.. _Section_FileType_subsets_trace:


Tracers Subset
==============

| **DOI:** https://doi.org/10.5439/1905839
| **File type abbreviation:** ``trace``

The tracers subset category contains variables extracted from the raw wrfout files related to the four inert tracers added to WRF for LASSO-CACTI. More information about the tracers is provided in the :ref:`Modeling Methodology Section <SectionModelingMethodology>`.
The data are on the raw model levels listed in :numref:`TableSubsetLevels`.

.. list-table:: Variables in the tracers subset files
    :name: TableSubsetTrace
    :header-rows: 1
    :class: tight-table

    * - Variable Name
      - Description

    * - PTRACER1
      - conserved tracer initialized at model start with height above sea level
    * - PTRACER2
      - conserved tracer initialized at model start with height above ground level
    * - PTRACER3
      - tracer emitted from surface and with a decay rate
    * - PTRACER4
      - conservative tracer initialized at 14 UTC to 1 for lowest 1 km above the surface and 0 above
    * - PTRACER4_ON
      - true/false flag for whether PTRACER4 is switched on