OxCal > Calibration Curves

Calibration Curves

• Atmospheric curves
• Marine curves

Atmospheric Curves

The main curves recommended for calibration are:

• IntCal series
  • IntCal20: Northern Hemisphere (Reimer et al. 2020)
  • SHCal20: Southern Hemisphere (Hogg et al. 2020)
• Bomb series (Hua et al. 2022 - published online 2021)
  • Bomb21NH1: North of 40°N; note this is prepended with the last 5000 years of IntCal20
  • Bomb21NH2: Between 40°N and mean summer intertropical convergence zone; note this is prepended with the last 5000 years of IntCal20
  • Bomb21NH3: Northern hemisphere mean summer intertropical convergence zone; note this is prepended with the last 5000 years of IntCal20
  • Bomb21SH12: Southern hemisphere (not in mean summer intertropical convergence zone); note this is prepended with the last 5000 years of SHCal20
  • Bomb21SH3: Southern hemisphere mean summer intertropical convergence zone; note this is prepended with the last 5000 years of SHCal20
• Kueppers04: Bomb series based on growth season (Kueppers et al. 2004)

For comparison with older calibrations the following are also included:

• IntCal13: Northern Hemisphere (Reimer et al. 2013)
• SHCal13: Southern Hemisphere (Hogg et al. 2013)
• IntCal09: Northern Hemisphere (Reimer et al. 2009)
• IntCal04: Northern Hemisphere (Reimer et al. 2004)
• IntCal98 (Stuiver et al. 1998)
• SHCal04: Southern Hemisphere (McCormac et al. 2004)
• Bomb series (Hua et al. 2013)
  • Bomb13NH1: North of 40°N; note this is prepended with the last 5000 years of IntCal20
  • Bomb13NH2: Between 40°N and mean summer intertropical convergence zone; note this is prepended with the last 5000 years of IntCal20
  • Bomb13NH3: Northern hemisphere mean summer intertropical convergence zone; note this is prepended with the last 5000 years of IntCal20
  • Bomb13SH12: Southern hemisphere (not in mean summer intertropical convergence zone); note this is prepended with the last 5000 years of SHCal20
  • Bomb13SH3: Southern hemisphere mean summer intertropical convergence zone; note this is prepended with the last 5000 years of SHCal20
• Bomb series (Hua et al. 2004)
  • Bomb04NH1: North of 40°N; note this is prepended with the last 300 years of IntCal04
  • Bomb04NH2: Between 40°N and mean summer intertropical convergence zone; note this is prepended with the last 300 years of IntCal04
  • Bomb04NH3: Northern hemisphere mean summer intertropical convergence zone; note this is prepended with the last 300 years of IntCal04
  • Bomb04SH: Southern hemisphere; note this is prepended with the last 300 years of SHCal04

For post-bomb results the function R_F14C() should be used which uses results in the form of F14C as defined by Reimer et al. 2004. As a default OxCal works on a resolution of 0.2yr with such data. To obtain results similar to those for the non-smoothed curve in CALIBomb (Reimer et al. 2004), you should set the resolution to 0.01. For many purposes you should consider adding a Reservoir time constant in this time period as even short-lived plants grow over several months.

Marine Curves

The recommended marine curve is:

• Marine20 - Modelled ocean average (Heaton et al. 2020)

For marine calibrations you will need to find an appropriate ΔR offset from the CHRONO Marine Reservoir Database. Note that these are different to those required for previous marine curves.

For comparison with older calibrations the following are also included:

• Marine13 - Modelled ocean average (Reimer et al. 2013)
• Marine09 - Modelled ocean average (Reimer et al. 2009)
• Marine04 - Modelled ocean average (Hughen et al. 2004)
• Marine98 (Stuiver et al. 1998)