calc

Provide tools for unit-aware, meteorological calculations.

Dry Thermodynamics

add_height_to_pressure(pressure, height)	Calculate the pressure at a certain height above another pressure level.
add_pressure_to_height(height, pressure)	Calculate the height at a certain pressure above another height.
density(pressure, temperature, mixing_ratio)	Calculate density.
dry_lapse(pressure, temperature[, …])	Calculate the temperature at a level assuming only dry processes.
dry_static_energy(height, temperature)	Calculate the dry static energy of parcels.
geopotential_to_height(geopotential)	Compute height above sea level from a given geopotential.
height_to_geopotential(height)	Compute geopotential for a given height above sea level.
mean_pressure_weighted(pressure, *args[, …])	Calculate pressure-weighted mean of an arbitrary variable through a layer.
potential_temperature(pressure, temperature)	Calculate the potential temperature.
sigma_to_pressure(sigma, pressure_sfc, …)	Calculate pressure from sigma values.
static_stability(pressure, temperature[, …])	Calculate the static stability within a vertical profile.
temperature_from_potential_temperature(…)	Calculate the temperature from a given potential temperature.
thickness_hydrostatic(pressure, temperature)	Calculate the thickness of a layer via the hypsometric equation.

Moist Thermodynamics

dewpoint(vapor_pressure)	Calculate the ambient dewpoint given the vapor pressure.
dewpoint_from_relative_humidity(temperature, …)	Calculate the ambient dewpoint given air temperature and relative humidity.
dewpoint_from_specific_humidity(pressure, …)	Calculate the dewpoint from specific humidity, temperature, and pressure.
equivalent_potential_temperature(pressure, …)	Calculate equivalent potential temperature.
mixing_ratio(partial_press, total_press[, …])	Calculate the mixing ratio of a gas.
mixing_ratio_from_relative_humidity(…)	Calculate the mixing ratio from relative humidity, temperature, and pressure.
mixing_ratio_from_specific_humidity(…)	Calculate the mixing ratio from specific humidity.
moist_lapse(pressure, temperature[, …])	Calculate the temperature at a level assuming liquid saturation processes.
moist_static_energy(height, temperature, …)	Calculate the moist static energy of parcels.
precipitable_water(pressure, dewpoint, *[, …])	Calculate precipitable water through the depth of a sounding.
psychrometric_vapor_pressure_wet(pressure, …)	Calculate the vapor pressure with wet bulb and dry bulb temperatures.
relative_humidity_from_dewpoint(temperature, …)	Calculate the relative humidity.
relative_humidity_from_mixing_ratio(…)	Calculate the relative humidity from mixing ratio, temperature, and pressure.
relative_humidity_from_specific_humidity(…)	Calculate the relative humidity from specific humidity, temperature, and pressure.
relative_humidity_wet_psychrometric(…)	Calculate the relative humidity with wet bulb and dry bulb temperatures.
saturation_equivalent_potential_temperature(…)	Calculate saturation equivalent potential temperature.
saturation_mixing_ratio(total_press, temperature)	Calculate the saturation mixing ratio of water vapor.
saturation_vapor_pressure(temperature)	Calculate the saturation water vapor (partial) pressure.
specific_humidity_from_dewpoint(pressure, …)	Calculate the specific humidity from the dewpoint temperature and pressure.
specific_humidity_from_mixing_ratio(mixing_ratio)	Calculate the specific humidity from the mixing ratio.
thickness_hydrostatic_from_relative_humidity(…)	Calculate the thickness of a layer given pressure, temperature and relative humidity.
vapor_pressure(pressure, mixing_ratio)	Calculate water vapor (partial) pressure.
vertical_velocity(omega, pressure, temperature)	Calculate w from omega assuming hydrostatic conditions.
vertical_velocity_pressure(w, pressure, …)	Calculate omega from w assuming hydrostatic conditions.
virtual_potential_temperature(pressure, …)	Calculate virtual potential temperature.
virtual_temperature(temperature, mixing_ratio)	Calculate virtual temperature.
wet_bulb_temperature(pressure, temperature, …)	Calculate the wet-bulb temperature using Normand’s rule.

Soundings

bulk_shear(pressure, u, v[, height, bottom, …])	Calculate bulk shear through a layer.
bunkers_storm_motion(pressure, u, v, height)	Calculate the Bunkers right-mover and left-mover storm motions and sfc-6km mean flow.
cape_cin(pressure, temperature, dewpoint, …)	Calculate CAPE and CIN.
critical_angle(pressure, u, v, height, …)	Calculate the critical angle.
el(pressure, temperature, dewpoint[, …])	Calculate the equilibrium level.
lcl(pressure, temperature, dewpoint[, …])	Calculate the lifted condensation level (LCL) using from the starting point.
lfc(pressure, temperature, dewpoint[, …])	Calculate the level of free convection (LFC).
lifted_index(pressure, temperature, …)	Calculate Lifted Index from the pressure temperature and parcel profile.
mixed_layer(pressure, *args[, height, …])	Mix variable(s) over a layer, yielding a mass-weighted average.
mixed_layer_cape_cin(pressure, temperature, …)	Calculate mixed-layer CAPE and CIN.
mixed_parcel(pressure, temperature, dewpoint)	Calculate the properties of a parcel mixed from a layer.
most_unstable_cape_cin(pressure, …)	Calculate most unstable CAPE/CIN.
most_unstable_parcel(pressure, temperature, …)	Determine the most unstable parcel in a layer.
parcel_profile(pressure, temperature, dewpoint)	Calculate the profile a parcel takes through the atmosphere.
parcel_profile_with_lcl(pressure, …)	Calculate the profile a parcel takes through the atmosphere.
parcel_profile_with_lcl_as_dataset(pressure, …)	Calculate the profile a parcel takes through the atmosphere, returning a Dataset.
significant_tornado(sbcape, …)	Calculate the significant tornado parameter (fixed layer).
storm_relative_helicity(height, u, v, depth, *)	Calculate storm relative helicity.
supercell_composite(mucape, …)	Calculate the supercell composite parameter.
surface_based_cape_cin(pressure, …)	Calculate surface-based CAPE and CIN.

Dynamic/Kinematic

absolute_momentum(u, v[, index])	Calculate cross-sectional absolute momentum (also called pseudoangular momentum).
absolute_vorticity(u, v[, dx, dy, latitude, …])	Calculate the absolute vorticity of the horizontal wind.
advection(scalar[, u, v, w, dx, dy, dz, …])	Calculate the advection of a scalar field by the wind.
ageostrophic_wind(height, u, v[, dx, dy, …])	Calculate the ageostrophic wind given from the height or geopotential.
coriolis_parameter(latitude)	Calculate the coriolis parameter at each point.
divergence(u, v, *[, dx, dy, x_dim, y_dim])	Calculate the horizontal divergence of a vector.
exner_function(pressure[, reference_pressure])	Calculate the Exner function.
frontogenesis(potential_temperature, u, v[, …])	Calculate the 2D kinematic frontogenesis of a temperature field.
geostrophic_wind(height[, dx, dy, latitude, …])	Calculate the geostrophic wind given from the height or geopotential.
inertial_advective_wind(u, v, u_geostrophic, …)	Calculate the inertial advective wind.
kinematic_flux(vel, b[, perturbation, axis])	Compute the kinematic flux from two time series.
montgomery_streamfunction(height, temperature)	Compute the Montgomery Streamfunction on isentropic surfaces.
potential_vorticity_baroclinic(…[, dx, …])	Calculate the baroclinic potential vorticity.
potential_vorticity_barotropic(height, u, v)	Calculate the barotropic (Rossby) potential vorticity.
q_vector(u, v, temperature, pressure[, dx, …])	Calculate Q-vector at a given pressure level using the u, v winds and temperature.
shearing_deformation(u, v[, dx, dy, x_dim, …])	Calculate the shearing deformation of the horizontal wind.
stretching_deformation(u, v[, dx, dy, …])	Calculate the stretching deformation of the horizontal wind.
total_deformation(u, v[, dx, dy, x_dim, y_dim])	Calculate the horizontal total deformation of the horizontal wind.
vorticity(u, v, *[, dx, dy, x_dim, y_dim])	Calculate the vertical vorticity of the horizontal wind.
wind_components(speed, wind_direction)	Calculate the U, V wind vector components from the speed and direction.
wind_direction(u, v[, convention])	Compute the wind direction from u and v-components.
wind_speed(u, v)	Compute the wind speed from u and v-components.

Boundary Layer/Turbulence

brunt_vaisala_frequency(height, …[, …])	Calculate the Brunt-Vaisala frequency.
brunt_vaisala_frequency_squared(height, …)	Calculate the square of the Brunt-Vaisala frequency.
brunt_vaisala_period(height, …[, vertical_dim])	Calculate the Brunt-Vaisala period.
friction_velocity(u, w[, v, perturbation, axis])	Compute the friction velocity from the time series of velocity components.
gradient_richardson_number(height, …[, …])	Calculate the gradient (or flux) Richardson number.
tke(u, v, w[, perturbation, axis])	Compute turbulence kinetic energy.

Mathematical Functions

cross_section_components(data_x, data_y[, index])	Obtain the tangential and normal components of a cross-section of a vector field.
first_derivative(f[, axis, x, delta])	Calculate the first derivative of a grid of values.
gradient(f[, axes, coordinates, deltas])	Calculate the gradient of a grid of values.
laplacian(f[, axes, coordinates, deltas])	Calculate the laplacian of a grid of values.
lat_lon_grid_deltas(longitude, latitude[, …])	Calculate the actual delta between grid points that are in latitude/longitude format.
normal_component(data_x, data_y[, index])	Obtain the normal component of a cross-section of a vector field.
second_derivative(f[, axis, x, delta])	Calculate the second derivative of a grid of values.
tangential_component(data_x, data_y[, index])	Obtain the tangential component of a cross-section of a vector field.
unit_vectors_from_cross_section(cross[, index])	Calculate the unit tanget and unit normal vectors from a cross-section.

Apparent Temperature

apparent_temperature(temperature, …[, …])	Calculate the current apparent temperature.
heat_index(temperature, relative_humidity[, …])	Calculate the Heat Index from the current temperature and relative humidity.
windchill(temperature, speed[, …])	Calculate the Wind Chill Temperature Index (WCTI).

Standard Atmosphere

altimeter_to_sea_level_pressure(…)	Convert the altimeter setting to sea-level pressure.
altimeter_to_station_pressure(…)	Convert the altimeter measurement to station pressure.
height_to_pressure_std(height)	Convert height data to pressures using the U.S.
pressure_to_height_std(pressure)	Convert pressure data to height using the U.S.

Smoothing

smooth_gaussian(scalar_grid, n)	Filter with normal distribution of weights.
smooth_window(scalar_grid, window[, passes, …])	Filter with an arbitrary window smoother.
smooth_rectangular(scalar_grid, size[, passes])	Filter with a rectangular window smoother.
smooth_circular(scalar_grid, radius[, passes])	Filter with a circular window smoother.
smooth_n_point(scalar_grid[, n, passes])	Filter with an n-point smoother.

Other

angle_to_direction(input_angle[, full, level])	Convert the meteorological angle to directional text.
azimuth_range_to_lat_lon(azimuths, ranges, …)	Convert azimuth and range locations in a polar coordinate system to lat/lon coordinates.
find_bounding_indices(arr, values, axis[, …])	Find the indices surrounding the values within arr along axis.
find_intersections(x, a, b[, direction, log_x])	Calculate the best estimate of intersection.
get_layer(pressure, *args[, height, bottom, …])	Return an atmospheric layer from upper air data with the requested bottom and depth.
get_layer_heights(height, depth, *args[, …])	Return an atmospheric layer from upper air data with the requested bottom and depth.
get_perturbation(ts[, axis])	Compute the perturbation from the mean of a time series.
isentropic_interpolation(levels, pressure, …)	Interpolate data in isobaric coordinates to isentropic coordinates.
isentropic_interpolation_as_dataset(levels, …)	Interpolate xarray data in isobaric coords to isentropic coords, returning a Dataset.
nearest_intersection_idx(a, b)	Determine the index of the point just before two lines with common x values.
parse_angle(input_dir)	Calculate the meteorological angle from directional text.
reduce_point_density(points, radius[, priority])	Return a mask to reduce the density of points in irregularly-spaced data.
resample_nn_1d(a, centers)	Return one-dimensional nearest-neighbor indexes based on user-specified centers.

Level3File add_height_to_pressure