Additional co-authors: TJ Heaton, AG Hogg, KA Hughen, KF Kaiser, B Kromer, SW Manning, RW Reimer, DA Richards, JR Southon, S Talamo, CSM Turney, J van der Plicht, CE Weyhenmeyer

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IntCal13 and Marine13 radiocarbon age calibration curves 0-50,000 years cal BP

The ERA5 global reanalysis

Radiocarbon (14C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international 14C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable 14C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the 14C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine 14C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals.

https://dspace.stir.ac.uk/bitstream/1893/30981/1/intcal20_northern_hemisphere_radiocarbon_age_calibration_curve_055_cal_kbp.pdf

The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0-55 cal kBP)

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 Northern 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. DOI:  10.2458/azu_js_rc.55.16783

/pdf/shcal13-southern-hemisphere-calibration-0-50-000-years-cal-10wx6l9hsr.pdf

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

Recent research has strengthened the understanding of the links between climate and tropical cyclones (TCs) on various timescales Geological records of past climates have shown century-long variations in TC numbers While no significant trends have been identified in the Atlantic since the late 19th century, significant observed trends in TC numbers and intensities have occurred in this basin over the past few decades, and trends in other basins are increasingly being identified However, understanding of the causes of these trends is incomplete, and confidence in these trends continues to be hampered by a lack of consistent observations in some basins A theoretical basis for maximum TC intensity appears now to be well established, but a climate theory of TC formation remains elusive Climate models mostly continue to predict future decreases in global TC numbers, projected increases in the intensities of the strongest storms and increased rainfall rates Sea level rise will likely contribute toward increased storm surge risk Against the background of global climate change and sea level rise, it is important to carry out quantitative assessments on the potential risk of TC-induced storm surge and flooding to densely populated cities and river deltas Several climate models are now able to generate a good distribution of both TC numbers and intensities in the current climate Inconsistent TC projection results emerge from modeling studies due to different downscaling methodologies and warming scenarios, inconsistencies in projected changes of large-scale conditions, and differences in model physics and tracking algorithms WIREs Clim Change 2016, 7:65–89 doi: 101002/wcc371

For further resources related to this article, please visit the WIREs website

/pdf/tropical-cyclones-and-climate-change-3hw75muhas.pdf

Tropical cyclones and climate change

Pandora Hope, Joelle Gergis, Nerilie Abram, Josephine Brown, Steven J. Phipps, Russell Drysdale, Benjamin J. Henley, Andrew M. Lorrey, Heidi Roop, Jonathan Tyler Australian Bureau of Meteorology; 2 School of Earth Sciences, University of Melbourne, Australia; 3 Research School of Earth Sciences, Australian National University; 4 ARC Centre of Excellence for Climate System Science, Climate Change Research Centre, University of New South Wales, Australia; 5 Climate Change Research Centre, University of New South Wales, Australia; 6 National Institute of Water and Atmospheric Research, New Zealand; 7 GNS Science and Antarctic Research Centre, Victoria University of Wellington, New Zealand; 8 School of Earth and Environmental Science, University of Adelaide, Australia.

Australasia's past climate variability—strengths drawn from palaeoclimate and model data over the last 2,000 years

Mountain glaciers are highly sensitive to climate change. However, the extent to which glaciers capture regional to hemisphere‐scale atmospheric processes remains uncertain, hindering paleoclimatic interpretations derived from moraine‐based glacier reconstructions. Here, we evaluate how mid‐latitude glacier systems monitor climate by comparing climate reanalysis products with glacier annual equilibrium line altitude (ELA) elevations from the antipodal Southern Alps of New Zealand and European Alps. We find significant regional and hemispheric correlations between glacier annual ELA and summer tropospheric temperatures. Annual ELA also exhibit positive correlations with the latitude of the westerly jets in both hemispheres. These results indicate that westerly wind‐belt latitude modulates the proportion of cold versus warm air masses influencing these glacier systems. These results highlight the sensitivity of mid‐latitude glaciers to atmospheric temperatures and circulation, with implications for interpreting moraine‐based paleoclimate reconstructions. Combined impacts of ongoing tropospheric warming and poleward‐shifting westerlies will likely accelerate recession of mid‐latitude glaciers.

Correspondence Among Mid‐Latitude Glacier Equilibrium Line Altitudes, Atmospheric Temperatures, and Westerly Wind Fields

In this paper, we leverage open data and open-source software to develop ﬂexible, probabilistic monthly and seasonal (three-month) precipitation forecasts for the Paciﬁc region. We use data from a Multi-Model Ensemble (MME), i.e

Open data and open source software for the development and validation of multi-model monthly-to-seasonal probabilistic forecasts for the Paciﬁc Islands

Meteorological data rescue: Citizen science lessons learned from Southern Weather Discovery

Australasian palaeoclimate of the last 2000 years: Inter-comparison of climate field reconstruction methodologies, modeling, and data synthesis approaches

Andrew Lorrey

Papers

Australasia's past climate variability—strengths drawn from palaeoclimate and model data over the last 2,000 years

Correspondence Among Mid‐Latitude Glacier Equilibrium Line Altitudes, Atmospheric Temperatures, and Westerly Wind Fields

Open data and open source software for the development and validation of multi-model monthly-to-seasonal probabilistic forecasts for the Paciﬁc Islands

Meteorological data rescue: Citizen science lessons learned from Southern Weather Discovery

Australasian palaeoclimate of the last 2000 years: Inter-comparison of climate field reconstruction methodologies, modeling, and data synthesis approaches