This icon extracts values from complex BUFR messages where coordinate descriptors are required to locate particular data. Briefly, when a BUFR element descriptor described as F'XX'YYY has an F of 0 and an XX of less than 10, it is a 'coordinate descriptor', which means that it retains its current value until redefined. In this way, a set of observations 'inherit' the same value for such a descriptor without it appearing explicitly for each observation. The purpose of this icon is to extract data that can only be described by using coordinate descriptors; for more complete BUFR data extraction, it can be used with BUFR output from the Observation Filter icon. The output is a geopoints file.The macro language equivalent is bufr_picker(derives (and returns) a Thermodynamic diagram data unit. In such diagram, temperature, humidity (represented by the dew point) and wind values are displayed with respect to pressure. There are mainly four different types of thermodynamic diagrams (Tephigram, Skew-T, Emagram and Stuve), but only the Tephigram diagram is currently implemented.
The Thermo data can be plotted (using default plotting specifications) or saved as a NetCDF data file. The input data are observations (upper air BUFR) or model field (GRIB) data.
The macro language equivalents are thermo_bufr() and thermo_grib() (depending on the specified data type). | 
