AWI-ESM-2.1-wiso Holocene transient simulation: seasonal-mean output for MLR analysis of monsoon δ¹⁸O

This is the model output behind the paper on Holocene monsoon precipitation oxygen isotopes that I'm submitting (manuscript reference will be added once the paper is accepted). The data come from an 8300-year transient run of
AWI-ESM-2.1-wiso, the isotope-enabled version of AWI-ESM, performed at AWI Bremerhaven on DKRZ Levante.

The simulation has two parts. The base run goes from about 8200 years before present to the pre-industrial, with time-varying orbital forcing, greenhouse gases and ice sheets — 8199 model years in total. The hosing run is a
100-year freshwater perturbation in the North Atlantic that captures the 8.2 ka cold event, conceptually prepended to the base run to make the full 8.3 ka to 0 ka transient.

Most of the files here are seasonal means on the model's native grid (192 longitudes by 96 latitudes). The "MJJAS" files are the boreal-summer mean (May to September) and feed into the analysis of the three Northern Hemisphere monsoon regions (Indian, East Asian, Central American). The "NDJFM" files are the austral-summer mean (November to March) for the four Southern Hemisphere regions (Indo-Australian, southwest South American, northeast South American, southern African).

Files

Base run seasonal means
    <variable>_<season>.nc
    for example: pr_MJJAS.nc, pw_do18_NDJFM.nc, tsurf_MJJAS.nc

Hosing run seasonal means
    hosing_<variable>_<season>.nc
    for example: hosing_pr_MJJAS.nc

Raw fields used to derive the large-scale climate indices
(AMOC, Niño3.4, SAM, AO, SACZ)
    <INDEX>_<period>.nc
    for example: OLR_monthly_8.2-0.0k.nc, AMOC_8.2-0.0k.nc

Same raw fields for the hosing period
    <INDEX>_8.3-8.2k.nc
    for example: SLP_annual_8.3-8.2k.nc

The land-sea mask
    SLM.nc

Variables:

pr        seasonal-mean precipitation, in kg m-2 s-1
          (multiply by 86400 to get mm/day)

pw_do18   precipitation-weighted δ18O of precipitation, in permille vs VSMOW
          This is the response variable in the MLR analysis.

do18      unweighted δ18O of precipitation, also in permille vs VSMOW

tsurf     surface air temperature, in Kelvin

evap      surface evaporation, in kg m-2 s-1

evap_do18 δ18O of evaporated vapour at the surface, permille vs VSMOW

u_surf    zonal wind at the lowest model level (1000 hPa), m/s
v_surf    meridional wind at the lowest model level, m/s
          These two are used to define moisture-source wind direction.

puq       column-integrated eastward moisture flux, in kg m-1 s-1
pvq       column-integrated northward moisture flux, in kg m-1 s-1
          Both are computed by integrating q*u (or q*v) over the 17 model
          pressure levels from the surface to 100 hPa:
              F = (1/g) * sum_k  q_k * u_k * |dp_k|
          The original 3D q, u, v fields are not archived because they're
          quite large (around 10 GB per season per variable) and the only
          thing the paper uses them for is this single column integral.
          Email me if you actually need the 3D fields.

SLM.nc    land-sea mask on the same Gaussian grid. The variable "SLM" is
          land fraction between 0 and 1; we use SLM > 0.5 to define land
          grid points for the precipitation regions, and SLM < 0.5 for the
          ocean source regions.

The climate-index raw fields (OLR, SLP, SST, AMOC):
    OLR_monthly_8.2-0.0k.nc  ECHAM6 variable 177, top-of-atmosphere thermal
                             radiation in the negative-up convention
                             (more negative means more outgoing longwave,
                             i.e. less deep convection). Monthly resolution.
                             Used for the OLR-based SACZ strength index.
    SLP_annual_8.2-0.0k.nc   sea-level pressure (var151), annual mean.
                             Used to compute SAM (Marshall index) and AO
                             (EOF1 of NH SLP).
    SST_annual_8.2-0.0k.nc   sea-surface temperature, annual mean.
                             Used to compute the Niño3.4 index over the
                             tropical Pacific box.
    AMOC_8.2-0.0k.nc         meridional overturning streamfunction, annual.
                             Used to compute the AMOC index (maximum of the
                             streamfunction near 27°N between 500 and 2000 m).

The same four raw fields for the hosing period are also included as AMOC_8.3-8.2k.nc, SLP_annual_8.3-8.2k.nc and SST_annual_8.3-8.2k.nc. OLR for the hosing period is not separately archived (the model output for that 100-year window was not saved as monthly TOA-thermal-radiation; only the precipitation-side fields were).

License and citation:

The files here are released under Creative Commons Attribution 4.0 International (CC BY 4.0). If you use them, please cite this Zenodo record along with:
    Shi et al. (in revision). Title and full reference to be added once the paper is accepted.
    Shi et al. (2023), Geoscientific Model Development, doi:10.5194/gmd-16-5153-2023, for the AWI-ESM-2.1-wiso model itself.

Contact:

Xiaoxu Shi, shixiaoxu@sml-zhuhai.cn

If something doesn't make sense, or you want the 3D fields, or anything else, just send me an email.