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Update PI-SWERL Sampling on Owens Lake . Maarten Schreuder, Air Sciences Inc. 3/17/2010. Outline. Background Updates to Sampling Plan Field Sampling Calibration Schedule for Current Dust Season. Background - Timeline. 07/08 - PI-SWERL first discussed with Panel
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UpdatePI-SWERL Sampling on Owens Lake Maarten Schreuder, Air Sciences Inc. 3/17/2010
Outline • Background • Updates to Sampling Plan • Field Sampling • Calibration • Schedule for Current Dust Season
Background - Timeline • 07/08 - PI-SWERL first discussed with Panel • 05/09 - First test on Owens Playa • 09/09 - Field demonstration with Panel and District • 11/09 - Panel§ recommended development of PI-SWERL sampling plan • 12/09 - Draft sampling plan presented to Panel and District • 1/10 - Updated sampling plan distributed to Panel and District § Expert Panel Position Statement, Nov. 10, 2009
Field Sampling Approaches • Routine sampling • Event sampling • Instrument comparison
Routine Sampling • Study Area 1 and Study Area 3 • Monthly sampling • Sampling time: 1 day per area • Up to 25 sampling points per area • Approx. one sample per 15 acres (~250x250 m) • Co-locate several points with District Sensits
Routine Sampling Study Area 1 Study Area 3
Event Sampling • Sampling across borders of delineated areas • Sampling within 5 days of wind event • Sampling time: 1 day per area • Up to 25 sampling points per area • Two or three transects per area • Co-locate several points with District Sensits (where possible)
Instrument Comparison District wind tunnel PI-SWERL MRI wind tunnel
Instrument Comparison • Recommended by Panel • Two or three sampling locations, representing different soil/surface types • Main criteria: • Surface emissivity (high/intermediate/low) • Accessibility • Sampling time: up to 1 day per site • Instruments: • MRI tunnel (N=4) • District tunnel (N=4) • PI-SWERL (N=8)
Calibration of OGS • Need: Conversion of Optical Gate Sensors (OGS) output to a mass-based sand flux • Several options available: • Use recent progress by DRI/DustQuant in calibrating OGS output to total sand mass • Calibrate OGS in PI-SWERL to mass-based sand flux in MRI tunnel • Place OGS devices inside the MRI tunnel for real-time calibration • Preferred option to be determined
Calibration of DustTrak • Need: Calibration factor(s) for DustTrak specific to Owens Lake material • Two or three representative soil types • 1O option: Procedure proposed by Jack Gillies§ • 2O option: Compare DustTrak filter mass with real-time output § Expert Panel Position Statement, March 12, 2010
Updated Schedule • Utilize remainder of current dust season for planning and coordination. • Realistic schedule: • Instrument calibration: starting Fall 2010 • Cross comparison: 2010-2011 dust season • Field sampling: 2010-2011 dust season • Collaboration with the District would speed the process and lead to a more acceptable end product.