MULTIPLEX Ian McCrea, Tim Yeoman, Mike Kosch, Farideh Honary Mike Rietveld, Anita Aikio, Ove Havnes, Ingrid Sandahl

Polar Atmosphere Working Group: Membership PPARC funded –Dr. Ian McCrea (RAL, chair) –Prof. Farideh Honary (Lancaster) –Dr. Tim Yeoman (Leicester) NERC funded –Prof. John Plane (UEA) –Dr. Howard Roscoe (BAS) Joint funded –Prof. Nick Mitchell (Bath)

Polar Atmosphere Working Group: Context PPARC “Solar system science strategy” (2002) –Three key themes Energy flow in the solar system Fundamental plasma processes Conditions for life NERC “Science for a sustainable future” (2002) –Importance of global change –Solar effect on climate identified as a priority Town Meeting – Coseners House 30/09/2003 –Synergy between PPARC and NERC programmes –Cross-council working group to map out strategy

Polar Atmosphere Working Group: Programmes MULTIPLEX (PPARC) –Fundamental physics of energy flow –Importance of non-linear coupling –New emphasis on active techniques –Based on facilities already in operating plan –Cost £8m over five years, but only £1m is new money DEEVERT (PPARC/NERC) –Effects of solar variability on climate –Importance of non-linear coupling and wave processes –Combines PPARC and NERC observation and modelling –Uses many of same facilities as MULTIPLEX –Cost £10m over five years, half from NERC –£0.5m new money from PPARC, leverages £5m from NERC

Solar-terrestrial energy flow The problem: –Good macroscopic description of energy transfer processes exists….. …but lacks predictive power –Energy flow depends critically on non-linear coupling –Need to know which mechanisms are important and when –Need to understand how system evolves from one state to another

Solar-Terrestrial Energy Flow Composition, circulation heat balance Solar energy input Conductivity Electro- magnetic radiation Acceleration mechanisms SW energetic particles Ionisation and particle heating Solar wind Magnetic reconnection Electron and proton aurora Induced E-fields Ion drift Storage and release Neutral wind Plasma irregularities and turbulence Anomalous heating Joule dissipation Ionospheric electrodynamics Chemistry and transport Anomalous resistivity

Solar-terrestrial energy flow The problem: –Good macroscopic description of energy transfer processes exists….. …but lacks predictive power –Energy flow depends critically on non-linear coupling –Need to know which mechanisms are important and when –Need to understand how system evolves from one state to another Strategy for solution: –Active experiments allow us to stimulate non-linear processes –New, improved diagnostics –Synthesis of experimentation and modelling

The MULTIPLEX programme Why now ? –Paradigm shift from phenomenology to directed experimentation –New active experimental techniques –Major new UK facilities (e.g. SPEAR) –Novel data raising new insights and questions Why UK ? –UK is world-leading in active experimentation –UK has access to world-class instruments –UK has state-of-the-art numerical models –UK has excellent track record of exploiting international programmes

EISCAT Tromsø HF Heater

Artificial Aurora Rings form initially, collapsing into blobs Rayed structures form along magnetic field

Non-thermal signatures show that collapse of rings corresponds to features descending in altitude

EISCAT shows that strong electron temperature enhancements occur….. ….but these cannot explain the observed emission

CUTLASS observations of plasma waves show which coupling processes are involved.

Dynamics of auroral arcs

Anomalous echoes from natural aurora  coherent scatter from ion acoustic waves  structure size under 300 m at 500 km altitude  varies on 0.2 second time scale

The EISCAT Svalbard Radar

Probing wave and particle populations on open field lines

SPEAR, CUTLASS and the ESR

Off On Off On Off Plasma line amplitude Ion line amplitude

The MULTIPLEX programme: Goals Understand energy exchange between magnetosphere, ionosphere and thermosphere –Move from qualitative to quantitative understanding Quantify role of non-linear coupling in –Auroral acceleration and structure –Field-aligned currents and waves –Ionospheric irregularities –Non-thermal plasmas –Ion-neutral coupling Linkages between processes at different scale sizes Understanding key mechanisms –Proton aurora –Artificial aurora –Coherent echoes

The MULTIPLEX programme: Questions What processes mediate energy flow ? –How important is non-linearity ? –Which non-linear processes are most important ? –How are they triggered ? How can we explain observed phenomena ? –Auroral acceleration and structure –Field-aligned currents and waves –Ionospheric irregularities –Non-thermal plasmas –Ion-neutral coupling Same questions important for whole plasma universe.

The MULTIPLEX programme: Facilities EISCAT –Definitive measurements of plasma parameters –Active experiment capabilities SPEAR –Unique new UK facility for active plasma experiments CUTLASS –Measurements of global electrodynamics –Essential support for SPEAR and EISCAT experiments SIF/Tromso Imager –Studies of auroral energisation and structure FPI/SCANDI –Understanding scale sizes in thermosphere dynamics Magnetometers –Relating ULF waves and field-aligned currents Riometers –Wide-scale measurements of energetic particles

Polar Mesosphere Summer Echoes (PMSE)  Seen in EISCAT radar in last 15 years  Charged dust/ice? Breaking of upgoing gravity waves?  Early phase in the formation of noctilucent clouds? PMSE

Overshoot effect – Lower dust density, or larger dust grains ?? PMSE modulation using the EISCAT Heater

EISCAT

The importance of EISCAT EISCAT Svalbard Radar EISCAT Svalbard Radar –Essential for understanding SPEAR science –Unique new auroral interferometry capability –Invaluable context for optical data EISCAT UHF Radars EISCAT UHF Radars –Tristatic capability unique for electrodynamics –Essential for ionosphere-thermosphere coupling –Unique IPS capability for solar wind studies EISCAT VHF Radar EISCAT VHF Radar –Optimised for low-density plasma (mesosphere and topside) –Essential for full height profiles of dynamics Tromso HF Heater Tromso HF Heater –World’s leading facility for active experiments in plasma physics –Unique active experiments on mesopause phenomena

Extended runs of high latitude data… 5-23 February 2001

Present IS Radar Status 10 radars operate routinely

AMISR 384 Panels, 12,288 AEUs 3 DAQ Systems 3 Scaffold Support Structures Advanced Modular Incoherent Scatter Radar

Phased array IS radar AEU 32 AEUs = 1 panel 128 panels = 1 face (4096 AEUs) at ~2MW Possible Andøya deployment 2 panels on far-field test rig

International Polar Year 2007 is the next International Polar Year (and the 50th, 75th, and 125th anniversaries of the International Geophysical Year and the first two International Polar Years) is the next International Polar Year (and the 50th, 75th, and 125th anniversaries of the International Geophysical Year and the first two International Polar Years). Will run (at least) the high-latitude incoherent scatter radars for the entire year as part of the ICESTAR/IHY ‘cluster’. Will run (at least) the high-latitude incoherent scatter radars for the entire year as part of the ICESTAR/IHY ‘cluster’.

Aims of MULTIPLEX Quantify temporal and spatial variability of energy deposition Study large and small-scale energy transfer processes Focus on energy coupling and non-linearity Exploit both natural and artificially-generated processes Assimilate data into models for predictive studies Synergy with other studies (CAWSES, LTCS, DEEVERT, ISPAM) Establish a legacy of instruments available after IPY