# Presentation: 579670

## Nealson Watkins & Dennis Mikel EPA - Office of Air Quality, Planning and Standards

- Nealson Watkins & Dennis Mikel EPA - Office of Air Quality, Planning and Standards

- Technical Support of NCore Implementation:
- _Meteorological Requirements_

## 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

## 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

- 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*

## Met Data Reported to AQS*

***Sites shown do not necessarily report more than one parameter**

- As of
- 1/22/07

## 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

- Used as supportive data at multi-pollutant sites (re: NCore)
- And who wants all this supportive meteorological data?
- Modelers
- Data Analysts
- Forecasters

## 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 EPA’s 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.”

## So why all the attention on meteorological data that’s currently NOT required??

- NCore

## 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!

## 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

## Tools of the trade...

- Wind speed
- Wind direction
- Ambient Temperature
- Relative humidity

## Additional Instrumentation

- Barometric Pressure
- Solar Radiation
- Precipitation
- *EPA’s reference to certain product types or brand-names
- does not translate into endorsement.

## Siting is very critical, as it directly determines what the data represent
The Issue:
	Siting for air pollution monitoring doesn’t always allow for ideal siting for meteorological monitoring
The Solution:
	Focus on NCore sites, and reference the revised QA Handbook for non-NCore sites.

- _The Issue_:
- 	Siting for air pollution monitoring doesn’t 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

## Ideal Siting Criteria

| Measurement | Distance from Obstruction | Distance Above Ground | Recommended Group Cover | Comments |
| --- | --- | --- | --- | --- |
| Wind Speed/Direction  | 10x the height of the obstruction | 10 meters | Grass or gravel | The standard exposure of the wind instruments over
level, open terrain is 10 meters above ground11 |
| Temperature/ Dew Point  | 1.5x  the tower diameter | 1.25 to 2 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.  |
| 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 Radiation  | 2 meters | 2 to 10 meters | No requirements | Sensor 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 meter | 1 to 10 meters | No requirements | The location should have uniform, constant temperature, shielded from the sun, away from drafts or heaters |
| Precipitation  | 2x to 4x the obstruction height  | 30 cm, minimum | Natural 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.

## 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!*

## QA Issues

- In most instances, Met data are collected for:
- Forecasting
- Modeling
- Data Analysis
- Public consumption
- Since Met data is supportive, generally, DQOs don’t 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* *

##  Suggested NCore Measurement Quality Objectives

| Measurement | Method | Reporting 
units | Required
Operating
Range | Resolution | Minimum
Sample
 Frequency | Raw Data
Collection
Frequency | Completeness |
| --- | --- | --- | --- | --- | --- | --- | --- |
| (Required) |  |  |  |  |  |  |  |
| Ambient Temperature | Thermistor | oC | -30 – 50 | 0.1 | Hourly | 1 minute | 75% |
| Relative Humidity | Psychrometer/Hygrometer | % | 0 – 100 | 0.5 | Hourly | 1 minute | 75% |
| Wind Speed | Cup, prop or sonic anemometer | m/s | 0.5 – 50.0  | 0.1 | Hourly | 1 minute | 75% |
| Wind Direction | Vane or sonic anemometer | Degrees | 0 – 360 (540)3 | 1.0 | Hourly | 1 minute | 75% |
| Vector Data
Wind Speed
	Wind Direction | DAS Calculations | m/s
degrees | 0 – 50.0
0 – 360  | 0.1
1.0 | Hourly | 1 minute
1 minute | 75% |
| (Optional) |  |  |  |  |  |  |  |
| Solar Radiation | Pyranometer | Watts/m2 | 0 – 1100 | 10 | Hourly | 1 minute | 75% |
| Precipitation | Tipping Bucket | mm/hr | 0 – 25 mm/hr | 0.2 mm | Hourly | 1 minute | 75% |
| Barometric Pressure | Aneroid Barometer | mb | 600 – 1100 | 0.5 | Hourly | 1 minute | 75% |

## Suggested NCore Calibration/Audit Recommendations

| Measurement | Calibration |  |  | Accuracy |  |  |
| --- | --- | --- | --- | --- | --- | --- |
|  | Type | Acceptance Criteria | Frequency | Type | Acceptance Criteria | Frequency |
| Ambient Temperature | 3 pt. Water Bath with NIST-traceable thermistor or thermometer | ±0.5 oC | Quarterly | 3 pt. Water Bath With NIST-traceable thermistor or Thermometer | ±0.5 oC  | Semi-Annually |
| Relative Humidity | NIST-traceable Psychrometer or standards solution  |  ±7% RH | Quarterly | NIST-traceable Psychrometer or standards solution | ±7% RH | Semi-Annually |
| Wind Speed | NIST-traceable Synchronous Motor | ±0.25m/s ≤5m/s; 5%>2m/s not to exceed 2.5m/s | Quarterly | NIST-traceable Synchronous Motor | 0.25m/s ≤5m/s; 5%>2m/s not to exceed 2.5m/s  | Semi-Annually |
| Wind Direction | Solar Noon, GPS Magnetic Compass | ±5 degrees; includes orientation error | Quarterly | Solar Noon, GPS or Magnetic Compass | ±5 degrees; includes orientation error | Semi-Annually |
| Solar Radiation | NIST-traceable Pyranometer | ±5% of mean observed interval | Quarterly | NIST-traceable Pyranometer | ±5% of mean  observed interval | Semi-Annually |
| Barometric Pressure | NIST-traceable Aneroid Barometer  | ±3 mb | Quarterly | NIST-traceable Aneroid Barometer  | ±3 mb | Semi-Annually |
| Precipitation | Separatory funnel and graduated cylinder   | ±10% of input volume | Quarterly | Separatory funnel and graduated cylinder   | ±10% of input volume  | Semi-Annually |

*Suggested* NCore Calibration/Audit Recommendations

## 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

## 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?

## 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)

## Miniature Met Stations

- Climatronics
- Includes:
- WS, WD, T, RH and
- self-orients to North

- Vaisala
- Includes:
- WS,WD, T, RH and precipitation

## Wind DataScalar Data vs. Vector Data

- Overall difference is more apparent at lower wind speeds
- Scalar: using arithmetic average
- Vector: either directly obtain or derive orthogonal components from scalar values
- In the case of wind speed, vector-averaged speeds are never larger than the scalar-averaged values and generally are lower
- Example: 10 minute total average
- North wind at 5 m/s for 5 minutes
- South wind at 5 m/s for 5 minutes
- Scalar average: 5 m/s & Easterly (90°) heading
- Vector average: 0 m/s & No net movement

## Data Handling

## Data Handling

- Once we’re sited and running, it’s time to review and move the data
- Many sensors providing analog data  to a translator (esp. wind data)
- Translators typically can output                digitally or analog
- Vector averaging requires    conversion from scalar  (by translator or data acquisition system)

## Slide 25

## Organize & move that data...

- The goal: *Timely reporting of high quality, highly time-resolved ambient monitoring data.*
- Data acquisition system is key
- Digital or analog (we like digital!             )
- Disseminate locally and/or nationally
- Move it where?
- AQS
- Local users (AQ forecasters, etc.)
- AIRNow-Tech

## AIRNow

- Public medium
- Focused on  the Air Quality Index (AQI)
- Current pollutant data (maps & data)
- Forecast products

## AIRNow-Tech

- _NOT_ public
- Controlled access; users only
- Data access
- Reporting status
- Tables
- “Navigator” GUI

## AIRNow-Tech Evolution

- Launched mid-2003
- Allowed access to all the hourly pollutant data
- Two subsequent upgrade versions (2005 & 2006)
- 2005 and 2006 improvements
- New OBS data file formatting
- Temporary site accommodations
- Improved data display graphics
- Interactive GIS based “Navigator” interface
- Increased acceptable data parameters

## Increased Reportable Parameters

- Current
- Parameters

- Precursor Gas
- Parameters

- Speciation
- Parameters

- Meteorological
- Parameters

- Required naming
- convention

**Precipitation**

**Precip**

**Millimeters**

## AIRNow-Tech Navigator

## HYSPLIT Trajectories in Navigator

## Overview of the Red Book

- There was a strong need to update the older QA Handbook Volume IV
- Newer technologies
- Digital Data Acquisition
- New 40 CFR 58 Requirements (i.e., NCore)
- 1st Draft revision comments are due back to OAQPS on 2/28/07 for review and incorporation
- First pass revision and review included S/L/T operators, NOAA staff, and private/contract industry staff
- 2nd Draft will be more openly available for review
- Air Mon Listserv shall be used to distribute

## What’s New: Towers

- Types of Towers Available

- Installations of Towers

- Tower Support

## What’s New:    Wind Systems

- Section 2 discusses Propeller and Vane Systems

- Section 2 discusses Cup and Vane Systems

- Calibrations, torque test and distance constants

**Notes:**
Another Ncore Level 2 correction needed

## What New:  Wind Systems

**There is a great discussion on Magnetic Declination for wind direction traceability**

**Detailed discussion on Solar Noon method for wind direction traceability**

## What’s New: Wind Systems

**Section 2 has in-depth discussion of sonic anemometers**

**The Handbook illustrates some side by side comparisons of prop vs. sonic **

**Notes:**
Another Ncore Level 2 correction needed

## What’s New:  Data Validation

- In-depth discussion of data validation
- Section discusses validation and verification
- Discusses how to “link” met data to pollution data
- Each “type of review” has a section number

## Other topics included in the Handbook:

** ****Multiple tables of MQOs**
**Illustrate differences between applications (PSD, PAMS, NCore, and others)**
** ****Data acquisition and validation**
** ****Upper Air Systems**
**OAQPS is also creating how-to video as an accompaniment to the new version**

## Summary

- EPA would like to see more of the existing data shared within our air monitoring communities (via AIRNow-Tech, AQS, local users)
- New monitoring requirements are the driver behind our renewed interest in met data
- Our goal is to provide appropriate, and updated guidance to S/L/Ts