.. _sphx_glr_auto_examples_satellite:

Satellite Comparison
--------------------

There are currently two satellite processing examples.

* OMI NO2 comparison without updating the model prior, and
* TropOMI NO2 comparison with an updated model prior.

Satellite NO2 use modeled NO2 (eg, GMI or TM5) to quantify the vertical
distribution of NO2, which allows for a quantitative translation from
measurements with differential vertical sensitivity to a best estimate
assuming equal sensitivity. Using your own model as the vertical
distribution ensures an apples to apples comparison.



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    <div class="sphx-glr-thumbnails">

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    <div class="sphx-glr-thumbcontainer" tooltip="This example compares CAMx to the Ozone Monitoring Instrument (OMI) for NO2 tropospheric vertical column densitities (tropNO2). OMI&#x27;s tropNO2 is derived from a measurement along the path light from the sun and reflected off the surface of the earth. The original measurement is called a slant column density (SCD). The SCD is split into tropospheric and stratospheric parts, based on a model profile (a priori). The a priori and slant path are combined with a sensitivity vector (scattering weight) to convert the tropospheric SCD to tropNO2 [molecules/cm2]. CAMx can output mixing ratios at all levels, which can be converted to molecules/cm2 and summed to make a tropNO2 product. Note, however, that the CAMx tropNO2 inherently assumes a different model profile. A more complete comparison would adjust OMI to use CAMx&#x27;s profile, or adjust CAMx to use OMI&#x27;s profile. Each has strengths and weaknesses.">

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  .. image:: /auto_examples/satellite/images/thumb/sphx_glr_run_satellite_01_simpleomi_thumb.png
    :alt:

  :doc:`/auto_examples/satellite/run_satellite_01_simpleomi`

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      <div class="sphx-glr-thumbnail-title">Simple OMI</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="This example pairs CAMx 3D data with TropOMI NO2 columns using the CMAQ Satellite Processors (cmaqsatproc). This includes (1) downloading TropOMI data from NASA&#x27;s Distribution and Active Archive Centers (DAAC), (2) regridding TropOMI to the CAMx grid, (3) subseting CAMx to just overpass times, (4) filtering CAMx to valid retrieval pixels/layers, and (5) applying the CAMx a priori shape to the TropOMI retrieval.">

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  .. image:: /auto_examples/satellite/images/thumb/sphx_glr_run_satellite_02_tropomiak_thumb.png
    :alt:

  :doc:`/auto_examples/satellite/run_satellite_02_tropomiak`

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      <div class="sphx-glr-thumbnail-title">Pair CAMx with TropOMI NO2</div>
    </div>


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    </div>


.. toctree::
   :hidden:

   /auto_examples/satellite/run_satellite_01_simpleomi
   /auto_examples/satellite/run_satellite_02_tropomiak