Day 095 Met Page

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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
 

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.