¶ Description
DKSS is DMI’s forecast model for storm surge, which includes forecast data for water level, sea temperature, salinity, ocean current, ice thickness and ice concentration. It is forced by DMI’s numerical weather model Harmonie and ECMWF’s global weather model from where it gets the weather forcing (10 meter wind, mean sea level atmospheric pressure, 2 meter temperature, 2 meter specific humidity, total cloud cover).
DKSS is based on DMI’s circulation model HBM (Hiromb-Boos model). HBM calculates forecasts for the physical state of the sea in three dimensions, in a number of fixed depths from surface to bottom. The model also calculates the extent and thickness of potential sea ice. HBM is developed for and especially suited for calculations in fairly shallow water, in this case the northwestern European shelf.
For additional information on DKSS, please see http://ocean.dmi.dk/models/hbm.php.
¶ Number of Runs and Forecast Range
The DKSS model is run 4 times a day (00z, 06z, 12z, and 18z). Each run provides a forecast for the three-dimensional state of the sea.
The forecast range is 5 days and is calculated with Harmonie input data for the first 60 hours and with data from ECMWF for the remaining part.
| DMI-DKSS runs | ||||
| Analysis | 00z | 06z | 12z | 18z |
| Forecast range | 5 days | |||
| Forcing | Harmonie DINI ECMWF |
|||
When is data normally available
¶
Model Areas
DKSS has six geographical areas:
- North Sea-Baltic Sea (dkss_nsbs)
- Inner Danish Waters (dkss_idw)
- Wadden Sea (dkss_ws)
- Limfjord (dkss_lf)
- Little Belt (dkss_lb)
- Roskilde/Isefjord (dkss_if)
| Model | North Sea-Baltic Sea (dkss_nsbs) | Inner Danish Waters (dkss_idw) | Wadden Sea (dkss_ws) | Limfjord (dkss_lf) | Little Belt (dkss_lb) | Roskilde/Isefjord (dkss_if) |
|---|---|---|---|---|---|---|
| Spatial resolution | 3' lat. 5' long. (3 nautical miles) |
30" lat. 50" long. (0.5 nautical miles) |
1' lat. 1'24" long. (1 nautical miles) |
6" lat. 10" long. (0.1 nautical miles) |
10" lat. 10" long. (0.15 nautical miles) |
10" lat. 10" long. (0.15 nautical miles) |
| Vertical layers | 50 | 52 | 24 | 21 | 42 | 10 |
| Maximum thickness of the top layer | 8 m | 2 m | 8 m | 2 m | 2 m | 2 m |
| Time step: Barotropic Baroclinic Ice |
20 sec 90 sec 900 sec |
10 sec 90 sec 900 sec |
20 sec 90 sec 900 sec |
2.5 sec 20 sec 900 sec |
5 sec 20 sec 900 sec |
5 sec 15 sec 900 sec |
| Atm. forcing | Harmonie DINI ECMWF GLM |
Harmonie DINI ECMWF GLM |
Harmonie DINI ECMWF GLM |
Harmonie DINI ECMWF GLM |
Harmonie DINI ECMWF GLM |
Harmonie DINI ECMWF GLM |
| Longitude | 4.1V-30.3E | 9.3E-14.8E | 6.2E-10.5E | 8.2E-10.3E | 9.5E-10.1E | 11.6E-12.1E |
| Latitude | Baltic Sea: 48.5N-65.9N North Sea: 48N-59N |
53.6N-57.6N | 53.2N-55.7N | 56.5N-57.1N | 55.2N-55.7N | 55.6N-56N |
| Open boundaries | 1. Surge contribution from NOAMOD 2. Tidal sea level based on 17 constituents 3. Monthly climatology fields for T and S via a sponge layer |
Nested in regional model | Nested in regional model | Nested in regional and Inner Danish Waters model | Nested in Inner Danish Waters model | Nested in Inner Danish Waters model |
¶
Parameters
The parameters available for DMI's DKSS model are listed below along with a description and the unit of the parameter. The parameters are available in up to 52 vertical layers.
The surface layer of DKSS is 8 meters thick in North Sea-Baltic Sea and Wadden Sea model areas and 2 meters thick in the remaining model areas. Below that the layers are 2 meters thick below the 8 meter surface layer and 1 meter thick below the 2 meter surface layer. Towards the ocean floor, the thickness of the layers increase and the bottom layer does not have a fixed thickness, but extends from the bottom of the second lowest layer to the ocean floor.
Bands 1-9 in below are the same for all models but the following bands differ due to the number of depth layers in the model and the distance between these layers. The surface layer is encoded twice: with depth=0, and with depth=middle-of-top-layer. The reason being that surface data is represented by different depths in different model domains. A parameter with vertical dependency is thereby represented by n+1 records, n being the number of vertical layers.
Current, temperature and salinity may be said to represent the vertical mean value of the layer in question. The encoded depth is the midpoint of the layer.
¶ North Sea Baltic Sea (dkss_nsbs)
| Number | ID | Depth in meters below sea level | Parameter code | Unit | Description |
|---|---|---|---|---|---|
| 1 | 82 | 0 | DSLM | m | Deviation of sea level from mean |
| 2 | 33 | 0 | UGRD | m/s | u-component of wind |
| 3 | 34 | 0 | VGRD | m/s | v-component of wind |
| 4 | 49 | 0 | UOGRD | m/s | u-component of current |
| 5 | 50 | 0 | VOGRD | m/s | v-component of current |
| 6 | 80 | 0 | WTMP | deg. C | Water temperature |
| 7 | 88 | 0 | SALTY | g/kg | Salinity |
| 8 | 92 | 0 | ICETK | m | Ice thickness |
| 9 | 91 | 0 | ICEC | fraction | Ice concentration (ice=1;no ice=0) |
| 10-59 | 49 | 4-525 | UOGRD | m/s | u-component of current |
| 60-109 | 50 | 4-525 | VOGRD | m/s | v-component of current |
| 110-159 | 80 | 4-525 | WTMP | deg. C | Water temperature |
| 160-209 | 88 | 4-525 | SALTY | g/kg | Salinity |
¶
Inner Danish Waters (dkss_idw)
| Number | ID | Depth in meters below sea level | Parameter code | Unit | Description |
|---|---|---|---|---|---|
| 1 | 82 | 0 | DSLM | m | Deviation of sea level from mean |
| 2 | 33 | 0 | UGRD | m/s | u-component of wind |
| 3 | 34 | 0 | VGRD | m/s | v-component of wind |
| 4 | 49 | 0 | UOGRD | m/s | u-component of current |
| 5 | 50 | 0 | VOGRD | m/s | v-component of current |
| 6 | 80 | 0 | WTMP | deg. C | Water temperature |
| 7 | 88 | 0 | SALTY | g/kg | Salinity |
| 8 | 92 | 0 | ICETK | m | Ice thickness |
| 9 | 91 | 0 | ICEC | fraction | Ice concentration (ice=1;no ice=0) |
| 10-61 | 49 | 1-75 | UOGRD | m/s | u-component of current |
| 62-113 | 50 | 1-75 | VOGRD | m/s | v-component of current |
| 114-165 | 80 | 1-75 | WTMP | deg. C | Water temperature |
| 166-217 | 88 | 1-75 | SALTY | g/kg | Salinity |
¶
Wadden Sea (dkss_ws)
| Number | ID | Depth in meters below sea level | Parameter code | Unit | Description |
|---|---|---|---|---|---|
| 1 | 82 | 0 | DSLM | m | Deviation of sea level from mean |
| 2 | 33 | 0 | UGRD | m/s | u-component of wind |
| 3 | 34 | 0 | VGRD | m/s | v-component of wind |
| 4 | 49 | 0 | UOGRD | m/s | u-component of current |
| 5 | 50 | 0 | VOGRD | m/s | v-component of current |
| 6 | 80 | 0 | WTMP | deg. C | Water temperature |
| 7 | 88 | 0 | SALTY | g/kg | Salinity |
| 8 | 92 | 0 | ICETK | m | Ice thickness |
| 9 | 91 | 0 | ICEC | fraction | Ice concentration (ice=1;no ice=0) |
| 10-31 | 49 | 4-49 | UOGRD | m/s | u-component of current |
| 32-53 | 50 | 4-49 | VOGRD | m/s | v-component of current |
| 54-75 | 80 | 4-49 | WTMP | deg. C | Water temperature |
| 76-97 | 88 | 4-49 | SALTY | g/kg | Salinity |
¶
Isefjord (dkss_if)
| Number | ID | Depth in meters below sea level | Parameter code | Unit | Description |
|---|---|---|---|---|---|
| 1 | 82 | 0 | DSLM | m | Deviation of sea level from mean |
| 2 | 33 | 0 | UGRD | m/s | u-component of wind |
| 3 | 34 | 0 | VGRD | m/s | v-component of wind |
| 4 | 49 | 0 | UOGRD | m/s | u-component of current |
| 5 | 50 | 0 | VOGRD | m/s | v-component of current |
| 6 | 80 | 0 | WTMP | deg. C | Water temperature |
| 7 | 88 | 0 | SALTY | g/kg | Salinity |
| 8 | 92 | 0 | ICETK | m | Ice thickness |
| 9 | 91 | 0 | ICEC | fraction | Ice concentration (ice=1;no ice=0) |
| 10-19 | 49 | 1-11 | UOGRD | m/s | u-component of current |
| 20-29 | 50 | 1-11 | VOGRD | m/s | v-component of current |
| 30-39 | 80 | 1-11 | WTMP | deg. C | Water temperature |
| 40-49 | 88 | 1-11 | SALTY | g/kg | Salinity |
¶
Limfjord (dkss_lf)
| Number | ID | Depth in meters below sea level | Parameter code | Unit | Description |
|---|---|---|---|---|---|
| 1 | 82 | 0 | DSLM | m | Deviation of sea level from mean |
| 2 | 33 | 0 | UGRD | m/s | u-component of wind |
| 3 | 34 | 0 | VGRD | m/s | v-component of wind |
| 4 | 49 | 0 | UOGRD | m/s | u-component of current |
| 5 | 50 | 0 | VOGRD | m/s | v-component of current |
| 6 | 80 | 0 | WTMP | deg. C | Water temperature |
| 7 | 88 | 0 | SALTY | g/kg | Salinity |
| 8 | 92 | 0 | ICETK | m | Ice thickness |
| 9 | 91 | 0 | ICEC | fraction | Ice concentration (ice=1;no ice=0) |
| 10-30 | 49 | 1-22 | UOGRD | m/s | u-component of current |
| 31-51 | 50 | 1-22 | VOGRD | m/s | v-component of current |
| 52-72 | 80 | 1-22 | WTMP | deg. C | Water temperature |
| 73-93 | 88 | 1-22 | SALTY | g/kg | Salinity |
¶
Little Belt (dkss_lb)
| Number | ID | Depth in meters below sea level | Parameter code | Unit | Description |
|---|---|---|---|---|---|
| 1 | 82 | 0 | DSLM | m | Deviation of sea level from mean |
| 2 | 33 | 0 | UGRD | m/s | u-component of wind |
| 3 | 34 | 0 | VGRD | m/s | v-component of wind |
| 4 | 49 | 0 | UOGRD | m/s | u-component of current |
| 5 | 50 | 0 | VOGRD | m/s | v-component of current |
| 6 | 80 | 0 | WTMP | deg. C | Water temperature |
| 7 | 88 | 0 | SALTY | g/kg | Salinity |
| 8 | 92 | 0 | ICETK | m | Ice thickness |
| 9 | 91 | 0 | ICEC | fraction | Ice concentration (ice=1;no ice=0) |
| 10-51 | 49 | 1-55 | UOGRD | m/s | u-component of current |
| 52-93 | 50 | 1-55 | VOGRD | m/s | v-component of current |
| 94-135 | 80 | 1-55 | WTMP | deg. C | Water temperature |
| 136-177 | 88 | 1-55 | SALTY | g/kg | Salinity |