June 4, 2004 Tucson Dust

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June 4, 2004 Tucson Dust

• Community Analysis PPT
• Please add your content by downloading this PPT,
  and returning to rhusar_at_me.wustl.edu

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June 4, 2004 Tucson Dust EventLee Alter, WRAP

• Last Friday (June 4) was the haziest day I've
  seen since moving to Tucson about 14 months ago.
  It was on the font page of the paper/etc. The
  visual range was literally 3-4 miles. It was
  much larger than just the valley and extended
  pretty high up too.
• I spoke with the local NWS science officer and
  the Pima County air monitoring chief, and there
  seems to be consensus that this dust originated
  from thunderstorms in west TX, NM, and northern
  Mexico (Chihuaha), probably during the evening of
  June 3, although there were storms on the 2nd
  too. It blew in here over night, then mixed down
  in the morning. People in the foothills actually
  smelled smoke at the base of the haze layer,
  probably because there were some fires in the
  Sierra Vista area which got mixed into the dust
  cloud, but it was probably mostly dust (see next
  paragraph).
• I've attached some continuous monitoring data
  from a site in Tucson. The PM data are from beta
  attenuation monitors. Data from other sites look
  the same. PM10 reached a peak of 530 ug/m3.
  PM2.5 was high too, but only 13 of the PM10
  value, which sounds like dust to me. And as you
  can see, these levels are not associated with
  local wind speed.
• I know this is one of the dust source types you
  are trying to identify in our project, but I
  thought I'd bring it to your attention as a
  possible case study, even though it wasn't an
  IMPROVE sampling day. (Might be good for the
  inter-RPO FASTNET project too.) I expect to get
  some pictures soon. I'd really like to overlay
  wind speed data (from ASOS, doppler radar,
  whatever) with land type/use information to see
  if the dust may have come from areas that are
  anthropogenically disturbed. Unfortunately, I
  think the highest winds occured at night, so
  there might not be any good visual imagery to
  verify the wind/land/dust source relationship.
• Vic gt You're not kidding. Those are pretty
  impressive PM10 values for
• gt non-locally generated dust. This might be a
  good "known" case to take a
• gt look at and see if there is any way to tease
  out what happened and apply
• gt it to the IMPROVE data.
• Thanks Rudy. I would appreciate it if you could
  add some of those photos in there. By the way,
  there weren't any thunderstorms in Tucson on June
  4. There were some cumulus clouds in the area
  during the day, which show up in the MODIS image,
  but the ones that caused all the wind were well
  to the east the night before. I'll send you
  something I just got from DRI on that, which you
  might want to add too. - Lee

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Tucson Dust PhotosLee Alter, WRAP

• Catalinas (10 miles) on a good day (last
  Saturday) and the regional dust day (last Friday).

• Rincon's (15 miles) on a good day, a bad day and
  a real bad day (last Friday).

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PM and Wind dataLee Alter

• Note
• PM25 is 10 of PM10
• Wind speed is really low

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FASTNETAIRNOW Map and time charts

• Note
• Phoenix is dust-free at 1300
• Contouring is only to guide the eye
• Uniformity of the dust peak

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FASTNETASOS_STI and AIRNOW Map and time charts

• The high resolution ASOS (yellow - passed from
  STI) shows high extinction in the Tucson region
• It coincides with high PM25 (blue - state hourly
  PM25 data passed through AIRNOW)
• Why is the ASOS peak (red) 5-6 hours ahead of
  the AIRNOW peak?? (need to work on this one)

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FASTNETLoRes ASOS Weather Service Map and
time charts

• ASOS Extinction coefficient, (_at_ RH lt 90)
• High Bext zone confined to Tucson area
• Spike occurs at four ASOS sites
• Peak at about 1600Z
• See dust event in Tucson through the Bext
  animation

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MODIS Rapidfire 040604 Aqua

• Convective clouds in the Tucson area
• No sign of dust

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GOES IRDave DuBois, DRI

• The infrared GOES image (0645 UTC (1145 pm
  pacific time) probably shows the thunderstorm
  outflow from mesoscale convective systems in
  NM/MX/TX. It's the light colored yellow arc of
  clouds in SE Arizona. Pretty impressive outflow.
  
• There was another strong outflow this past week
  (early am on June 3rd) in Eastern NM/West TX.

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