources

About

Interhemispheric gradient of atmospheric radiocarbon reveals natural variability of Southern Ocean winds

Abstract: Abstract.Tree ring 14 C data McCormac et al., 2004) indicate that atmospheric 14 C varied on multi-decadal to centennial timescales, in both hemispheres, over the period between AD 950 and 1830.

Cited by 39 publications

References 61 publications

SHCal13 Southern Hemisphere Calibration, 0–50,000 Years cal BP

SHCal13 Southern Hemisphere Calibration, 0–50,000 Years cal BP

Compiled records of carbon isotopes in atmospheric CO&lt;sub&gt;2&lt;/sub&gt; for historical simulations in CMIP6

Low-resolution Australasian palaeoclimate records of the last 2000 years

Contact Info

Product

Resources

About

Compiled records of carbon isotopes in atmospheric CO<sub>2</sub> for historical simulations in CMIP6