Whistler Waves in the Foot of Quasi-Perpendicular Supercritical Shocks

Lalti, AhmadUppsala universitet,Institutet för rymdfysik, Uppsalaavdelningen,Rymd- och plasmafysik (author)

Whistler waves are thought to play an essential role in the dynamics of collisionless shocks. We use the magnetospheric multiscale spacecraft to study whistler waves around the lower hybrid frequency, upstream of 11 quasi-perpendicular supercritical shocks. We apply the 4-spacecraft timing method to unambiguously determine the wave vector k of whistler waves. We find that the waves are oblique to the background magnetic field with a wave-normal angle between 20 degrees and 42 degrees, and a wavelength of around 100 km, which is close to the ion inertial length. We also find that k is predominantly in the same plane as the magnetic field and the normal to the shock. By combining this precise knowledge of k with high-resolution measurements of the 3D ion velocity distribution, we show that a reflected ion beam is in resonance with the waves, opening up the possibility for wave-particle interaction between the reflected ions and the observed whistlers. The linear stability analysis of a system mimicking the observed distribution suggests that such a system can produce the observed waves.

Khotyaintsev, Yuri V.Uppsala universitet,Institutet för rymdfysik, Uppsalaavdelningen(Swepub:uu)ykh28990 (author)
Graham, Daniel B.Uppsala universitet,Institutet för rymdfysik, Uppsalaavdelningen(Swepub:uu)dangr618 (author)
Vaivads, AndrisKTH Royal Inst Technol, Sch Elect Engn & Comp Sci, Space & Plasma Phys, Stockholm, Sweden. (author)
Steinvall, KonradUppsala universitet,Rymd- och plasmafysik(Swepub:uu)konst774 (author)
Russell, Christopher T.Univ Calif Los Angeles, Dept Earth Planetary & Space Sci, Los Angeles, CA USA. (author)
Uppsala universitetInstitutet för rymdfysik, Uppsalaavdelningen (creator_code:org_t)

In:Journal of Geophysical Research - Space Physics: American Geophysical Union (AGU)127:52169-93802169-9402

By the author/editor: Lalti, Ahmad; Khotyaintsev, Yu ...; Graham, Daniel B ...; Vaivads, Andris; Steinvall, Konra ...; Russell, Christo ...

About the subject

NATURAL SCIENCES: NATURAL SCIENCES; and Physical Science ...; and Astronomy Astrop ...

NATURAL SCIENCES: NATURAL SCIENCES; and Physical Science ...; and Fusion Plasma an ...

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.