{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Metop-A/B/C GOME-2 AAI product"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"```{hint} \n",
"Execute the notebook on the training platform >>\n",
"```"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"The following example introduces you to the Absorbing Aerosol Index (AAI) Level 3 data product from the GOME-2 instrument onboard the three Metop satellites Metop-A/B/C.\n",
"The Absorbing Aerosol Index (AAI) indicates the presence of elevated absorbing aerosols in the Earth's atmosphere. The aerosol types that are mostly seen in the AAI are `desert dust` and `biomass burning aerosols`. The Absorbing Aerosol Index is derived from reflectances measured by GOME-2 at 340 and 380 nm. The data of the Metop-A/B/C GOME-2 `Absorbing Aerosol Index (AAI)` are provided by KNMI in the framework of the EUMETSAT Satellite Application Facility on Atmospheric Composition Monitoring (AC SAF).\n",
"\n",
"Find more information on the GOME-2 Level 3 AAI data product processed by KNMI here."
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"```{admonition} Basic facts\n",
"**Spatial resolution**: `1° x 1°`, gridded onto a regular lat-lon grid
\n",
"**Spatial coverage**: `Global`
\n",
"**Temporal resolution**: `daily and monthly aggregates`
\n",
"**Data availability**: `Metop-A: since 2007`, `Metop-B: since 2012`, `Metop-C: since 2019`\n",
"```"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"```{admonition} How to access the data\n",
"GOME-2 AAI Level 3 data are available for download via TEMIS, a web-based service for atmospheric satellite data products maintained by KNMI. TEMIS provides daily and monthly aggregated Level 3 (gridded) data products for the three satellites Metop-A, -B, and -C.
\n",
"\n",
"To replicate the example below, you can go to the download page, select under `GOME-2 / MetOp-A AAI daily gridded` the year `2024` and then click on `5 April 2024`. The download of the selected NetCDF file will start.\n",
"```"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"
<xarray.Dataset> Size: 650kB\n", "Dimensions: (longitude: 360, latitude: 180)\n", "Coordinates:\n", " * longitude (longitude) float32 1kB -179.5 -178.5 ... 179.5\n", " * latitude (latitude) float32 720B -89.5 -88.5 ... 88.5 89.5\n", "Data variables:\n", " absorbing_aerosol_index (longitude, latitude) float32 259kB ...\n", " number_of_observations (longitude, latitude) int16 130kB ...\n", " solar_zenith_angle (longitude, latitude) float32 259kB ...\n", "Attributes: (12/32)\n", " Conventions: CF-1.7\n", " title: ESA CCI absorbing aerosol index level 3 product\n", " description: Multi-Sensor AAI field for 05-04-2024\n", " institution: Royal Netherlands Meteorological Institute (K...\n", " project: Climate Change Initiative - European Space Ag...\n", " references: http://www.esa-aerosol-cci.org\n", " ... ...\n", " geospatial_lon_resolution: 1.0\n", " geospatial_lat_units: degrees_north\n", " geospatial_lon_units: degrees_east\n", " comment: Sun glint and solar eclipse events were filte...\n", " license: ESA CCI Data Policy: free and open access\n", " summary: This dataset contains absorbing aerosol index...
<xarray.DataArray 'absorbing_aerosol_index' (longitude: 360, latitude: 180)> Size: 259kB\n", "[64800 values with dtype=float32]\n", "Coordinates:\n", " * longitude (longitude) float32 1kB -179.5 -178.5 -177.5 ... 178.5 179.5\n", " * latitude (latitude) float32 720B -89.5 -88.5 -87.5 ... 87.5 88.5 89.5\n", "Attributes:\n", " long_name: absorbing aerosol index averaged for each grid cell\n", " units: 1
<xarray.DataArray 'absorbing_aerosol_index' (time: 3, longitude: 360,\n", " latitude: 180)> Size: 778kB\n", "dask.array<concatenate, shape=(3, 360, 180), dtype=float32, chunksize=(1, 360, 180), chunktype=numpy.ndarray>\n", "Coordinates:\n", " * longitude (longitude) float32 1kB -179.5 -178.5 -177.5 ... 178.5 179.5\n", " * latitude (latitude) float32 720B -89.5 -88.5 -87.5 ... 87.5 88.5 89.5\n", "Dimensions without coordinates: time\n", "Attributes:\n", " long_name: absorbing aerosol index averaged for each grid cell\n", " units: 1
<xarray.DataArray 'absorbing_aerosol_index' (time: 3, longitude: 360,\n", " latitude: 180)> Size: 778kB\n", "dask.array<concatenate, shape=(3, 360, 180), dtype=float32, chunksize=(1, 360, 180), chunktype=numpy.ndarray>\n", "Coordinates:\n", " * longitude (longitude) float32 1kB -179.5 -178.5 -177.5 ... 178.5 179.5\n", " * latitude (latitude) float32 720B -89.5 -88.5 -87.5 ... 87.5 88.5 89.5\n", "Dimensions without coordinates: time\n", "Attributes:\n", " long_name: absorbing aerosol index averaged for each grid cell\n", " units: 1
<xarray.DataArray 'absorbing_aerosol_index' (satellite: 2, time: 3,\n", " longitude: 360, latitude: 180)> Size: 2MB\n", "dask.array<concatenate, shape=(2, 3, 360, 180), dtype=float32, chunksize=(1, 1, 360, 180), chunktype=numpy.ndarray>\n", "Coordinates:\n", " * longitude (longitude) float32 1kB -179.5 -178.5 -177.5 ... 178.5 179.5\n", " * latitude (latitude) float32 720B -89.5 -88.5 -87.5 ... 87.5 88.5 89.5\n", "Dimensions without coordinates: satellite, time\n", "Attributes:\n", " long_name: absorbing aerosol index averaged for each grid cell\n", " units: 1
<xarray.DataArray 'absorbing_aerosol_index' (satellite: 2, time: 3,\n", " longitude: 360, latitude: 180)> Size: 2MB\n", "dask.array<concatenate, shape=(2, 3, 360, 180), dtype=float32, chunksize=(1, 1, 360, 180), chunktype=numpy.ndarray>\n", "Coordinates:\n", " * longitude (longitude) float32 1kB -179.5 -178.5 -177.5 ... 178.5 179.5\n", " * latitude (latitude) float32 720B -89.5 -88.5 -87.5 ... 87.5 88.5 89.5\n", " * time (time) datetime64[ns] 24B 2024-04-05 2024-04-06 2024-04-07\n", "Dimensions without coordinates: satellite\n", "Attributes:\n", " long_name: absorbing aerosol index averaged for each grid cell\n", " units: 1
<xarray.DataArray 'absorbing_aerosol_index' (time: 3, longitude: 360,\n", " latitude: 180)> Size: 778kB\n", "dask.array<mean_agg-aggregate, shape=(3, 360, 180), dtype=float32, chunksize=(1, 360, 180), chunktype=numpy.ndarray>\n", "Coordinates:\n", " * longitude (longitude) float32 1kB -179.5 -178.5 -177.5 ... 178.5 179.5\n", " * latitude (latitude) float32 720B -89.5 -88.5 -87.5 ... 87.5 88.5 89.5\n", " * time (time) datetime64[ns] 24B 2024-04-05 2024-04-06 2024-04-07