About ARII

ARII is a general air quality site geared primarily towards source attribution by the public, as well as the air quality research community, and is based on a highly accessible Google Maps/Earth platform. ARII integrates available regulatory and field campaign data for Houston.  Among the distinguishing features of ARII is the ability to visualize back trajectories within a Google Earth framework, so that the user can trace the path of pollution to a particular monitoring station from nearby industrial facilities, especially around the time of reported emission events.

Available Data

 

Continuous Ambient Monitoring Stations (CAMS) Data (Jan. 2005 to Jun 2009): TCEQ air quality data. The parameters measured include O3, CO, NO, NO2, NOx, SO2, H2S and PM2.5. Also it contains meteorological parameters such as wind speed, resultant wind speed, resultant wind direction, maxwind gust, standard deviation of the horizontal wind direction, outdoor temperature, relative humidity, solar radiation, barometric pressure and precipitation.

 

Automated Gas Chromatography (AutoGC) Data (Jan. 2005 to Aug 2009): Measurements of 1 to 55 targeted VOCs measured at 10 stations in Houston.

 

Texas Air Quality Field Study II (TexAQS II)-2006 Study:  TexAQS II was started in June 2005 and continued through October 2006 to understand the photochemical and meteorological processes contributing to ozone formation in eastern Texas.

 

Study of Houston Atmospheric Radical Precursors (SHARP) 2009 Study : SHARP-2009 study was a follow up to TexAQS II study to investigate the contribution of direct emissions of radical precursors HCHO and HONO from flares, stacks, and other point and mobile sources, to identify formation pathways of HONO (Night/Day, surface, heterogeneous, homogenous), to study the impact of soot (fresh and coated) on chemistry, radiation (photochemistry/climate), and dynamics, to measure the ambient levels of ClNO2 in Houston and potential as a radical source, to study the relative importance of measured radicals and other "missing" radical sources and to identify important Springtime ozone formation mechanisms in Houston. Please visit the TERC air quality website for further information about the individual projects.

 

Emission Events (2004-2009): It is required by law to report an emission event within 24 hours of its occurrence, which resulted in an unauthorized emission equal to or in excess of the reportable quantity. Reportable quantity for most VOCs is 5000 lbs and that for HRVOCs is 100 lbs.

 

Back Trajectories (2006): Back trajectory data outlines the path of the air mass flow prior to reaching the monitoring site. Back trajectory data was estimated using the University of Houston Trajectory Analysis tool, which is based on the 3D meteorological fields generated by the objective analysis tool in the Fifth Generation Mesoscale Model (MM5) system. Surface and upper air observations are downloaded from the web-site hourly and translated to specific format for performing objective analysis. LITTLE_R in MM5 system is used for objective analysis in order to generate 3D real-time meteorological fields with those observations. The generated wind fields are then used with the Air Resource Laboratory (ARL) Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to produce the backward trajectories.

 

ARII is developed by HARC and supported in part by TERC and USEPA. Please contact project personnel for any questions or comments.

 

Air Exposure Research Online (AERO) sub-portal:  AERO provides access to a subset of the air quality data available through ARII, specifically the datasets associated with the RIOPA and HEATS personal exposure field studies, and supplementary data required for more detailed analysis of those field study datasets. AERO employs a specialized GIS platform, specifically ESRI's ArcGIS Server 10.0, and is geared towards the professional air pollutant exposure and health effects researcher. Click here to access AERO Web portal.

 

Available Data

 

Research data from RIOPA (Relationships of Indoor, Outdoor, and Personal Air, May 1999 - Feb 2001) and HEATS (Houston Exposure to Air Toxics Study Oct. 2007 - Feb. 2009): Personal exposure, outdoor and indoor concentrations of VOCs measured at residences during each visit; Questionnaires, air exchange rate, house volume, and average temperature and humidity inside and outside during the sampling; Information concerning time and location of microenvironment where participants spent time during sampling.

 

Ambient Monitoring Data: VOC, carbonyl and PM2.5 data from TCEQ including 24-hour average concentrations measured every six days; One-hour speciated VOC data including some of the RIOPA and HEATS VOCs, measured by AutoGCs; Hourly wind speed, wind direction and temperature data collected at the TCEQ monitoring sites during the RIOPA and HEATS study periods.

 

NATA 1999 and 2002 data: Annual average ASPEN-modeled ambient concentrations and HAPEM-modeled population exposures at census tract level for Harris County for RIOPA VOC, carbonyl and PM2.5 compounds.

 

Emissions Inventory data from TCEQ: Speciated point source emissions for 18 VOC classes used for Houston SIP modeling (August/September 2000 episode) were obtained from the TCEQ. The inventory covers the emission sources in Harris County and contains 7,608 records.

 

Emissions Inventory data from NEI 1999: Facility-based annual average emission rates of 153 hazardous air pollutants from point and low-level point sources compiled from USEPA's NEI of 1999 and processed by the RIOPA researchers.

 

AERO is developed by Houston Advanced Research Center and supported by the Mickey Leland National Urban Air Toxics Research Center.