Two Infrared Montgolfières launched on 18 February

by Jean-Pierre Pommereau and Anne Garnier

We have succeeded to launch the two MIR (Montgolfière Infrarouge) on Friday 18 February 2000. The first (O3/Labs and meteorology LMD) 16:30 UT and the second (SAOZ, CH4, Flash-B) at 18:00 UT. For the first night they were flying at 3.6 and 4.5 hPa respectively and since the length of the day at 80N, where there are presently was very short, it is likely that they will stay at high altitude until tomorrow morning.

From the comparison with the maps of Mimosa, both are deep in the vortex which was possible yesterday only from Kiruna.

All gondolas are performing as expected including meteorological sensors and radiometers. It is too early to say something about other scientific instruments since they will not be activated before the balloon drops to 10 hpa. The only problem detected is the failure of a pressure / temperature sonde on the SALSA / SAOZ gondola when it dropped accidentally on the launch pad during launch operations. However, this will have limited consequences since there are other P and T measurements onboard the flight train.

Update on 21 February

Among the two MIRs launched last Friday one survived and the second not, automatically cut down at 55N above the Hudson Bay. The one cut down is the SAMBA O3 / LABS, LMD. Since it still emitting we are investigating the possibility of recovering it. The one which survived is the SAMBA / SAOZ / CH4 /H2O presently above Eastern Greenland and moving tonight to Spitzbergen. According to long term trajectory forecast there is a chance to keep it for at least one or two more turns around the pole. All instruments are providing data. That of SAOZ (O3, NO2, OClO, O2, O4) are excellent with small error bars. A new MIR launch is anticipated during the next pass of the vortex above Kiruna, carrying a CNES Samba payload, a LMD meteorological Rumba payload and a simple SAOZ.

Update on 24 February

MIR1 landed in the Hudson Bay will be recovered. We have found a helicopter company based 100 km from the landing point at Pointe Louis XIVin Quebec which will do it for cheap. We have had a technical debriefing meeting today to look at the 2 days of data to examine the performances achieved and identify corrections, if needed, for the future.

MIR2 is today over northern Yakutia moving toward the North Pole and Canada. All instruments are working : SAOZ, CH4, H2O, meteorological sensors and IR radiometer. The onboard SAOZ analysis is particularly perfomant. Full sunrise and sunset profiles everyday at constant tangent height steps of 1 km. Species definitely measured : O3, NO2, OClO, BrO, H2O (including stratosphere), O2, O4, atmospheric extinction and colour index.

The stratospheric vortex is still cold, denoxified below 22 km and activated (high OClO). As anticipated, trajectory and temperature predictions using the new ECMWF model are by far better than those of last year. The balloon follows closely Bjoern's predictions

The CNES meteorological data is being stored in almost real time at NILU. That of the other experiments will be transferred hopefully rapidly also. We recall you that all the data are avaible for all Lagrangian participants for carrying studies you want to, whatever is the balloon and the instrument.

The Web site http://ballon.cnes.fr:8180/ is now working very well. Informations available now are the following Derniere Position des ballons : Last ARGOS and GPS localisation. ARGOS less precise but GPS could be sometimes wrong because of transmission. GPS altitude. Updated every satellite overpass. Trajectoire des MIR : map of actual and predicted trajectories of the MIR actually in flight, updated once a day in the morning. Carte de la derniere prevision de lacher : predicted trajectory for a a launch from Kiruna at 18:00 UT today (P0), tomorrow (P1), and on the following days (P2 and P3).

Update : once a day every morning Prevision de la trajectoire des MIR. Table of predicted location and SZA every hour during the next 8 days. Updated every 30 minutes starting from the last available location. Date of the current file is that of the previous day since it uses ECMWF forecast strating at 12UT the day before.
MIR in flight : folder 928, file tp00mmdd.928. E. g. today the 24th : tp000223.928
Les fichiers de mesure: CNES Samba data : lat, long, Alt, air temp (2), pressure (2), upward and downard radiometers temperature. Updated every satellite overpass.

SHORT TERM PLANS

Support MIR flight.

MIR2 is expected to be back above Scandinavia on Sunday, in a very cold vortex with high probability of PSC. For controlling the performances of the MIR we intend to fly a small balloon also on Sunday carrying SAOZ, CH4, 2 LABS instruments of different optical arrangement and 2 O3UCAM, + PTU sondes at Kiruna and Sodankyla for checking the quality of the met sensors. It is also possible to get some good correlative measurements with the NASA OMS in situ payload willing to fly on the same day and that of the ER2 planned for Saturday and Sunday. We have made a talk at the Science team meeting yesterday at Arena Arctica to start discussing. We will be there also tomorrow. We could anticipate that the presence of PSC could change a little the planning.

MIR3 technical is ready for launch. Payloads : CNES Samba met sensors, LMD Rumba and a SAOZ. From vortex forecast there could be an opportunity as early as Saturday or Sunday. The decision will be made from predicted trajectories.
Objective: to minimise the risk of being cut rapidly at 55N.

Support MIR 2 flight. Later depending on MIR2 and MIR3 trajectories.

LONG TERM PLANS

CNES is definitely willing to have a tropical long duration / small balloon campaign in Nov/Dec 2000 in Brasil which could give us the possibility of flying spare or recovered instruments. More on that subject later.

Below you can see photos from the launch of the balloons.

Click on image to see in full resolution. Click on image to see in full resolution.
Part of the flight train under the first MIR.

Photo: Patrick Ragazzo

The second MIR is inflated and ready for launch.

Photo: Patrick Ragazzo

Click on image to see in full resolution.
The second MIR is launched and on the way to the stratosphere.

Photo: Patrick Ragazzo

Updated by Geir Braathen on 24 Feb. 2000.