M agnetosphere i onosphere c oupling m ore i s d ifferent
This presentation is the property of its rightful owner.
Sponsored Links
1 / 21

M AGNETOSPHERE -I ONOSPHERE C OUPLING M ORE I S D IFFERENT PowerPoint PPT Presentation


  • 85 Views
  • Uploaded on
  • Presentation posted in: General

M AGNETOSPHERE -I ONOSPHERE C OUPLING M ORE I S D IFFERENT. William Lotko, Dartmouth College. System perspective  qualitative differences Life cycle of an ionospheric O + plasma element Creation & Evolution Transport & Fate Impacts Reconciling models with measurements.

Download Presentation

M AGNETOSPHERE -I ONOSPHERE C OUPLING M ORE I S D IFFERENT

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


M agnetosphere i onosphere c oupling m ore i s d ifferent

MAGNETOSPHERE-IONOSPHERE COUPLING

MORE IS DIFFERENT

William Lotko, Dartmouth College

  • System perspective  qualitative differences

  • Life cycle of an ionospheric O+ plasma element

    • Creation & Evolution

    • Transport & Fate

    • Impacts

  • Reconciling models with measurements


M agnetosphere i onosphere c oupling m ore i s d ifferent

1730 UT

30º Lat

20 Nov 2003

Foster et al. ‘05


M agnetosphere i onosphere c oupling m ore i s d ifferent

1820 UT

30º Lat

20 Nov 2003

Foster et al. ‘05


M agnetosphere i onosphere c oupling m ore i s d ifferent

1945 UT

CUSP

POLAR WIND

Downward J||

BPS

Downward J||

30º Lat

20 Nov 2003

Foster et al. ‘05


M agnetosphere i onosphere c oupling m ore i s d ifferent

CUSP

Midlatitude plume

+

Electron precipitation

+

Alfvénic Poynting flux

O+ outflow

30º Lat

cf. Strangeway et al. ‘05

Zheng et al. ‘05


M agnetosphere i onosphere c oupling m ore i s d ifferent

1945 UT

BPS

30º Lat

20 Nov 2003

Foster et al. ‘05


M agnetosphere i onosphere c oupling m ore i s d ifferent

Auroral BPS

  • Patch/Plume Dynamics

  • Convects across CRB

  • Upward Vi const

  • before, during, after

  • The enhancement produces massive

  • upflux as it drifts

  • through the Boundary Plasma Sheet region.

Semeter et al. ‘03


M agnetosphere i onosphere c oupling m ore i s d ifferent

Auroral BPS

Alfvénic Poynting Fluxes

Statistical Distributions

Keiling et al. ‘03

Polar satellite data


M agnetosphere i onosphere c oupling m ore i s d ifferent

Auroral BPS

  • Intense Alfvén waves

  • Superthermal electrons

  • Ion  heating

  • Massive outflows

  • How is the Alfvénic power converted to ion heat?

    • ICRH

    • BBELF

    • coherent energization

    • stochastic energization

      What regulates the outflow mass flux?

Chaston et al. ‘03


M agnetosphere i onosphere c oupling m ore i s d ifferent

Auroral BPS

Outflow in other auroral-zone regions

Paschmann et al. ‘03


M agnetosphere i onosphere c oupling m ore i s d ifferent

1945 UT

Downward J||

Downward J||

30º Lat

20 Nov 2003

Foster et al. ‘05


M agnetosphere i onosphere c oupling m ore i s d ifferent

Downward Currents

  • BBELF turbulence

  • Superthermal electrons

  • Filamentary J||

  • Ion  heating

  • Downward E||

  •  “pressure cooker”

  • Large outflows, but limited

  • by downward E||

Lynch et al. ‘02


M agnetosphere i onosphere c oupling m ore i s d ifferent

Active Ionization and Depletion

Evans et al. ‘77


M agnetosphere i onosphere c oupling m ore i s d ifferent

Auroral Electrodynamics

Opgenoorth et al. ‘02


M agnetosphere i onosphere c oupling m ore i s d ifferent

Alfvén Wave Intensification

Feedback Instability in the

Ionospheric Alfvén Resonator

equator

J||

ENS

8.25

L = 7.25

ionosphere

t = 0 s

-5 A/m2

  • Conditions

    • Low-conductivity E region

    • Large-scale downward J||

    • Large-scale intense E

    • Strong  gradient in P

  • Effects

    • Reduced Joule dissipation

    • Filamentary J||

    • 1-10 km -scale turbulence

    • Enhanced outflow

    • Superthermal, bidirectional e

31 s

62 s

93 s

637 mV/m

124 s

-36 A/m2

Streltsov and Lotko ‘04


M agnetosphere i onosphere c oupling m ore i s d ifferent

Streltsov and Lotko ‘04


M agnetosphere i onosphere c oupling m ore i s d ifferent

Simulated Time Variation of Ne Profile in Downward Current Region

Cavity formation on bottomside is more

efficient than at F-region peak

 Bottomside gradient steepens

Doe et al. ‘95


M agnetosphere i onosphere c oupling m ore i s d ifferent

FATE

  • Plasmasheet

  • Normally H+ dominant

  • O+-rich during storms

    • O+ injections from

      Cusp fountain

      Nightside BPS

  • Stormtime substorms

  • H+ is swept away

  • Leaving O+ dominant

    pressure and density

  • Earthward injected O+

    dominates ring current

Kistler et al. ‘05


M agnetosphere i onosphere c oupling m ore i s d ifferent

FATE

Ring Current & Plasma Sheet Composition

Nose et al. ‘05


M agnetosphere i onosphere c oupling m ore i s d ifferent

IMPACT

Simulated O+/H+ Outflow into Magnetosphere

Winglee et al. ‘02


M agnetosphere i onosphere c oupling m ore i s d ifferent

Feedback

Instability

IAR

Modes

1 min

1-10 s

< 10 km

Ion Outflow ~ 10 min

Patch

Dynamics

Bottomside

Depletion

10 s

Cavity

Formation


  • Login