SWING: Stable water isotope intercomparison group

Experiment S1A

The SWING experiment S1A has been defined as a first climatology control run with prescribed SST from HadISST data set, mean of period 1980-1999, and all other boundary conditions (e.g. CO2) set to 1980's value.

For more detailed information about the different simulation experiments, please contact Martin Werner (Echam4), Gavin Schmidt (GissE) or Jospehine Brown (MUGCM).

The different GCM model grids have been interpolated to a common 2x2 degree grid for comparison reason.

Monthly data

Monthly values of the following GCM model variables are available:

Variable	Dimension	Echam4	GissE	MUGCM
2m temperature	2D	x	x	x
surface pressure	2D	x	x	x
sea level pressure	2D	x	x	x
10m wind speed	2D	x	x	-
precipitation (H216O, H218O, HDO)	2D	x	x	x
surface flux (H216O, H218O, HDO)	2D	x	x	x
temperature	3D	x	x	x
zonal wind	3D	x	x	x
meridional wind	3D	x	x	x
specific humidity (H216O, H218O, HDO)	3D	x	x	x

Download

All available data files are found here.

Important Remarks:

2D variables represent surface values (if not indicated otherwise).
3D Variables are stored on the following pressure levels:
100, 250, 500, 700, 850, and 1000 hPa
To convert values (e.g., PRTH218O) to conventional "delta" notation, use the formulations
```
   deltaD   = ((HDO/H2O)  /(modelStandardRatio) - 1)*1000
   delta18O = ((H218O/H2O)/(modelStandardRatio) - 1)*1000
```
where modelStandardRatio refers to the appropriate value given above for each specific model and isotope species as below. The variables "H2O" are total water (meaning sum of all species).
```
  Echam4:  H218O: 2.0052e-3  /  HDO: 1.5576e-4
  GissE:   H218O: 2.2280e-3  /  HDO: 3.2900e-4
  MUGCM:   H218O: 2.0052e-3  /  HDO: 3.1152e-4
```
(Explanation: While Echam4 and MUGCM are using isotope mole ratios, the GissE Model is using isotope mass ratios. For the HDO in Echam4 results, the values in the model are for D/H rather than HDO/H2O.)