Long Duration Geomagnetic Balloon Missions as a Complement to SWARM Mission?
Filippov, Sergey; Tsvetkov, Yury
IZMIRAN, RUSSIAN FEDERATION

We promote the idea to support forthcoming Swarm multi-satellite geomagnetic mission by the long duration balloon flights that will aim at simultaneous measurement of geomagnetic field at stratospheric altitudes (20-30 km).

Tsvetkov et al. (2011a) have proposed the method allowing the experimental recovery of lithospheric field along balloon flight. The method is based on magnetic gradiometry and is patented in Russia (Tsvetkov et al., 2011b). The detailed description of the method is presented in a companion presentation (Tsvetkov et al., 2013).

IZMIRAN has designed the balloon system (Tsvetkov et al., 2005) which measures the total magnetic field (intensity F) at three altitudes with separations of 3 and 6 km (see Figures below). Twelve testing flights (1986-2010) at stratospheric altitudes have proven the reliability of the system (Tsvetkov et al., 2011c). Note that in addition to these flights there have been a few geomagnetic field balloon missions conducted by France (Cohen Y. et al., 1986; J. Achache et al., 1991) and by Japan (M. Ejiri et al., 1994).

There are a few launching pads where balloons with long duration of flight (lasting more than two weeks, and covering a few thousand km) could start on a regular basis. Most of the pads are located in Polar Regions: Longyearbyen (Svalbard Islands, Norway), Esrange (Kiruna, Sweden) and McMurdo (Antarctica). Note that Polar Regions are the most challenging regions for the geomagnetic modelling due to extremely irregular and very large contributions from the external sources. As for Russia, there are two launching pads: the first one is located near town Volsk (Volga river region) and the second one - at peninsula Kamchatka (Far East).

In summary, we believe that there are a few pros for positive answer on the title question:

  • Balloon geomagnetic measurements could provide more detailed information about the lithospheric field compared with satellite measurements;
  • The data from the balloon magnetometers could be used for validating geomagnetic field models;
  • If flights will be performed on a regular basis and measurements of a field will have satisfactory accuracy, the obtained data can be used not only for validation of the satellite models, but also for including these data for constructing of the field models;
  • Balloons could allow the geomagnetic field measurements in remote regions (oceans and polar caps), where the ground based and near-Earth data coverage is poor;
  • Magnetic measurements at balloons could be complemented by the measurements of the electric fields and atmospheric ionizers (say, cosmic rays). This could give new insight on some features of the external magnetic field;
  • Measurements of the geomagnetic field vertical gradients during the balloon flights allow more accurate separation of the lithospheric signal and the signals from the external sources.

    IZMIRAN plans to launch a few balloon flights with magnetic gradiometer onboard during Swarm mission (Prof. Yu. Tsvetkov team is included in the list of principal investigators of Swarm mission). However, only efforts of IZMIRAN will be far insufficient for the proper solution of the aforementioned problems. In this context, we invite balloon community, geomagnetic community and ESA officers to think about: how people can use available experience of the long duration balloon missions for the geomagnetic researches, in particular, for supporting Swarm mission?

    REFERENCES

    Y. P. Tsvetkov et al., 2005. Stratospheric balloon gradiometer with satellite communication link. Proceedings of the 17th ESA Symposium on European Rocket and Balloon Programmes and Related Research, Sandefjord, Norway, 30 May - 2 June, p.280 -285, ESA, SP-590, August 2005.

    Yu. P. Tsvetkov et al., 2011a. Extraction of the Anomalous Magnetic Field of the Earth from Stratospheric Balloon Magnetic Surveys at Altitudes of 20-40 km. Doklady Earth Sciences, 2011, Vol. 436, Part 1, pp. 117-121.

    Yu. P. Tsvetkov et al., 2011b. Method of separation of lithospheric field components of magnetic field of the Eath. Patent of Russian Federation N2437125 of 20.12.2011.

    Tsvetkov Yu. et al., 2011c. Balloon gradient geomagnetic surveys at stratospheric altitudes. 20th ESA Symposium on European Rocket and Balloon Programmes and Related Research, Proceedings, 22-26 May 2011, Hyeres, France.

    Yu. Tsvetkov et al., 2013. Comparison of the global analytical models of the main geomagnetic field with the stratospheric balloon magnetic data. The 2013 European Space Agency Living Planet Symposium, 9-13 September, Edinburgh, UK.

    Cohen Y. et al., 1986. Magnetic measurements on a board of stratospheric balloon. Phys. Earth and Plan. Int., V. 44. p.348-354.

    J. Achache et al., 1991. Unal. The French Programm of Circumterrestrial Magnetis Surveys Using Stratospheric Balloons. EOS Trans. Amer. Geoph. Un., V. 72, p. 97-101.

    M. Ejiri et al., 1994. Polar Patrol Balloon Project in Japan. Adv. Space Res., V.14. No. 2, p.201-209.

    The deployed system:
    3, 8, 13 - instrumental containers
    2, 7, 12 - magnetic field sensors
    5, 10 - brake parachutes
    14 - pyrolock, ensuring safe landing
    15 - saving parachute

    Launching pad at Kamchatka

    Launching pad at Volsk

    Magnetic gradiometer aboard a stratospheric balloon at the start position (Volsk)

    Examples of results: geomagnetic field (1) and its vertical gradient (2) measured at 30 km altitude, (3) - IGRF gradient

    One of the tracks of the balloon flight from Kamchatka to Ural Mountains (1996 year, 30 km height, ~6000 km length)