cloudtopheight_IR

typhon.cloudmask.aster.cloudtopheight_IR(bt, cloudmask, latitude, month, method='modis')[source]

Cloud Top Height (CTH) from 11 micron channel.

Brightness temperatures (bt) are converted to CTHs using the IR window approach: (bt_clear - bt_cloudy) / lapse_rate.

See also

skimage.measure.block_reduce()

Down-sample image by applying function to local blocks.

lapserate_moist_adiabate()

Constant value 6.5 [K/km]

lapserate_modis()

Estimate of the apparent lapse rate in [K/km] depending on month and latitude acc. to Baum et al., 2012.

Parameters:

  • bt (ndarray) – brightness temperatures form 11 micron channel.

  • cloudmask (ndarray) – binary cloud mask.

  • month (int) – month of the year.

  • latitude (ndarray) – latitudes in [°], positive North, negative South.

  • method (str) – approach used to derive CTH: ‘modis’ see Baum et al., 2012, ‘simple’ uses the moist adiabatic lapse rate.

Returns:

cloud top height.

Return type:

ndarray

References

Baum, B.A., W.P. Menzel, R.A. Frey, D.C. Tobin, R.E. Holz, S.A. Ackerman, A.K. Heidinger, and P. Yang, 2012: MODIS Cloud-Top Property Refinements for Collection 6. J. Appl. Meteor. Climatol., 51, 1145–1163, https://doi.org/10.1175/JAMC-D-11-0203.1