Graphical Summaries

NIWA regularly updates results from several greenhouse gas measurement projects and makes them available as graphical summaries. Some of these summary graphs include the latest preliminary data.

Data that have been carefully checked are available in tabular form via anonymous FTP as selected trace gas and associated datasets.

More details

Baseline atmospheric CO₂ at Baring Head, New Zealand

CO₂ concentrations in units of 10^–6 mole/mole (ppm) are shown to the period 2007. Data points represent measurements during southerly wind events extracted from a near-continuous record which has much greater high frequency variability but displays the same long term trend. The red curve shows a time varying trend with the seasonal cycle removed.

Atmospheric CO₂ growth rates at Baring Head, New Zealand

This growth rate curve is derived as the derivative of the time varying smooth trend fitted to southerly wind event CO₂ data at Baring Head and shown as a separate figure.

¹⁴C in CO₂ from measurements near Wellington, New Zealand

The ¹⁴C/¹²C ratio in atmospheric CO₂ expressed as the relative difference from 0.95 of NBS oxalic acid standard after fractionation correction to a δ¹³C value of –25 ‰. Data points represent individual samples collected over typically two week periods at roughly monthly intervals. The more recent data is being measured using Accelerator Mass Spectrometry by the National Isotope Centre (NIC) at GNS Science, New Zealand, whereas early data used a gas counting technique.

CH₄ concentrations at Baring Head, New Zealand

The CH₄ concentration is shown in units of 10^–9 mole/mole (ppb) for the period 1989 to 2005. Data points are measurements from samples collected during southerly wind conditions. The green line is a smooth curve through the data based on a time varying trend and seasonal cycle. The red curve is a time varying trend in which the seasonal cycle has been removed.

Atmospheric CH₄ growth rates at Baring Head, New Zealand

This growth rate curve is derived as the derivative of the time varying smooth trend fitted to southerly wind event CH₄ data at Baring Head and shown as a separate figure.

δ¹³C in CH₄ at Baring Head, New Zealand

The ¹³C/¹²C isotope ratio in CH₄ is shown as the relative difference from the PDB standard in permil (‰). Data points are measurements on samples collected during southerly wind conditions. The green line is a smooth curve through the data based on a time varying trend and seasonal cycle. The red curve is a time varying trend in which the seasonal cycle has been removed.

CO concentrations at Baring Head, New Zealand

The CO concentration is shown in units of 10^–9 mole/mole (ppb) for the period 1989 to 2005. Data points are measurements from samples collected during southerly wind conditions. The green line is a smooth curve through the data based on a time varying trend and seasonal cycle. The red curve is a time varying trend in which the seasonal cycle has been removed.

δ¹³C in Carbon Monoxide at Baring Head, New Zealand

The ¹³C/¹²C isotope ratio in CO is shown as the relative difference from the PDB standard in permil (‰). Data points are measurements on samples collected during southerly wind conditions. The green line is a smooth curve through the data based on a time varying trend and seasonal cycle. The red curve is a time varying trend in which the seasonal cycle has been removed.

Surface ozone concentrations at Baring Head, New Zealand

Surface ozone concentrations in units of 10^–9 mole/mole (ppb) are shown for the period 1991 to 2005. Data points are monthly means of measurements during all wind conditions at Baring Head station. The green line is a smooth curve through the data based on a time varying trend and seasonal cycle. The red curve is a time varying trend in which the seasonal cycle has been removed.

N₂O concentrations at Baring Head, New Zealand

The N₂O concentration is shown in units of 10^-9 mole/mole (ppb) for the period 1997 to 2005. Data points are measurements from samples collected during southerly wind conditions. The green line is a smooth curve through the data based on a time varying trend and seasonal cycle. The red curve is a time varying trend in which the seasonal cycle has been removed.

O₂ measurements at Baring Head, New Zealand

O₂ is measured as the relative difference in the O₂/N₂ ratio from a known standard represented as a permeg value (the relative difference scaled by the factor of 10⁶). Data points represent measurements during southerly wind events extracted from a near-continuous record which has much greater high frequency variability but displays the same long term trend. The green line is a smooth curve through the data based on a time varying trend and seasonal cycle. The red curve shows a time varying trend with the seasonal cycle removed.