Compare ERA5 SEVIRI Synsat with Meteosat SEVIRI Observation

Here, we will have a look into the Synsat example data created with notebook 02-Run-Synsat-on-ERA5-Data-for-SEVIRI.ipynb.

Libraries

Setup Env and Load Libraries

import os, sys
os.environ['RTTOV_PYTHON_WRAPPER'] = '/work/bb1262/tools/rttov/rttov-v13.2/wrapper'

import synsatipy

import synsatipy.utils.colormaps as colormaps
import synsatipy.utils.timetools as timetools

Import Standard Libraries

import xarray as xr
import numpy as np

import pylab as plt
import cartopy.crs as ccrs

Data Input

Input Meteosat Data

obsfile = '/work/bb1174/data/meteosat-seviri-subregions/medi/msevi-medi-20200915_2300.nc'

msg = xr.open_dataset( obsfile )

t = timetools.convert_timevec( msg.time.data )

msg['time'] = t

/work/bb1262/tools/conda/python3.10_synsatipy/lib/python3.10/site-packages/xarray/namedarray/core.py:496: UserWarning: Duplicate dimension names present: dimensions {'ndim'} appear more than once in dims=('ndim', 'ndim'). We do not yet support duplicate dimension names, but we do allow initial construction of the object. We recommend you rename the dims immediately to become distinct, as most xarray functionality is likely to fail silently if you do not. To rename the dimensions you will need to set the ``.dims`` attribute of each variable, ``e.g. var.dims=('x0', 'x1')``.
  warnings.warn(

Input ERA5 Synsat Data

synsatfile = './Data/seviri_synsat_era5_example_data.nc'

if not os.path.isfile( synsatfile ):
    raise SystemExit('Synsatfile not found')

else:
     era_synsat = xr.open_dataset( synsatfile )

Plotting

pkws = dict(
    subplot_kws=dict(
        projection=ccrs.Geostationary(0), facecolor="lightgray",
    ),
   # figsize=(18, 6),
    transform=ccrs.PlateCarree(),
)

def map_plotter(v, **spkws):

    map = v.plot(**spkws)

    map.axes.coastlines(color = 'white')
    map.axes.set_extent([-5, 35, 28, 48], crs=ccrs.PlateCarree())


    fig = plt.gcf()
    fig.set_size_inches(18, 5)

Window Channel

spkws = dict(
    x="lon",
    y="lat",
    cmap=colormaps.enhanced_colormap(),
    vmin=200,
    vmax=300,
    **pkws )

map_plotter( msg['bt108'], **spkws )
plt.figure()
map_plotter( era_synsat['bt108'], **spkws )

Water Vapor Channels

spkws = dict(
    x="lon",
    y="lat",
    cmap=colormaps.enhanced_wv62_cmap(),
    vmin=200,
    vmax=260,
    **pkws )

map_plotter( msg['bt062'], **spkws )
plt.figure()
map_plotter( era_synsat['bt062'], **spkws )

spkws = dict(
    x="lon",
    y="lat",
    cmap=colormaps.enhanced_wv62_cmap(vmed2 = 255, vmax = 280),
    vmin=200,
    vmax=280,
    **pkws )

map_plotter( msg['bt073'], **spkws )
plt.figure()
map_plotter( era_synsat['bt073'], **spkws )

BT Differences

for d in [msg, era_synsat]:
    d['BTD_108_120']  = d['bt108'] - d['bt120']
    d['BTD_087_120']  = d['bt087'] - d['bt120']
    d['BTD_087_108']  = d['bt087'] - d['bt108']

/work/bb1262/tools/conda/python3.10_synsatipy/lib/python3.10/site-packages/xarray/namedarray/core.py:496: UserWarning: Duplicate dimension names present: dimensions {'ndim'} appear more than once in dims=('ndim', 'ndim'). We do not yet support duplicate dimension names, but we do allow initial construction of the object. We recommend you rename the dims immediately to become distinct, as most xarray functionality is likely to fail silently if you do not. To rename the dimensions you will need to set the ``.dims`` attribute of each variable, ``e.g. var.dims=('x0', 'x1')``.
  warnings.warn(
/work/bb1262/tools/conda/python3.10_synsatipy/lib/python3.10/site-packages/xarray/namedarray/core.py:496: UserWarning: Duplicate dimension names present: dimensions {'ndim'} appear more than once in dims=('ndim', 'ndim'). We do not yet support duplicate dimension names, but we do allow initial construction of the object. We recommend you rename the dims immediately to become distinct, as most xarray functionality is likely to fail silently if you do not. To rename the dimensions you will need to set the ``.dims`` attribute of each variable, ``e.g. var.dims=('x0', 'x1')``.
  warnings.warn(
/work/bb1262/tools/conda/python3.10_synsatipy/lib/python3.10/site-packages/xarray/namedarray/core.py:496: UserWarning: Duplicate dimension names present: dimensions {'ndim'} appear more than once in dims=('ndim', 'ndim'). We do not yet support duplicate dimension names, but we do allow initial construction of the object. We recommend you rename the dims immediately to become distinct, as most xarray functionality is likely to fail silently if you do not. To rename the dimensions you will need to set the ``.dims`` attribute of each variable, ``e.g. var.dims=('x0', 'x1')``.
  warnings.warn(

spkws = dict(
    x="lon",
    y="lat",
    cmap=plt.cm.RdYlBu_r,
    vmin=-5,
    vmax=5,
    **pkws )

map_plotter( msg['BTD_108_120'], **spkws )
plt.figure()
map_plotter( era_synsat['BTD_108_120'], **spkws )

spkws = dict(
    x="lon",
    y="lat",
    cmap=plt.cm.RdYlBu_r,
    vmin=-5,
    vmax=5,
    **pkws )

map_plotter( msg['BTD_087_108'], **spkws )
plt.figure()
map_plotter( era_synsat['BTD_087_108'], **spkws )

spkws = dict(
    x="lon",
    y="lat",
    cmap=plt.cm.RdYlBu_r,
    vmin=-5,
    vmax=5,
    **pkws )

map_plotter( msg['BTD_087_120'], **spkws )
plt.figure()
map_plotter( era_synsat['BTD_087_120'], **spkws )