Wind Coloured By Temperature Example

#Metview Macro

#  **************************** LICENSE START ***********************************
# 
#  Copyright 2019 ECMWF. This software is distributed under the terms
#  of the Apache License version 2.0. In applying this license, ECMWF does not
#  waive the privileges and immunities granted to it by virtue of its status as
#  an Intergovernmental Organization or submit itself to any jurisdiction.
# 
#  ***************************** LICENSE END ************************************
# 

# read grib file - contains model level data, one timestep
fs = read("fc_ml.grib")

# define model level to read
level = 96 # around 500 hPa

# read temperature and scale it to C
t = read(data : fs, param : "t", level: level)
t = t - 273.16

# read wind components
u = read(data : fs, param : "u", level: level)
v = read(data : fs, param : "v", level: level)

# define wind plotting - will be coloured by temperature
wp = mwind(
    wind_thinning_factor                  : 1,
    legend                                : "on",
    wind_advanced_method                  : "on",
    wind_advanced_colour_parameter        : "parameter",
    wind_advanced_colour_max_level_colour : "red",
    wind_advanced_colour_min_level_colour : "violet",
    wind_advanced_colour_direction        : "clockwise",
    wind_arrow_unit_velocity              : 35,
    wind_arrow_thickness: 2
    )


# define coastlines
coast = mcoast(
    map_coastline_land_shade : "on",
    map_coastline_land_shade_colour : "RGB(0.8,0.8,0.8)",
    map_coastline_sea_shade : "on",
    map_coastline_sea_shade_colour : "RGB(0.9,0.9,0.9)",
    map_coastline_colour : "RGB(0.2,0.2,0.2)",
    map_coastline_resolution : "medium"
    )
    
# define geo view
view = geoview(
    coastlines: coast,
    map_area_definition : "corners",
    area : [30,-30,75,40]
)

# define the vector structure for plotting - wind will be coloured by t
v = grib_vectors(u_component: u,
                 v_component: v,
                 colouring_field: t)

# define the output plot file
setoutput(pdf_output(output_name : 'wind_coloured_by_t'))

# generate plot
plot(view,v,wp)

#  **************************** LICENSE START ***********************************
# 
#  Copyright 2019 ECMWF. This software is distributed under the terms
#  of the Apache License version 2.0. In applying this license, ECMWF does not
#  waive the privileges and immunities granted to it by virtue of its status as
#  an Intergovernmental Organization or submit itself to any jurisdiction.
# 
#  ***************************** LICENSE END ************************************
# 

import metview as mv

# read grib file - contains model level data, one timestep
fs = mv.read("fc_ml.grib")

# define model level to read
level = 96 # around 500 hPa

# read temperature and scale it to C
t = mv.read(data = fs, param = "t", level = level)
t = t - 273.16

# read wind components
u = mv.read(data = fs, param = "u", level = level)
v = mv.read(data = fs, param = "v", level = level)

# define wind plotting - will be coloured by temperature
wp = mv.mwind(
    wind_thinning_factor                  = 1,
    legend                                = "on",
    wind_advanced_method                  = "on",
    wind_advanced_colour_parameter        = "parameter",
    wind_advanced_colour_max_level_colour = "red",
    wind_advanced_colour_min_level_colour = "violet",
    wind_advanced_colour_direction        = "clockwise",
    wind_arrow_unit_velocity              = 35,
    wind_arrow_thickness                  = 2
    )


# define coastlines
coast = mv.mcoast(
    map_coastline_land_shade = "on",
    map_coastline_land_shade_colour = "RGB(0.8,0.8,0.8)",
    map_coastline_sea_shade = "on",
    map_coastline_sea_shade_colour = "RGB(0.9,0.9,0.9)",
    map_coastline_colour = "RGB(0.2,0.2,0.2)",
    map_coastline_resolution = "medium"
    )
    
# define geo view
view = mv.geoview(
    coastlines = coast,
    map_area_definition = "corners",
    area = [30,-30,75,40]
)

# define the vector structure for plotting - wind will be coloured by t
v = mv.grib_vectors(u_component = u,
                    v_component = v,
                    colouring_field = t)

# define the output plot file
mv.setoutput(mv.pdf_output(output_name = 'wind_coloured_by_t'))

# generate plot
mv.plot(view, v, wp)