This icon derives (and returns) a Thermodynamic diagram data unit. In such a diagram, temperature, humidity (represented by the dew point) and wind values are displayed with respect to pressure.
The Thermo Data icon can be plotted (using a default visualisation and with the plot area based on the range of data values) or saved as a NetCDF data file. The input data types are observation (upper air BUFR) or model field (GRIB) data.
If access to the output computed values is not required, or for more control of the plotting, use the icon Thermo View.
The macro language equivalents are thermo_bufr() and thermo_grib() (depending on the specified data type).
The Thermo Data Editor
The Thermo Data editor belongs to a type of editor known as family editor, which allows related sets of input specifications to be grouped in the same icon editor, each in its own tabbed pane. The available input panes are:
Bufr Thermo - provides input for thermodynamic diagrams based on observation (BUFR) data.
Grib Thermo - provides input for thermodynamic diagrams based on model field (GRIB) data.
To operate with this icon first select one of the above options by clicking the appropriate menu option from the Data_Type parameter.
Data (Bufr Thermo)
Specifies the data to be used in the plotting of a thermodynamic diagram from observations data. The icon field assist button provides a tailor made MARS request to help with the data specification. The data should be upper air sounding data (VSNS - Vertical Sounding Non-Satellite ). Please note that PILOT observations (winds only) do not have enough data for plotting a thermodynamic diagram.
Data (Grib Thermo)
Specifies the data to be used in the plotting of a thermodynamic diagram from model field data. The icon field assist button provides a tailor made MARS request to help with the data specification. The data should include gridded model fields of Temperature and Specific Humidity. These parameters must have the same number of levels and they will be used to compute the Dew Point parameter. Fieldsets U and V wind components are optional, but if given they will be used to compute the wind vectors data unit. These two components must have the same number of levels, but not necessarily have the same number of levels of Temperature and Specific Humidity. If the data is given in model levels then a Logarithm of Surface Pressure field must be provided too. The data can be provided as a single GRIB file or as multiple GRIB files.
Point Selection
Specifies how the geographical location, for which the diagram is to be plotted, will be selected. Options are: Coordinates, Area Average and Station.
Coordinates
Specifies the geographical location for which the diagram is to be plotted. Enter the coordinates (lat/long) of a point separated by a "/" (lat/long). Alternatively, use the coordinate assist button.
Area Average
Specifies a geographical area over which an area average value will be used, instead of a point value, to produce the diagram. Enter the coordinates (lat/long) of an area separated by a "/" (top left lat and long, bottom right lat and long). Alternatively, use the coordinate assist button.
Station
Specifies the location for which the diagram is to be plotted. In the Bufr Thermo dialogue, this must define a meteorological station that provides full upper air soundings. In the Grib Thermo dialogue, this may represent any arbitrary geographical point.
Point Extraction
Specifies the way to calculate values at the point location for GRIB thermodynamic diagrams. Options are:
Interpolate - interpolate values from the surrounding grid points (default)
Nearest Gridpoint - using the data of the nearest grid point
Dew Point Formulation
Specifies the equation to compute the Dew Point parameter. Options are: Saturation Over Water and Mixed Phase 0 to -23.
Temperature Param
Specifies the parameter number of the temperature, if the data is a non-ECMWF. ECMWF uses specific parameter numbers different from the WMO ones.
Specific Humidity Param
Specifies the parameter number of the specific humidity, if the data is a non-ECMWF. ECMWF uses specific parameter numbers different from the WMO ones.
Lnsp Param
Specifies the parameter number of the Lnsp, if the data is a non-ECMWF. ECMWF uses specific parameter numbers different from the WMO ones.
U Wind Param
Specifies the parameter number of the U wind component, if the data is a non-ECMWF. ECMWF uses specific parameter numbers different from the WMO ones.
V Wind Param
Specifies the parameter number of the V wind component, if the data is a non-ECMWF. ECMWF uses specific parameter numbers different from the WMO ones.