Emission Inventory Special Studies

This page last reviewed August 2, 2010

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The California Air Resources Board (ARB) gathers air quality data for the state of California, ensures the quality of this data, distributes data sets to our stakeholders, designs and implements air models, and sets ambient air quality standards for the state. The ARB also performs air quality and emissions inventory special studies.

Below, you will find listed areas of this web site which provide materials regarding special studies performed by the ARB.


Mobile Measurement of Greenhouse Gas Emissions
Field research efforts to verify the California greenhouse gas (GHG) emissions inventory, as instructed by Assembly Bill 32, are currently underway using mobile measurement platforms. Two electric vehicles outfitted with an extensive suite of analytical instrumentation complete data collection experiments using several sampling methodologies to assess the GHG emissions from a variety of source categories. Measurements include GHG mixing ratios (CH4, N2O, CO2 and CO), particulate concentration metrics (PM2.5 mass, PM1.0 number, and Black Carbon), and meteorology metrics (wind speed, wind direction, temperature and relative humidity). Active research collaborations with industry and academia are fostered where available, and collocated data collection events are pursued to enhance the power of each data set and provide intercomparison. These field studies serve to develop and refine measurement protocols to accurately ascertain the GHG source emissions such that the existing emissions inventory values can be validated and uncertainty in future values can be reduced. For more information, please contact Mike FitzGibbon at (916) 323-2389.

Research Division's Pilot Methane Monitoring Network
The objective of this project is to establish a pilot methane (CH4) monitoring network in California. Starting in May 2010, this network will provide high quality measurements of CH4 concentrations at selected monitoring stations. The design of this pilot CH4 monitoring network is to install state-of-the-art analyzers at air quality monitoring stations that will compliment the existing GHG measurement sites in California. When the proposed pilot CH4 stations are operational, it will become a high density CH4 monitoring network in California (Figure 1 - PDF 62KB). Currently, there are six GHG monitoring stations in the state. As shown in Figure 1, there are no measurements in the San Joaquin Valley and the Sacramento Valley where there are many CH4 emission sources such as landfills, natural gas systems, rice paddies, dairies, waste water treatment facilities, and other sources. The current proposed plan is to set up to three stations in the San Joaquin Valley and two stations in the Sacramento Valley at locations where they represent the regional atmospheric compositions. The Research Division’s pilot CH4 monitoring network is the first of its kind deployed at the regional level and with a monitoring network dense enough to identify emission sources and to true-up an already well developed anthropogenic CH4 inventory. If the network is proven successful, over time it will provide data to evaluate the effectiveness of California’s efforts to reduce CH4 emissions. For more information, contact Ying Hsu at (916)323-5774.

SARMAP Study Ozone Study
The development of the SARMAP Air Quality Model has been completed and the model has been applied in central California which includes the San Joaquin Valley and surrounding air basins, to prepare the 1994 State Implementation Plan. The model has been extensively tested and evaluated using the rich database of the San Joaquin Valley Air Quality Study. The model passed the model evaluation criteria of U.S. EPA and the California Air Resources Board. The model has many important attributes which include: map projection capability to account for the curvature of the earth; telescoping grid capability; a coordinate system that matches the coordinate system of MM5 to avoid interpolation between the two models; grid nesting capability (both one-way and two-way nesting is possible); a high resolution verticle grid system (the thickness of the layer near the ground is about 10 m); two chemical mechanisms (Carbon-bond-IV and Statewide Air Pollution Research Center (SAPRC)); a Plume-in-Grid module; and three advection schemes. An aerosol module is being incorporated into the model. For more information, please contact Ajith Kaduwela at (916) 327-3955.

Central California Ozone Study
The Central California Ozone Study is a project proposed to enhance existing tools and information applicable for evaluating the scientific merit of various air quality management activities. It will further the current understanding of how major air pollution sources influence the existing 1-hour and new 8-hour federal air quality standard for ozone. The project will advance model evaluation and the characterization of related uncertainties. The proposed project will also enhance existing tools and information applicable for evaluating the scientific merit of different air quality management activities. The project will provide the information needed for the development of a new State Implementation Plan for ozone by 2003 and particulate matter in central California by 2005 as required by recent federal regulation. For more information, please contact Ajith Kaduwela at (916) 327-3955.

California Regional PM10 / 2.5 Air Quality Study
The California Regional PM10 / 2.5 Air Quality Study is a comprehensive program of monitoring, emissions inventory development, data analysis, and modeling. The study is intended to provide an improved understanding of PM10 and PM2.5, establish a strong scientific foundation for informed decision making, and develop and identify the most efficient and cost-effective emission control strategies to achieve PM10 and PM2.5 standards in Central California. The study is funded and managed through an innovative cooperative partnership between the public and private sector with completion expected in 2003. For more information, please contact Karen Magliano at (916) 322-7137.

1995 Integrated Monitoring Study
The 1995 Integrated Monitoring Study (IMS95) was a preliminary field program designed to collect PM10 and PM2.5 data to more effectively plan the overall California Regional PM10/2.5 Air Quality Study. The IMS95 had three primary components; a two week fall sampling program in November 1995, a four week winter sampling program in December 1995 and early January 1996, and a two-week fog sampling program in January 1996. Data from the study are available at this address. For more information, please contact Karen Magliano at (916) 322-7137.

1999 / 2000 Annual and Episodic Field Programs
The major effort of the California Regional PM10 / 2.5 Air Quality Study will involve annual and episodic field programs designed to collect data to support modeling and data analysis of PM10 and PM2.5 in Central California. The annual field program will commence in December of 1999 and continue through January of 2001. Fall and winter episodic monitoring will take place from September 2000 through January 2001. The field programs will include comprehensive measurements of gaseous and particulate pollutants and meteorology both at the surface and aloft. For more information, please contact Karen Magliano at (916) 322-7137.

Southern California Air Quality Studies
Southern California Ozone Study
In order to develop databases to support detailed photochemical modeling and analysis for a better understanding of the processes involved in the formation of high ozone concentrations in the Southern California region, the ARB and several other groups co-sponsored the 1997 Southern California Ozone Study - North American Research Strategy for Troposheric Ozone (SCOS97-NARSTO).

Research Activities