This page last reviewed August 10, 2009

Gridded Shipping Emissions for the August 3-7, 1997 SCOS Ozone Episode

The shipping emission files include hourly emissions of CO, NOx, TOG, and PM for ships using the LA/Long Beach Harbor. There are two types of files. The first type contains the gridded emissions and has suffix .meds, the second type contains the stack parameters and has suffix .stack. Emission estimates include the entire shipping channels contained within the SCOS modeling region as well as port activity. The emissions are based on actual ship activity records supplied to the ARB by the Marine Exchange. All emissions are hourly and gridded for the SCOS97 modeling grid:
  • Origin: 150.000 km E-W, 3580 km N-S
  • UTM Zone: 11
  • 100 grid cells E-W & 74 grid cells N-S @ 5 km by 5 km

There are both emission and stack record files both in MEDS-2 format. The Word document meds04.doc contains a description of these formats as well as for all related files needed for processing these shipping emissions. Some past photochemical modeling studies have treated ships as surface emissions sources. These files allow ships to be treated as "moving" elevated point sources. However, the way these files are combined into an elevated emissions file will vary with the air quality model used. For instance, with the UAM Airshed model a point source may have to be logically defined for each grid cell a ship moves through during a simulation.

The document incorporating the details of the emission calculations, as of November 2000, has been prepared as part of an evaluation of potential marine vessel control strategies, and is available as M13_final_report-nov2000.pdf (803 KB). If you wish to print this document, it should be printed at 300 dpi.

Questions regarding day-specific ship activity should be directed to Mena Shah at (916) 324-7165 or For information on the above document contact Peggy Taricco at (916) 323-4882 or If you have any questions regarding these emission files please contact Paul Allen at (916) 324-6915 or