Regional So2 Removal Simulations With Hadgem3-Ga4

• Main Authors: Kasoar, Matthew, Shawki, Dilshad, Voulgarakis, Apostolos
• Format: Dataset
• Language: unknown
• Published: Zenodo 2018
• Subjects: Climate; Modelling; Sea ice
• Online Access: https://dx.doi.org/10.5281/zenodo.1300979; https://zenodo.org/record/1300979

This dataset contains time-averaged model output from simulations performed with the UK Met Office HadGEM3-GA4 (UM Version 8.2) climate model, investigating the climate response to regional reductions in anthropogenic sulfur dioxide (SO 2 ) emissions. The model configuration and experimental setup are described in: Kasoar, M., Shawki D. & Voulgarakis, A. (2018), Similar spatial patterns of global climate response to aerosols from different regions, npj Climate and Atmospheric Science , 1(1), doi:10.1038/s41612-018-0022-z . An overview of the experimental setup, experiment identifiers and file naming convention for this dataset, is given below. Simulations were performed as 200-year long coupled atmosphere-ocean simulations. The model was run with repeating year-2000 values for aerosol emissions and greenhouse gas concentrations throughout the simulation. The first 50 years were discarded as spin-up, and 150-year annual and seasonal averages calculated over the remaining simulation period. Data is provided as NetCDF files, containing the 150-year means of all the diagnostics that were output from these model runs. Additionally, 26-year long atmosphere-only simulations with prescribed year-2000 sea surface temperatures (SST) and sea ice concentrations were also performed. For these fixed-SST simulations, the first year was discarded as spin-up and the remaining 25 years averaged over. Six 200-year atmosphere-ocean control simulations were carried out to assess internal variability, with different initial atmospheric states but otherwise identical inputs. Only one 26-year fixed-SST control simulation was performed. For both atmosphere-ocean and fixed-SST setups, a series of perturbation experiments were then carried out in which SO 2 emissions were set up zero over a particular region of the world, while being kept the same as in the control runs elsewhere. Each SO 2 removal experiment was run with one simulation for atmosphere-ocean and fixed-SST setups. File naming convention: [JOBID]_[number of years averaged][season]_avg.nc JOBID is a five-letter run identification number (see below). Number of years averaged over is either 150 (atmosphere-ocean simulations) or 25 (fixed-SST simulations). Season is either 'year' for annual means, or 'djf', 'mam', 'jja', 'son', for December-January-February, March-April-May, June-July-August, or September-October-November seasonal averages, respectively. Experiment identifiers and descriptions are as follows: Atmosphere-ocean simulations: xizko: Base control run (year-2000 aerosol emissions and greenhouse gas concentrations everywhere) xizka: Alternative control simulation with different initial atmospheric state (i.e. perturbed initial conditions). Emissions/GHG concentrations unchanged. xizkp: Alternative control simulation with different initial atmospheric state xkhqb: Alternative control simulation with different initial atmospheric state xkhqc: Alternative control simulation with different initial atmospheric state xkhqd: Alternative control simulation with different initial atmospheric state xizkm: No SO 2 emissions from the northern hemisphere mid-latitudes (30°N-60°N). Outside this region, emissions kept the same as in the control simulations. xizks: No SO 2 emissions from East Asia (105°E-145°E, 20°N-45°N) xizkv: SO 2 emissions removed from North America (235°E-290°E, 30°N-50°N). *For North America, SO 2 emissions were not completely reduced to zero as in the other regions. Instead, emissions were set to zero from the following major emission sectors: energy production, industry, transport, domestic use, and waste. In practice though, this corresponds to a 97% removal of SO 2 emissions over this domain. xizkw: No SO 2 emissions from Europe. For Europe, instead of a latitude-longitude box, the domain was defined following the HTAP Phase II European region definition (described at: http://iek8wikis.iek.fz-juelich.de/HTAPWiki/WP2.1) which follows country borders. xkhqa: No SO 2 emissions from South Asia (70°E-90°E, 10°N-30°N) Fixed-SST simulations: xjnda: Atmosphere-only control run (year-2000 aerosol emissions and greenhouse gas concentrations everywhere, prescribed year-2000 sea surface temperatures and sea-ice concentrations) xjnde: Atmosphere-only; no SO 2 emissions from the northern hemisphere mid-latitudes (30°N-60°N) xjndh: Atmosphere-only; no SO 2 emissions from East Asia (105°E-145°E, 20°N-45°N) xjndp: Atmosphere-only; SO 2 emissions removed from North America (235°E-290°E, 30°N-50°N). *For North America, SO 2 emissions were not completely reduced to zero as in the other regions. Instead, emissions were set to zero from the following major emission sectors: energy production, industry, transport, domestic use, and waste. In practice though, this corresponds to a 97% removal of SO 2 emissions over this domain. xjndq: Atmosphere-only; no SO 2 emissions from Europe. For Europe, instead of a latitude-longitude box, the domain was defined following the HTAP Phase II European region definition (described at: http://iek8wikis.iek.fz-juelich.de/HTAPWiki/WP2.1) which follows country borders. xjndr: Atmosphere-only; no SO 2 emissions from South Asia (70°E-90°E, 10°N-30°N) : Simulations with HadGEM3-GA4 were performed using the MONSooN system, a collaborative facility supplied under the Joint Weather and Climate Research Programme, which is a strategic partnership between the Met Office and the Natural Environment Research Council. The authors were funded by the Natural Environment Research Council under grant NE/K500872/1, and by the Grantham Institute for Climate Change and the Environment.