P-3 Chief Scientist Event/Radar Log

 

Flight Number: 011218H

 

IMPROVE-II Flight #8

Date:  December 18, 2001    Aircraft ID: N42RF 

Chief Scientist: Bond

            ---------------------------------------------------------------------------------------------------

            Doppler Scientist: Smull  Radar Tech: Nash

          Cloud Physics Sci: Steed Data Tech:McMillan

          Radar parameters:         PRF1=PRF2 =1600, 0.50 microsecond pulse

                                      Setup file = IMPR1

                                      Pulses/sample = 32

                                      Threshold on REF

                                      Alternate Setup = IMPR2

          Mission Description:

          Scientific Crew: Nick Bond (PI), Brad Smull (radar), Steed (cloud physics)

          AOC Crew: Taggart (P), Halverson (P), Wade (FE), Damiano (FD), Newman (N), Rogers (tech), Lynch (data), McNamara (tech), Delgado (dropsonde), Fields (observer), Floyd (observer)

           

 

Event Log

Time (Lat, Lon), Track (deg), Static Pressure (mb), Radar Alt (m)

Event & Comments

164021 Z (47.90018, -122.28056) 187.461°, 984.3 mb, 6728.0 m

Scientists in seats

164639 Z (47.90016, -122.28053) 189.691°, 985.1 mb, 0.0 m

Block-out

165656 Z (47.91212, -122.28571) 179.011°, 986.3 mb, 0.0 m

Takeoff Rwy 16R

170322 Z (47.68405, -122.58386) 205.962°, 722.3 mb, 2636.0 m

Radar system up & recording

172256 Z (46.69894, -122.45473) 133.855°, 567.1 mb, 3729.0 m

Very continuous stratiform precipalong our track, echo top ~4 km

173711 Z (45.99378, -121.41220) 134.405°, 567.6 mb, 3646.0 m

Descending for gorge run. Echo still very continuous but weak, peaks ca. 20-25 dBZ. Beautiful cloud physics profile, rimed stellars.

174220 Z (45.98515, -121.35172) 256.281°, 747.1 mb, 1865.0 m

Level at FL 8kft/2.5 km, approaching gorge, precip still solid, a bit deeper than near Puget Sound, echo top ca 5 km, tracking along gorge

175002 Z (45.89145, -121.94844) 257.064°, 747.1 mb, 1892.0 m

Nearing W exit of gorge, echoremains continuous, tail Doppler data quality look excellent

175344 Z (45.84782, -122.20552) 255.374°, 746.8 mb, 1606.0 m

Tail radar back up after ~3min gap. Must have jinxed it w/ last comment...

175523 Z (45.82664, -122.32658) 256.754°, 747.0 mb, 2060.0 m

Turning to track 185. Planning S-bound run to Pt F and an abbreviated microphysics stack prior to Convair's arrival

180558 Z (45.29343, -122.43539) 206.398°, 775.6 mb, 1930.0 m

Climbing for S-bound run.

181104 Z (45.16316, -122.71799) 235.741°, 640.9 mb, 3546.0 m

Leveling at FL 120. Echo much reduced, patchy, thin mid-level layer at/just above FL.

181339 Z (45.08992, -122.87631) 236.949°, 641.3 mb, 3538.0 m

In sunshine. S-POL reports that first band is narrow & exiting area, however comma-cloud moving in from wst

181545 Z (45.02713, -123.01631) 230.996°, 641.7 mb, 3532.0 m

At Pt A,. LF suggests widespread precip to our W beyond 100 km, but may be getting some sea clutter return as well.

181919 Z (44.82338, -123.03435) 179.223°, 641.7 mb, 3403.0 m

Seeing some 2nd trip return. FL wind speeds jumping up here in clear.

182056 Z (44.73415, -123.02849) 174.951°, 641.6 mb, 3534.0 m

Radar down briefly, back up at 1822:03

182503 Z (44.50752, -123.03520) 183.449°, 641.7 mb, 3517.0 m

Radar down again, back up at 1827:20. Echo picking up again, but not too widespread. More structure, suggestion of fallstreaks off RHS at 1828-29.

 183452 Z (43.92133, -123.03767) 177.886°, 641.7 mb, 3456.0 m

Considering possibility of microphysical spiral (vs. Stack) through band to expedite sampling before it exits study area. Echo tops now 5-7 km.

183823 Z (43.73472, -123.08307) 304.192°, 640.8 mb, 3200.0 m

At Pt F, tracking toward N.

185220 Z (44.44820, -121.78845) 79.123°, 514.1 mb, 4008.0 m

Turning planning 200 ft/min from 17.5 to 15 kft for "short-stack" leg back to SW. Mass says comma is moving in quickly, makes for excellent/unique mission objective, so we'll expedite stack in order to be back in lawn-mower pattern for comma cloud arrival.

190720 Z (44.23783, -122.37680) 67.458°, 568.9 mb, 3681.0 m

Echo remains solid  Now tracking NE

191404 Z (44.39368, -121.78415) 253.015°, 579.5 mb, 3087.0 m

Turning to track SW, descending on this leg. LF is showing signs of distinct N-S band

192306 Z (44.16237, -122.43259) 288.319°, 628.9 mb, 2950.0 m

Turning to track NE at 10 kft.

192733 Z (44.33087, -122.06317) 56.763°, 629.4 mb, 2496.0 m

Track adjustment. Coastal range terrain & lower altitude partially blocking LF view of approaching band (comma cloud?) but

193255 Z (44.48905, -121.56305) 221.065°, 629.5 mb, 2545.0 m

Turning to track SW

194013 Z (44.31584, -122.04581) 239.107°, 679.8 mb, 2340.0 m

Re-booting radar system. Recording back on at 1941.

194434 Z (44.20309, -122.32155) 241.280°, 694.5 mb, 2095.0 m

Seeing echo enhancement over sloped terrain on RHS.

194641 Z (44.21304, -122.42740) 30.452°, 695.0 mb, 2189.0 m

Turning to track NW. Echo fell off rapidly neat this end of stack, clouds looked more convective w/ blue sky surrounding. Bond notes that liquid water concentrations bumped up to 0.4-0.5 g/kg near SW end of track; picked up a lot of rime ice

195537 Z (44.49869, -121.56516) 196.384°, 695.0 mb, 1776.0 m

Turning to track SW, descending slowly to 6kf if possiblet. Ultimately climb to 17.5 kft and track to Point F (or location identical to IP)

200331 Z (44.31933, -122.06152) 239.638°, 707.3 mb, 1680.0 m

Nearing SW point, again more convective character visually

200922 Z (44.17089, -122.41576) 216.541°, 751.6 mb, 1654.0 m

At SW point, taildown at 20:09:30, re-booting. Back up & recording 20:11. Continued eidence of orographic enhancement NW of our track. Descending to 6 kft as we near Pt F.

202402 Z (44.06465, -123.03087) 2.049°, 812.0 mb, 1661.0 m

On N-bound track F--->A. S+ at flight level. King probe continues to show appreciable liquid water (ca. 0.5 g/kg) yet tail radar indicates only stratiform structure.

202755 Z (44.32046, -123.01698) .582°, 812.0 mb, 1526.0 m

Echo weakening. But thereafter quite cellular in patches

203743 Z (44.97674, -123.02823) 11.706°, 811.9 mb, 1725.0 m

At Pt A, re-booting radar at 2039; back up at

204447 Z (44.84671, -122.55753) 184.552°, 750.6 mb, 1617.0 m

Tracking B-->G at 8 kft.

205318 Z (44.34588, -122.55576) 178.095°, 750.1 mb, 1638.0 m

Echo filling in as we approach N edge of band. Good orographic enhancement on LHS.

205921 Z (43.98380, -122.56822) 179.863°, 750.7 mb, 1843.0 m

King-probe liquid water has again increased to ca. 0.5 g/m**3. Cloud physics data shows nice riming. Tail Doppler shows only moderately deep (4 km) but solid radar echo.

210338 Z (43.73866, -122.57130) 234.492°, 750.3 mb, 1617.0 m

Turning at Pt G to track north to intercept track for microphysics stack

211007 Z (44.10764, -122.71889) 251.578°, 562.0 mb, 4092.0 m

Climbing to 17.5 kft.

211442 Z (44.20441, -122.34384) 55.765°, 514.7 mb, 4175.0 m

Out of ice, terminating climb          

213303 Z (44.15630, -122.52612) 171.907°, 590.8 mb, 3866.0 m

Back in seat after taking multiple photos of mod/severe rime ice accumulations on windscreen, spinners. Present FL is near echo top. Approaching SW point.

213439 Z (44.15184, -122.38374) 50.417°, 591.2 mb, 3529.0 m

Turning to track 050 at FL 11 kft

214110 Z (44.45158, -121.75676) 117.525°, 591.6 mb, 2990.0 m

At Santiam Pass, turning to track 240.

215026 Z (44.19232, -122.33676) 247.228°, 668.2 mb, 2454.0 m

Finally lost precip probe (iced up) at 2245. Plan is to descend at SW point to drop off appreciable ice load. Aircraft is shimmying,lots of banging as ice breaks off and hits fuselage/windows.Contemplating quick run to ocean to descend and melt off this crap. Radar continues to work well.

220322 Z (43.79528, -123.31104) 240.508°, 841.8 mb, 1308.0 m

At 5 kft over Wilammette, nice cellular (presumably open-cellular post-frontal) convection, anvil structures. All ice has been shed from airframe. Climbing to 12 kft & reversing course at 2208. Cloud & precip probes both working well again.

221505 Z (43.97646, -122.95691) 64.999°, 645.0 mb, 3416.0 m

Cruising through tops of convection at FL 12kft. Tail radar velocities have been somewhat noisier. Will try re- setting COHO.

224212 Z (44.17358, -122.44063) 321.275°, 696.0 mb, 2460.0 m

At far NE point in stack @ 10 kft, echo very shallow, not much in way of in situ microphysics data for much of this leg, though tail Doppler shows evidence of *shallow* orographic enhancement.

225518 Z (44.50709, -121.50473) 264.558°, 673.2 mb, 2214.0 m

Tail down. Back up at 2257. Echo has been on wane.Some light shallow stuff over hills

231356 Z (44.19987, -122.82361) 299.588°, 575.1 mb, 4231.0 m

At end of leg. Heading NW to pick up E-W track.Planning three legs: 15, 12.5 & 10 kft

232254 Z (44.45208, -123.40541) 85.435°, 571.8 mb, 4351.0 m

In solid echo

232632 Z (44.44413, -122.97610) 91.872°, 571.4 mb, 4170.0 m

Echo reduced, but still observed in patches.

233540 Z (44.36935, -122.11624) 269.865°, 578.6 mb, 3018.0 m

Briefly considered moving this stack W to coastal range where yet another band is approaching, but as echo has picked up somewhat have elected to remain close to S-POL.

233929 Z (44.36725, -122.43269) 268.906°, 588.5 mb, 3544.0 m

Some 2nd trip even in single-PRF. Planning to run dual-PRF next leg. Return leg will be at 12.5 kft

235052 Z (44.36387, -123.41676) 269.137°, 630.3 mb, 3610.0 m

Turning to track 090. Switching radar to MEAPRS1 dual-PRF setup (3200/2133).

000733 Z (44.44151, -121.78403) 115.379°, 630.7 mb, 2440.0 m

Turning to track 270, will do slow descent to 10kft. Opting to stay in dual-PRF

001940 Z (44.38986, -122.70425) 268.589°, 676.3 mb, 3025.0 m

Cutting thru tops of weakcells. Considerable 2nd trip contamination, esp. On RHS. Completing our slow descent to 10 kft.

002426 Z (44.39230, -123.10486) 269.924°, 694.5 mb, 2935.0 m

Turning to track 092 at 10 kft.

003746 Z (44.43443, -121.82796) 91.989°, 694.8 mb, 1505.0 m

Turning for final W-bound leg (track 271); will maintain minimum possible altitude this run. Next lower will be 8 kft.

004511 Z (44.38008, -122.27180) 271.143°, 722.0 mb, 1420.0 m

Descending to 8 kft.  Have been punchingsome reasonably well-defined cells, but nothing too rough turbulence wise yet.

004717 Z (44.38010, -122.44267) 269.811°, 737.4 mb, 1940.0 m

Out of 8.5 kft for 7kft. Continued cellular enhancement of terrain-hugging ~stratiform echoes, only ~2 km deep.  Cleared to 6kft, out of 7.2 kft at 0050.

005427 Z (44.50030, -122.91034) 356.165°, 727.2 mb, 2550.0 m

Completed leg. Climbing/turning for ferry home to KPAE.

013620 Z (47.94588, -122.41412) 8.407°, 874.8 mb, 1067.0 m

Radar system secured.

015047 Z (47.91921, -122.28581) 180.372°, 990.2 mb, 2.0 m

Landed 16R

015623 Z (47.90021, -122.28062) 256.952°, 988.2 mb, 1.0 m

Block-in. Block-to-block duration 9.2 h