Modeling

MOZART

MOZART: Model for OZone and Related chemical Tracers

MOZART chemical mechanisms

The MOZART chemical mechanisms used in CAM-chem and WACCM (components of the Community Earth System Model) are developed, maintained and updated at NCAR, with collaborations from the community. A full description of the mechanism and its implementation in CESM2 has been submitted to the CESM2 Special Collection issue of the Journal of Advances in Modeling Earth Systems and is available from the CESM website: Emmons et al., The Chemistry Mechanism in the Community Earth System Model version 2 (CESM2).

The current family of MOZART chemical mechanisms include:

T1: The MOZART tropospheric chemistry mechanism has been updated and expanded significantly from MOZART-4 to include an expansion of the isoprene oxidation scheme, splitting lumped aromatics and terpenes to individual species and updating their oxidation products, and a more detailed representation of organic nitrates. A preliminary version of the T1 mechanism, including a description of the aromatic oxidation, was published in (Knote et al., 2014). Previous MOZART-4 users should note that the new treatment of aromatics replaces the MOZART-4 lumped aromatic (confusingly called 'TOLUENE') with the specific species BENZENE, TOLUENE and XYLENES. The lumped monoterpene is now called MTERP, and a sesquiterpene, BCARY, has been added.

TS1: The T1 tropospheric mechanism, plus halogen compounds and reactions to represent stratospheric chemistry.

TSMLT1: A comprehensive mechanism for use in WACCM, including chemistry for the Troposphere, Stratosphere, Mesosphere and Lower Thermosphere.

The species and reactions included in the T1-TS1-TSMLT1 family of mechanisms are provided in these documents: Species List and Table of Reactions

 

MOZART chemical transport model (CTM)

The MOZART CTM has not been updated since the publication of MOZART-4 in 2010, and therefore is quite out of date. The source code is freely available to the community, however it is no longer being developed or supported. Documentation on Downloading and Running MOZART-4 Source Code

The capabilities of MOZART-4, with numerous improvements, are available in CAM-chem and we recommend that it be used instead of MOZART-4.  CAM-chem is a component of the Community Earth System Model, so can be run as a fully coupled free-running climate model, but can also be run with specified dynamics (nudged to reanalysis meteorology) to produce results similar to the MOZART CTM.

The MOZART-4 chemical mechanism and model description were published in Emmons et al. (2010). The MOZART-4 mechanism contains a detailed description of tropospheric inorganic chemistry and of organic species with 3 carbons or less, and a reasonably thorough treatment of isoprene chemistry. Larger alkanes and alkenes, terpenes, and aromatics are also included in the mechanism, albeit with lumping and simplification.

MOZART-4 output for several years is made available for regional model boundary conditions from the WRF-chem webpage.  These are now superseded by CAM-chem output for Jan 2001-June 2017.  See the CAM-chem wiki page for instructions to access these files.

Several tools are available for processing MOZART-4 or CAM-chem output or inputs.

WACCM chemical forecasts

Chemical Forecasts from WACCM are run each day, providing a 3-day forecast of global tropospheric composition. 

MOZART-4 Chemical Forecasts (no longer being produced)

MOZART-4 chemical forecasts are no longer being created.  You can see images of the historical forecasts at http://www.acom.ucar.edu/acresp/forecast/.

MOZART-4 simulations (up to Jan 26, 2018) are available for downloading, with options for subsetting on the WRF-Chem MOZART download webpage.  

MOZART forecasts have been used as boundary conditions for regional forecasts:

 

Please contact Louisa Emmons if you have further questions.

UCAR/NCAR Share

                  

                  

ACOM | Atmospheric Chemistry Observations & Modeling