Note: the PMIP variables were originally defined in Newsletter 6. Make sure you read this newsletters to understand all the technical details!
The following variables are functions of longitude, latitude, time (in the case of seasonal and monthly data), and for zg, ta, u, v, hus, hur, stfuv, and potuv they are also a function of pressure level (as indicated in the NOTES column).
| Name | Units | Title | Notes | |
|---|---|---|---|---|
| orog | m | Surface Elevation | ||
| sftland | % | Percentage Land | % of grid cell that is land | 1 |
| seaice | % | Percentage of Area Covered by Sea Ice | % of area of grid cell that is sea-ice covered; i.e., 100 times the product of (fraction of time sea ice is present in cell) and (fraction of cell covered) | 2 |
| snow | % | Percentage of Area Covered by Snow | % of area of grid cell that is snow covered; i.e., 100 times the product of (fraction of time snow is present in cell) and (fraction of cell covered) | 2 |
| sim | kg/(m²) | Sea Ice Mass per Unit Area | ||
| rsdt | W/(m²) | TOA Incident Shortwave Radiation | insolation (+ down) | |
| rsut | W/(m²) | TOA Reflected Shortwave Radiation | + up | |
| rlt | W/(m²) | TOA Outgoing Longwave Radiation | + up | |
| rsds | W/(m²) | Surface Incident Shortwave Radiation | + down | |
| rsus | W/(m²) | Surface Reflected Shortwave Radiation | + up | |
| rls | W/(m²) | Surface Net Longwave Radiation | + down | |
| hfss | W/(m²) | Surface Sensible Heat Flux | + down | |
| hfls | W/(m²) | Surface Latent Heat Flux | + down | |
| mrso | kg/(m²) | Soil Moisture | AMIP units were cm | |
| snm | kg/(m²) | Snow Mass per Unit Area | mass of snow on ground per unit area | |
| mrro | mm/day | Runoff | ||
| pr | mm/day | Total Precipitation | include liquid & solid phase, convective & large scale precip | |
| prc | mm/day | Convective Precipitation | if available; (include both liquid & solid phase precip.) | |
| prsnwe | mm/day | Snowfall (Liquid Water Equivalent) | include both convective & large scale | |
| evs | mm/day | Surface Evaporation | include both evaporation & sublimation | |
| prw | kg/(m²) | Total Precipitable Water | AMIP units were mm | |
| tas | C | Surface Air Temperature | 2-meter screen temp | |
| tg | C | Ground Temperature | skin temperature | |
| pmsl | hPa | Mean Sea Level Pressure | ||
| usfc | m/s | Eastward Surface Wind Speed | at 10 m | |
| vsfc | m/s | Northward Surface Wind Speed | at 10 m | |
| tauu | N/(m²) | Eastward Surface Wind Stress | at surface | |
| tauv | N/(m²) | Northward Surface Wind Stress | at surface | |
| hursfc | % | Surface Relative Humidity | at 2 m | |
| clt | % | Total Cloudiness | % of atmospheric column covered by clouds | |
| clw | g/(m²) | Cloud Water Content | if available | |
| rltcs | W/(m²) | TOA Outgoing Longwave Clear Sky Radiation | Method II; + up | 3 |
| rstcs | W/(m²) | TOA Net Shortwave Clear Sky Radiation | (net=incident-reflected) + down | 3 |
| rlscs | W/(m²) | Surface Net Longwave Clear Sky Radiation | Method II; + down | 3 |
| rsdscs | W/(m²) | Surface Incident Shortwave Clear Sky Radiation | Method II; + down | 3 |
| rsuscs | W/(m²) | Surface Reflected Shortwave Clear Sky Radiation | Method II; + up | 3 |
1 In calculating the "Percentage Land" for a
grid cell, include sea ice as "ocean" and glacial ice as "land". For
models with non-fractional coverage of land or ocean within a grid
cell, the "Percentage Land" should either be 0.0 or 100.0.
2 In calculating "Percentage Sea Ice" for a grid
cell, compute
(100/n) * [sum-over-n f-sub-n]
where n is the time-index and f-sub-n is the fraction of sea ice in
the grid cell at time n. For models that allow a grid cell to be
partially ocean and partially land, the fraction of sea-ice in the
grid cell should be calculated relative to the total area of the cell,
not just the ocean area.
3 Method II for calculating clear-sky fluxes is
the normal procedure used in model-model intercomparisons (see, for
example, Cess, R.D. and G.L. Potter, 1987: Exploratory studies of
cloud radiative forcing with a general circulation model. Tellus,
39A, 460-473) The clear-sky fluxes are computed during each sampling
interval and then time-averaged (without weighting by cloud
fraction).
The following variables are functions of longitude, latitude, pressure level (as indicated in the NOTES column), and time (in the case of seasonal and monthly data).
| Name | Units | Title | Notes |
|---|---|---|---|
| zg | m | Geopotential Height | at 200, 500 and 850 hpa |
| ta | C | Temperature | at 200 and 850 hpa |
| u | m/s | Eastward Wind Speed | at 200 and 850 hpa |
| v | m/s | Northward Wind Speed | at 200 and 850 hpa |
| hus | g/kg | Specific Humidity | at 200 and 850 hpa |
| hur | % | Relative Humidity | at 200 and 850 hpa |
| stfuv | m²/s | Horizontal Wind Velocity Stream Function | at 200 and 850 hpa |
| potuv | m²/s | Horizontal Wind Velocity Potential | at 200 and 850 hpa |
The following variables are functions of latitude, pressure level and time (in the case of seasonal and monthly data). The pressure levels od the cross sections are : 10, 20, 30, 50, 70, 100, 150, 200, 250, 300, 400, 500, 700, 850, 1000 hPa.
| Name | Units | Title | Notes |
|---|---|---|---|
| u | m/s | Eastward Wind Speed | |
| v | m/s | Northward Wind Speed | |
| ta | C | Temperature | |
| hus | g/kg | Specific Humidity | |
| hur | % | Relative Humidity | |
| clt | % | Percent Clouds | % of layer occupied by clouds |
| stfmm | m²/s | Mean Meridional Stream Function |