1. Recent PM 2.5 Events in Burlington, VT on 2/19-20/04 & 3/1/04 (by FDMS TEOM which includes Volatile PM missed by SES TEOMs) Note: Volatile Fine Mass of 15-25 ug/m3 on event days

2. VT FDMS TEOMs have generally shown good agreement with FRM Mass (but not on 3/1/04 FRM day, when TEOM > FRM by about 10 ug/m3). One possible interpretation could be loss of volatile Nitrate from FRM filters.

3. High Fine Mass in Gt. Lakes on 2/29 and then in VT on 3/1

4. Lake Champlain & the Adirondacks from Burlington VT CAMNET

5. Burlington, VT AQI > 100 was New England Max on 2/19 (& 3/1), although similar (& even higher) PM 2.5 was reported in Southern Quebec. At L’Acadie, Quebec (SE of Montreal), collocated BAM and 30 deg SES TEOM showed BAM > TEOM by 15-30 ug/m2 (data from Michel Bisson) Tom Dann observed similar differences of 15-25 ug/m3 for colo BAM & SES TEOM in Ottawa on 2/19/03

6. Continuous Nitrate of 15 to 20 ug/m3 observed in Toronto on 2/19 & 2/29 (data from Jeff Brook) Similarly High Nitrate of 15 to 20 ug/m3 in Chicago on 2/18/03 (data from Donna Kenski & Chris Price

7. Extreme Haze observed by ASOS in BTV on 2/19 & 20 and 3/1/04 (these data are not RH-adjusted - from STI & CAPITA FASTNET) Note Similar conditions all along Eastern US/Canada border.

9. Transport generally parallels US/Canada Border for both events (Note: low HY-SPLIT start heights employed because Mx Ht was very low for both events. Transport Plus Local Stagnation were likely contributors)

10. PM 2.5 from EPA AIRNOW & RH-adjusted b scat : 2/18-20/04 Note Separate areas of high PM concentration and haze in both Northeast and Southwest Border Regions on 2/19/04. KBIM television reporter Abby Roedel films a vehicle accident during a dust storm Thursday (2/19/04) in New Mexico.

11. Bob Vet reports high concentrations of dust in deposition samples from Chicago & southern Ontario with suspected origin from Tex/Mex dust storm. Michel Bisson reports “beige/orange snow” on Mt. Tremblent, Quebec and VT has multiple reports of “brown” or “reddish-brown” snow on 2/21/04.

12. NRL NAAPS global forecast model patterns for Dust & SO4 (no NO3 modeled) are consistent with surface Obs from RH-adjusted Bext. How much of Northern event was SO4 or NO3? Did the dust contribute too? What will STN, IMPROVE & Canadian filters show? SOUTHLAND, Texas (AP) -- Thick, reddish-brown dust swirled over parts of West Texas, contributing to a series of traffic accidents that killed two people and injured dozens of others. As many as 30 vehicles crashed Thursday (2/19) on U.S. Highway 84 between Southland and Post, about 20 miles southeast of Lubbock, said Cpl. John Gonzalez with the Department of Public Safety.

13. TexDust Feb 19 12:00 UTC Feb 19 18:00 UTC Feb 20 00:00 UTC Feb 20 06:00 UTC Feb 20 12:00 UTC NAAPS Surface DustMETAR Surface FBextMETAR Surface Wind