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Date: 09-Mar-2000
Route: Oberpfaffenhofen - Oberpfaffenhofen (Test flight)
Take-off and landing time:
09:09:32 - 10:32:51 (UTC)
32972 s - 37971 s (seconds past 00:00:00 UTC)
Crew: Welser, Vogel (pilots), Hinz (flight engineer), Ström, Petzold, Stock, LaMP? (payload operators)
Flight log:
A test flight was performed in Oberpfaffenhofen on Thursday, March 9. It lasted about 90 minutes with two flight legs at FL 310 and FL 370. Most of the instrumentation worked perfect, some remaining deficiencies have been improved after the flight. Overall the atmosphere was very clean with low aerosol and nitric oxide concentrations. The ability of the instruments to measure very low values, which are also expected to occur in Punta Arenas, could be confirmed at this occasion. The upper leg at FL 370 was in the tropopause region with water vapor mixing ratios down to 10 ppm, but only slightly enhanced ozone mixing ratio.
top of page 
overviewDate: 13-Mar-2000
Route: Oberpfaffenhofen - Keflavik (Ferry flight)
Take-off and landing time:
09:18:56 - 13:16:58 (UTC)
33536 s - 47818 s (seconds past 00:00:00 UTC)
Crew: Welser, Vogel (pilots), Hinz (flight engineer), Krejci, Stock (payload operators)
Flight log:
After take off we reached for a while FL 370 and after that most of the time we spent at FL 390. In the beginning of the flight we had clear sky and beautifull view of Alps. After first hour we reached the front over NW Europe and it was cloudy all the rest of the flight to Keflavik. Almost all flight we spent in stratosphere. Ozone was between 200 and 400 ppb, almost no NO and high NOy. Particles well below 100. During latter part of the flight the particle concentration decreased below 50 pp/cc (minimum around 20 pp/cc). Those are the same value as we seen during two Amsterdam flight on STREAM 98. This particle concentration we saw at altitudes where PV was around 10. OPC showed rougly between 5 and 20 pp/cc and sample flow was 0.4 sccm/sec. It means roughly 1 to 5 pp/cc ambient. Most of the counts were in first 5 channels, some of them up to channel 10. Thermodenuder worked well. Most of the time all CPCs followed each other. In some cases I saw increase for CVI CPC and 120 deg C CPC and decrease for 250 deg C CPC. We passed some old contrails, already unvisible, but our particle counters saw them. During descent to Keflavik we passed tropopause somewhere between 9 and 11 km. At FL 210 we passed over some convective clouds and counters showed spikes in particle concetration.PSAP flow I set to 0.5 l/min. (Radek Krejci)
top of page overviewDate: 14-Mar-2000, 1st flight
Route: Keflavik - Goose Bay (Ferry flight)
Take-off and landing time:
08:24:01 - 12:32:24 (UTC)
30241 s - 45144 s (seconds past 00:00:00 UTC)
Crew: Welser, Vogel (pilots), Hinz (flight engineer), Krejci, Stock (payload operators)
Flight log:
Falcon was parked outside. The temperature overnight was well below zero together with strong wind and snowing. Fortunatelly no rime was observed on inlets and aircraft. During preparation no major problems occurred. Most of the time we flown in tropopause region or in stratosphere. Particle concentration during first part of the flight was around (N6) 100 pp/cc. When we entered stratopshere more deep, ozone concentration incresed to 300 400 ppb and particle concentration (N6) decresed to 20 40 pp/cc. However we did not probably enter stratosphere so deep as suring the flight to Kefla-vik. Accumulation mode particle concentration was low between 0 and 5 pp/cc. Later after 9:00 we entered probably upper troposphere or tropopau-se. Ozone concentration was lower and particle concntration (N6) was around 300 pp/cc. During this time we flown close to the top of cirrus cloud layer with changing thicknes roughly until 11:00. (Radek Krejci)
top of page overviewDate: 14-Mar-2000, 2nd flight
Route: Goose Bay - Peoria (Ferry flight)
Take-off and landing time:
13:53:14 - 17:45:54 (UTC)
49994 s - 63954 s (seconds past 00:00:00 UTC)
Crew: Welser, Vogel (pilots), Hinz (flight engineer), Krejci, Stock (payload operators)
Flight log:
Refuling stop in Goose Bay was without problems. Weather was sunny and really winter like with 3 meters tick snow cover. Only small complication was power failure during start up. Similar to previous stage, we flown probably in tropopause lower stratosphere region during the whole leg. (Radek Krejci)
top of page overviewDate: 16-Mar-2000, 1st flight
Route: Peoria - Mexico City (Ferry flight)
Take-off and landing time:
15:59:46 - 19:56:09 (UTC)
57586 s - 71769 s (seconds past 00:00:00 UTC)
Crew: Welser, Vogel (pilots), Hinz (flight engineer), Krejci, Stock (payload operators)
Flight log:
We had a small delay as we did not get permission to land in Mexico City and we had to wait to get landing permission on some other airport nearby Mexico City. At the beginning we flew in upper troposphere and tropopause region passing a cold front. At around FL270 we reached a cirrus layer. Particle concentration was very high (above 10 000 pp/cc) just under or in the lowes part of the cloud. We stayed at FL 310 while of cirrus clouds and the CVI was turned ON. After that we climbed to FL 350 to most upper part of the cirrus layer or into sub-visible cirrus cloud. CVI data showed the same "wave structure" as during the flight to Goose Bay. Ozone at that time was between 150 and 200 ppb and total aerosol particle concentration (N6) between 200 and 600 pp/cc. As we get further S, we moved from Upper troposphere - tropopause, maybe lower stratosphere more into troposphere. Over S of USA ozone dropped down well below 100 ppb and particles stabilized at 250 pp/cc. Flying further S particle concentration slowly increased up to 400 pp/cc and ozone continued to decrease. During descent to Mexico City there were no big change in vertical profile observed in free troposphere, most probably because of influence from subsiding air connected with subtropics high pressure system. Boundary layer was very much in contrast with free troposphere. All measured paramters were generally "out of scale". Particles between 5000 and 15 000 pp/cc, CO above 300 ppb. The BL was very nicely capped with scattered Cu clouds. (Radek Krejci)
top of page overviewDate: 16-Mar-2000, 2nd flight
Route: Mexico City - Panama City (Ferry flight)
Take-off and landing time:
21:54:25 - 01:22:37 (UTC)
78865 s - 91357 s (seconds past 00:00:00 UTC)
Crew: Welser, Vogel (pilots), Hinz (flight engineer), Krejci, Stock (payload operators)
Flight log:
After refueling we continued towards Panama City. First we flew above SW Mexico and then over the Pacific close to the Central America coast. Final part of the flight we flew above Panama. During all of the flight we measured in the upper free torposphere. Concentrations of all measured parameters were very, very stable. Ozone slightly varied between 30 and 50 ppb and particles between 200 and 250 pp/cc. This caused two results. Paul checked the sensitivity of the instruments if it is really measuring and I (Radek) felt a sleep for some 30 minutes. The part of the flight above the ocean was cloud free but still hazy, only towards the E we could see some big Cb’s. During final part above Panama we reached at FL 370 cirrus cloud layer where CVI was turned ON. (Radek Krejci, Paul Stock)
top of page overviewDate: 17-Mar-2000, 1st flight
Route: Panama City - Lima (Ferry flight)
Take-off and landing time:
15:24:31 - 18:41:59 (UTC)
55471 s - 67319 s (seconds past 00:00:00 UTC)
Crew: Welser, Vogel (pilots), Hinz (flight engineer), Krejci, Stock (payload operators)
Flight log:
After the night in Panama City we took off at 15:24 UTC heading towards Lima. Most of the flight we flown over the Pacific Ocean, only final part we passed over coastal region of Peru. Boundary layer over Panama was capped with scattered Cu clouds. Above boundary layer we entered 2 hazy layers below trade wind inversion. During the climb to cruising altitude 37 000 ft we passed cirrus outflow from large Cb located SE from Falcon. Top of the cirrus cloud layer was at FL 330. Close to the cirrus base we observed large increase in particle concentration. Close to the equator the cloud structure become very complex and clouds were present in many different altitudes. As we get closer to ITCZ, we intercept outflow region from Intertropical Convergence Zone. ITCZ was located at this time few degrees from Equator. At 16:52 we crossed the Equator and few minutes latter we passed few thousands feets above large Cb cloud and its outflow with cirrus clouds. Above the cloud aerosol concentration (> 6nm) increased very rapidly to thousands of particles per cc. This part of flight was bumpy. Flying above cirrus outflow from Cb, intensity of turbulence decreased. The same pattern was observed for aerosol concentration. Roughly 30 minutes after we passed through the top and outflow of another of Cb clouds. NO concentration increased indicating lightning activity. The rest of the flight we flown partly inside or above cirrus clouds. During the descent to Lima we entered hazy layer in middle troposphere. Boundary layer over the coastal region of Peru close to Lima was very polluted and hazy, similar to the pollution level over Mexico City. Aerosol concentration > 6 nm was between 10 000 and 15 000 pp/cc, accumulation mode aerosol >110 nm concentration was in order of thousands per cc. We landed in Lima at 18:42 UTC. (Radek Krejci)
top of page overviewDate: 17-Mar-2000, 2nd flight
Route: Lima - Santiago de Chile (Ferry flight)
Take-off and landing time:
20:15:31 - 23:28:58 (UTC)
72931 s - 84538 s (seconds past 00:00:00 UTC)
Crew: Welser, Vogel (pilots), Hinz (flight engineer), Krejci, Stock (payload operators)
Flight log:
At 20:15 UTC we took off from Lima. During ascend we passed 3 hazy layers with enhanced aerosol concentration. At our cruising altitude 37 000 ft we intercept for 15 minutes layer of cirrus clouds. Particle concentration (> 6 nm) was relatively high between 1500 and 5000 pp/cc close to the cirrus clouds. Enhancement in aerosol concentration continued for next 50 minutes after we left cirrus clouds behind. At 20o S compact layer of stratiform clouds over the Pacific was observed. Around 25o S aerosol concentration (> 6 nm) decreased rapidly close to 100 pp/cc as we probably passed through subtropical jet stream. During the descent towards Santiago, in boundary layer we observed similar level of pollution as over Lima and Mexico City. (Radek Krejci)
top of page overviewDate: 18-Mar-2000
Route: Santiago de Chile - Punta Arenas (Ferry flight)
Take-off and landing time:
18:31:43 - 21:24:13 (UTC)
66703 s - 77053 s (seconds past 00:00:00 UTC)
Crew: Welser, Vogel (pilots), Hinz (flight engineer), Krejci, Stock (payload operators)
Flight log:
Take off from Santiago was delayed by more than 3 hours due to complications with handling at the airport. Finally we took off at 18:31 UTC. Similar to previous vertical profiles we passed number of hazy layers in lower troposphere with enhanced aerosol concentration. During first 20 minutes no clouds were observed with exception of stratocumulus cloud deck over the Pacific and particle concentration (> 6 nm) was very low around 50 pp/cc. At 35o S and flight level 370 Falcon flown into upper part of cirrus clouds. All measured parameters were very low (aerosol, No, NOy, CO, O3). As we moved towards south, we flown closer and closer to tropopause and some 20 minutes before descent to Punta Arenas we intercept tropopause at altitude 37 000 ft. Landing at 21:24 UTC. (Radek Krejci)
top of page overviewDate: 23-Mar-2000, 1st flight
Route: Punta Arenas - Punta Arenas (Technical flight)
Take-off and landing time:
14:39:16 - 16:02:10 (UTC)
52756 s - 57730 s (seconds past 00:00:00 UTC)
Crew: Welser, Sauer (pilots), Hinz (flight engineer), Fink (Chilean Air Force), Seifert, Gayet, Petzold (payload operators)
Flight log:
The flight track was of triangle shape with a climb to the South (55°30' S, 71° W), then a leg towards North-West with the end point at 54° S and 74° W, and from there back to Punta Arenas. The second leg of the triangle was almost completely in cirrus clouds at 8100 m altitude (350 hPa, 230 K air temperature). Ascents and descents trough the cloud layer were performed. The air chemistry payload was not operated on this flight. During descent to Punta Arenas penetration of low level clouds. (Andreas Petzold)
top of page overviewDate: 23-Mar-2000, 2nd flight
Route: Punta Arenas - Punta Arenas (Technical flight)
Take-off and landing time:
19:05:00 - 20:28:27 (UTC)
68700 s - 73707 s (seconds past 00:00:00 UTC)
Crew: Welser, Sauer (pilots), Hinz (flight engineer), Fink (Chilean Air Force), Seifert, Baehr, Minikin (payload operators)
Flight log:
The flight track was identical to the first technical flight. On this flight the Polar Nephelometer was not operated. and the cirrus layer had partly dissolved compared to the first flight. Nevertheless some cirrus cloud fields have been penetrated. First results of the air chemistry measurements: In the first part of the flight during measurements in the upper troposphere the observed NO, NOy, O3, and CO volume mixing ratios were pretty low around 10 pptv, 100 pptv, 30 ppbv, and 50 ppbv, respectively. During the second part of the flight the Falcon sampled air near the local tropopause with much higher trace gas abundance's, e.g. 130 ppbv O3. The measured NO/NOy-ratios of about 0.1 in the upper troposphere are significantly smaller than observed at northern mid-latitudes over the eastern North Atlantic.
top of page overviewDate: 24-Mar-2000
Route: Punta Arenas - Punta Arenas (Mission flight)
Take-off and landing time:
20:20:01 - 23:14:48 (UTC)
73201 s - 83688 s (seconds past 00:00:00 UTC)
Crew: Welser, Sauer (pilots), Hinz (flight engineer), Seifert, Baehr, Petzold, Fournol (payload operators)
Flight log:
For the first mission a cirrus cloud field over sea north-west of Punta Arenas was identified as target area. Takeoff was at 20:20 UTC, the Falcon climbed towards North-West to reach a cirrus cloud field over sea. From FL 300 the crew selected a cirrus field slightly south of the actual position. L-shaped pattern were flown inside the cloud at three different levels (FL 246, 210, and 195, respectively). The relevant temperatures at these levels were 237, 244, and 246 K. The legs of the L were oriented against the wind direction and perpendicular to it. In the medium level the cloud structure was quite homogeneous inside the cirrus, in the upper level the cirrus was thinner, and in the lower level probably some tops of cumulus type clouds have been penetrated. At the end a profile up to FL 350 was flown, which clearly reached into the stratosphere. During descent the cirrus layer top was recorded at about 7230 m altitude (238 K), the base was at about 5000 m altitude (252 K). Lower level clouds were observed to be clearly separated from this cirrus layer. (Andreas Petzold)
top of page overviewDate: 31-Mar-2000, 1st flight
Route: Punta Arenas - Punta Arenas (Mission flight)
Take-off and landing time:
13:22:54 - 16:34:30 (UTC)
48174 s - 59670 s (seconds past 00:00:00 UTC)
Crew: Scherdel, Sauer (pilots), Marschall (flight engineer), Ström (mission scientist), Stock, Gayet, Minikin (payload operators)
Flight log:
The second measuring flight went well and according to schedule. From take-off the Falcon climbed to a level well above all clouds to find the cloud top altitude. The cirrus cloud was part of a system that approached from the west, with humid air extending trough out the troposphere. The top of the cloud was composed of a thin layer with some hundred meters of cloud free air in between this layer and the main body of the cloud. The first flight level was performed at an altitude of about 10 km in the top of the cloud. Six flight legs of approximately 10 to 15 minutes were performed above each other with an altitude difference of about 600m. The interior of the cloud was fairly homogenous and opaque. At the upper level a 22-degree Halo phenomenon could be observed. At the lowest flight level, at an altitude of about 6km, liquid water was present. The Falcon ascended through the cloud again before commencing a stepwise descent back to the airport. For part of the flight the 2DC-probe did not operate and the PCASP for residual particles was inoperative during the entire flight. (Johan Ström)
top of page overviewDate: 31-Mar-2000, 2nd flight
Route: Punta Arenas - Punta Arenas (Mission flight)
Take-off and landing time:
19:20:58 - 23:11:28 (UTC)
69658 s - 83488 s (seconds past 00:00:00 UTC)
Crew: Sauer, Scherdel (pilots), Marschall (flight engineer), Petzold (mission scientist), Seifert, Baehr, Fournol (payload operators)
Flight log:
The second flight of today was set up similar to the morning flight. The cloud system has moved 2 degree towards east compared to the morning situation, while the lateral extension remained almost constant. Contrary to the morning flight, the pattern was reduced to 4 levels inside the cirrus clouds, while the length of each leg was extended to get as close as possible to the rear edge of the system. After take-off at 19:20 UTC the Falcon climbed to FL 370 to get above the cloud top. Flight legs were then performed at FL 360 (T = 214K), FL 330 (T = 222K), FL 300 (T = 228K), and FL 270 (T = 235K). Uppermost and lowermost tracks matched cloud top and cloud base, respectively, very good. By extending the flight time per leg, we managed to get almost to the rear edge of the system, as expected. The cloud system itself turned out to be very homogeneous in the lateral direction. There was a clear gap between the cirrus deck and clouds at the lower levels. Most of the instruments worked very well during this flight. Total flight time was 3 hours 50 minutes. (Andreas Petzold)
top of page overviewDate: 03-Apr-2000
Route: Punta Arenas - Punta Arenas (Mission flight)
Take-off and landing time:
19:17:30 - 22:48:02 (UTC)
69450 s - 82082 s (seconds past 00:00:00 UTC)
Crew: Scherdel, Sauer (pilots), Marschall (flight engineer), Petzold (mission scientist), Krejci, Stock, Gayet (payload operators)
Flight log:
Satellite images of today showed a cirrus field southwest of Punta Arenas at an altitude of about 350 hPa. Ahead of the cloud field there was an area of dry air being completely cloud-free. The flight pattern was chosen such that at the cloud level a distinct part of the flight track should lead through dry air to get a good contrast between in cloud and out of cloud. Take-off for that flight mission was at 19:17 UTC. The upper cirrus field was found at FL 300 were the flight pattern started. Three transects were flown at FL 300, FL 310, and FL 320. Respective temperatures were 226 K, 222 K, and 219 K. At all flight levels the clouds showed a very patchy lateral structure with well developed sequences in cloud and out of cloud. From that point the observed cirrus clouds showed the lateral structure cirrus clouds are usually thought to have. After finishing this three flight legs the following tracks were shifted to the south along with the wind to catch same air masses again. Two legs at FL 310 and FL 290 were repeated inside clouds as well as ahead of the leading edge of the cirrus field. The flight was finished by a climb to FL 350 followed by a stacked decent to Punta Arenas. Landing was at 22:38 UTC. (Andreas Petzold)
top of page overviewDate: 04-Apr-2000
Route: Punta Arenas - Punta Arenas (Mission flight)
Take-off and landing time:
18:04:33 - 21:44:38 (UTC)
65073 s - 78278 s (seconds past 00:00:00 UTC)
Crew: Scherdel, Sauer (pilots), Marschall (flight engineer), Ström (mission scientist), Minikin, Baehr, Auriol (payload operators)
Flight log:
The objective of todays flight was to fly to the southwest to intercept a cloud field that was approaching the continent from the west. The air mass trajectories suggested that this cloud field might be made up of air of different origin. After about a one-hour transfer flight in clear air, but with high clouds around, the Falcon reached the main cloud field. Two longer stretches at flight level (fl) 300 and 280 were performed towards the southwest in rather patchy cirrus. Before returning back an ascent to above the cloud field at fl 330 was shortly followed by a descent to fl 230 in order to get a vertical profile close to the turning point. This two levels where different by some 30 degrees in temperature, and very different crystal shapes. The lowest levels presented the most clear hexagonal type crystals whereas the intermediate levels showed some very complexes shapes. At the upper levels the crystals where generally very small. After reaching the lowest level the aircraft again ascended to fl 260, where it remained until the cloud had been traversed completely. The flight was ended by performing the standard ” Schlager profile”, which means to first climb to fl350 and then make a stepwise descent stopping for some minutes at different levels. All instruments appear to have worked well. (Johan Ström)
top of page overviewDate: 05-Apr-2000
Route: Punta Arenas - Punta Arenas (Mission flight)
Take-off and landing time:
16:58:26 - 20:39:05 (UTC)
61106 s - 74345 s (seconds past 00:00:00 UTC)
Crew: Scherdel, Sauer (pilots), Marschall (flight engineer), Petzold (mission scientist), Seifert, Gayet, Stock (payload operators)
Flight log:
Forecast for today’s flight showed strong lee wave activities well above Punta Arenas. The flight therefore was dedicated to investigate aerosol-cloud interaction under lee wave conditions. Take-off time was 16:58. During climb to flight level 310 a very thick cloud layer was traversed which extended from 2780 m altitude (T = 265 K) to 9300 m Altitude (T = 228 K). In the lower part a mixture of supercooled droplets and ice crystals was observed. The wave cloud itself was penetrated at flight levels 310 (T = 227 K) and 300 (T = 230 K). At both levels the dry air masses upwind of the lee wave were measured before entering the wave cloud to provide comparison data for the measurements inside the cloud. Additionally the lower flight level was flown twice to measure both NOy and NO. The plume of the Falcon was traversed on the final leg inside the cloud. All instruments worked well during the flight. Landing was at 20:39. (Andreas Petzold)
top of page overviewDate: 06-Apr-2000
Route: Punta Arenas - Punta Arenas (Mission flight)
Take-off and landing time:
22:06:38 - 01:59:00 (UTC)
79598 s - 93540 s (seconds past 00:00:00 UTC)
Crew: Scherdel, Sauer (pilots), Marschall (flight engineer), Minikin (mission scientist), Baehr, Auriol, Seifert (payload operators)
Flight log:
Today’s flight was scheduled for a take-off at late afternoon to allow for measurements in darkness under conditions of negligible photochemical activity. The satellite image showed a cirrus cloud band extending roughly from north-west to south-east and approaching Punta Arenas from the west. Due to maintenance work at the airport, take-off, originally scheduled for 21:00 UTC, had to be delayed for one hour. Take-off finally was at 22:07 UTC (18:07 local time). During climb to flight level (FL) 330 water clouds were passed between 3400 m and 5100 m altitude. The heading was set south-west in the direction of a point assumed to be well behind the cloud band at 80 degrees west and 60 degrees south. After 30 min of flight in clear sky the cirrus field was reached and entered from above at FL 290. Descent into the cirrus cloud was continued down to FL 250 (236 K) where cirrus was visually still perceivable. Continuing at that level for about 20 min the far end of the cloud field was passed. We returned at that point, climbed to FL 285 (227 K) and re-entered the cirrus close to the top of the clouds, continuing at that level for about 30 min (129 nm distance). During that flight leg, around 19:30 local time (23:30 UTC), it was getting too dark outside to determine visually the presence of cirrus. We decided to return once more to the far end of the cloud and fly two intermediate flight legs at levels FL 275 (outward) and FL 265 (homeward). Cloud particles were detected by the instruments on board at all levels in the flight pattern, however the cloud field proved to be rather patchy. It appeared that in contrast to day-time measurements the concentration of ultra-fine condensation particles in the cloud tops is distinctly lower. On the flight back to Punta Arenas the usual descend profile was flown after a climb to FL 350. Cirrus clouds were penetrated during this descend. Unfortunately, parallel measurements of the ground-based LIDAR of the AWI were not possible due to lower level water clouds over Punta Arenas. Touch-down was at 21:59 local time (1:59 UTC on April 7, 2000). All instruments seem to have performed very well. (Andreas Minikin).
top of page overviewDate: 10-Apr-2000
Route: Punta Arenas - Punta Arenas (Mission flight)
Take-off and landing time:
19:35:41 - 23:31:45 (UTC)
70541 s - 84705 s (seconds past 00:00:00 UTC)
Crew: Scherdel, Sauer (pilots), Marschall (flight engineer), Minikin (mission scientist), Baehr, Gayet, Seifert (payload operators)
Flight log:
The main objective of today's flight was to fly into the very thin and scattered cirrus which has been observed on many flights before to occur somewhat separated on top of larger cirrus cloud fields. Satellite pictures showed a cirrus cloud field approaching from the west. It was expected that this field would reach Punta Arenas around local evening time allowing potentially for parallel LIDAR measurements from the ground. Take-off was at 19:35 UTC (15:35 local time). Course was set to a waypoint lying about 150 nm southwest (heading 240 deg) of Punta Arenas. After climbing to FL 380 some thin and patchy cirrus was encountered occasionally whilst a larger but scattered cirrus cloud field was visible below. To continue measurements close to the top of the cirrus clouds we turned around at the outer waypoint and flew between there and Punta Arenas altogether five more flight legs at different altitudes (FL 375, FL 370, FL 365, FL 350, FL 345/340). In-between, one leg was extended to fly directly over Punta Arenas at FL 260 through cirrus which was observed by the LIDAR system at the same time as was reported by direct radio communication. The flight ended with a climb to FL 380 and the standard stepwise descent performed this time directly over Punta Arenas. Again cirrus was encountered which was measured at the same time by the LIDAR. Landing was at 23:31 UTC (19:31 local time). Though it turned out that the more homogeneous main cirrus field that was observed on the satellite image was reached close to the outer waypoint only at the last two of the six flight legs, the flight was successful in obtaining measurements at the tops of several cirrus clouds at relatively cold temperatures (down to -60 deg C). The topmost visible cirrus layers were extremely thin (clearly much less than 500 ft) and very scattered, therefore measurement times in individual topmost cloud fractions range from only seconds to minutes at most. This time there were a few instrument problems (3025 CN counter and cloud aerosol DMA not working) but apart from that the main set of instruments performed very well again. (Andreas Minikin)
top of page overviewDate: 12-Apr-2000
Route: Punta Arenas - Punta Arenas (Mission flight)
Take-off and landing time:
12:55:31 - 16:43:08 (UTC)
46531 s - 60188 s (seconds past 00:00:00 UTC)
Crew: Scherdel, Sauer (pilots), Marschall (flight engineer), Ziereis (mission scientist), Fiebig, Auriol, Seifert (payload operators)
Flight log:
The flight on April 12 was dedicated to probe a cirrus cloud belt associated with a jet stream west of Punta Arenas. Take off was at 9 local time. Landing 12:45. All instruments on board worked well. A flight pattern was chosen that crossed the cloud belt several times flying with the wind outside the cloud belt and against the wind inside the cloud belt. The crossings were performed at the FL330, 320, 310, and 290. The cirrus cloud was hit several times. This was clearly detected by all particle instruments on board of the Falcon. Associated with the jet stream was a tropopause fault. This could be derived by the trace gas and water vapor measurements. In the cloud free, presumably stratospheric part of the flight track, ozone values up to 200 ppbv and water vapor values down to 10 ppmv. CO was perfectly anticorrelated with ozone with minimum values of about 20 ppbv. During the flight back to Punta Arenas an other cirrus cloud was crossed. (Helmut Ziereis)
top of page overviewDate: 13-Apr-2000
Route: Punta Arenas - Punta Arenas (Mission flight)
Take-off and landing time:
20:56:31 - 00:46:50 (UTC)
75391 s - 89210 s (seconds past 00:00:00 UTC)
Crew: Scherdel, Sauer (pilots), Marschall (flight engineer), Minikin (mission scientist), Krejci, Auriol, Baehr (payload operators)
Flight log:
Today was the last scientific mission flight from Punta Arenas. It was scheduled for a take-off in late afternoon to repeat cirrus cloud measurements under conditions of low or negligible photochemical activity. A cirrus cloud band connected to a cold front was approaching from the west. After take-off at 20:56 UTC (16:56 local time) we headed southwest to find the cloud tops at around flight level (FL) 350. We then descended to the apparent base of the cirrus cloud layers close to FL 210 continuing out to a distance of 170 nm from Punta Arenas. On that track seven more flight legs were flown at increasing altitudes (FL 250, 275, 280, 300, 330, 335, 350). Unfortunately, the cloud system was moving very quickly south east leaving only rather scattered and dissolving cirrus behind, which was only barely visible after sunset. Therefore there was almost no cirrus encountered above FL 300. However, before landing in Punta Arenas cirrus observations by the LIDAR were reported from ground. Several flight levels were tested in darkness and cirrus was found over Punta Arenas mainly near to FL 290. The LIDAR was measuring at the same time. It appeared that this cirrus cloud was rather stationary and therefore caused by lee wave activity. Landing was at 00:47 UTC (20:47 local time). All flight operations throughout the campaign in Punta Arenas went very smooth and on behalf of all scientists I would like to express our gratitude towards the excellent flight crew. (Andreas Minikin)
top of page overviewDate: 16-Apr-2000, 1st flight
Route: Punta Arenas - Puerto Montt (Ferry flight)
Take-off and landing time:
13:12:35 - 15:02:57 (UTC)
47555 s - 54177 s (seconds past 00:00:00 UTC)
Crew: Scherdel, Sauer (pilots), Marschall (flight engineer), Baehr (payload operator)
Flight log:
At 13:12 UTC we left Punta Arenas. While the Falcon climbed to Flightlevel 345 we did not enter clouds. The field of stratocumuli was not very dense and at about a 13:45 UTC we could see very well the mountains and glaciers of the national park Torre de Peine. The CO detector measured max. 70 ppb CO as expected in this area. At 14:36 we began to descend. When we landed at 15:00 UTC the weather in Puerto Montt was sunny and only a few high cirrus could be seen. Before the next take off there was about an hour left for calibration of the NO-measurement system. (Janine Baehr)
top of page overviewDate: 16-Apr-2000, 2nd flight
Route: Puerto Montt - Fóz do Iguaçú (Ferry flight)
Take-off and landing time:
16:16:47 - 19:52:54 (UTC)
58607 s - 71574 s (seconds past 00:00:00 UTC)
Crew: Scherdel, Sauer (pilots), Marschall (flight engineer), Baehr (payload operator)
Flight log:
The Take off in Puerto Montt was at 16:16 UTC. After about half an hour we reached the FL 370 and below us was a stratocumuli field. The ozone concentration at this flightlevel was between 90 and 140 ppb (max. 200 ppb). Above the low cloud level there could be seen thin Cirrus layers. The Falcon was flying above this highest cloud level (maybe in tropopause). Particle concentrations (N3) were around 100 pp/cc. After 17:45 UTC the ozone decreased to ca. 40 ppb propably entering the upper tropospere. Until 18:15 UTC the Falcon was approaching the top of the cirrus layer and about 18:30 UTC this layer was already above the Falcon. Because the cirrus level was around the cruising altitude the particle counter > 3,5 nm showed higher counting rates (e.g. 600 pp/cc). Whereas at the beginning of the flight about 60 ppb CO were measured, the CO concentration increased continously during the flight and transcended 130 ppb at about 19:00 UTC. In Fóz do Iguaçú heavy rainfalls were predicted. During the descent we passed several layers of clouds (in cirrus at FL 370; layer between FL 300 and FL 285; cumuli below FL 250). Because of the bad weather conditions we had a turbulent landing (landing about 20:00 UTC). (Janine Baehr)
top of page overviewDate: 18-Apr-2000, 1st flight
Route: Fóz do Iguaçú - Recife (Ferry flight)
Take-off and landing time:
11:55:16 - 15:49:03 (UTC)
42916 s - 56943 s (seconds past 00:00:00 UTC)
Crew: Scherdel, Sauer (pilots), Marschall (flight engineer), Baehr (payload operator)
Flight log:
Before the start (11:55 UTC) it was raining very strongly. The lowest cloud level (scattered cumuli) began at 1500 ft. During the climb we passed several cloud layers (e.g. 12:22 UTC FL 340 in cloud). Above the cumuli nimbus was a thin cirrus layer that we more or less entered in cruising altitude (FL 370). At around 13:00 UTC the clouds dispersed that one could shortly see the Brazilian ground. The low stratocumuli as well as the different higher cloud layers accompanied us until Recife. Being in the upper cirrus layer you could see the halo 22° very well. At cruising altitude the CO concentration was around 130 ppb until 14:10 UTC. Then the CO level dropped to 90 ppb. The ozone concentration did not pass 60 ppb during the whole flight. At 15:20 UTC the descend began. When the Falcon landed at around 15:45 UTC the cloud ceiling was at 3000 ft. (Janine Baehr)
top of page overviewDate: 18-Apr-2000, 2nd flight
Route: Recife - Sal (Ferry flight)
Take-off and landing time:
17:36:35 - 21:42:27 (UTC)
63395 s - 78147 s (seconds past 00:00:00 UTC)
Crew: Scherdel, Sauer (pilots), Marschall (flight engineer), Baehr (payload operator)
Flight log:
The take off in Recife was at 17:36 UTC (29° C; ceiling of the stratocumuli at 1200 ft). We climbed to FL 370. You could see the Atlantic under some stratocumuli fields. The ozone concentration was varying around 40 ppb. At 19:01 UTC we passed the equator. At 19:45 UTC we observed the cirrus outflow of a cumulus nimbus. After advancing further we measured partly in a thin cirrus layer. From 20:00 UTC on to 20:30 UTC the ozone level increased to 65 ppb. After sunset the moon rose at 20:15 UTC. In the moonshine one could still see the scattered stratocumuli over the ocean and some high cirrus. At 21:13 UTC the Falcon began to descend in order to reach Sal at around 21:30 UTC. (Janine Baehr)
top of page overviewDate: 19-Apr-2000
Route: Sal - Sevilla (Ferry flight)
Take-off and landing time:
13:57:58 - 17:31:27 (UTC)
50278 s - 63087 s (seconds past 00:00:00 UTC)
Crew: Scherdel, Sauer (pilots), Marschall (flight engineer), Baehr (payload operator)
Flight log:
In Sal the temperature was about 27°C and it was hazy when we started at 13:58 UTC. The first clouds have been in the altitude of 3000 ft. At FL 150 we left the stratus below us. Ozone concentrations in the troposphere were around 50 ppb. At 14:35 UTC we reached the cruising altitude of 37000 ft. The ozone concentration increased slowly reaching its maximum at 160 ppb at about 15:00 UTC. Flying over the Islas Canarias it was often turbulent because of the influence of the jetstream. This phenomenon provoced variations in the NO concentration and the particle counts. After passing the jetstream the Tropopause was according to the weather forecast at FL 400. At 17:10 UTC the Falcon began to descend. Above Spain stratocumuli and a few cirrus clouds could be seen. The maximum CO-concentration measured during this flight was around 160 ppb. The landing was at 17:31 UTC. (Janine Baehr)
top of page overviewDate: 20-Apr-2000
Route: Sevilla - Oberpfaffenhofen (Ferry flight)
Take-off and landing time:
11:58:53 - 14:29:21 (UTC)
43133 s - 52161 s (seconds past 00:00:00 UTC)
Crew: Scherdel, Sauer (pilots), Marschall (flight engineer), Baehr (payload operator)
Flight log:
The Take off in Sevilla was at 11:59 UTC. The lower limit of the stratocumuli was in the altitude of 1400 ft. Above the first cloud layer were a few scattered altocumuli and finally a thin cirrus layer (~ FL 340). The planned cruising altitude – as long as the air traffic it allowed – was FL 350. At 13:00 UTC we followed for some minutes a contrail measuring about 0,5 ppb NO and 1,5 ppb NOy respectively. The Falcon probably crossed another contrail because the concentrations increased for a short period up to 2,5 ppb NO and 4 ppb NOy. At 13:27 UTC we reached the top of a cloud field and the NO concentrations decreased to less than 0,05 ppb NO and 0,4 ppb NOy respectively. After crossing the cloud field one could see the Alps with cirrus clouds above. At 14:30 UTC we landed in the sunny Oberpfaffenhofen. (Janine Baehr)
top of page overviewDate: 20-Sep-2000
Route: Oberpfaffenhofen - Oberpfaffenhofen (Test flight)
Take-off and landing time:
14:29:47 - 16:17:59 (UTC)
52187 s - 58679 s (seconds past 00:00:00 UTC)
Crew: Welser, Widmann (pilots), Hinz (flight engineer), Petzold, Krejci, Fournol, Stock (payload operators)
Flight log:
[No report]
top of page overviewDate: 25-Sep-2000
Route: Oberpfaffenhofen - Prestwick (Ferry flight)
Take-off and landing time:
08:12:51 - 10:24:22 (UTC)
29571 s - 37462 s (seconds past 00:00:00 UTC)
Crew: Welser, Widmann (pilots), Hinz (flight engineer), Minikin, Baehr, Seifert (payload operators)
Flight log:
The main purpose of this flight was the transfer of the Falcon from Oberpfaffenhofen to Glasgow Prestwick International Airport, the base of the INCA flight operations in the next three weeks. The Falcon already carried the full scientific instrumentation, however the polar nephelometer, the LMD hygrometer and the 2D-C probe were inoperative during this flight. All other instruments were working nicely, so the few problems found during the previous test flight were fixed successfully. The flight took us on a fairly direct route from Munich to Prestwick over the central Netherlands and the North Sea. At the cruising altitude of 35000 ft (10650 m) the Falcon was out of clouds for most of the time with the exception of a few thin cirrus clouds encountered for about 10 min during the first part of the flight. During descend water clouds extended from about 2400 m altitude down to about 200 m above ground. The Falcon landed in Prestwick in heavy Scottish autumn rain. (Andreas Minikin)
top of page overviewDate: 27-Sep-2000
Route: Prestwick - Prestwick (Mission flight)
Take-off and landing time:
13:09:35 - 16:04:50 (UTC)
47375 s - 57890 s (seconds past 00:00:00 UTC)
Crew: Welser, Widmann (pilots) , Hinz (flight engineer), Petzold (mission scientist), Stock, Gayet, Seifert (payload operators)
Flight log:
The first flight of the INCA Prestwick period was dedicated to probe a cirrus field approaching from SW. After take-off the Falcon was heading north to 59°N 5°W. From this turning point the cloud field was entered at flight levels 330, 310, and 290. Flight tracks were oriented SW - NE, being almost aligned with the wind. Each leg lasted about 25 min. The Falcon flew perpendicular to the westbound traffic from Europe to North America. The operation area was located NE from the flight corridor, so that polluted air masses were transported into the operation area. The cloud top was located at FL 330 with T = 222 K. Respective temperatures at lower flight levels were 228 K and 234 K, respectively. The tropopause was located at FL 340 (T = 219 K). The SW to NE oriented flight tracks partially covered cloud-free areas, which gives good sequences for in-cloud out-of-cloud comparison studies. At the end of the flight a climb into the lowermost stratosphere and a stacked descent towards Prestwick were performed. No cirrus clouds were observed above the thermal tropopause. All instruments were working well. (Andreas Petzold)
top of page overviewDate: 29-Sep-2000
Route: Prestwick - Prestwick (Mission flight)
Take-off and landing time:
13:33:45 - 16:41:20 (UTC)
48825 s - 60080 s (seconds past 00:00:00 UTC)
Crew: Welser, Widmann (pilots), Hinz (flight engineer), Minikin (mission scientist), Auriol, Baehr, Krejci (payload operators)
Flight log:
For today satellite images and model predictions indicated the presence of a pronounced moisture band east of the Scottish mainland with very strong winds blowing northward. Cirrus was expected to occur here, though latest satellite images shortly before take-off already indicated that probably due to subsidence in upper levels the cirrus was partly dissolving. After take-off the Falcon flow east to a waypoint at 56°N and 2.5°E located above the North Sea. At flight level (FL) 330 maximal wind velocities of up to 58 m/s were found between 2°W and 0° longitude. Some thin cirrus was encountered here, however the cirrus field was indeed very scattered and appeared to be dissolving. Following the filed flight plan the Falcon turned north at the waypoint and flew in cloud-free air for about 10 min with the wind and then back to the west at a lower flight level (FL 300). During the northward flight leg fairly homogeneous cirrus was visually observed to the right of the aircraft, therefore we decided to return to the original waypoint but this time extend the flight to the east until reaching this cirrus, again at FL 330. Inside the cirrus we turned north and continued to stay in the cloud until about 58°N. Returning back south the same cloud field was penetrated again at lower level (FL 300) and then quickly left behind after turning west to the direction of Prestwick. We descended to FL 250 to enter a lower cloud field. This was found to already consist of mixed phase cloud particles. Heading home we climbed up to FL 370 to perform the routine stepwise descent profile. Temperature and ozone measurements showed that FL 370 was still below the tropopause. During the whole of the flight, when no cloud was present, condensation nuclei (CN) concentrations were rather high at the upper levels, reaching at times 4000 particles/cm³. In cloud concentrations were up to two orders of magnitude less. The presence of ultrafine particles, both in cloud and out of cloud, indicated that particle production occurred. Non-volatile particle fractions were significantly lower than observed during the previous mission flight of 27-Sep-2000. In general we expect that this flight provided a very valuable data set for the case of dissolving cirrus. Total flight time was 3 hours 7 min. All instruments worked very well. (Andreas Minikin)
top of page overviewDate: 01-Oct-2000
Route: Prestwick - Prestwick (Mission flight)
Take-off and landing time:
13:42:01 - 16:59:05 (UTC)
49321 s - 61145 s (seconds past 00:00:00 UTC)
Crew: Welser, Widmann (pilots) , Hinz (flight engineer), Petzold (mission scientist), Ziereis, Gayet, Seifert (payload operators)
Flight log:
For this day strong southerly winds were expected throughout the whole troposphere. The Falcon was heading north of the Scottish coast at FL 330. During climb the cloud top was passed at 9800 m (T = 222 K). Like in the two flights before, a dissolving cirrus cloud field was probed. Clouds showed up to be very scattered at FL 330, with large cloud-free regions in between. However, few small haze particles seemed to be present in this cloud-free regions most of the time. The first part of the flight was spent probing a thin cirrus layer close to the cloud top (FL 330, T = 222 K) aligned with the wind, and at the very cloud base, flying against the wind (FL 310, T = 228 K). Within the cirrus cloud field, a very pronounced change of aerosol properties was observed. This change was observed on both flight altitudes. After finishing this pattern, the Falcon was heading back to the main island, looking for lee wave activities triggered by the hills of Northern Scotland. Lee wave clouds were observed only at lower levels, but not in the upper troposphere. The final climb to the lowermost stratosphere, followed by the stacked descent was performed along the lidar beam over Prestwick. Unfortunately, the lidar beam was blocked by thick low-level clouds. All instruments performed well. (Andreas Petzold)
top of page overviewDate: 03-Oct-2000, 1st flight
Route: Prestwick - Prestwick (Mission flight)
Take-off and landing time:
08:02:42 - 11:07:10 (UTC)
28962 s - 40030 s (seconds past 00:00:00 UTC)
Crew: Welser, Widmann (pilots) , Hinz (flight engineer), Petzold (mission scientist), Stock, Auriol, Seifert (payload operators)
Flight log:
For this day, a situation was expected, which permitted a quasi-lagrangian experiment. The morning flight was planned to head to SW towards the coast of Ireland to characterise an air mass with only few clouds in it. Forward trajectories indicated a slight lifting of this air mass during its transport to the NE of Scotland. This situation offered therefore the possibility to study the formation of young cirrus clouds in a beforehand characterised air mass. During the morning flight, the air mass was probed at two levels, aligned to the wind and cross-wind. The pattern was completed by a vertical profile from the uppermost free troposphere down to the flight altitude, which corresponded to –25 °C. At the upper level (FL 330, T = 228 K), only very few scattered cirrus clouds were found. On the other hand, several evaporating contrails and aged plumes were encountered. A very pronounced change in background aerosol size distribution and number concentration was observed at his level, as soon as the flight path was leading above a cirrus cloud field. This change in aerosol properties again appeared at the lower flight level (FL 280, T = 235 K). During the descent to FL 240, clouds were encountered at 8700 m (238 K), the cloud base was found at 7320 m (248 K). The lower flight level was partially in clouds partially out of clouds. For the afternoon flight the flight pattern was chosen based on the results of forward trajectory analyses and latest satellite images to allow for probing the same air mass flown through during the morning flight. The first part of the flight was conducted in the area of NE Scotland and the Orkney Islands at an altitude of 8200 m (FL 270), where the temperature was -33 °C. Here, a very homogeneous, fairly dense cirrus field was entered twice. It consisted for most of the time of ice particles, but in-between, for short time periods, the presence of super-cooled water could be measured. For the second part of the flight the Falcon ascended to 10100 m (FL 330, temperature -44 °C). Since there was no higher level cloud visible in the target region, it was decided at this stage do deviate from the original flight plan and head towards the north east to probe the only higher level cirrus that could be visually observed from the aircraft. On the way back, a descend profile down to FL 240, corresponding to the one in the morning flight, was not allowed by the air traffic control due to military operations. The flight ended with the usual climb to FL 370 end the step descend. During the descend scattered cirrus clouds with the typical shape of wave clouds were observed and partly probed. Unfortunately, during the second flight the 2D-C probe was not working due to a failure of the laser, but all other instruments worked fine. (Andreas Petzold, Andreas Minikin).
top of page overviewDate: 03-Oct-2000, 2nd flight
Route: Prestwick - Prestwick (Mission flight)
Take-off and landing time:
12:57:06 - 16:15:10 (UTC)
46626 s - 58510 s (seconds past 00:00:00 UTC)
Crew: Welser, Widmann (pilots) , Hinz (flight engineer), Minikin, Baehr, Gayet, Krejci (payload operators)
Flight log:
For this day, a situation was expected, which permitted a quasi-lagrangian experiment. The morning flight was planned to head to SW towards the coast of Ireland to characterise an air mass with only few clouds in it. Forward trajectories indicated a slight lifting of this air mass during its transport to the NE of Scotland. This situation offered therefore the possibility to study the formation of young cirrus clouds in a beforehand characterised air mass. During the morning flight, the air mass was probed at two levels, aligned to the wind and cross-wind. The pattern was completed by a vertical profile from the uppermost free troposphere down to the flight altitude, which corresponded to –25 °C. At the upper level (FL 330, T = 228 K), only very few scattered cirrus clouds were found. On the other hand, several evaporating contrails and aged plumes were encountered. A very pronounced change in background aerosol size distribution and number concentration was observed at his level, as soon as the flight path was leading above a cirrus cloud field. This change in aerosol properties again appeared at the lower flight level (FL 280, T = 235 K). During the descent to FL 240, clouds were encountered at 8700 m (238 K), the cloud base was found at 7320 m (248 K). The lower flight level was partially in clouds partially out of clouds. For the afternoon flight the flight pattern was chosen based on the results of forward trajectory analyses and latest satellite images to allow for probing the same air mass flown through during the morning flight. The first part of the flight was conducted in the area of NE Scotland and the Orkney Islands at an altitude of 8200 m (FL 270), where the temperature was -33 °C. Here, a very homogeneous, fairly dense cirrus field was entered twice. It consisted for most of the time of ice particles, but in-between, for short time periods, the presence of super-cooled water could be measured. For the second part of the flight the Falcon ascended to 10100 m (FL 330, temperature -44 °C). Since there was no higher level cloud visible in the target region, it was decided at this stage do deviate from the original flight plan and head towards the north east to probe the only higher level cirrus that could be visually observed from the aircraft. On the way back, a descend profile down to FL 240, corresponding to the one in the morning flight, was not allowed by the air traffic control due to military operations. The flight ended with the usual climb to FL 370 end the step descend. During the descend scattered cirrus clouds with the typical shape of wave clouds were observed and partly probed. Unfortunately, during the second flight the 2D-C probe was not working due to a failure of the laser, but all other instruments worked fine. (Andreas Petzold, Andreas Minikin).
top of page overviewDate: 06-Oct-2000
Route: Prestwick - Prestwick (Mission flight)
Take-off and landing time:
10:18:34 - 13:35:00 (UTC)
37114 s - 48900 s (seconds past 00:00:00 UTC)
Crew: Welser, Widmann (pilots), Hinz (flight engineer), Minikin (mission scientist), Auriol, Baehr, Seifert (payload operators)
Flight log:
This flight was planned to coincide with ground based measurements by the AWI lidar and with a satellite overpass over Prestwick. The meteorological situation was such that at upper altitudes high latitude air carrying humidity was advected by the jetstream from the north. While cirrus clouds where expected to appear in upper layers there seemed to be a good chance of having no lower clouds. For the first part of the flight a pattern was chosen where several flight levels between FL 270 and 350 were flown roughly in southwest/northeast direction north of Glasgow including several overpasses of Prestwick. Cirrus clouds were rather scattered, but visible at different altitudes. Near Prestwick cirrus was encountered by the Falcon mainly at FL 310 (temperature 250 K) and FL 330 (240 K), however, it turned out that the lidar could not detect the same clouds concurrently because of a persistent cloud cover at lower altitude. Since the cirrus in the region seemed to be dissolving and actual satellite images indicated the advection of cirrus clouds from the north the second part of the flight was directed towards the north of Scotland’s coast. The air was cloud-free for almost 45 min of flight at FL 370. Then a thin cirrus band aligned with the wind was found and followed inside at FL 330 (240 K) until to 59.3°N. The aircraft returned in the same cloud at the same altitude, which may allow for some later analysis of short scale temporal development. Aitken mode condensation nuclei concentration were generally remarkably low during the flight (between 30 and 100 particles/cm³), however it seems likely that a number of aircraft plumes have been crossed due to rather heavy aircraft traffic in the area. Particle production was observed as well. During the step descent near Prestwick cirrus clouds were penetrated again at different altitudes. This time ice clouds were present down to FL 210. There were no problems with the instruments with the exception of one channel of the Noy instrument not working, so there are no particulate NOy data available this time. (Andreas Minikin)
top of page overviewDate: 10-Oct-2000
Route: Prestwick - Prestwick (Mission flight)
Take-off and landing time:
15:14:10 - 18:24:40 (UTC)
54850 s - 66280 s (seconds past 00:00:00 UTC)
Crew: Widmann, Scherdel (pilots), Hinz (flight engineer), Minikin (mission scientist), Gayet, Seifert, Stock (payload operators)
Flight log:
Today’s satellite images showed that cloud fields at high altitudes were present over the North Sea area moving counter-clockwise around the Scottish mainland due to a rather stable low pressure system situated over Great Britain. The higher cirrus clouds in that area north of Scotland were expected to be relatively cold, which is one of the main reasons why today’s flight was directed there. After take-off at late afternoon the Falcon headed first north-west towards Stornoway on Lewis, one of the Outer Hebrides islands. The time of flight was chosen to coincide with an overpass of the NOAA-14 satellite over that area. At the time of the overpass the Falcon just entered a cloud-free area after having been in a cirrus cloud field close to the top of the clouds at flight level (FL) 280 for some minutes before, so that a comparison of in-situ data with satellite derived data is possible in this case. The Falcon continued to fly north up to 61°N and then turned east continuing to the region of the Shetland islands. This flight leg was situated all the way inside a large and fairly homogeneous cirrus field with the top of clouds gradually increasing from FL 280 to FL 300. Over the Shetland Islands we entered a triangular flight pattern with one leg flown against the wind and one perpendicular to the wind. This was done at two flight levels with the upper one at FL 330. Thin, somewhat patchy cirrus, visually hardly visible after sunset, was encountered here at a temperature of –55°C, where only very small ice crystals were detected. On the homeward flight we climbed to FL 380, which proved to be well inside the lower stratosphere, followed by the usual step descend. It was very interesting to see that the troposphere this time was rather polluted up to an altitude of 7000 m but very clean higher than that. There were no major instrument problems, so this flight produced again plenty of cirrus cloud data, fortunately this time also including cold cirrus. (Andreas Minikin)
top of page overviewDate: 12-Oct-2000, 1st flight
Route: Prestwick - Prestwick (Mission flight)
Take-off and landing time:
10:58:27 - 13:28:47 (UTC)
39507 s - 48527 s (seconds past 00:00:00 UTC)
Crew: Widmann, Scherdel (pilots), Dreiling (flight engineer), Minikin (mission scientist), Auriol, Krejci, Ziereis (payload operators)
Flight log:
The first of today’s flights was planned to include several overpasses of the ground based AWI lidar at Prestwick to provide in-situ data for comparison with the lidar measurements. Furthermore, there was a Terra satellite overpass in this area at 11:54 UTC. During the first hour of the flight the Falcon flew over Prestwick at different altitudes from east to west and back. However, again due to the presence of low level clouds, lidar measurements were not possible at the same time. Since there were only very few cirrus clouds present in the Prestwick area anyway and because we had information from the ground that according to satellite images cirrus wave clouds were developing over the central highlands we then headed north-east. Cirrus clouds were indeed found in the area. They proved to be vertically comparably thick and laterally very patchy. Wind speeds were low in the area. Measurements were made at two flight levels, at FL 270 at a temperature of 227 K and at FL 260 at 230 K. The tropospheric air even at high altitudes was found to be again quite polluted with condensation nuclei concentrations up to 5000 particles/cm³ (Aitken mode) and CO higher than 100 ppbv. Particle NOy was higher than ever observed before during both INCA campaigns. There were no instrument problems during this flight. (Andreas Minikin)
top of page overviewDate: 12-Oct-2000, 2nd flight
Route: Prestwick - Prestwick (Mission flight)
Take-off and landing time:
14:30:20 - 17:53:31 (UTC)
52220 s - 64411 s (seconds past 00:00:00 UTC)
Crew: Widmann, Scherdel (pilots), Hinz (flight engineer), Minikin (mission scientist), Baehr, Gayet, Seifert (payload operators)
Flight log:
The second of today’s flights was dedicated to the investigation of a major cirrus field at relatively cold temperatures between the Shetland Islands and the coast of Norway. Similarly to the flight made two days before, the meteorological situation was dominated by a low pressure system over the British isles and the general wind direction in the target area was north-west. The transfer to the Shetland Islands area was made at FL 330, which was well in the stratosphere this time. During the descend into the cirrus clouds close to the target area the tropopause was found to be located at around 9000 m altitude (FL 300, 222 K, -51°C). The cirrus field appeared to be very extended in all directions, though with some gaps in-between, and the top of clouds reached up to FL 290. L-shaped flight patterns was flown at three different altitudes (FL 290, 280 and 270) with one leg aligned with the wind and one perpendicular to the wind. Embedded in the cirrus were cloud turrets caused by rather intensive convection as also indicated by the occasional presence of turbulence. On the way home to Prestwick the flight level was chosen at FL 260 and below to enter the very many present convective and characteristically shaped wave clouds over the ocean and the Scottish mainland. Turbulence was encountered several times indicating strong updrafts extending into the upper troposphere. The last hour of the flight was already in twilight conditions (where the wave clouds proved to be visually particularly attractive). Obviously at this time particle production was reduced in comparison to the first part of the flight. There were two relevant satellite overpasses during the flight, one of NOAA-14 at 15:21 UTC and one of NOAA-12 at 16:20 UTC. This was the last mission flight with full scientific instrumentation during the second INCA campaign. There were fortunately no major problems with both, the aircraft and the complex instrumentation this time and during all of the campaign. For all scientists I would like to thank the excellent flight crew and everybody who contributed to the success of these measurements.
top of page overviewDate: 13-Oct-2000
Route: Prestwick - Oberpfaffenhofen (Ferry flight)
Take-off and landing time:
09:38:54 - 11:44:34 (UTC)
34734 s - 42274 s (seconds past 00:00:00 UTC)
Crew: Widmann, Scherdel (pilots), Hinz (flight engineer), Minikin (mission scientist), Baehr, Gayet, Seifert (payload operators)
Flight log:
[No report]
top of page overview