Lake Champlain & the Adirondacks from Burlington VT CAMNET

FASTNET Event Report: 040203NENitrate

Winter PM Event over the Northeast and Quebec:Nitrate? Sulfate?

Contributed by the FASNET CommunityCorrespondence to R Poirot, R Husar

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 from FRM filters.

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

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

Weather Research and Forecasting Model (WRF) PM-2.5 & NOx, 2/28-3/1/04

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.

Over the Upper Midwest, between Feb. 15-19, the dew point temperature increased from –20 to

+30 F

Similarly, the temperature rose from –10 to +40 F.

the over four days, causing a rapid taw

through out the region

Interestingly, the rise in aerosol Bext during Feb 16-19 coincided with the rising temperatures and

humidity.

Is there a causality??

Possible nitrate release?

Weather Research and Forecasting Model (WRF) PM-2.5 & NOx, 2/18-20/04

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)

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.

Real-time Surface Meteorology provided a rich met context.Link to the Animation of the period Feb 19-21