Data from the University L' Aquila Chemistry Climate Model (ULAQ-CCM), part of the International Global Atmospheric Chemistry (IGAC)/ Stratosphere-troposphere Processes and their Role in Climate (SPARC) Chemistry-Climate Model Initiative phase1 (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: senC1SDfEmis, senC1SSI, senC2fCH4, senC2fEmis, senC2fGHG, senC2fN2O, senC2fODS, senC2fODS2000, senC2rcp26, senC2rcp45, senC2rcp85 and senC2SlrTrnd.

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.

senC1SDfEmis: 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. (“SD” stands for specified dynamics.)

senC1SSI: The same as ref-C1 but using a solar forcing dataset with increased UV intensity.

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).

senC2fEmis: Similar to ref-C2 but with surface and aircraft emissions fixed to their respective 1960 levels.

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.

senC2fODS2000: The same as ref-C2 but with ODSs fixed at their year 2000 levels.

senC2rcp26: The same as ref-C2, but with the GHG scenario changed to RCP 2.6 (Meinshausen et al., 2011).

senC2rcp45: The same as ref-C2, but with the GHG scenario changed to RCP 4.5 (Meinshausen et al., 2011).

senC2rcp85: The same as ref-C2, but with the GHG scenario changed to RCP 8.5 (Meinshausen et al., 2011).

senC2SlrTrnd: Reduction of solar activity akin to the Maunder Minimum of the 17th and 18th centuries.