UKSSDC archive of WACCM-X model data 1950–2024
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Dataset
Files are in netcdf (HDF5) format. They are split into daily output, named
WACCMXhistory.cam.h1.YYYY-MM-DD-00000.nc, where YYYY-MM-DD is replaced with
the date the file corresponds to. These files are split into yearly folders, from 1950 through to 2024
inclusive.
- Latitude span:
- -90 to 90 degrees at 1.9 degree resolution (96 steps)
- Longitude span:
- 0 to 357.5 degrees at 2.5 degree resolution (144 steps)
- Levels:
- 126 levels at quarter scale height resolution from ground-level to ~400–700 km (upper boundary varies in altitude as the atmosphere expands)
- Time:
-
01-01-1950T00:00:00to31-12-2024T23:00:00at hourly resolution - Time format used:
- days (as a float) since the date stored in the time metadata (since the model start, noting the model run was split into 3 so not all start from 1950-01-01).
Data Description
| Short name | Long name | Coordinates | Units |
|---|---|---|---|
| gw | Latitude weights | 1D: lat | – |
| hyam | hybrid A coefficient at layer midpoints | 1D: lev | – |
| hybm | hybrid B coefficient at layer midpoints | 1D: lev | – |
| P0 | reference pressure | None | Pa |
| hyai | hybrid A coefficient at layer interfaces | 1D: ilev | – |
| hybi | hybrid B coefficient at layer interfaces | 1D: ilev | – |
| date | current date (YYYYMMDD) | 1D: time | – |
| datesec | current seconds of current date | 1D: time | – |
| time_bnds | time interval endpoints | 1D: time | – |
| date_written | Date model ran | 1D: time | – |
| time_written | Time model ran | 1D: time | – |
| ndbase | base day | None | – |
| nsbase | seconds of base day | None | – |
| nbdate | base date (YYYYMMDD) | None | – |
| nbsec | seconds of base date | None | – |
| mdt | timestep | None | s |
| ndcur | current day (from base day) | 1D: time | – |
| nscur | current seconds of current day | 1D: time | – |
| co2vmr | co2 volume mixing ratio | 1D: time | ppm |
| ch4vmr | ch4 volume mixing ratio | 1D: time | ppm |
| n2ovmr | n2o volume mixing ratio | 1D: time | ppm |
| f11vmr | f11 volume mixing ratio | 1D: time | ppm |
| f12vmr | f12 volume mixing ratio | 1D: time | ppm |
| sol_tsi | total solar irradiance | 1D: time | Wm-2 |
| f107 | 10.7 cm solar radio flux (F10.7) | 1D: time | sfu |
| f107a | 81-day centered mean of 10.7 cm solar radio flux (F10.7) | 1D: time | sfu |
| f107p | Previous day 10.7 cm solar radio flux (F10.7) | 1D: time | sfu |
| kp | Daily planetary K geomagnetic index | 1D: time | – |
| ap | Daily planetary A geomagnetic index | 1D: time | – |
| colat_crit1 | First co-latitude of electro-potential critical angle | 1D: time | degrees |
| colat_crit2 | Second co-latitude of electro-potential critical angle | 1D: time | degrees |
| nsteph | current timestep | 1D: time | – |
| CO2 | CO2 concentration | 4D (lev) | mol/mol |
| EDens | e Number Density (sum of O2+,NO+,N2+,O+) | 4D (lev) | cm3 |
| H | H concentration | 4D (lev) | mol/mol |
| N | N concentration | 4D (lev) | mol/mol |
| N2_vmr | invariant density | 4D (lev) | mol/mol |
| NO | NO concentration | 4D (lev) | mol/mol |
| O | O concentration | 4D (lev) | mol/mol |
| O2 | O2 concentration | 4D (lev) | mol/mol |
| Op | Op concentration | 4D (lev) | mol/mol |
| PS | Surface pressure | Surface (lat, lon, time) | Pa |
| QJOULE | Joule Heat | 4D (lev) | Ks-1 |
| T | Temperature | 4D (lev) | K |
| TElec | Electron Temperature | 4D (lev) | K |
| TIon | Ion Temperature | 4D (lev) | K |
| U | Zonal wind | 4D (lev) | ms-1 |
| V | Meridional wind | 4D (lev) | ms-1 |
| Z3 | Geopotential Height (above sea level) | 4D (lev) | m |
| He | He concentration (scaled from MSIS) | 4D (lev) | mol/mol |
| DEN | Neutral density from ideal gas law | 4D (lev) | kgm-3 |
Notes
- 4D is lat, lon, time, and either lev or ilev
- 1 sfu is 10-22 W m-2 Hz-1
- mol/mol are volume mixing ratios
- To convert the volume mixing ratios to mass densities, first calculate the total number density, , by where is the Boltzmann constant, and (temperature) and lev (level) are available in the files. Then calculate the total mass density of a constituent, , by where is the Avogadro constant, is the molar mass of the constituent, and is the volume mixing ratio of the constituent from the file (i.e. O for atomic oxygen).
- Helium (He) and neutral density (DEN) were added post-run. This has been done by scaling the helium number density from the empirical, Naval Research Lab Mass Spectrometer and Incoherent Scatter radar (NRLMSISE-00) mode, by the ratio of the sums of O, O2, N2 number densities in WACCM-X to the similar sum in NRLMSISE-00. Neutral mass densities for each constituent were then calculated and summed for DEN.