# Presentation: 934021

## AMS Short Course on the Fundamentals of Boundary Layer Wind and Temperature Profiling Using Radar and Acoustic TechniquesFebruary 8 & 9, 2003Boundary Layer Profilersfor Regulatory Applications(An Air Quality Perspective)Kevin R. DurkeeSatoru J. Mitsutomi, Ph.D.South Coast Air Quality Management DistrictDiamond Bar, CaliforniaAlex BarnettPCR Services CorporationSanta Monica, California

## Overview

- Air Quality Measurement Programs
- Examples of regulatory applications for BL profilers
- Upper-air measurement incentives from the US EPA PAMS program
- Regulatory profiler data management issues and recommendations

## Air Quality Measurement ProgramsApplying Boundary Layer Profiler Data

- National Programs
- Multi-State & Large Regional Studies
- Regional & Local Programs
- Special Interests & Consortiums

## Air Quality Measurement ProgramsApplying Boundary Layer Profiler Data

- National Programs
- Multi-State & Large Regional Studies
- Regional & Local Programs
- Special Interests & Consortiums

- US Environmental Protection Agency (EPA) has supported boundary layer profiling work for many years
- Sodars, RWP/RASS, lidars, microwave radiometers, balloons, aircraft

## National ProgramsUS EPA PAMS Program

- Main focus is monitoring of photochemical ozone precursors
- Approximately 24 areas designated Serious Non-Attainment of the federal 1-hour ozone standard
- Approximately 60 Volatile Organic Compounds (VOCs) analyzed
- Not an Air Toxics monitoring program,but there are many target compounds in common

## National ProgramsPAMS Overview

- ~80 PAMS Air Monitoring Stations in 22 Networks
- ~24 Ozone Non-Attainment Areas
- 14 Main Target Parameters
- total non-methane hydrocarbons (TNMHC) and 13 volatile organic compounds (VOCs) & Carbonyls
- EPA grants State, local, and consolidated environmental agencies approximately $3 million annually to monitor, characterize and analyze PAMS data
- including upper air portion

## National ProgramsPAMS Goals

- Contribute to overall understanding of ozone formation and transport
- Objectives:
- Verification of control strategy effectiveness
- Emission inventory review & refinement
- Emission-based model support
- Ozone/Precursor trend analysis
- Exposure modeling & analysis

## PAMS Target Volatile Organic Compounds (1996)

## PAMSNon-Attainment Areas

| Atlanta, GA | Serious |
| --- | --- |
| Baltimore, MD | Severe |
| Baton Rouge, LA | Serious |
| Boston-Lawrence-Worcester, MA-NH | Serious |
| Dallas-Fort Worth, TX | Serious |
| El Paso, TX | Serious |
| Greater Connecticut, CT | Serious |
| Houston-Galveston-Brazoria, TX | Severe |
| South Coast-SEDAB:  Greater Los Angeles & SEDAB, CA2 | Extreme |
| Lake Michigan:  Chicago, IL & IN & Milwaukee-Racine, WI1 | Severe |
| New York-New Jersey-Long Island, NY-NJ-CT | Severe |
| Phoenix, AZ | Serious |
| Philadelphia-Wilmington-Trenton, PA-NJ-DE-MD | Severe |
| Portsmouth-Dover-Rochester, NH-ME | Serious |
| Providence-Pawtucket-Fall River, RI-MA | Serious |
| Sacramento, CA | Severe |
| San Diego, CA  | Serious |
| San Joaquin Valley, CA | Serious |
| Santa Barbara-Santa Maria-Lompoc, CA | Serious |
| Springfield, MA | Serious |
| Ventura County, CA | Severe |
| Washington, DC-MD-VA | Serious |

| 1) Chicago and Milwaukee are combined into one PAMS area referred to as Lake Michigan. |
| --- |
| 2) Los Angeles-South Coast and SE Desert Modified AQMA are combined into one PAMS area referred to as South Coast-SEDAB |

- PAMSNon-Attainment Areas

## Slide 10

## (source:  http://www.epa.gov/oar/oaqps/pams/general.html)

## National ProgramsPAMS Upper Air Monitoring Requirement

- _Clean Air Act Requirement_
*(Title 40, Chapter I, Part 58, Appendix D, Section 4 .6 PAMS Meteorological Monitoring)*
- Upper air meteorological monitoring is required for each PAMS area
- The location should be representative of the upper air data in the nonattainment area
- _PAMS Technical Assistance Documentation_
- The optimal design for a given PAMS region is expected to be some combination of remote sensing and conventional atmospheric soundings

## PAMS Upper Air Data Objectives

- PAMS requirements
- one upper-air station/network with a minimum of four soundings/day of winds and temperature
- Support Trajectory Analyses
- For source apportionment & transport analyses
- Help Identify Critical Meteorological Phenomena
- e.g., mixing height evolution, nocturnal jet, recirculation, sea-breeze, etc.
- Support Air Quality Modeling
- Development & evaluation of 3-D wind, temperature & mixing height fields
- Support Ozone Episode Predictions
- Inversion strength & breaking temperature
- mixing height
- Precursor & pollutant carryover, recirculation & transport potential

## Air Quality Measurement ProgramsApplying Boundary Layer Profiler Data

- National Programs
- Multi-State & Large Regional Studies
- Regional & Local Programs
- Special Interests & Consortiums

- Ozone Transport Affects Multi-State Regions
- Multi-State or Multi-Basin approach due to wide-ranging emissions or transport of pollutants & their precursors
- Examples
- Mid-Atlantic Regional Air Management Association (MARAMA)
- Northeast States for Coordinated Air Use Management (NESCAUM)

## Mid-Atlantic & Northeast Cooridor

| 1-hour Average Peak Concentration |  |
| --- | --- |
|                         | 0-60 ppb |
|                         | 61-79 ppb |
|                         | 80-99 ppb |
|                         | 100-110 ppb |
|                         | 111-124 ppb |
|                         | 125+ ppb |

- Source:  US EPA AIRNOWhttp://www.epa.gov/airnow/

## Mid-Atlantic Profiler Network(October 2001)Source:  MARAMA Profiler Work Group, http://www.meteo.psu.edu/~wfryan/marama/ProfilerWorkGroup.htm

**Currently:**
**Rutgers, NJ**
**Philadelphia, PA**
**Fort Meade, MD**
**Richmond, VA**
**Raleigh, NC**
**Charlotte, NC**

## Air Quality Measurement ProgramsApplying Boundary Layer Profiler Data

- National Programs
- Multi-State & Large Regional Studies
- Regional & Local Programs
- Special Interests & Consortiums

- Air Basin approach to Air Quality Management
- e.g., South Coast Air Basin, Southeast Desert Air Basin, etc.
- Geographic and meteorological boundaries *can* help confine air pollution
- Controlled by local (county or regional) and state agencies
- e.g., SCAQMD, SDCAPCD

## Source:  US EPA AIRNOWhttp://www.epa.gov/airnow/

| 1-hour Peak Concentration |  |
| --- | --- |
|                         | 0-60 ppb |
|                         | 61-79 ppb |
|                         | 80-99 ppb |
|                         | 100-110 ppb |
|                         | 111-124 ppb |
|                         | 125+ ppb |

- Source:  US EPA AIRNOWhttp://www.epa.gov/airnow/

## Houston Area

| 1-hour Peak Concentration |  |
| --- | --- |
|                         | 0-60 ppb |
|                         | 61-79 ppb |
|                         | 80-99 ppb |
|                         | 100-110 ppb |
|                         | 111-124 ppb |
|                         | 125+ ppb |

- Source:  US EPA AIRNOWhttp://www.epa.gov/airnow/

## Air Quality Measurement ProgramsApplying Boundary Layer Profiler Data

- National Programs
- Multi-State & Large Regional Studies
- Regional & Local Programs
- Special Interests & Consortiums

- For Specific Problems or Multi-Disciplinary Projects
- Examples
- UC Davis/California Modeling Consortium
- Northwest Regional Modeling Consortium
- Puget Sound, WA
- Owens Lake PM10 Dust Control Project
- Great Basin Unified APCD & Dept. of Water & Power

## Washington State University AIRPACT(Air Indicator Report for Public Awareness and Community Tracking)Real-time Air Quality Forecasting System using MM5 & CALGRID

## Owens Lake, CaliforniaDust Management

## Some Regulatory ApplicationsImproved by Boundary Layer Profilers

- Air Quality Forecasting
- Air Quality Modeling
- Source Evaluations
- Field Programs & Case Analyses
- Other Environmental Efforts

## Some Regulatory Applicationsof Boundary Layer Profilers

- Air Quality Forecasting
- Air Quality Modeling
- Source Evaluations
- Field Programs & Case Analyses
- Other Environmental Efforts

- Forecasts for public health protection & episode awareness
- Criteria Pollutants(O3, PM10, PM2.5, CO, NO2)
- Routine (daily) or episodic forecasts
- Specific forecasts for field study intensive operations

## Air Quality Forecasting

- AQ forecasts typically consider
- recent trends/current concentrations of smog & precursors
- weather patterns & progs
- Surface Met Data Needs
- winds (stagnation), pressure gradients, temperatures, humidity, solar insolation
- Upper-Air Data Needs
- Inversion height and strength, mixing depth, breaking potential
- Heating aloft (e.g., 850 mb Temps)
- Winds - for transport & recirculation potential
- Humidity profile (marine layer structure, PM chemistry)

## Some Regulatory Applicationsof Boundary Layer Profilers

- Air Quality Forecasting
- Air Quality Modeling
- Source Evaluations
- Field Programs & Case Analyses
- Other Environmental Efforts

- Regional Modeling
- Point-Source Modeling
- Model Evaluation (Validation)
- Trajectory & Pollutant Transport Assessment
- Within Air Basin
- Across Basin Boundaries
- Long-Range

## Upper Air Data in Regional Modeling

- _Air Quality Models_
- Episodic AQ Modeling are used for Attainment Demonstration & Control Strategy Development
- Regional models simulate meteorology, emissions & smog chemistry for multi-day episodes
- Can then evaluate effects of emissions changes due to growth and various control strategies
- AQ models require meteorological inputs from met models for each time step:
- (3-D) gridded fields of winds, temperature, & humidity and (2-D) mixing height fields
- AQ model examples:
-  Urban Airshed Model, CALGRID, Models3

## Upper Air Data in Regional Modeling

- _Meteorological Models_
- Sufficient Upper Air data input critical formodel performance
- UA data needed for evaluation (validation)  & development of met & AQ models
- Met model examples:
- CALMET, a diagnostic model
- Pennsylvania State University/National Center for Atmospheric Research Mesoscale Meteorological Model (MM5), a prognostic model

## Southern California Surface Data

## Southern California RWP/RASS DataSCOS97 Modeling Domain

- Southern California RWP/RASS DataSCOS97 Modeling Domain

## Upper-Air Site Data Validation Plot Example

## Upper-Air Multiple Site Data Validation Plot Example

## Model Wind Field with RWP Data

## Model Wind Field with RWP Data

## Model Wind Field with RWP Data

## Some Regulatory Applicationsof Boundary Layer Profilers

- Air Quality Forecasting
- Air Quality Modeling
- Source Evaluations
- Field Programs & Case Analyses
- Other Environmental Efforts

- Regulatory Compliance & Violation Evaluation
- UA data used to support monitoring studies for  smoke, dust, odor & emissions limit compliance
- Permit Processes
- Source Modeling Evaluations
- New Source Review & PSD
- Source Apportionment
- Trajectory analysis
- UA data used to help define boundaries for Air Toxics Reporting

## Source Evaluations

- Sodars widely used for:
- stack/plume analysis
- mixing depth detail
- MiniSodars used for:
- street-level traffic emissions studies
- detailed shallow mixed layer analyses
- prescribed & wildland fire impact analysis
- Profilers now being used for
- Transportation emission impact studies
- long-range transport analyses
-  e.g., power plant plume studies

## Some Regulatory Applicationsof Boundary Layer Profilers

- Air Quality Forecasting
- Air Quality Modeling
- Source Evaluations
- Field Programs & Case Analyses
- Other Environmental Efforts

- Support of Local, Regional & National air monitoring programs
- Ongoing, e.g., PAMS
- Intensive field monitoring to support research & model development
- Regulatory Compliance Analyses
- Natural Event Evaluation & Documentation
- e.g., volcanic activity, wildfires, high winds

## Field ProgramsTemporary Profiler Applications

- Small Field Studies
- e.g., Lynwood Carbon Monoxide Study used sodars to evaluate morning mixing and transport under strong radiation inversions
- Large Field Programs
- Cooperation between government agencies, university groups and private sector is critical
- Southern California Ozone Study 1997 (SCOS97-NARSTO)
- http://www.arb.ca.gov/research/scos/scos.htm
- NARSTO NE
- Lake Michigan Ozone Study (LMOS)
- New England Air Quality Study (NEAQS) 2002
- http://www.al.noaa.gov/NEAQS/
- Central California Ozone Study (CCOS)
- http://www.arb.ca.gov/airways/ccos/ccos.htm

## Slide 40

## SCOS97-NARSTO Upper Air Sites

## Some Regulatory Applicationsof Boundary Layer Profilers

- Air Quality Forecasting
- Air Quality Modeling
- Source Evaluations
- Field Programs & Case Analyses
- Other Environmental Efforts

- Emergency Planning & Response
- Natural disaster, fire, nuclear & toxics
- Burn Management
- Wildland fire response
- Prescribed burns
- Agricultural burns
- Energy Management
- power generation planning
- repair weather support
- wind power turbine optimization
- Acid Deposition & Regional Haze Studies

## Airshed Modeling Issueswith RWP/RASS Data

- Data Management Issues
- Mixing Height Issues
- Data Gap to Lowest Range Gates
- Vertical Velocity Issues
- Moisture Profile Measurements

- Format inconsistencies from different instrumentation and data sources
- Inconsistent data validation practices
- Data validation process is time consuming (expensive)
- More validation steps can be automated and graphics tool incorporated

## Airshed Modeling Issueswith RWP/RASS Data

- Data Management Issues
- Mixing Height Issues
- Height Coverage Issues
- Vertical Velocity Issues
- Moisture Profile Measurements

- Developing good mixing height analysis fields are labor intensive (expensive)
- Mixing heights derived from refractive index parameter (CN2) are valuable, but
- Model analysis fields subject to inaccuracies  due to terrain, missing data, sea-breeze interaction, differential heating across analysis domain, etc.

## Airshed Modeling Issueswith RWP/RASS Data

- Data Management Issues
- Mixing Height Issues
- Height Coverage Issues
- Vertical Velocity Issues
- Moisture Profile Measurements

- Height coverage often limited by atmospheric conditions, interference
- Can estimate with nearby soundings
- Data Gap to Lowest Range Gates  (~120m AGL)
- Winds within shallow mixed layer are critical to air quality models
- Can fill with additional met towers and sodars, when available
- Typically must interpolate

## Airshed Modeling Issueswith RWP/RASS Data

- Data Management Issues
- Mixing Height Issues
- Height Coverage Issues
- Vertical Velocity Issues
- Moisture Profile Measurements

- Important to understand the atmospheric processes
- Not clear if vertical velocity correction should be used with RASS temperatures
- corrected Tv often does not pass through the averaging criteria
- Corrected Tv often appears over-corrected

## Airshed Modeling Issueswith RWP/RASS Data

- Data Management Issues
- Mixing Height Issues
- Height Coverage Issues
- Vertical Velocity Issues
- Moisture Profile Measurements

- Especially important for aerosol modeling
- Used for conversion of virtual temperature data (Tv to T fields)
- Can use mixing height field with surface humidity field to estimate 3-D humidity field

## Upper Air Data Recommendations(based on Main & Roberts, 2001)

- Continue UA Measurements & Increase Use of Data
- Prepare Support Information & Procedures
- list of profilers, locations, operating agencies, hardware, software, operating periods, standard operating procedures (SOPs), contact names, data archive location, & remote access directions
- Develop Regional (or Network) Standardized Approach
- to data validation, data access & analysis tool development
- Develop a Data Repository
- Work with EPA to develop a national data repository
- US EPA Air Information Retrieval System (AIRS) ???
- NOAA – FSL ???
- Otherwise, create regional UA database
- for easier archiving, access & dissemination
- with data reporting deadlines

## NOAA Forecast Systems LaboratoryMulti-Agency Profiler Graphical Data Display

**NOAA Forecast Systems Laboratory****Multi-Agency Profiler Graphical Data Display**

- Source:  http://www.profiler.noaa.gov/jsp/profiler.jsp

## Coastal Wind Profiler PageSource:  Dick Lind, Naval Postgraduate School, Monterey, CAhttp://www.weather.nps.navy.mil/profiler/coastprof.html

## Profiler & Coastal Winds for Southern CaliforniaSource:  Dick Lind, Naval Postgraduate School, Monterey, CAhttp://www.weather.nps.navy.mil/profiler/coastprof.html

## Upper Air Data Recommendations(continued)

- Integrate Surface Met, Sodar & RWP/RASS Data
- Archive Both Consensus Averaged and Moments Data from RWP/RASS
- Consensus data good for near-real-time use and most applications
- Moments data can be post-processed to retrieve data where consensus averaging is ineffective
- Boundary layer info may be best retrieved from moments
- Use Workgroups and Other Forums
- to share data analysis results and techniques
- expand outside the air quality community
- Increase UA network where needed
- Consider year-round UA data collection
- to support PM2.5 & other pollutant programs

## Summary of Drawbacksof Boundary Layer Profiling for Air Quality Applications

- Instrument Cost
- Initial Purchase & Maintenance
- Siting can be Difficult
- RWP frequency considerations, Sodar & RASS noise, interference, site availability, permitting, ...
- Vertical coverage is dependent upon atmospheric conditions
- i.e., poor data coverage in dry/stable air due to strong temperature inversion, stagnant conditions, desert locations, etc.
- measurements in such conditions are often important for air quality interests
- Data quality control can be laborious & time consuming(costly)
- Few air quality agencies have staff dedicated to upper air measurements
- “It’s a helluvah lot of data!”

## Summary of Benefitsof Boundary Layer Profiling for Air Quality Applications

- Require Less Manpower & Expendables
- compared to balloon-borne soundings
- Can operate, optimize and collect data remotely via modem, internet, satellite link
- Continuous, Automated
- Reduce need to predict Intensive Operational Periods (IOPs) during field programs
- Allow for continuous measurements
- Can get near-real-time data feedback for field study operational decisions and public notification of pending air quality events

## ReferencesProfiler Application Guidance for Air Quality

- EPA Meteorological Measurements:
- EPA Vol. IV (mainly surface met & sodars)  (US EPA, 1995a)
- EPA Photochemical Modeling Guidance  (US EPA, 2000)
- EPA Photochemical Assessment Monitoring Stations (PAMS) Program
- EPA PAMS Analysis Guidance  (US EPA, 1994b, 1995b, 1996, 1997)
- EPA PAMS Implementation Manual  (US EPA, 1994a)
- EPA Technical Assistance Document for the Sampling and Analysis of Ozone Precursors (EPA/600-R-98-161, Sept. 1998)
- http://www.epa.gov/ttn/amtic/files/ambient/pams/newtad.pdf
- Section 6:  Guidance for PAMS Meteorological Monitoring
- Section 6.5:  Upper Air Meteorological Monitoring
- Little on Radar Wind Profilers/RASS Measurements
- CFR Title 40, Chapter I, Part 58, Appendix D, Section 4:   Network Design for Photochemical Assessment Monitoring Stations (PAMS)
- http://www.access.gpo.gov/nara/cfr/cfr-table-search.html

## References

- Blumenthal D.L., Lurmann F.W., Roberts P.T., Main H.H., MacDonald C.P., Knuth W.R., and Niccum E.M., 1997:  Three-dimensional distribution and transport analyses for SJVAQS/AUSPEX. Draft report prepared for the San Joaquin Valleywide Air Pollution Study Agency, California Air Resources Board, Sacramento, CA by Sonoma Technology, Inc., Santa Rosa, CA, STI-91060-1705-DFR, February.
- CFR Title 40, Chapter I, Part 58, Appendix D, Section 4:   Network Design for Photochemical Assessment Monitoring Stations (PAMS).  http://www.access.gpo.gov/nara/cfr/cfr-table-search.html
- Chang J.C. and Hanna S.R. (1993) Trajectory calculation for selected LMOS periodsDye T.S., Lindsey C.G., and Anderson J.A., 1995:  Estimates of mixing depths from "boundary layer" profilers. In *Preprints of the 9th Symposium on Meteorological Observations and Instrumentation, Charlotte, NC, March 27-31*, STI-94212-1451.
- Dye T.S., Roberts P.T., and Korc M.E., 1995:  Observations of transport processes for ozone and ozone precursors during the 1991 Lake Michigan Ozone Study. *J. Appl. Meteorol.* 34, 1877-1889. (STI-1384).
- Lindsey C.G., Dye T.S., Blumenthal D.L., Ray S.E., and Arthur M., 1995:  Meteorological aspects of summertime ozone episodes in the Northeast. Paper FA 5.8 to be presented at the *9th Joint Conference on the Applications of Air Pollution Meteorology at the 76th AMS Annual Meeting, Atlanta, GA, January 28-February 2, 1996*, (STI-1549).
- Lindsey C.G., Dye T.S., Roberts P.T., Anderson J.A., and Ray S.E., 1995:  Meteorological aspects of ozone episodes in southeast Texas. Paper No. 95-WP96.02 presented at the *88th Air & Waste Management Association Annual Meeting, San Antonio, TX, June 18-23*.
- Lindsey C.G., Dye T.S., and Baxter R.A., 1995:  Draft guidelines for the quality assurance and management of PAMS upper-air meteorological data. Final report prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC by Sonoma Technology, Inc., Santa Rosa, CA, Work assignment 10-95, EPA Contract No. 68D30020, STI-94611-1556-FR, December.
- Main, H.H. and P.T. Roberts, 2001:  Recommendations for the PAMS Network in the Northeast and Mid-Atlantic States. Final report prepared for NESCAUM, Boston, MA by Sonoma Technology, Inc., Petaluma, CA.  STI-900860-2067-FR. _[http://64.2.134.196/PAMS/recommendations/Recommendations_report.pdf](http://64.2.134.196/PAMS/recommendations/Recommendations_report.pdf)_

## References (cont.)

- Roberts P., Korc M., Blumenthal D., and Mueller P.K., 1995:  NARSTO-Northeast 1995 summer ozone study. Version 1. Report prepared for Electric Power Research Institute, Palo Alto, CA by Sonoma Technology, Inc., Santa Rosa, CA, STI-95135-1538-WD1; Research project EPRI WO9108-01 White A.B. (1993) Mixing depth detection using 915 MHz radar reflectivity data. In: Preprints, AMS 8th Symposium on Meteorological Observations and Instruments, Anaheim, CA, January 17-22.
- US EPA, 1994a: Photochemical Assessment Monitoring Stations (PAMS) Implementation Manual.  Section 6.0 of Appendix N, Guidance for PAMS Meteorological Monitoring.  (EPA-454/B-93-051, March 1994, Section 6.0 revised June 1995, download from http://www.epa.gov/oar/oaqps/montring.html).
- US EPA, 1994b:  Recommendations for Analysis of PAMS Data. http://www.epa.gov/air/oaqps/pams/rec_aop.pdf
- US EPA, 1995a:  Quality Assurance Handbook for Air Pollution Measurement Systems, Volume IV - Meteorological Measurements, (EPA-600/R-94-038d, download PDF Part 1 from http://www.etl.noaa.gov/ams_measurement/qa_iv_1.pdf, and Part 2 from http://www.etl.noaa.gov/ams_measurement/qa_iv_2.pdf)
- US EPA, 1995b:  A Workbook for Exploratory Analysis of PAMS Data. _[http://www.epa.gov/air/oaqps/pams/workbook.pdf](http://www.epa.gov/air/oaqps/pams/workbook.pdf)_
- US EPA, 1996:  PAMS Data Analysis Results Report, 1996. _[http://www.epa.gov/air/oaqps/pams/pamsrr.html](http://www.epa.gov/air/oaqps/pams/pamsrr.html)_
- US EPA, 1997:  PAMS Data Analysis Workshop Workbook. _[http://](http://www.epa.gov/air/oaqps/pams/analysis/)__[www.epa.gov/air/oaqps/pams/analysis](http://www.epa.gov/air/oaqps/pams/analysis/)__[/](http://www.epa.gov/air/oaqps/pams/analysis/)_
- US EPA, 1998:  Technical Assistance Document for the Sampling and Analysis of Ozone Precursors (EPA/600-R-98-161, Sept. 1998). http://www.epa.gov/ttn/amtic/files/ambient/pams/newtad.pdf
- US EPA, 2000:  Meteorological Monitoring Guidance for Regulatory Modeling Applications (EPA-454/R-99-005, February 2000, download PDF from _[http://www.epa.gov/scram001/guidance/met/mmgrma.pdf](http://www.epa.gov/scram001/guidance/met/mmgrma.pdf)_)
- Wilczak J.M., Strauch R.G., Weber B.L., Merritt D.A., Ralph F.M., Jordan J.R., Wolfe D.E., Lewis L.K., Wuertz D.B., Gaynor J.E., McLaughlin S., Rogers R., Riddle A., and Dye T. (1995) Contamination of wind profiler data by migrating birds: characteristics of corrupted data and potential solutions. *J. of Oceanic and Atmos. Tech*., 12, 449-467.

## Slide 58