# NetCDF synoptic data at multiple locations

### From BAWiki

# Short Description

Synoptic data for multiple locations are described. A few examples for typical variables are shown.

# Additional Descriptions

- NetCDF multiple locations: coordinates as well as coordinate transformation for multiple locations.
- NetCDF time coordinate: coordinate variable
*time*. - NetCDF vertical coordinate: time and space dependent vertical coordinate variable.

# Version *Discrete Sampling Geometry* **timeSeriesProfile**

Data for several individual locations are stored in a netCDF file in accordance with the concept of a *Discrete Sampling Geometry* with **featureType=timeSeriesProfile**. An example (output from NCDUMP) for geometry as well as data is shown in L_synop_ncdump_2D.pdf.

## Data without Z-Dependence

Water level typically depends on time and location. But it is independent from the z-coordinate. Water level is therefore a good example for a geophysical variable without z-dependence.

float **Mesh0_node_Wasserstand_2d**(nMesh0_data_time, nMesh0_node) ;

- :long_name = "Wasserstand [ node ]" ;
- :units = "m" ;
- :name_id = 3 ;
- :_FillValue = 1.e+31f ;
- :ancillary_variables = "Mesh0_node_Gesamtwassertiefe_2d" ;
- :cell_measures = "area: Mesh0_node_Wasserflaeche_2d" ;
- :cell_methods = "nMesh0_data_time: point nMesh0_node: mean" ;
- :comment = "ancillary variables may be used ..." ;
- :coordinates = "Mesh0_node_lon Mesh0_node_lat Mesh0_node_x Mesh0_node_y Mesh0_node_long_name" ;
- :grid_mapping = "Mesh0_crs" ;
- :standard_name = "sea_surface_height" ;

Remarks:

- Invalid data may be present (see
*_FillValue*). - Auxiliary variable (see
*ancillary_variables*)**Mesh0_node_Gesamtwassertiefe_2d**may be used during processing (data analysis and visualization) to neglect data for locations with very shallow water. - Water level is synoptic and (in our case) an area mean value (see
*cell_methods*). - Variable
**Mesh0_node_Wasserflaeche_2d**contains the relevant area for area mean values. - Label coordinate variable
**Mesh0_node_long_name**can be used for selection of locations (see*coordinates*).

## Data with Z-Dependence

Salinity typically depends on time, location and depth. In our case the z-coordinate reflects the center of water mass for the respective volume. Salinity is therefore a good example for a geophysical variable with z-dependence.

float Mesh0_node_Salzgehalt_2d(nMesh0_data_time, nMesh0_layer_2d, nMesh0_node) ;

- :long_name = "Salzgehalt [ node ]" ;
- :units = "1e-3" ;
- :name_id = 5 ;
- :_FillValue = 1.e+31f ;
- :ancillary_variables = "Mesh0_node_Gesamtwassertiefe_2d" ;
- :cell_measures = "volume: Mesh0_node_Wasservolumen_2d area: Mesh0_node_Wasserflaeche_2d" ;
- :cell_methods = "nMesh0_data_time: point nMesh0_layer_2d: mean nMesh0_node: mean" ;
- :comment = "ancillary variables may be used ..." ;
- :coordinates = "Mesh0_node_lon Mesh0_node_lat Mesh0_node_x Mesh0_node_y Mesh0_node_z_node_2d Mesh0_node_long_name" ;
- :grid_mapping = "Mesh0_crs" ;
- :standard_name = "sea_water_salinity" ;

Remarks:

- Invalid data may be present (see
*_FillValue*). - Auxiliary variable (see
*ancillary_variables*)**Mesh0_node_Gesamtwassertiefe_2d**may be used during processing (data analysis and visualization) to neglect data for locations with very shallow water. - Salinity is synoptic and (in our case) an volume mean value (see
*cell_methods*). - Variable
**Mesh0_node_Wasservolumen_2d**contains the relevant volume for volume mean values. - With additional help of
**Mesh0_node_Wasserflaeche_2d**exact values for salt mass per area can be derived. - Label coordinate variable
**Mesh0_node_long_name**can be used for selection of locations (see*coordinates*).

## Data for several Fractions

Suspended sediment concentration typically depends on time, location and depth. Also different sediment fractions *nMesh0_suspension_classes* can be available. In our case the z-coordinate reflects the center of water mass for the respective volume. Suspended sediment concentration is therefore a good example for a geophysical variable with dependence on a label coordinate variable for one or more fractions.

float Mesh0_node_Schwebstoffgehalt_2d(nMesh0_data_time, nMesh0_suspension_classes, nMesh0_layer_2d, nMesh0_node) ;

- :long_name = "Schwebstoffgehalt [ node ]" ;
- :units = "kg m-3" ;
- :name_id = 7 ;
- :_FillValue = 1.e+31f ;
- :ancillary_variables = "Mesh0_node_Gesamtwassertiefe_2d" ;
- :cell_measures = "volume: Mesh0_node_Wasservolumen_2d area: Mesh0_node_Wasserflaeche_2d" ;
- :cell_methods = "nMesh0_data_time: point nMesh0_suspension_classes: point nMesh0_layer_2d: mean nMesh0_node: mean" ;
- :comment = "ancillary variables may be used ..." ;
- :coordinates = "Mesh0_node_lon Mesh0_node_lat Mesh0_node_x Mesh0_node_y Mesh0_node_z_node_2d Mesh0_node_long_name Mesh0_Schwebstoffklassen_2d" ;
- :grid_mapping = "Mesh0_crs" ;
- :standard_name = "concentration_of_suspended_matter_in_sea_water" ;

Remarks:

- Invalid data may be present (see
*_FillValue*). - Auxiliary variable (see
*ancillary_variables*)**Mesh0_node_Gesamtwassertiefe_2d**may be used during processing (data analysis and visualization) to neglect data for locations with very shallow water. - Suspended sediment concentration is synoptic and (in our case) an volume mean value (see
*cell_methods*). - Variable
**Mesh0_node_Wasservolumen_2d**contains the relevant volume for volume mean values. - With additional help of
**Mesh0_node_Wasserflaeche_2d**exact values for suspended sediment mass per area can be derived. - Label coordinate variable
**Mesh0_node_long_name**can be used for selection of locations (see*coordinates*). - Label coordinate variable
**Mesh0_Schwebstoffklassen_2d**can be used for selection of fractions (see*coordinates*).

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