April 05 00Z Radiosonde temperature humidity
April 05 00Z Radiosonde winds
April 05 03Z Radiosonde temperature humidity (Launched 01:45 UTC)
April 05 03Z Radiosonde winds
Afternoon AVHRR
Nighttime AVHRR
noaa-16 at 1707 (0207 LT)
From the OPS Center
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GENERAL OVERVIEW
The anticyclone which has dominated the low-level circulation for the
last 48
hours continues to have a strong influence. In Image
1, the weather
depiction for 0000 UTC on Friday, April 6, the high is shown east of
Korea near
40 N, and is predicted to be moving toward the east, and have
associated a ridge line extending south of 35 N and east of 145 E.
An area of
clouds and possible rainfall is located SW of Japan, and cirrus clouds
are likely in this area as well, associated with fluctuations in the
jet-steam
level winds. The surface-level winds will be from the NE at both the
ship's
location and in the area around Cheju. At higher elevations the flow
is strongly
sheared, so that flow from the north is expected at elevations around
1500 m, and from the west above 2800 m. The chemical transport models
suggest
that the flow above the surface layers will be aerosol-laden, and
these features motivate the C-130 flight legs just east of 124 E which
are being
planned for.
The depiction in Image 2 is for Saturday,
April 7 at 0000 UTC. The surface high
presure center will have moved to the east, past 142 E, and the
surface ridge south of there will have weakened. The winds at the ship
and in
the Cheju area will have shifted somewhat, into the ESE and SE,
respectively. A significant low pressure system in northern China will
bring
clouds and showers of rain, and perhaps steady rain, to the Yellow
Sea
area north of 35 N. This and rapidly-moving systems following it will
generate
frequent and significant dust outbreaks in the arid regions of China.
At Kosan the winds will be generally from the east over the next 36-48
hours. At
1200 UTC on the 5th, E-NE at 3-5 ms-1; at 0000 UTC on the
6th, strengthening to E-NE at 5-8 ms-1; at 1200 on the 6th, E at 5-8
ms-1; at
0000 UTC on the 7th, SE at about 5 ms-1; and at 1200 UTC on the
7th, S-SE at 5-8 ms-1. If the surface anticyclone moves to the SE sufficiently,
the chemical transport model results suggest that plumes with high
aeroosl loading would move far enough south to beocme accessible to
aircraft
sampling. We will monitor the progess of this movement closely.
Along the expected track of the R/V Ron Brown the winds are predicted
to
fluctuate as follows: at 1200 UTC on the 5th, light and variable; at
0000
UTC on the 6th, NE at about 8 ms-1; at 1200 on the 6th, NE at 8-10
ms-1; at 0000
UTC on the 7th, SE at about 5 ms-1; and at 1200 UTC on the
7th, SW at 8-10 ms-1.
DISCUSSION
Upper level, lee-wave clouds were present at and to the east of the
east coast
(downwind) of Korea this morning. We were not aware of this as a
frequent feature, and while we now understand its origin we need to
develop a
predicative capability for this. The coverage and persistence seem
to
vary, and these clouds could siginificantly impact radiative measurements
on
flights in the Sea of Japan. Given that there are no immediate plans
for
flights in this area we might hope to acquire forecasting skill before
it is too
late.
The discussion of the meteorological situation presented at the planning
meeting
on Thursday, April 5 did not emphasize features south and west of
Japan, nor those east of Japan. The former omission was intentional
and the
latter unintentional. In the area SW of Japan the probability is high
that
significant, multilevel clouds will be present. This is virtually certain
for
Friday, April 6 and likely for Saturday, April 7. There is also the
possibility of
precipitation in this area, altough the meteorological model results
do not show
this consistently, making our confidence lower.
OPS SUMMARY
Conditions are generally favorable for the planned flights of the Twin
Otter and
the C-130 for Friday, April 6. It is possible that clouds will intervene
in the area west of Cheju, and also in the northernmost areas of the
north-south
legs along 124.25 E in the C-130 flight. It is probable that the latter
region will become less cloudy as the day goes by.
MISSION PLANS:
PRIMARY MISSION:
Twin Otter will conduct radiation column closure
flight west of Cheju Is.
C-130 will conduct a radiation gradiant flight
west of Cheju
Is.(Coordinated with a Terra overpass) and along a south-north line
(approximately 124 30E) off the west coast
of Korea.
SECONDARY MISSION:
Twin Otter will conduct coordinated observations
with R.V. Ron Brown in
vicinity of 32 55N, 127 50E.
TAKE OFF / LANDING TIMES:
Plane
Take-off Times(UTC) Landing
Times(UTC)
NCAR C-130
0000 UTC (0900 JLT)
0900 UTC
CIRPAS Twin Otter 2300 UTC (4/5), 0800 JLT
0530 UTC
Pre-flight briefing times(UTC): 2100 UTC (4/5), (0600 JLT)
Update times(UTC): NONE
AIRBORNE MISSION SCIENTIST NAMES:
NCAR C-130 : HUEBERT
CIRPAS Twin Otter : JONSSON
ARA King Air :
SHIP OPERATIONS:
Overnight, Ron Brown will steam from current
position to 32 55N, 127 50E
for possible coordinated observations with Twin Otter after 0000 UTC.