ST MEETING 07 July, Forecast for 08 July - DOY 189



ST meeting 0707 Monday

Meteo outlook

DAY N+, N+2: Upper levels: Trough W of Portugal moving eastward,
somewhat
deepening MBL-depth and increasing cloudiness (mainly medium and high)
just W of Portugal and Sagres; high over northern Africa (thermal);
upward movements between Madeira and Sagres, and subsidence over the
remaining (with no significant change in MBL-depth). W and SW winds,
which tend to introduce dust over Canaries from SE above 700 mb. Low
levels: High pressure area with two centers, one W of Azores (1028 mb),
another over British Isles; thermal low over Sahara; low pressure area
SW of the Iberian Peninsula; trajectories show similar patterns to day N
around Sagres and the Iberian Peninsula, but winds vary significantly:
across Gibraltar Strait winds still from E but weaker, and around Sagres
and Portugal winds will blow variable tending to NW (due to circulation
around the low). Trajectories show fairly polluted air arriving at all
levels from England along the "race-track"; polluted air arriving also
Sagres in the MBL (by the Mediterranean) and in the FT (from NW-Africa);
over Tenerife perhaps 
polluted air in the MBL (trajectories hug Iberian), and possibility of
dust above 700 mb since trajectories come from Africa. Cloud-deck of
stratocumulus and stratus similar to day N, with increasing cloudiness
since winds will be gradually more moist due to the trough aloft
(increasing cloudiness W of Portugal moving E).

DAY N+3,N+4: Conditions change from previous days. Aloft: Trough over
Northern Atlantic moving eastward; westerly winds and prevailing
subsidence, except over the northern-corner. Low levels: high W of
Azores -1028 mb- and low SE of British Isles with associated cold-front
crossing the northern part of the area, increasing cloudiness and
MBL-depth, with NW winds reaching S of Sagres, then veering to NE toward
Canaries and Madeira. Clean air again everywhere, including Sagres and
Tenerife (ending the possibility of dust).


Operations

Today Monday
1. AVHRR shows 0.2 - 0.3 AOD patches coming out of Gibraltar and  from
N. Europe along Portugal. Aerosol layers were detected by yesterday's
and today's ARAT flights in the Eastern part of the ACE-2 area.
Increasing pollution was reported yesterday at Sagres and  Madeira.
Today PDH also reported increasing pollution. It looks like ACE-2 is
experiencing its first major pollution outbreak !
2. First signs of dust were also reported by IZO LIDAR.
3. Successful CLOUDYCOLUM transect in polluted cloud with Merlin,
Dornier and Pelican
4. No CLEARCOLUMN above ship, because of cloudiness

Tuesday
5. CLOUDYCOLUMN closure flight planned with Merlin, Dornier, Pelican and
ARAT. GONOGO decision at 0600 LT.
6. Ship to arrive at 34N00' 15W30' in the afternoon  in NW branch of
European outflow
7. Citation MBL flight upwind of Tenerife, for intercomparison with PDH. 

Wednesday
8. Start of full LAGRANGIAN planned at 0200Z. 

General
- Today quite some differences existed in radio soundings of S/C(900m),
PDH(1300m) and aircraft(1000m) upwind Tenerife.

To:     Shane Beard
From:   Randy Johnson
We were able to track the balloon through the 3rd C130 flight
at a distance of up to 230 miles.   About 27 hrs.
Altitude control seemed to work very well and responds
very quickly.  The Pelican went out on the 4th flight and
was never able to recieve it.  I do not know what happened
to cause no reception - the Pelican receiver seems to be good.
I appreciate the good launch.
How did the balloon shelter work?
Is there any additional assistance that you need prior to
and during launch?
How much helium is required per balloon?
How much ballast wt. is required per balloon?
To keep balloons in a 4 hour launch window, will we need to
limit the launch to 2 balloons rather than 3?

Next Balloon Launch:
It looks like 02:00 on Wednesday morning - use same parameters
as before.
Change one item - do not launch with less than 300
grams of net lift.  Last time it had to release ballast
to reach altitude.
Expect to launch 2 balloons and set up antenna and receiver for
maximum tracking range.  We will want the initial balloon data
to launch the plane later in the day.
You may want to see if one of the crew may have a better knot
for the ballast line knots.

Randy