22 November 2002

[Report published in *Astronomy & Geophysics* **44**, 1.30-1.31 (February 2003)]

Programme

- 1000
**Coffee**(served in the Library)

- 1030
,__J Eastwood__**A Balogh**,**E Lucek**(IC),**I Dandouras**and**C Mazelle**(CESR),*Cluster observations of waves and particles in the terrestrial foreshock*- 1045
,__G A Abel__**A J Smith**(BAS),**N P Meredith**(MSSL) and**R R Anderson**(Iowa),*The evolution of substorm enhanced whistler mode waves: Why is electron energy dispersion not reflected in the waves?*- 1100
(MSSL),__N P Meredith__**R M Thorne**(UCLA),**R B Horne**(BAS),**D Summers**(MUN),**B J Fraser**(Newcastle) and**R R Anderson**(Iowa),*Statistical analysis of relativistic electron energies for cyclotron resonance with EMIC waves observed on CRRES*- 1115
and__Y Taroyan__**R Erdelyi**(Sheffield),*Steady state excitation of field line resonances by global waveguide modes in the magnetosphere*- 1130
and__A Dobbin__**A Aylward**(UCL),*Revisiting the basics of middle atmosphere flow using CMAT*- 1145
,__N Balan__**H Alleyne**(Sheffield),**S Kawamura**and**S Fukao**(Kyoto),*Mean wind velocity and tidal parameters in the mid latitude thermosphere*- 1200
and__S England__**N Arnold**(Leicester),*The impact of gravity waves on the dynamics of the mesosphere-lower thermosphere region - recent model results*- 1215
,__J A Wild__**S E Milan**,**S W H Cowley**(Leicester),**C J Owen**(MSSL) and**H Frey**(Berkeley),*Space- and ground-based observations of the structure and dynamics of the auroral ionosphere during an interval of B*_{Y}dominated interplanetary magnetic field- 1230
**A J Smith**(BAS),*MIST announcements*- 1235
**Lunch**(available in the Library)

- 1330
and__R W Sims__**S E Pryse**(Aberystwyth),*ESR line-of-sight velocities and the open/closed boundary during northward IMF in summer*- 1345
,__J P Dewhurst__**C J Owen**and**A N Fazakerley**(MSSL),*Cluster PEACE observations of thinnings and expansions of the substorm plasma sheet*- 1400
,__B Hnat__**S C Chapman**and**G Rowlands**(Warwick),*Intermittency, scaling and the Fokker-Planck approach to fluctuations of the solar wind bulk plasma parameters as seen by WIND*- 1415
,__S C Chapman__**B Hnat**(Warwick),**,**G Rowlands**N W Watkins**and**M P Freeman**(BAS),*Scaling of solar wind epsilon and the AU, AL and AE indices as seen by WIND*- 1430
and__S W Ellacott__**W P Wilkinson**(Brighton),*The heating of directly transmitted ions at perpendicular shocks: a new approach based on Lagrangian dynamics*- 1445
(IC) and__K Nykyri__**A Otto**(Alaska),*Influence of Hall effects on the Kelvin-Helmholtz instability*- 1500
**A N Fazakerley**,and__C J Owen__**J P Dewhurst**(MSSL),*Cluster PEACE observations of X-line Hall current electrons in the Earth's magnetotail?*- 1515
**Tea**(served in the Library)

- 1545
,__J Scuffham__**A Balogh**and**G Giampieri**(IC),*Modelling Mercury's magnetosphere*- 1600
,__J D Nichols__**S W H Cowley**and**E J Bunce**(Leicester),*Magnetosphere-ionosphere coupling currents in Jupiter’s middle magnetosphere: Dependence on ionospheric Pedersen conductivity and Iogenic plasma mass outflow rate*- 1615
,__P Hanlon__**M Dougherty**and**G Giampieri**(IC),*Jovian plasma sheet dynamics*- 1630
and__G Giampieri__**M K Dougherty**(IC),*Modelling of the ring current in Saturn's magnetosphere*- 1645
(UCL),__I C F Mueller-Wodarg__**R V Yelle**(Arizona),**M Mendillo**(Boston) and**A D Aylward**(UCL),*Eclipses on Titan: Effects on its upper atmosphere*- 1700
,__T Moffat__**A Aylward**and**I Mueller-Wodarg**(UCL),*Battles with the god of war: Taming the UCL Mars model*- 1715
**Close**

Alaska: University of Alaska, Fairbanks, USA

Arizona: University of Arizona, USA

BAS: British Antarctic Survey

Berkeley: University of California at Berkeley, USA

Boston: Boston University, USA

Brighton: University of Brighton

CESR: Centre d'Etude Spatiale des Rayonnements, Toulouse, France

IC: Imperial College, London; Space & Atmospheric Physics Group

Iowa: University of Iowa, USA

Kyoto: Kyoto University, Kyoto, Japan

Leicester: University of Leicester, Radio and Space Plasma Physics

MSSL: Mullard Space Science Laboratory

MUN: Memorial University of Newfoundland, Canada

Newcastle: University of Newcastle, Australia

Sheffield: University of Sheffield

UCL: University College, London; Atmospheric Physics Laboratory

UCLA: University of California at Los Angeles, USA

Warwick: University of Warwick; Space and Astrophysics Group

Meeting Report

by **J A Wild** (University of Leicester)

Published in
*Astronomy & Geophysics* **44**, 1.30-1.31 (February 2003)

This year's one-day autumn meeting of the MIST (Magnetosphere, Ionosphere and Solar-Terrestrial) community was held on 22 November 2002 at the Geological Society, Burlington House. Jim Wild reports.

The morning session of the meeting began under the
chairmanship of **Ingo Mueller-Wodarg** (University College
London). **Jonathan Eastwood** (Imperial College) presented
observations of Ultra Low-Frequency (ULF) waves in the
foreshock standing upstream of the Earth's magnetosphere.
Employing plasma and magnetic field data from the
four-spacecraft Cluster mission he was able to compare the
properties of the observed waves using single and
multi-spacecraft analysis techniques. Transferring the
discussion to the interior of the magnetospheric cavity, **Gary
Abel** (British Antarctic Survey) discussed why it is that the
energy dispersion observed in substorm-injected electrons is
not reflected in substorm-enhanced whistler waves. He
demonstrated that the evolution of whistler mode waves
would be controlled by a number of factors such as the
electron energy distribution function, as well as diffusion
and propagation effects. By studying over 800 electromagnetic
ion cyclotron wave events observed by the CRRES spacecraft
**Nigel Meredith** (Mullard Space Science Laboratory) was able to
demonstrate that pitch-angle scattering due to wave-particle
interactions with electrons of less than 2 MeV are found
within the local time range 13-18 MLT for L > 4.5. He went on
to show that these electrons are only subject to strong
scattering over a small fraction of their drift orbits,
resulting in drift averaged scattering lifetimes in
the range several hours to a day. **Youra Taroyan** (Sheffield)
addressed the shortcomings of many descriptions of long-period
magnetic pulsations. By adopting a unified approach, rather
than the separate treatment of the problems of wave excitation
and resonant coupling, a new field line resonance excitation
mechanism was presented that goes some way to reconciling some
of the discrepancies between waveguide/cavity
mode theories and observations.

In the first of three talks on the neutral atmosphere, **Alison
Dobbin** (UCL) discussed recent
developments in the Coupled Middle Atmosphere and Thermosphere
(CMAT) model. The consequences of removing gravity wave drag
and auroral momentum and energy inputs from the model were
presented and compared with a staged turn-on of each
individual process. It was suggested that during periods of
low solar and geomagnetic activity, the dynamics of the middle
atmosphere are influenced by the ionosphere above 100 km.
**Balan Nanan** (Sheffield) presented incoherent scatter radar
observations of variations in the diurnal mean wind velocity,
and the amplitude and phase of tidal effects in the
mid-latitude thermosphere. He reported that mean wind
velocity and tidal amplitudes decrease with increasing solar
activity and that the rate of decrease is notably faster for
stronger tides. **Scott England** (Leicester) went on to discuss
results from the newly developed Stratosphere to Thermosphere
Energy Variability Experiment (STEVE). After outlining the
model, the results of an investigation into the impact of
gravity waves on the dynamics of the mesosphere and lower
thermosphere using various gravity wave parameterisations in
the model were presented. Moving on to issues of
magnetosphere-ionosphere coupling, **Jim Wild** (Leicester)
employed ground- and space-based observations of the auroral
ionosphere to investigate the motion and size of the polar cap
during *B _{Y}* dominant (

Following lunch, **Nigel Meredith** (MSSL) took the chair.
**Ricky Sims** (Aberystwyth)
continued the discussion of the location of the open/closed
boundary during IMF *B _{Z}* positive conditions. Using EISCAT
Svalbard radar observations of ion temperature and flow
velocity in the dayside summer ionosphere, he demonstrated the
existence of open flux tubes convecting rapidly away from a
high latitude reconnection site and made comparisons with the
Tsyganenko magnetic field model configuration in that
region. Crossing to the magnetotail,

**Bogdan Hnat** (Warwick) presented the first of two talks to
address the multi-fractal nature of variations in geophysical
time-series. A model-independent technique of differencing
and rescaling was described that identifies self-similarity in
the Probability Density Fluctuations (PDF) in the solar wind
plasma parameters observed by the WIND spacecraft. The
discussion was continued by **Sandra Chapman** (Warwick) who
applied the finite size scaling technique to quantify the
statistical properties of the fluctuations in the *AU*, *AL* and
*AE* indices and the epsilon parameter that quantifies energy input
from the solar wind to the magnetosphere. She reported that
the exponents required to rescale the PDF of the fluctuations
are the same for all of these quantities, that self-similarity
was evident in each, and suggested that this placed important
constraints on current models of the coupled solar
wind/magnetosphere system. In the next presentation, **Steve
Ellacott** (Brighton) discussed the results of a theoretical
study in which the evolution of a Maxwellian ion velocity
distribution transmitted through a stationary 1-D
perpendicular model shock profile was investigated. By using a
Lagrangian/Hamiltonian formulation of the ion equations, he
demonstrated that it is possible to reproduce the stretching
and rotation effects observed in such ion velocity
distributions. Whilst the resultant velocity distribution
remains Gaussian in the low-temperature limit, this was found
not to be the case for higher temperature. In the final talk
to report on recent developments in modelling and simulation,
**Katariina Nykyrib** (IC) presented the results
of MHD simulations of magnetic reconnection inside small-scale
filamentary field and current structures that develop at the
flank magnetopause due to the Kelvin-Helmholtz instability.
She explained that due to the small scale of these current
structures the MHD approximation is invalid, and
that the Hall term of Ohm's law must be included. The
subsequent results of 2-D Hall-MHD simulations were presented
and compared with those from plain 2-D MHD models. **Chris
Owen** (MSSL) presented
electron and magnetic field observations from a different
reconnection region, this time in the Earth's magnetotail.
Using multi-spacecraft data from the Cluster mission, the
possible signatures of Hall currents in the vicinity of a
reconnection X-line were reported and compared with previous
single spacecraft studies. Whilst similarities with these
earlier studies were demonstrated, is was not clear whether or
not subtle differences observed during this event could be
reconciled in the framework of the model inspired by previous
observations.

The final session of the meeting, with **Gary Abel** (BAS) in the chair,
was devoted to planetary
science. **James Scuffham** (IC) reported on
the development of a magnetic field model of Mercury,
beginning with an overview of the limited observations of the
planet's magnetic field. He went on to discuss the
applicability and modifications required of existing
Terrestrial magnetospheric models in order to describe realistically
the Hermean magnetic field,
and what differences are expected between the two systems.
Switching attention to Jupiter, **Jon Nichols** (Leicester)
presented a study of magnetosphere-ionosphere coupling in the
Jovian magnetosphere. By considering the breakdown in
corotation of plasma originating from the moon Io, he
demonstrated that magnetosphere-ionosphere coupling currents
are generated and presented a realistic model of the system.
**Paul Hanlon** (IC) used magnetic field
observations from the Galileo mission to Jupiter to
investigate the structure of the current carrying plasma sheet
that dominates the Jovian magnetosphere. By studying many
plasma sheet encounters with the spacecraft, he concluded that
at distances of less than ~ 30 Jupiter Radii (*R _{J}*) from the
planet the plasma sheet is ~ 4-6

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