temperature

Functions to make adjustments to temperature maps.

template(ds, var, out_var=None)

Example enhancer function.

Parameters

ds (xr.Dataset) – Input dataset.
var (str) – Variable to adjust.
out_var (str, optional) – variable to store new variable, by default None.

Returns

Output dataset.

Return type

xr.Dataset

kelvin_to_celsius(ds, var, in_var=None, out_var=None)

Convert units of a variable from Kelvin to degrees Celsius.

Parameters

ds (xr.Dataset) – Dataset containing var.
var (str) – Variable name.
in_var (str, optional) – Overwrites var, by default None.
out_var (str, optional) – Instead of overwriting var, store the new data in out_var, by default None.

Returns

Adjusted data.

Return type

xarray.Dataset

celsius_to_kelvin(ds, var, out_var=None)

Convert units of a variable from Kelvin to degrees Celsius.

Parameters

ds (xr.Dataset) – Dataset containing var.
var (str) – Variable name.
out_var (str, optional) – Instead of overwriting var, store the new data in out_var, by default None.

Returns

Adjusted data.

Return type

xarray.Dataset

lapse_rate(ds, var, out_var=None, lapse_var='z', radius=0.25, lapse_rate=-0.006)

Apply a lapse-rate to var inside ds based on the difference between the actual value of lapse_var and its local (defined by radius) mean.

Parameters

ds (xarray.Dataset) – Dataset with the data.
var (str) – Name of the variable inside ds to apply this function to (y).
out_var (str, optional) – Instead of overwriting var, store the new data in out_var, by default None.
lapse_var (str, optional) – The variable used to calculate dx.
radius (float, optional) – The local altitude is compared to the local mean altitude, radius (in degrees) defines over which area to calculate the mean, by default 0.25.
lapse_rate (float, optional) – dy/dx, i.e. how much should var be adjusted per difference in lapse_var, by default -0.006.

Returns

Adjusted data.

Return type

xarray.Dataset

create_circle(pixel_size_x, pixel_size_y, radius, boolean=False)

Create a 2d array with pixel values representing the distance to the center of the array.

Parameters

pixel_size_x (float) – Size of a pixel in the x-direction. Unit can be anything, as long as it is the same as for pixel_size_y and radius.
pixel_size_y (float) – Size of a pixel in the y-direction. Unit can be anything, as long as it is the same as for pixel_size_x and radius.
radius (float) – Size of the circle. Unit can be anything, as long as it is the same as for pixel_size_x and pixel_size_y.
boolean (bool, optional) – Return distances to center (False) or whether or not the distance to the center is smaller than radius (True), by default False.

Returns

Values representing the distance to the center of the array.

Return type

ndarray

local_mean(array, pixel_size, radius, method=3)

Calculate local means.

Parameters

array (ndarray) – Two dimensional array for which local means will be calculated.
pixel_size (tuple) – Size of the pixels in array in x and y direction respectively.
radius (float) – Size of the circle around each pixel from which to calculate the local mean.

Returns

Array with the local mean of each pixel.

Return type

ndarray

bt_to_lst(ds, x, ndvi_s=0.2, ndvi_v=0.5, emis_s=0.97, emis_v=0.985)

Convert brightness temperature to land surface temperature according to Sobrino et al (2008).

Parameters

ds (xr.Dataset) – Input.
x (None) – Not used.
ndvi_s (float, optional) – Threshold value, by default 0.2
ndvi_v (float, optional) – Threshold value, by default 0.5
emis_s (float, optional) – Threshold value, by default 0.97
emis_v (float, optional) – Threshold value, by default 0.985

Returns

Dataset in which bt has been replaced with lst.

Return type

xr.Dataset