EPA Precursor Gas Training Workshop Nealson Watkins & Dennis Mikel EPA - Office of Air Quality,...
Embed Size (px)
Transcript of EPA Precursor Gas Training Workshop Nealson Watkins & Dennis Mikel EPA - Office of Air Quality,...
- Slide 1
- EPA Precursor Gas Training Workshop Nealson Watkins & Dennis Mikel EPA - Office of Air Quality, Planning and Standards Technical Support of NCore Implementation: Meteorological Requirements
- Slide 2
- EPA Precursor Gas Training Workshop Outline Introduction NCore Requirements Sensors (Calibrations and QA issues) Siting Sonic Anemometers Equipment miniaturization Data Handling Issues Data Acquisition Systems Overview of the revision of the QA Handbook, Volume IV: Meteorological Measurements
- Slide 3
- EPA Precursor Gas Training Workshop Currently only required for PAMS sites (~ 92 sites) However, many S/L/Ts measuring even without a requirement Reporting to AQS and/or AIRNow Approximately 31 users submitting to AIRNow-Tech AIRNow-Tech Navigator illustrating PM2.5 and Wind barbs The State of State, Local, and Tribal Meteorological Monitoring
- Slide 4
- EPA Precursor Gas Training Workshop Met Data Reported to AQS* *Sites shown do not necessarily report more than one parameter As of 1/22/07
- Slide 5
- EPA Precursor Gas Training Workshop What is meteorological data supposed to do for us? Used as supportive data at multi-pollutant sites (re: NCore) And who wants all this supportive meteorological data? Modelers Data Analysts Forecasters
- Slide 6
- EPA Precursor Gas Training Workshop What are some known S/L/T issues with reporting meteorological data? Primary Issue: Many State/Local agencies are hesitant to use the meteorological data they collect because of uncertainty in data quality. Several State/Local agencies have trouble accessing meteorological data both from their own agency and from neighboring agencies. Some traditional meteorological monitoring methods (e.g. siting criteria) are not appropriate for air quality applications. Possible Solution: Quality Assurance (QA) requirements at NCore multi-pollutant sites to promote better data quality. Enhance EPAs databases (e.g. AIRNow and AQS) to improve their capability for storing and sharing meteorological data. Create measurement methods specific to meteorological monitoring for air quality management. Specifically, investigate ways to appropriately use met data from a site that may not be perfect.
- Slide 7
- EPA Precursor Gas Training Workshop So why all the attention on meteorological data thats currently NOT required?? NCore
- Slide 8
- EPA Precursor Gas Training Workshop NCore Design Criteria 40 CFR 58 Appendix D.3.b states, The NCore sites must measure, at a minimum, PM2.5, .wind speed, wind direction, relative humidity and ambient temperature. Additional parameters may include: Solar Radiation Precipitation Barometric Pressure Wind data in vector format!
- Slide 9
- EPA Precursor Gas Training Workshop NOAA vs. S/L/T Met Data S/L/Ts provide hourly averaged data NOAA data is a 2 minute average taken 10 to 20 minutes before the top of the hour S/L/T wind data can be vector averaged! NOAA wind data is scalar only Vector data is needed to follow (model) air parcel movements S/L/T met. data will be co-located with air pollution data S/L/T data may represent multiple siting scales Regional, Neighborhood, Middle, & Microscale
- Slide 10
- EPA Precursor Gas Training Workshop Tools of the trade Wind speed Wind direction Ambient Temperature Relative humidity
- Slide 11
- EPA Precursor Gas Training Workshop Additional Instrumentation Barometric Pressure Solar Radiation Precipitation *EPAs reference to certain product types or brand-names does not translate into endorsement.
- Slide 12
- EPA Precursor Gas Training Workshop Siting is very critical, as it directly determines what the data represent The Issue: Siting for air pollution monitoring doesnt always allow for ideal siting for meteorological monitoring The Solution: Focus on NCore sites, and reference the revised QA Handbook for non-NCore sites. Siting Issues
- Slide 13
- EPA Precursor Gas Training Workshop Ideal Siting Criteria Measurement Distance from Obstruction Distance Above Ground Recommended Group Cover Comments Wind Speed/Direction 10x the height of the obstruction 10 metersGrass or gravelThe standard exposure of the wind instruments over level, open terrain is 10 meters above ground 11 Temperature/ Dew Point 1.5x the tower diameter 1.25 to 2 metersNon-irrigated or un-watered short grass, or natural earth The surface should not be concrete or asphalt or oil-soaked. Reflection from these surfaces may affect the performance of the sensor. Vertical Temperature Difference 1.5x the tower diameter 2 meters and 10 meters Non-irrigated or un-watered short grass, or natural earth The surface should not be concrete or asphalt or oil-soaked. Reflection from these surfaces may affect the performance of the sensor. Solar Radiation2 meters2 to 10 metersNo requirementsSensor should be free from obstructions above the plain of the sensor. It should be located so that shadows will not cast on the device. Barometric pressure 1 meter1 to 10 metersNo requirementsThe location should have uniform, constant temperature, shielded from the sun, away from drafts or heaters Precipitation2x to 4x the obstruction height 30 cm, minimumNatural vegetation or gravel Asphalt or concrete should be avoided to avoid splashing the gage. The gage should be high enough to avoid it being covered by snow. Note : More details on siting and exposure are available in the individual sections of the QA Handbook. Please see the installation section of each chapter for more information.
- Slide 14
- EPA Precursor Gas Training Workshop Siting issues with towers Section 2.4 of QA Handbook is updated. Ideally, NCore sites will follow NWS type setup The remaining majority of sites likely will have more relaxed criterion Remember: EPA can only make recommendations!
- Slide 15
- EPA Precursor Gas Training Workshop QA Issues In most instances, Met data are collected for: Forecasting Modeling Data Analysis Public consumption Since Met data is supportive, generally, DQOs dont need to be generated. Without DQOs, how do we get the Measurement Quality Objectives (MQOs)? The answer: QA Handbook has tables of MQOs for programs that recommend or require Met data
- Slide 16
- Suggested NCore Measurement Quality Objectives MeasurementMethod Reporting units Required Operating Range Resolution Minimum Sample Frequency Raw Data Collection Frequency Completeness (Required) Ambient Temperature ThermistorC-30 500.1Hourly1 minute75% Relative HumidityPsychrometer/ Hygrometer %0 1000.5Hourly1 minute75% Wind SpeedCup, prop or sonic anemometer m/s0.5 50.00.1Hourly1 minute75% Wind DirectionVane or sonic anemometer Degrees0 360 (540) 3 1.0Hourly1 minute75% Vector Data Wind Speed Wind Direction DAS Calculations m/s degrees 0 50.0 0 360 0.1 1.0 Hourly1 minute 75% (Optional) Solar RadiationPyranometerWatts/m 2 0 110010Hourly1 minute75% PrecipitationTipping Bucketmm/hr0 25 mm/hr0.2 mmHourly1 minute75% Barometric Pressure Aneroid Barometer mb600 11000.5Hourly1 minute75%
- Slide 17
- Measurement CalibrationAccuracy Type Acceptance Criteria FrequencyType Acceptance Criteria Frequency Ambient Temperature 3 pt. Water Bath with NIST- traceable thermistor or thermometer 0.5 CQuarterly3 pt. Water Bath With NIST- traceable thermistor or Thermometer 0.5 CSemi- Annually Relative HumidityNIST-traceable Psychrometer or standards solution 7% RHQuarterlyNIST-traceable Psychrometer or standards solution 7% RHSemi- Annually Wind SpeedNIST-traceable Synchronous Motor 0.25m/s 5m/s; 5%>2m/s not to exceed 2.5m/s QuarterlyNIST-traceable Synchronous Motor 0.25m/s 5m/s; 5%>2m/s not to exceed 2.5m/s Semi- Annually Wind DirectionSolar Noon, GPS Magnetic Compass 5 degrees; includes orientation error QuarterlySolar Noon, GPS or Magnetic Compass 5 degrees; includes orientation error Semi- Annually Solar RadiationNIST-traceable Pyranometer 5% of mean observed interval QuarterlyNIST-traceable Pyranometer 5% of mean observed interval Semi- Annually Barometric Pressure NIST-traceable Aneroid Barometer 3 mbQuarterlyNIST-traceable Aneroid Barometer 3 mbSemi- Annually PrecipitationSeparatory funnel and graduated cylinder 10% of input volume QuarterlySeparatory funnel and graduated cylinder 10% of input volume Semi- Annually Suggested NCore Calibration/Audit Recommendations
- Slide 18
- EPA Precursor Gas Training Workshop Sonic Anemometers Sonics are a relatively new to our market Use time-of-flight of sonic impulses to determine wind speed and direction Pros: High Sensitivity No moving parts Cons: Harder to QA and calibrate in the field
- Slide 19
- EPA Precursor Gas Training Workshop Sonic Data Issues Electrical hiccups can occur Data interpretation can be slightly different Example1: When winds go to calm conditions, what happens to the wind direction? Do we want to emulate old systems for data continuity purposes? Example2: How much of an issue is eddy turbulence? Either Self produced or from nearby obstacle?
- Slide 20
- EPA Precursor Gas Training Workshop Miniaturization Several vendors now have miniature weather stations available Climatronics & Vaisala OAQPS is obtaining one of each unit for evaluation purposes Vendors claim accuracy and resolution metrics within those in the suggested NCore MQO table Could be an answer for some QA issues associated with sonic and other methods (think co-location)
- Slide 21
- EPA Precursor Gas T