POLINAT-II

Status

(20 Nov. 1997)


The Falcon deployment in Shannon for POLINAT-2 has been completed successfully on 25 Oct. 1997. We had two intensive measuring phases (Phase I: 5 - 30 Sept. 1997, Phase II: 9 - 25 Oct. 1997). Measurements during Phase I included intercomparison flights of the Falcon with the C-130 (ACSOE/TASCIA, Figure 1), an instrumented A340 (MOZAIC, Figure 2), and the Swissair B747 (POLINAT-2/NOXAR).

The Phase II was closely co-ordinated with SONEX (SASS Ozone and Nitrogen Oxide Experiment) with 3 joint Falcon / NASA-DC-8 missions out of Shannon (Figure 3). The co-ordinated POLINAT-2/SONEX missions included formation flights for instrument intercomparison, near-field measurements of the Falcon in the DC-8 exhaust plume (Figure 4), and a joint long-range southbound survey flight. Details on the objectives and flight pattern for the missions of Phase I and II are given below.

The Falcon and DC-8 measurements are complemented by measurements on board the Swissair B747 by ETH Zuerich during in-service flights over the North Atlantic from 15-August to 20 November 1997.

The flight planning in Shannon was based on meteorological forecasts by KNMI and (for the first time for POLINAT) chemical forecasts by Uni. Bergen (special thanks to Peter van Velthoven and Frode Flatoy). In addition ATC data and also SONEX forecast products (during Phase II) were used. The Phase I and II missions provided very interesting data, in particular with respect to large scale air-traffic impacts over the eastern North Atlantic.


Flight Overview:

Measuring Phase I

Flight F1: 19 Sept. 1997, 9.30 - 14.10 UTC
Objectives: Northbound flight corridor survey; search of corridor effects.
Pattern: Constant altitude legs through (FL350) and below (FL250) flight corridor along 8 W between 53 N and 61 N, vertical soundings up to FL410 west of Shannon and east of 61 N.

Flight F2: 21 Sept. 1997, 6.25 - 10.15 UTC
Objectives: Southbound survey of trace gas distributions in the upper troposphere from Shannon to Azores.
Pattern: Constant altitude leg at FL350 from 54 N to 38 N, vertical soundings north of Shannon and north of Santa Maria up to FL390.

Flight F3: 21 Sept. 1997, 12.25 - 16.40 UTC
Objectives: Southbound survey of trace gas distributions in the middle troposphere, intercomparison between C- 130 and Falcon measurements, intersection of polluted air masses from USA north of Azores.
Pattern: 50-min formation flight of C-130 and Falcon north of Santa Maria at FL200 and FL180, constant altitude leg at FL210 from 44 N to 50 N, vertical soundings north of Santa Maria and south of Shannon.

Flight F4: 24 Sept. 1997, 5.30 - 9.45 UTC
Objectives: Intercomparison of MOZAIC and POLINAT instrumentation, measurements in conditions of long- living contrails.
Pattern: 30-min parallel measurements of Falcon behind MOZAIC/A340 (DAIGI) at a separation of 5 to 20 miles in Shannon radar zone (waypoints: EVRIN-CRK-52 20N) at FL350, return leg of Falcon along same track, vertical sounding of flight corridor south-west of Shannon up to 13km.

Flight F5: 26 Sept. 1997, 11.15 - 15.50 UTC
Objectives: Observation of accumulation of aircraft emissions in a stagnant high over central Europe, intersection of polluted air masses from USA over Shannon.
Pattern: Traverse of anticyclone at FL350 and FL410 along 53 N from 9 W to 10 E, vertical soundings over Shannon and at 53 N/10 E up to FL410.

Flight F6: 28 Sept. 1997, 10.00 - 12.35 UTC
Objectives: Intercomparison of instrumentation of NOXAR/Swissair-B747 (HBIGD) and Falcon.
Pattern: 20-min parallel measurements of Falcon and B747 in Shannon radar zone (waypoints: BANLO-DOLIP- 52 30N/14 W) at FL 320.

Flight F7: 28 Sept. 1997, 13.20 - 16.50 UTC
Objectives: Northbound flight corridor survey, search of corridor effects, intersection of polluted air masses from USA.
Pattern: Constant altitude leg through (FL350) and below flight corridor along 8 W between 53 N and 61 N, vertical soundings north of Shannon and east of 61 N/8 W up to FL400.

Measuring Phase II

Flight F8/F9: 14 Oct. 1997, 7.00 - 11.40 UTC + 13.00 - 17.30 UTC
Objectives: Southbound survey flight to Tenerife, observations in regions of high airtraffic and high lightning impact, respectively.
Pattern: Constant altitude legs at FL290 (below flight corridor levels) and FL350 (most used flight corridor level) between 52 N and 30 N, vertical profiles near Shannon and north of Tenerife.

Flight F10: 18 Oct. 1997, 13.00 - 17.00 UTC
Objectives: Crossings of flight corridor tracks with SONEX/DC-8, intercomparison of Falcon and DC-8 measurements.
Pattern: Shuttle flight between waypoints Giper (51 N/12 W) and Baban (54 N/12 W) across corridor tracks together with DC-8 at four flightlevel (FL290, FL330, FL370, FL350). For the first two flightlevel Falcon and DC-8 were at the same altitude with Falcon at about 5 miles separation behind DC-8. For the last two flightlevel DC-8 was 500 feet below Falcon to sample simultaneously primary and secondary aircraft plumes.

Flight F11/F12: 20 Oct. 1997, 8.00 - 13.00 UTC + 14.00 - 18.40 UTC
Objectives: Southbound survey flight with SONEX/DC-8 at two altitudes (below and within corridor.
Pattern: Constant altitude leg at FL370 (DC-8 at FL290) during southbound track and FL280 (DC-8 at FL350) during northbound track. Vertical profiles near Shannon and north of Tenerife (DC-8 vertical profile at 36 N and 52 N).

Flight F13: 23 Oct. 1997, 9.45 - 13.30 UTC
Objective: Intercomparison of POLINAT/Falcon and SONEX/DC-8 measurements. Near-field observations in DC-8 exhaust plume.
Pattern: Falcon/DC-8 formation flight (wing-tip by wing-tip with mile separation) with joint sampling at three altitudes (FL290, FL330, FL350) during shuttle flight between 55 N/9 W and 60 N/9 W (58 N/9 W) with a sampling time of about 40 min each level. Penetrations in DC-8 plume at a distance of about 150 meters to DC-8.

Falcon-Hercules Fly-by Falcon-Mozaic (A340) Fly-by