Data from the New Zealand National Institute of Water and Atmospheric Research - United Kingdom Chemistry and Aerosol (NIWA-UKCA) model, part of the International Global Atmospheric Chemistry (IGAC)/ Stratosphere-troposphere Processes and their Role in Climate (SPARC) Chemistry-Climate Model Initiative phase 1 (CCMI-1).

CCMI-1 is a global chemistry climate model intercomparison project, coordinated by the University of Reading on behalf of the World Climate Research Programme (WCRP).

The dataset includes data for the following CCMI-1 experiments:

Reference experiments: ref-C1 and ref-C2.

Sensitivity experiments: senC1fEmis, senC2fCH4, senC2fGHG, senC2fN2O and senC2fODS.

ref-C1: Using state-of-knowledge historic forcings and observed sea surface conditions, the models simulate the recent past (1960–2010).

ref-C2: Simulations spanning the period 1960–2100. The experiments follow the WMO (2011) A1 baseline scenario for ozone depleting substances and the RCP 6.0 (Meinshausen et al., 2011) for other greenhouse gases, tropospheric ozone (O3) precursors, and aerosol and aerosol precursor emissions.

senC1fEmis: Surface emissions such as nitrogen oxides (NOx ), carbon monoxide (CO), non-methane volatile organic compounds (NMVOCs), and aerosol precursors are prescribed at 1960 levels throughout, allowing the influence of meteorological variability on tropospheric composition to be established.

senC2fGHG: Similar to ref-C2 but with greenhouse gasses (GHGs) fixed at their 1960 levels, and sea surface and sea ice conditions prescribed as the 1955–1964 average (where these conditions are imposed).

senC2fCH4: Similar to ref-C2 but the methane surface-mixing ratio is fixed to its 1960 value.

senC2fN2O: Similar to ref-C2 but the nitrous oxide surface-mixing ratio is fixed to its 1960 value.

senC2fODS: Similar to ref-C2 but with ozone-depleting (halogenated) substances (ODSs) fixed at their 1960 levels.