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Regional Transported Dust To The Las Vegas Valley From Mojave and Sonoran Desert Areas. CDAWG November, 2013. Transported Dust Presentation Overview. Clark County PM 10 monitoring network Clark County PM 10 design values July 3, 2011 transported dust event
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Regional Transported Dust To The Las Vegas Valley From Mojave and Sonoran Desert Areas CDAWG November, 2013
Transported Dust Presentation Overview • Clark County PM10 monitoring network • Clark County PM10design values • July 3, 2011 transported dust event • May 10, 2012 transported dust event • April 15, 2013 transported dust/high-wind event • Conclusions and suggested next steps
Where Is All This Dust Coming From? • July 3, 2011 PM10 Transported Dust Event • Meteorology assessment indicates desert sources south of Bullhead City, Arizona (Haboob) • Low velocity winds transported the airborne dust from Bullhead City to the Las Vegas Valley • Winds picked up in afternoon and cleared transported dust out of the Las Vegas Valley - Local wind driven sources did not contribute to the high PM concentrations
Desert Storm “Haboob” Source: Desert Meteorology. Thomas T. Warner. 2004
12hr Backward Trajectory HYSPLIT for Boulder City and J. D. Smith DAQ Monitoring Stations July 3, 2011 10:00 PST
Where Is All This Dust Coming From? • May 10, 2012 PM10 Transported Dust Event • Meteorology assessment indicates northwestern Arizona Haboob/Weather event near Phoenix, Arizona pushed large desert storm dust concentrations into the Eldorado Valley (Boulder City) corridor into the Las Vegas Valley • Winds picked up in afternoon and cleared transported dust out of the Las Vegas Valley to the Northwest - No local sources of dust in Las Vegas Valley added to the mix
HYSPLIT at the Boulder City and Jean DAQ Monitoring Stations for 10 Meters Above Ground Level Note: NOAA HYSPLIT model shows two different source regions; one out of California and the other from northwestern Arizona. However, the bulk of the dust came from the northwestern Arizona desert storm (HABOOB).
Attainment Status Las Vegas Valley Dust Transport Event (July 3, 2011) • PM10 • Design Values • *Excludes exceptional events that have been flagged Dust Transport Event (May 10, 2012)
Where Is All This Dust Coming From? • April 15, 2013 PM10 Dust Transport/High-Wind Event • Meteorology assessment indicates dust was transported from sources in the desert east of Edwards AFB and the cities of Barstow and Baker, California and the Jean dry lake bed, in the Ivanpah Valley (Southern Nevada) • Dust followed the transportation corridor to the Las Vegas Valley; the I-15 corridor
Dust Transport/High-Wind Event (April 15, 2013) • PM10 Exceedance Concentrations for the Day: • Palo Verde – 213 µg/m3 • Paul Meyer – 165 µg/m3 • Joe Neal – 227 µg/m3 • Sunrise Acres -268 µg/m3 • J.D. Smith - 238µg/m3 • Green Valley - 197µg/m3 • Jean (Ivanpah Valley) - 169µg/m3 • Boulder City (Eldorado Valley) – 246 µg/m3
Additional information on April 15, 2013 Transported Dust/High-Wind Event: • A strong pre-frontal trough moved through the Baker, and Barstow, California area on the 14th which raised a large amount of dust. • The large mass of suspended dust moved north, east and into parts of southern Nevada and northwest Arizona. • The high winds over the western Mojave Desert continued to transport suspended dust into Clark County for most of the day.
Conclusions • Conditions exist that are out of our control • Transport follows I-15 corridor out of the Mojave Desert and the 93/95 corridor out of the Sonoran/Mojave Desert • Continued impacts from high-wind events • Transported dust is major contributor to high/elevated PM concentrations in Clark County for the past 3 – 4 years and the trend is continuing • Modeling analyses indicate that transported/high- wind dust events in the Las Vegas Valley do not impact other areas either to or towards the Grand Canyon (Visibility degradation) or areas immediately north-north west of the Las Vegas Valley
Suggested Next Steps • Facilitate multi-state collaborative efforts to address pollutant transport issues • Re-activate the Best Available Control MeasureWorking Group(BACM) • Provides mechanism for collaboration between air agencies in the desert southwest (AZ, CA and NV) • Group can focus on transport issues, involving Particulate Matter and Ozone, including impacts from wildfires and high-wind events
Suggested Next Steps (continued) • Share modeling data and collaborate on refining input data • Collaboratively share and analyze modeling results • Collaboratively develop approaches to reduce emissions from major sources of dust in the desert southwest • Collaborate on atmospheric field measurement studies and mutually support other agencies studies, to the extent possible
Questions?Russell Merle: 702-455-1662Rodney Langston: 702-455-1661