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

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 form FRM filters.

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

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

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

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.

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)

PM2.5 from EPA AIRNOW & RH-adjusted bscat: 2/18-20/04

Note Separate areas of high PM concentration and

haze in both Northeast and

Southwest Border Regions on

2/19/04.

What’s that about?

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.