discussion809

Mission Summary for 09 August

Ed Zipser, Aircraft Mission Coordinator

Robbie Hood, DC8 Chief Scientist

Peter Hobbs, Convair 580 Chief Scientist

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Aircraft Mission Coordinator Report

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09-10 Aug UTC, 10 Aug LT. All times below are in UTC

2-aircraft mission for Convair and DC-8.

DC-8 t/o ~2220, land ~0142 (not exact)

Convair t/o ~2230, land ~0220 (not exact).

(TRMM Overpass later, at 0313)

At sunrise on 10 Aug (LT) there were moderate sized precipitation

areas remaining from overnight convective systems. While these were

decreasing in coverage, by takeoff time there were still areas of deep

convection breaking out, mostly to the S and W of Kwaj. The DC8

started working a small system to the northeast, but it collapsed so

quickly that the first coordinated flight legs were flown on a more

active, small N-S line about 50 nm south of Kwaj.

Good coordinated flights were performed on this system from about

2240-2340 UTC. The early legs included some growing cells and some

reported turbulence on one DC8 penetration that caused them to climb

from FL 350 to 390. The last few lines were as the system was

declining fast.

The aircraft were directed to an E-W line of strong cells, initially

centered west of Kwaj from 60-80 miles and beyond. There was a strong

cell just outside the 80 km (150 km) quantitative radar coverage, so we

did not extend the line through that cell. The coordinated flights in

this system were from about 0000-0055 UTC. After the E-W line had to

be shorted too much for useful coverage, most of this coordinated set

of legs were done in bowtie fashion with the main line oriented ~S-N.

The DC8 was concerned enough about the last recommended leg that they

offset it about 4 nm to the east, so coordination with the Convair may

not be good on last leg.

The last part of the mission was in an isolated group of cells near

0906/16656 (moving westward with time). The DC8 made 2 passes over

this area between 0110-0120. The Convair made spirals up and down

through these cells, remaining for some time after the DC-8 departed.

The Convair spent most of its sampling time in this mission between

11Kft and 20 Kft, covering the altitides close to the freezing level.

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DC-8 Mission Scientist Report

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The DC-8 took off at about 2220 UTC for a coordinated mission with the University of Washington Convair. The DC-8 began by climbing to 35,000 feet to set up on a line between 8 degrees, 06 minutes North latitude, 168 degrees, East longitude and 8 degrees, 52 minutes, 168 degrees, 28 minutes East longitude. Unfortunately, the rain on this line was not significant so the DC-8 was directed to an isolated cell in the general vicinity of 7 degrees, 53 minutes North latitude, 167 degrees, 38 minutes East longitude. The Desert Research Institute 2D-C probe quit collecting data after a turbulent pass made over this storm at 2258 UTC.

The DC-8 climbed to 39,000 feet around 2320 UTC in an effort to fly above the turbulence. Many turrets were reaching this level or higher. The DC-8 experienced mild turbulence on several occasions when passing over the centers of convective cells. The DC-8 also flew through cirrus clouds quite often.

Despite the turbulence, the rain below was only moderate according to ARMAR observations. The coldest 85 GHz brightness temperatures observed by the AMPR were between 165 - 190 Kelvin. The one exception to this rule was a cell observed during a turn at 0005 UTC that displayed 85 GHz temperatures closer to 130 Kelvin.

All the DC-8 instruments performed reasonably well during the flight except for the 2D-C probe failure. The AMPR and the ARMAR experienced a few very short crashes that should not seriously affect data quality. The AMPR imagery also displays rapid roll variations during the turbulent passes, but these may be smoothed out in data quality processing after the experiment. A total of 3.5 flight hours were used during this mission leaving 90.6 hours left for research use.

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Convair Mission Scientist Report

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UNIVERSITY OF WASHINGTON FLIGHT FOR KWAJEX

DATE: 09 August 1999

UW FLIGHT : 1791

Goals of Flight: Coordinated flight with DC-8 in isolated Cbs

Accomplishments : Achieved goals , with CV-580 obtaining in-cloud measurements from 20,000 ft to cloud base.

Period of flight: 1028-1421 LT

Approx: Local Time (UTC=local time minus 12 hours)	Activity
1034	Take-off
1034 - 1050	headSE, climb to 10,000 ft
LINE 1 A = 08 deg 00' / 167 deg 38' for isolated cells
1050 - ?	Clime to 12 k ft
LINE 2 A = 07 deg 48' / 167 deg 39' B = 08 deg06' / 167 deg 34'
1102	at A
1103 - ?	A -> B(cut short)
LINE 3 A = 08 deg 09' / 167 deg 30' B = 07 deg 50' / 167 deg 34'
1107 - 1113	To A, climb to 14k ft
1113 - ?	A -> B
LINE 4 A = 07 deg 48' / 167 deg 26' B = 08 deg 13' / 167 deg 25'
1121 - 1126	Head to A, climb to 16 k ft
1126 - 1138	A -> B at 16 k ft (climb to 18 kft near B and in turn)
1138 - 1145	B -> A at 18 k ft
LINE 5 A = 08 deg 46' / 167 deg 07' B = 08 deg 39' / 166 deg 27' (Max 30 dBz at west end)
1145 - 1206	Head to new point A at 18 k ft (Nice columns on CPI at 1148)
(1150 started climb to 20 kft)
1206 - 1214	A -> B (cut short) at 20 k ft (-9 C)
LINE 6 A = 08 deg 51' / 166 deg 36' B = 08 deg33' / 166 deg 49'
1214 - 1218	Head to new A at 20 kft
1218 - 1223	A -> B ( cut short) Freezing rain near A at about 1220. Light snow (virga) at 1222
LINE 7 A = 08 deg 52' / 166 deg 28' B = 08 deg 32' / 166 deg 42'
1230 - 1238	Head to A, climb to 20 kft
1238 - 1241	A -> B, Drop to 16 k ft
LINE 8 A = 08 deg 33' / 166 deg 33' B = 08 deg 51' / 166 deg 24'
1243 - 1241	Head to A at 16 kft (-0.8 C) (visual spot of DC-8 at 12 50)
1247	A -> B (Shifted 1 mile west of line AB at 1250)
LINE 9 A= 09 deg 07 min/166 deg 57 min
1254	Head to A at 12 kft (-0.8 deg C). Hit isolated cell within 3 miles of A
1306	At A. Drop to 15 kft ( 0 deg C). Hit cell we went thru at 16kft
1309	Drop to 14 kft. went thru same cell as above.
1313-1330	Spiralled up from 14 to 20 kft intercepting Cb periodically in spiral. At 1338 in cloud at 20 kft (-7.5 deg C, plates on CPI). DC-8 overhead at 1316. CV-580 penetrated same same over.
1330-1348	Descended in spiral at 2kft/min. Intercepted many cells in descent between 20-3 kft
1348	Headed back to Kwajalein descending to cloud base (FSSP-100 died during this period. Also, CPI fogged up in descent, but cleared later)

Instrument mulfunctions:

1)Text read-out continues intermittent

2) Bag and CN leaks (??)

30 Radar

KWAJEX hours remaining: 66.70

Peter Hobbs

Univ. of Wash.