Guest Investigators - Cluster Science Archive
CLUSTER GUEST INVESTIGATOR OPERATIONS
The Cluster Guest Investigator (GI) Programme was established in 2010 to provide access to Cluster spacecraft science operations to the scientific community.
To date, two Announcements of Opportunity (AO) for GI operations have been issued soliciting investigations which identify compelling utilization of the Cluster spacecraft payload for scientific study. The first AO was issued on 8 July 2010 and the second AO was issued on 17 February 2014. Both AO's were open to all scientists of any nationality and research funding for the selected proposals was supported by national or other funding agencies.
Details of the GI proposals that were selected are available below:
Cluster Guest Investigator Operations, 2011-2013
Cluster Guest Investigator Operations, 2015-2016
Cluster Guest Investigator Operations, 2020-2021
CLUSTER GUEST INVESTIGATOR OPERATIONS, 2011-2013
The first Announcement of Opportunity (AO) in the Cluster Guest Investigator (GI) Programme was issued on 8 July 2010. More details about the AO can be found here: http://sci.esa.int/Cluster_AO.
Following a review in Spring/Summer 2011, by the Cluster Science Working Team and Science Operations Working Group, and by a panel organized by the Chair of the Solar System and Exploration Working Group, six GI proposals were selected.
Guest Investigator | GI proposal title | Laboratory | Implementation period |
B. Walsh | High Latitude Magnetopause Electrons | Boston University (USA) | Spring 2011 |
E. Yordanova | Small scale turbulence | Institutet för rymdfysik (Swedish Institute of Space Physics), Uppsala (Sweden) | February to April 2012 |
A. Retinò | Multi-scale observations of magnetic reconnection in the magnetosphere | LPP/UPMC/Ecole Polytechnique/CNRS (France) | May and August 2012 |
C. Foullon | Magnetopause boundary layer: evolution of plasma and turbulent characteristics along the flanks | Warwick University (United Kingdom) | November 2012 |
Z. Pu | Generation and 3-D features of flux transfer events at the dayside magnetopause | Peking University (China) | January and February 2013 |
F. Pitout | Particle acceleration and field aligned currents in the cusp | IRAP/Paul Sabatier University/CNRS (France) | Autumn 2013 |
Nominally, data is acquired all along the Cluster orbit as follows: 52.5 hours Normal Mode (NM) and 1.5 hours Burst Mode (BM). During the period of the GI operation implementation, the Cluster Science Operations Working Group defined a new style of spacecraft operations to enhance the amount of burst mode data per orbit, which benefitted the science objectives of the GI activities and other Cluster science targets. This was made possible by imposing a period of no data taking during another part of the orbit, to offset the increased load of the enhanced BM. The NM data rate is around 17 kbps (kbps: kilo bits per second) and BM is 105 kbps. So, for every extra hour of BM data, we impose 6 hours of no data taking. During the GI implementation, the maximum BM period implemented was 5 hours.
Information on specific operations is detailed below, including periods of enhanced/extended BM periods, in the order in which they were implemented.
It should be noted that the data periods discussed below were specially implemented for the GI programme and as such, the GIs have exclusive rights to the data for a 1 year proprietary period after the observations were made.
Should you wish to analyse Cluster data from during the GI periods, you are strongly encouraged to contact the project scientist team at ESTEC, via Matt Taylor (email: matthew.tayloresa.int), who will liaise with the GI teams.
GUEST INVESTIGATOR: B. WALSH
PROPOSAL TITLE: HIGH LATITUDE MAGNETOPAUSE ELECTRONS
Abstract
We propose to study electrons along the magnetopause poleward of the cusp. Many observations show energetic electrons up to hundreds of keV within the exterior cusp. Some pitch angle measurements show these particles flowing along field lines out of the cusp. We plan to observe the region along the magnetopause poleward of the cusp to determine if the energetic electron population within the cusp can be contributing to a layer of energetic particles along the magnetopause.
Implementation
As the focus of the operations was energetic electrons and there were some constraints due to the observations being located close to payload off times due to eclipses, the so-called NM3 mode was implemented, which allowed for a higher resolution data to be taken by the RAPID IES electron instrument (9 polar and 16 azimuthal angular bins at spin resolution for all 8 energy bins (40 -400 keV)).
There were no constraints on the spacecraft formation or separation, but the maximum distance between spacecraft during the magnetopause target crossings was ~1.7 RE (between spacecraft 2 and 3).
Precise timing of the NM3 data periods were as follows (from JSOC planning database):
29/03/2011
C1: 10:03:00 – 15:00:00
C2: 10:46:00 – 15:03:00
C3: 11:36:00 – 16:01:00
C4: 11:40:00 – 16:40:00
31/03/2011
C1: 15:29:00 – 20:07:00
C2: 16:07:00 – 21:34:00
C3: 17:04:00 – 21:59:00
C4: 17:09:00 – 22:39:00
02/04/2011-03/04/2011
C1: 22:06:00 – 03:06:00
C2: 22:44:00 – 03:39:00
C3: 23:00:00 – 04:30:00
C4: 23:09:00 – 04:44:00
This set of GI operations are reported in:
Walsh, B.M., Haaland, S.E., Daly, P.W., Kronberg, E.A., and Fritz, T.A., Energetic electrons along the high-latitude magnetopause, Ann. Geophys., 30, 1003-1013, 2012; doi:10.5194/angeo-30-1003-2012.
GUEST INVESTIGATOR: E. YORDANOVA
PROPOSAL TITLE: SMALL-SCALE PLASMA TURBULENCE
Abstract
The goal of the proposal is to address one of the hottest and still open questions in turbulence studies - the dissipation/dispersion range in plasma turbulence. In detail: what physical processes are responsible for the spectrum formation below the ion cyclotron scale; what turbulence is present in the dispersive range (whistler, Kinetic Alfvén Waves (KAWs), magnetoacoustic); what role does anisotropy and compressibility play in the dispersive cascade; and at which scales is the energy dissipated (ion or electron larmor radius) and what dissipation mechanism acts (ion cyclotron, electron Landau damping).
The difficulty in investigating this matter is that the small (kinetic) scales of turbulence are usually not well resolved or even inaccessible from satellite measurements. Another problem is that long data samples are necessary to ensure better quality of analysis. For this purpose, our proposal includes requests on burst mode operations when the Cluster spacecraft are in the solar wind and magnetosheath. The requests for particular instrument modes and Cluster configuration are described in the proposal.
The suggested proposal collaborates with an already running ISSI proposal: Team 185 "Dispersive cascade and dissipation in collisionless space plasma turbulence observations and simulations". Additional observations from the Artemis and STEREO missions will be used for cross-checking and comparison with the Cluster measurements.
The results from the investigation of the proposed scientific goals will help to establish the role of turbulence dissipation in processes such as plasma heating and acceleration, and small-scale magnetic reconnection, which is of general interest concerning a broader scientific (astrophysical, interplanetary and laboratory plasmas) community, as well as the design of future space missions.
Implementation
The goal was to examine turbulence anisotropy and the relative importance of the bulk speed and magnetic field direction on the plasma turbulence and development. Aligning parallel and perpendicular to the Sun–Earth direction was the closest configuration we could implement to match these requirements. This was carried out for a single pair of spacecraft, C3 and C4, which were targeted to have a separation of only ~40km shortly after apogee. The perpendicular configuration was implemented and optimised between 3 and 18 February 2012. Following manoeuvres from 20 February to 7 March, the parallel configuration was implemented and optimised between 7 and 22 March. These operations were carried out during the eclipse seasons. This constrains operations somewhat, as data must be downlink before the eclipse as, since the spacecraft is powered down during eclipse and hence the onboard memory is wiped.
The GI had identified a number of periods in the solar wind and magnetosheath suitable for the observations, with a mix of magnetosheath, and solar wind targets. Specific BM periods were then implemented within those periods as follows, in some cases with enhanced BM for the particular orbit (3 hours in stead of 1.5 hours).
2012-02-04T03:00:00 - 04:32:00
2012-02-04T11:15:00 - 12:43:00
2012-02-09T00:00:00 - 03:00:00
2012-02-11T00:00:00 - 03:00:00
2012-02-22T09:00:00 - 10:30:00
2012-02-22T13:30:00 - 15:00:00
2012-02-26T20:30:00 - 22:00:00
2012-02-27T02:30:00 - 04:00:00
2012-03-11T08:00:00 - 09:30:00
2012-03-11T17:00:00 - 18:30:00
2012-03-12T09:00:00 - 10:30:00
2012-03-12T18:00:00 - 19:30:00
2012-04-03T04:40:00 - 07:48:00
GUEST INVESTIGATOR: A. RETINÒ
PROPOSAL TITLE: MULTI-SCALE OBSERVATIONS OF MAGNETIC RECONNECTION IN THE MAGNETOSPHERE
Abstract
Magnetic reconnection is a universal process that is responsible for the major energy conversion/dissipation in the magnetosphere. A key but yet poorly understood aspect of reconnection is the coupling between electron, ion and fluid scales. Understanding this coupling requires simultaneous multi-point measurements at different scales. Such measurements are not yet available and are a current topic of discussion for future magnetospheric missions. At present the only way to investigate such coupling, although only partially, is using Cluster multi-scale configuration where two spacecraft are closely separated (~ 10 km ~ sub-ion scales) while having large separation from the others (~ 10000 km ~ MHD/fluid scales). The goal of this proposal is to investigate the cross-scale coupling at (1) the dayside magnetopause (2) near-Earth flow braking region, by using multi-instrument multi-point data from orbits in multi-scale configuration. The results expected from this study will be important to start understanding the scale coupling in reconnection and to provide a background for future multi-spacecraft spacecraft missions such as NASA/MMS and JAXA/SCOPE.
Implementation
As mentioned in the abstract above, the proposal was divided into two parts. The first part focused on multi-scale observations of the magnetopause. The observations were carried out in May 2012 and the spacecraft C1,C2 and C3 were configured in a large irregular triangle (4000-8000 km) parallel to the plane of the magnetopause. The fourth spacecraft was separated from Cluster 3 by ~65 km, in the direction perpendicular to the magnetopause. The specific GI intervals of BM are listed below:
2012-05-21T08:25:00 - 12:25:00
2012-05-23T14:19:00 - 16:19:00
2012-05-23T17:02:00 - 19:02:00
2012-05-25T21:05:00 - 2012-05-26T01:05:00
2012-05-28T03:25:00 - 07:25:00
In addition, a 40 minute period from 16:19:00-17:02:00 UT was sandwiched between BM periods and was used for WBD operations at the request of the GI. This is because WBD and BM telemetry mode are mutually exclusive.
The second part of this GI investigation focused on flow breaking in the magnetotail region. The criteria set by the GI was to focus on observations in the region (-12 < x < -9, -2 < y < 2, and -2 < z < 2, in Earth Radii in Geocentric Solar Magnetospheric coordinates). The spacecraft configuration was set up with a large-scale irregular triangle of side 9500 -5400 km formed by spacecraft C1, C2 and C3, with spacecraft C4 separated from spacecraft C3 by 310 km.
GUEST INVESTIGATOR: C. FOULLON
PROPOSAL TITLE: MAGNETOPAUSE BOUNDARY LAYER: EVOLUTION OF PLASMA AND TURBULENT CHARACTERISTICS ALONG THE FLANK
Abstract
The magnetopause and its adjacent boundary layers are a key science target for many satellite missions. They have been sampled, at the same time, either locally by a maximum of 4 to 5 closely spaced spacecraft (from the Cluster constellation and the Double Star TC-1 satellite) or on larger scales by missions such as Geotail, Cluster and THEMIS. Unfortunately, none of the spacecraft configurations has so far permitted the gevolutionh of perturbations along their main direction of propagation to be tracked. The study of the evolution of magnetic field and plasma perturbations, such as Kelvin-Helmholtz (KH) waves or Flux Transfer Events (FTEs), together with the (associated or not) generation of Kinetic Alfvén Waves (KAWs) and the turbulence developing at the flank magnetopause boundary layer, is important for our understanding of the mechanisms that mediate solar wind plasma entry into the magnetosphere, i.e. magnetic reconnection and diffusive processes. Complete study of the evolution of plasma perturbations at the magnetopause would require a series of spacecraft to be well aligned along the propagation track of the perturbations (i.e. along the flank magnetopause). We would therefore like to propose all four Cluster spacecraft to be manoeuvered along their orbits, so that they align as much as possible longitudinally along the flank at low latitudes, with approximately similar relative distances from a model magnetopause. Since the propagation speeds of the perturbations to be studied are much faster than the spacecraft speed, their tracking remains possible in this frame. Inter-spacecraft separations of ~1 Earth radii are necessary to relate the disturbances and deduce their evolution.
Implementation
As indicated in the abstract, this proposal targeted very large-scale spacecraft separations at the magnetopause, around 1 Earth radii for spacecraft pairs, resulting in separations of up to 36000 km across the constellation at the magnetopause. The resultant configuration for this set of operations was the largest separation ever for the Cluster mission. At other parts of the orbit, the spacecraft were separated along the orbit by up to 13 hours, providing very large-scale configurations in the inner magnetosphere. To obtain such a large separation with the limited fuel available was a challenge and was carried out by using a long drift time, where the spacecraft initiated a drift manoeuvre several weeks before the target period, with a secondary manoeuvre to arrest the drift just before the observation window. Due to the variable location of the magnetopause, a significant margin was used to ensure capture of the boundary and hence a large window of burst mode was implemented, bracketed by normal mode. Non-data taking periods were placed in between these and perigee so as to not lose coverage of the inner magnetosphere, to ensure conjugate measurements with the newly launched Radiation Belt Storm Probes (now renamed as the Van Allen Probes) would be lost.
The observation period spanned 9 orbits from 2 – 22 November 2012. The GI observations consisted of 10 hours of normal mode (NM), 5 hours of BM then another 10 hours of NM (although some orbits had more NM coverage later in the period). This 25-hour window was centred at the point at which the four spacecraft were almost the same distance from the magnetopause.
The specific observation times were:
2012-11-03T04:15:00 2012-11-03T14:15:00 NM
2012-11-03T14:15:00 2012-11-03T19:15:00 BM
2012-11-03T19:15:00 2012-11-04T05:15:00 NM
2012-11-05T10:40:00 2012-11-05T20:40:00 NM
2012-11-05T20:40:00 2012-11-06T01:40:00 BM
2012-11-06T01:40:00 2012-11-06T11:40:00 NM
2012-11-07T16:50:00 2012-11-08T02:50:00 NM
2012-11-08T02:50:00 2012-11-08T07:50:00 BM
2012-11-08T07:50:00 2012-11-08T17:50:00 NM
2012-11-09T23:10:00 2012-11-10T09:10:00 NM
2012-11-10T09:10:00 2012-11-10T14:10:00 BM
2012-11-10T14:10:00 2012-11-11T00:10:00 NM
2012-11-12T05:10:00 2012-11-12T15:10:00 NM
2012-11-12T15:10:00 2012-11-12T20:10:00 BM
2012-11-12T20:10:00 2012-11-13T06:10:00 NM
2012-11-14T11:20:00 2012-11-14T21:20:00 NM
2012-11-14T21:20:00 2012-11-15T02:20:00 BM
2012-11-15T02:20:00 2012-11-15T12:20:00 NM
2012-11-16T17:45:00 2012-11-17T03:45:00 NM
2012-11-17T03:45:00 2012-11-17T08:45:00 BM
2012-11-17T08:45:00 2012-11-17T18:45:00 NM
2012-11-18T03:55:00 2012-11-19T09:55:00 NM
2012-11-19T09:55:00 2012-11-19T14:55:00 BM
2012-11-19T14:55:00 2012-11-20T10:11:00 NM
2012-11-20T10:11:00 2012-11-21T16:05:00 NM
2012-11-21T16:05:00 2012-11-21T21:05:00 BM
2012-11-21T21:05:00 2012-11-22T16:28:00 NM
GUEST INVESTIGATOR: Z. PU
PROPOSAL TITLE: CLUSTER OBSERVATIONS OF GENERATION AND THREE-DIMENSIONAL FEATURES OF FLUX TRANSFER EVENTS AT THE DAYSIDE MAGNETOPAUSE
Abstract
Flux transfer events (FTEs) at the magnetopause play an important role in solar wind-magnetosphere coupling. It is widely accepted that they are a result of transient magnetic reconnection (MR) near the sub-solar magnetopause. Despite many years of study, a number of fundamental questions still remain unclear. Of particular interest are the generation mechanism and three-dimensional (3D) structures of FTEs. A few well-known models have existed for more than 30 years. Nevertheless, we still do not know which model best represents reality. This is mainly due to the fact that generation of FTEs is 3D in nature, whereas the 3D features of FTEs can only be revealed through multiple spacecraft measurement, which only recently became possible after the launch of Cluster in 2000. This proposal aims to promote the study of FTEs a step further based on coming Cluster measurements at the subsolar magnetopause around February, 2013 and 2014 with focus on multi-spacecraft measurements of 3D features of FTEs. We are also going to examine the differences under solar maximum in 2013-2014 and contrast to already obtained data during solar minimum (2007-2008), when Cluster sampled the same region. Three or so orbits data from FGM, HIA, PEACE, (and RAPID /IES, EDI) are required. In addition, the studies will be carried out in conjunction with concurrent measurements by THEMIS P3, P4 and P5.
Implementation
The key aspect of this proposal is to make multi-scale observations of the magnetopause close to the sub-solar region. This region will be crossed by Cluster (due to its orbit evolution) in early 2013. The operations are complicated by being coincident with the eclipse season, which requires additional attention to ground station allocation before the spacecraft are powered down for eclipse, as was the situation with the Yordanova observations discussed previously. The spacecraft configuration forms an irregular large-scale triangle (C1, C2 and C3) of side 1600-4500 km, with C4 ~200 km perpendicular to this plane at the magnetopause crossing.
The periods of burst mode targeted were:
2013-01-22T07:20:00 2013-01-22T10:20:00
2013-01-26T20:25:00 2013-01-26T22:25:00
2013-01-31T08:25:00 2013-01-31T11:25:00
2013-02-09T09:30:00 2013-02-09T12:30:00
GUEST INVESTIGATOR: F. PITOUT
PROPOSAL TITLE: PARTICLE ACCELERATION AND FIELD ALIGNED CURRENTS IN THE CUSP
Abstract
The increasing tilt of Cluster spacecraft orbits allows us to access and probe new regions of the magnetosphere. Among these, the low-altitude dayside magnetosphere and cusp are key regions where injected magnetosheath particles may be accelerated. We propose first to use the CIS and PEACE particle sensors to probe this region. Then, once cases are clearly identified, we shall try to figure out what acceleration processes come into play with wave instruments (STAFF, EFW) since wave-particle interaction processes are expected. We shall also complement our observations with low-altitude satellites (DMSP, REIMEI) and ground-based instruments (EISCAT radars) whenever possible. We shall eventually be able to compare newly collected data with the work done at higher altitudes and have a full view in altitude of acceleration processes and field-aligned currents.
Implementation
The target of this proposal was the cusp region. The configuration has Cluster 1 and 2 roughly on the same field line, with C2 ~3000km below C1. Spacecraft C4, C3 and C1 are separated along track by 1800 km, with C1 and C2 offset by ~1000 km perpendicular to the orbit track of C3 and C4. Precise timing of observations has not yet been decided, but the observation period will cover October 2013-December 2013.
The periods of burst mode targeted were:
12/11/2013 14:10-14:50 UT
21/11/2013 14:50-15:50 UT
30/11/2013 15:30-16:30 UT
16/12/2013 11:50-12:50 UT
18/12/2013 13:50-16:10 UT
25/12/2013 12:50-13:50 UT
CLUSTER GUEST INVESTIGATOR OPERATIONS, 2015-2016
The second Announcement of Opportunity (AO) in the Cluster Guest Investigator (GI) Programme was issued on 17 February 2014. More details about the AO can be found here: http://sci.esa.int/Cluster_AO2.Following a review in Summer/Autumn 2014 by the Cluster Science Operations Working Group, and by a Peer Review Committee with members from the Solar System and Exploration Working Group, eight GI proposals were selected. These are detailed below:
Guest Investigator | GI proposal title | Laboratory | Implementation period |
Olga Alexandrova | Study of the dissipation range of solar wind turbulence | Meudon Observatory, F | February and March 2015 |
David Burgess | Ion pickup coupling in the solar wind associated with thruster operations | QMUL, UK | March 2015 |
M. Dunlop | Coordination of Cluster/Swarm for FACs | RAL, UK | June 2015 |
Yulia V. Bogdanova | Mid-altitude cusp properties, dynamics, small-scale plasma structure and ion outflow: simultaneous Cluster measurements at different MLT sectors | RAL, UK | November and December 2015 |
Yuri Khotyaintsev | Multi-spacecraft Investigation of Electron Scales at Bow Shock | IRF-U, S | January 2016 |
Primoz Kajdic | Magnetic reconnection in the solar wind: search for small-scale events | ESA/ESTEC, NL | February 2016 |
Xochitl Blanco-Cano | Upstream transients and their influence on the bow shock and magnetosheath | Mexico University, Mexico | April 2016 |
Claire Foullon | Magnetopause boundary layer: evolution of plasma and turbulent characteristics along the flank - repeats | Exeter University, UK | May-June 2016 |
Nominally, outside eclipses, data is acquired all along the Cluster orbit as follows: 52.5 hours Normal Mode (NM) and 1.5 hours Burst Mode (BM). During the period of the GI operation implementation, the Cluster Science Operations Working Group defined a new style of spacecraft operations to enhance the amount of burst mode data per orbit, which benefitted the science objectives of the GI activities and other Cluster science targets. This was made possible by imposing a period of no data taking during another part of the orbit, to offset the increased load of the enhanced BM. The NM data rate is around 17 kbps (kbps: kilo bits per second) and the BM data rate is 105 kbps. So, for every extra hour of BM data, we impose 8 hours of no data taking on the C1, C2 and C3 spacecraft while C4 continues to acquire data.
Information on specific operations is detailed below (once in the planning), including periods of enhanced/extended BM periods, in the order in which they were or will be implemented.
The proprietary data period for the GI will be at least 6 months after measurements were made. During this period data access is limited to the GIs and the PI teams. After at most 9 months the PI teams will deliver the data to the Cluster Science Archive (CSA) where it will be publicly accessible. This will enable the PI teams to keep to their agreed CSA delivery schedule and provide GIs time to carry out their analysis.
Should you wish to analyse Cluster data from during the GI periods, you are strongly encouraged to contact the project scientist team at ESTEC, via Philippe Escoubet (email: philippe.escoubetesa.int), who will liaise with the GI teams.
GUEST INVESTIGATOR: OLGA ALEXANDROVA
PROPOSAL TITLE: STUDY OF THE DISSIPATION RANGE OF SOLAR WIND TURBULENCE
Abstract
Turbulence is a universal and omnipresent multi-scale process in plasmas. Despite many observations of the turbulence in space plasmas, a number of key issues are still poorly understood; one of them is the collisionless dissipation. Recent Cluster observations in the solar wind show that the dissipation of the electromagnetic turbulent cascade probably happens at electron scales. This is well supported by recent kinetic simulations and theory. Two dissipation mechanisms at kinetic scales have been proposed: reconnection within thin current sheets and resonant damping of fluctuations on electrons. We propose to study these different scenarios using magnetic and electric field fluctuations and particles data at the highest possible rate in time and with spatial measurements at electron scales. The results expected from this study will improve our understanding of the dissipation in space plasma turbulence and provide a background for future missions.
Implementation
The requirement is to have two spacecraft (C3-C4) collecting data in the solar wind and magnetosheath, at a few kilometres from each other and in addition to do measurements when this distance varies from a few kilometres to around 1000 km. The other spacecraft are a few 1000s kilometres upstream of C3 and C4. We will use orbits when the spacecraft are in eclipse at perigee since there is enough time to dump solar wind data to the ground before switching off the spacecraft for the eclipse.
The periods where burst mode 1 (BM1) will be used are the following (SW indicates solar wind and MS magnetosheath):
C3-C4=6-7 km (3h BM1)
SW | 06/02/2015 | 20:00-23:00 |
SW | 09/02/2015 | 02:00-05:00 |
SW | 11/02/2015 | 07:45-10:45 |
MS | 12/02/2015 | 22:35-01:35 |
SW | 15/02/2015 | 20:45-23:45 |
SW | 18/02/2015 | 02:15-05:15 |
MS | 19/02/2015 | 17:10-20:10 |
SW | 22/02/2015 | 14:45-17:45 |
SW | 24/02/2015 | 20:45-23:45 |
MS | 26/02/2015 | 11:50-14:50 |
C3-C4=7 -> 1000 km (1h BM1)
SW | 10/03/2015 | 10:15-11:15 |
SW | 12/03/2015 | 16:30-17:30 |
SW | 14/03/2015 | 22:45-23:45 |
SW | 19/03/2015 | 11:20-12:20 |
SW | 21/03/2015 | 17:40-18:30 |
SW | 23/03/2015 | 23:55-00:55 |
SW | 26/03/2015 | 06:15-07:15 |
GUEST INVESTIGATOR: DAVID BURGESS
PROPOSAL TITLE: ION PICKUP COUPLING IN THE SOLAR WIND ASSOCIATED WITH THRUSTER OPERATIONS
Abstract
Thruster operations are vital for maintaining spacecraft orbit and attitude. Chemical thrusters, as used by Cluster, produce a plume of neutral molecules which in turn produce ions via photo- and impact ionization. The new-born ions represent the injection of a new plasma constituent which mass loads the solar wind flow. Furthermore they have a high velocity in the solar wind frame, due to the relative velocity of spacecraft and solar wind, which acts as a free energy source for coupling between the solar wind and the injected ions. The effects of thruster operations on the ambient plasma are important for mission planning where the science aims are to measure the ambient plasma. They are also interesting in themselves, viewed as the observational results of an active plasma experiment. We propose a programme of Cluster science operations during thruster operations to make comparisons with simulations being carried out to study the large scale effects of interaction between the ambient solar wind and ions injected from the thruster plume. Special simulations will be run specific to the Cluster configurations and events in order to validate the simulation methods. The simulations will have possible implications for mission planning for future missions such as Solar Orbiter and Solar Probe Plus, where the effects of thruster firings on the ambient plasma might have to be taken into account.
Implementation
The goal of this investigation is to collect electric and magnetic field data at spin resolution during the thrusters firing on one spacecraft. We will use three thrusters firing intervals where one is a long firing interval of 17 min (Cluster 1) and the two others are 7-8 s long (Cluster 3). We will use burst mode 2 (BM2) for 1 h during these intervals since there is a special interest from the WBD team to acquire data while other instruments (WEC and FGM) collect normal mode equivalent data.
The planned periods are:
Cluster 3 thrusters firing: 09/03/2015 09:14:41-09:14:49
Cluster 1, Cluster 3 and Cluster 4 with WEC + FGM on in BM2: 09/03/2015 09:10-10:10
Cluster 1 thrusters firing: 17/03/2015 14:04-14:22
Cluster 1, Cluster 3 and Cluster 4 with WEC + FGM on in BM2: 17/03/2015 13:59 -14:59
Cluster 3 thrusters firing: 25/03/2015 05:28:03-05:28:11
Cluster 1, Cluster 3 and Cluster 4 with WEC + FGM on in BM2: 25/03/2015 05:23-06:23
GUEST INVESTIGATOR: M. DUNLOP
PROPOSAL TITLE: COORDINATION OF CLUSTER/SWARM FOR FACS
Abstract
This proposal is designed to establish special operations between Cluster and Swarm, in order to take best advantage of conjunctions between the two missions. A special configuration which optimized the coverage of the ring current, sampled in situ by Cluster, was established for the beginning of Swarm science operations in 2014, when all three Swarm orbits will be closely aligned. It is hoped and anticipated that the optimum constellations of Cluster in the ring current (RC) will be maintained into 2015, but also secondary science targets (for example, at high-latitude conjunctions) are possible during closely conjugate periods between Cluster and Swarm, and here we seek to focus on these for a special Cluster operational phase during 2015. The exact periods and phasing will not actually be known in detail until the end of the Swarm commissioning phase and final completion of manoeuvres. However, it is known that conjunctions will occur at intervals during the Cluster phase. The LT drifts of the Swarm orbital planes are between 100 deg (spacecraft B) and 130 deg (pair A/C) per year, so that Cluster and Swarm will come into LT alignment about every ~1.3 years, and will remain closely aligned for a month or so; a suitable target period for special GI operations. It is desirable to establish this coordination in 2015 when the Swarm A,C and B are not too far apart in LT. In addition to this consideration, it is likely that constellations set up for the best ring current coverage will also provide good sampling of the high latitude region either side of perigee where field aligned currents (FAC) and electron flux can be targeted for magnetically conjugate times. The best Cluster orientations for nightside FACs (e.g. SCW) and dayside FACs (e.g. Cusp) occur around June and December 2015. We intend to target the best regions (and hence periods) when the final orbits of Swarm are known, but anticipate this will be during either June or December each year.
Implementation
The spacecraft were configured to make the best measurements of the ring current in June 2015. The spacecraft have a separation around 1500 km with C2 closer to the Earth, C3/C4 further away and C1 in between, at perigee around the equatorial plane.
Normal mode 1 (NM1) data has been acquired around perigee during the month of June 2015.
GUEST INVESTIGATOR: YULIA V. BOGDANOVA
PROPOSAL TITLE: MID-ALTITUDE CUSP PROPERTIES, DYNAMICS, SMALL-SCALE PLASMA STRUCTURE AND ION OUTFLOW: SIMULTANEOUS CLUSTER MEASUREMENTS AT DIFFERENT MLT SECTORS
Abstract
The magnetospheric cusp is a key region in the solar wind-magnetosphere-ionosphere coupling and the investigation of the cusp region has been one of the aims of the Cluster mission. Recent observations reveal that the cusp is a dynamic and complex region governed by changes in external conditions, with multi-scale physical processes co-existing inside the cusp and cleft, including plasma injections from the reconnection site(s), small-scale electron beams and filamentary field-aligned currents, different mode wave excitation corresponding to plasma injections, local ion heating and outflow. The observations inside the cusp also have been successfully used in the past for the estimation of the geometry and properties of the reconnection at the magnetopause. In 2015/2016 Cluster is expected to cross the mid-altitude northern cusp region along the azimuthal direction, from the dusk to dawn, thus providing a unique opportunity to investigate azimuthal structure of the cusp and cleft regions. To facilitate this study, we propose to shift Cluster spacecraft along the orbit in a way that SC1 and SC2, and SC2 and SC3/4 will be separated by 1 h in MLT and can simultaneously monitor plasma processes at different parts of the cusp/cleft. The goals of this GI proposal are twofold: (i) investigation of the large scale cusp dynamics and morphology at different MLT sectors; cusp azimuthal extension and plasma properties corresponding to the different reconnection geometries at the magnetopause, and estimation of the location and properties of the reconnection site(s) responsible for the cusp injections at different MLT sectors; (ii) Investigation of the local ionospheric ion heating and outflow as observed along the heating wall at different MLT sectors and small-scale plasma processes related to this outflow, including characterisation of the electron beams, filamentary field-aligned currents, and excitation of the plasma waves responsible for the ion heating. We plan to use data from the following Cluster instruments: PEACE, CIS/CODIF on SC4, FGM, EFW, STAFF, and WHISPER. To complement Cluster data analysis, we plan to use EISCAT data for monitoring the ionosphere and MHD modelling for estimation of the large-scale reconnection geometry corresponding to Cluster observations at different MLT sectors.
Implementation
The selected intervals are:
30/10/2015 10:45-13:45 UT - BM1
01/11/2015 15:45-19:45 UT - NM1
08/11/2015 11:30-14:30 UT - BM1
10/11/2015 16:30-20:30 UT - NM1
19/11/2015 17:00-21:00 UT - NM1
26/11/2015 13:00-16:00 UT - BM1
28/11/2015 17:45-21:45 UT - NM1
05/12/2015 13:00-17:00 UT - BM1
14/12/2015 13:30-17:30 UT - NM1
23/12/2015 13:45-17:45 UT - BM1
Bogdanova, Y., Escoubet, C.-P., Fear, R., Trattner, K., Berchem, J., Fazakerley, A., and Pitout, F.: Mid-altitude cusp dynamics and properties during the IMF By dominated intervals, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7443, https://doi.org/10.5194/egusphere-egu2020-7443, 2020
Bogdanova, Y.V, Fazakerley, A., Escoubet, P., Fear, R., Pitout, F., Trattner, K., Jean Berchem, J., Andre, M., Canu, P., Carr, C., Dandouras, I., Khotyaintsev, Y., Kistler, L., Mouikis, C., and Rauch, J. : Mid-altitude cusp properties: simultaneous Cluster observations at different MLT sectors, 20th EGU General Assembly, EGU2018, Proceedings from the conference held 4-13 April, 2018 in Vienna, Austria, Vol. 20, p.9057, 2018
GUEST INVESTIGATOR: YURI KHOTYAINTSEV
PROPOSAL TITLE: MULTI-SPACECRAFT INVESTIGATION OF ELECTRON SCALES AT BOW SHOCK
Abstract
Shocks are ubiquitous in the Universe, producing some of the most spectacular, visually striking, and energetic phenomena. Astrophysical shock waves can be generated by supernovae, stellar winds, and the rapid motion of objects such as neutron stars. There are a wide variety of shock waves in the heliosphere driven by transients, fast streams, and obstacles (e.g., magnetized or unmagnetized planets) in the solar wind. Shock waves are believed to be one of the most efficient particle accelerators in astrophysical plasmas. The majority of the plasmas in the Solar System are classified as collisionless. Meaning, their associated energy dissipation cannot rely upon particle collisions. The dissipation occurs on kinetic scales (e.g., gyroradius and/or inertial scale) of different particle species, electrons and ions. Such scales are not accessible to remote observations and can only be studied in situ. Observations at ion scales have been well addressed by Cluster. However, these show that shocks often have scales as small as electron scales, and at these scales there are presently no multi-spacecraft measurements available. This project will require at least 2 of the Cluster spacecraft to move within a few km separation while in burst mode operation (BM1) for expected bow-shock locations. We would also like to increase the amount of EFW internal burst data taken for high-resolution E & B measurements by having more frequent BM3 dumps. We prefer all the data to be distributed via CAA/CSA.
Implementation
10 orbits with 7h BM1 on C3-C4 and 1h BM1 on C1-C2 centred on the bow shock were selected during January 2016. EFW internal memory was dumped through BM1 every hour using WEC internal commands.
Spacecraft | Mode | Start | End | Duration (h) |
C1 | BM1 | 05/01/2016 13:10:00 | 05/01/2016 14:10:00 | 1.0 |
C2 | BM1 | 05/01/2016 16:05:00 | 05/01/2016 17:05:00 | 1.0 |
C3 | BM1 | 05/01/2016 10:05:00 | 05/01/2016 17:05:00 | 7.0 |
C4 | BM1 | 05/01/2016 10:05:00 | 05/01/2016 17:05:00 | 7.0 |
C1 | BM1 | 07/01/2016 20:20:00 | 07/01/2016 21:20:00 | 1.0 |
C2 | BM1 | 07/01/2016 23:45:00 | 08/01/2016 00:45:00 | 1.0 |
C3 | BM1 | 07/01/2016 17:45:00 | 08/01/2016 00:45:00 | 7.0 |
C4 | BM1 | 07/01/2016 17:45:00 | 08/01/2016 00:45:00 | 7.0 |
C1 | BM1 | 10/01/2016 03:10:00 | 10/01/2016 04:10:00 | 1.0 |
C2 | BM1 | 10/01/2016 06:55:00 | 10/01/2016 07:55:00 | 1.0 |
C3 | BM1 | 10/01/2016 00:55:00 | 10/01/2016 07:55:00 | 7.0 |
C4 | BM1 | 10/01/2016 00:55:00 | 10/01/2016 07:55:00 | 7.0 |
C1 | BM1 | 12/01/2016 10:00:00 | 12/01/2016 11:00:00 | 1.0 |
C2 | BM1 | 12/01/2016 13:40:00 | 12/01/2016 14:40:00 | 1.0 |
C3 | BM1 | 12/01/2016 07:50:00 | 12/01/2016 14:50:00 | 7.0 |
C4 | BM1 | 12/01/2016 07:50:00 | 12/01/2016 14:50:00 | 7.0 |
C1 | BM1 | 14/01/2016 16:40:00 | 14/01/2016 17:40:00 | 1.0 |
C2 | BM1 | 14/01/2016 20:20:00 | 14/01/2016 21:20:00 | 1.0 |
C3 | BM1 | 14/01/2016 14:40:00 | 14/01/2016 21:40:00 | 7.0 |
C4 | BM1 | 14/01/2016 14:40:00 | 14/01/2016 21:40:00 | 7.0 |
C1 | BM1 | 16/01/2016 23:15:00 | 17/01/2016 00:15:00 | 1.0 |
C2 | BM1 | 17/01/2016 03:00:00 | 17/01/2016 04:00:00 | 1.0 |
C3 | BM1 | 16/01/2016 21:25:00 | 17/01/2016 04:25:00 | 7.0 |
C4 | BM1 | 16/01/2016 21:25:00 | 17/01/2016 04:25:00 | 7.0 |
C1 | BM1 | 19/01/2016 05:45:00 | 19/01/2016 06:45:00 | 1.0 |
C2 | BM1 | 19/01/2016 09:35:00 | 19/01/2016 10:35:00 | 1.0 |
C3 | BM1 | 19/01/2016 04:00:00 | 19/01/2016 11:00:00 | 7.0 |
C4 | BM1 | 19/01/2016 04:00:00 | 19/01/2016 11:00:00 | 7.0 |
C1 | BM1 | 21/01/2016 12:15:00 | 21/01/2016 13:15:00 | 1.0 |
C2 | BM1 | 21/01/2016 16:05:00 | 21/01/2016 17:05:00 | 1.0 |
C3 | BM1 | 21/01/2016 10:35:00 | 21/01/2016 17:35:00 | 7.0 |
C4 | BM1 | 21/01/2016 10:35:00 | 21/01/2016 17:35:00 | 7.0 |
C1 | BM1 | 23/01/2016 18:40:00 | 23/01/2016 19:40:00 | 1.0 |
C2 | BM1 | 23/01/2016 22:35:00 | 23/01/2016 23:35:00 | 1.0 |
C3 | BM1 | 23/01/2016 17:05:00 | 24/01/2016 00:05:00 | 7.0 |
C4 | BM1 | 23/01/2016 17:05:00 | 24/01/2016 00:05:00 | 7.0 |
C1 | BM1 | 26/01/2016 01:05:00 | 26/01/2016 02:05:00 | 1.0 |
C2 | BM1 | 26/01/2016 05:00:00 | 26/01/2016 06:00:00 | 1.0 |
C3 | BM1 | 25/01/2016 23:35:00 | 26/01/2016 06:35:00 | 7.0 |
C4 | BM1 | 25/01/2016 23:35:00 | 26/01/2016 06:35:00 | 7.0 |
GUEST INVESTIGATOR: PRIMOZ KAJDIC
PROPOSAL TITLE: MAGNETIC RECONNECTION IN THE SOLAR WIND: SEARCH FOR SMALL-SCALE EVENTS
Abstract
The most commonly studied signatures of magnetic field reconnection in the un- perturbed solar wind (SW) are the so called reconnection exhausts (e.g. Gosling, 2005; Davis et al., 2006; Lavraud et al., 2009; Gosling, 2012). These have been observed in the magnetic field and plasma data of several missions (ACE, Wind, Stereo, Cluster, etc.). When a spacecraft crosses a reconnection exhaust it observes a rotation of the interplanetary magnetic field (IMF). This rotation occurs in two steps, at two distinct rotational discontinuities (RD) or Alfvén waves that bound the event and represent its edges. Magnetic field configuration between the edges is intermediate to those bounding the reconnection exhaust on each side. The two Alfvén waves propagate parallel (antiparallel) with respect to the B-field and hence produce anticorrelated (correlated) changes in SW bulk velocity and the IMF. The measured SW speed inside the reconnection exhaust is increased with respect to the surrounding values if the spacecraft crosses the event anti-sunwards of the reconnection X-line while it appears diminished on the sunward side.
Here we propose to use high-time-resolution magnetic field and plasma data of the four Cluster spacecraft in order to search for 1) small scale reconnection events with durations of less than three seconds and 2) the regions in which the magnetic reconnection actually takes place.
Implementation
10 orbits with 3h BM1 in the solar wind were selected in February-March 2016. C3 and C4 were separated by 100 km while C2 was 10 000 km in front of them and C1 10 000 km behind them.
2016-02-01 09:30-12:30 - BM1
2016-02-03 15:50-18:50 - BM1
2016-02-05 21:10-00:10 - BM1
2016-02-10 06:10-09:10 - BM1
2016-03-08 18:50-21:50 - BM1
2016-03-11 02:30-05:30 - BM1
2016-03-13 08:30-11:30 - BM1
2016-03-15 14:30-17:30 - BM1
2016-03-17 20:30-23:30 - BM1
2016-03-20 02:10-05:10 - BM1
GUEST INVESTIGATOR: XOCHITL BLANCO-CANO
PROPOSAL TITLE: UPSTREAM TRANSIENTS AND THEIR INFLUENCE ON THE BOW SHOCK AND MAGNETOSHEATH
Abstract
The solar wind interaction with the terrestrial environment begins well ahead of the magnetopause when the solar wind encounters the foreshock, bow shock and magnetosheath. In these regions a variety of waves and magnetic structures exist and modify solar wind properties. The foreshock is permeated by a variety of ultra-low frequency (ULF) waves and magnetic transient structures such as shocklets, SLAMs, and cavitons (Blanco-Cano et al., 2009; Kajdic et al., 2013). These structures can be very compressive and are generated by the solar wind interaction with backstreaming particles plus non-linear processes. In the case of cavitons, it is the interaction between two types of waves which leads to the formation of large depressions in density (n) and magnetic field magnitude (B) bounded by enhanced compressive shoulders in n and B.
The purpose of this project is to use the Cluster multi-spacecraft, high time resolution capabilities to study foreshock transients, their evolution and their influence on the bow shock and magnetosheath structures. These transients can contribute to bow shock rippling and part of the research focus on determining quasi-parallel shock rippling scales.
Implementation
10 orbits with the spacecraft in NM1 in the solar wind and at the quasi-parallel shock were selected in March-April 2016. NM3 was used on C1 and 1h of BM1 at the inbound bow shock. The spacecraft followed each other with around 1 RE separation distance along their orbit.
Orbit | Outbound | Inbound |
2467 | 21/03/2016 11:30-02:30 | 22/03/2016 09:30-00:30 |
2468 | 23/03/2016 17:30-08:30 | 24/03/2016 14:30-05:30 |
2469 | 26/03/2016 00:00-15:00 | 26/03/2016 21:00-12:00 |
2470 | 28/03/2016 06:30-21:30 | 29/03/2016 03:00-18:00 |
2471 | 30/03/2016 13:00-04:00 | 31/03/2016 09:00-00:00 |
2472 | 01/04/2016 19:00-10:00 | 02/04/2016 15:00-06:00 |
2473 | 04/04/2016 01:30-16:30 | 04/04/2016 21:00-12:00 |
2474 | 06/04/2016 08:00-23:00 | 07/04/2016 03:00-18:00 |
2475 | 08/04/2016 14:30-05:30 | 09/04/2016 08:30-23:30 |
2476 | 10/04/2016 21:00-12:00 | 11/04/2016 14:30-05:30 |
GUEST INVESTIGATOR: CLAIRE FOULLON
PROPOSAL TITLE: MAGNETOPAUSE BOUNDARY LAYER: EVOLUTION OF PLASMA AND TURBULENT CHARACTERISTICS ALONG THE FLANK - REPEATS
Abstract
The magnetopause and its adjacent boundary layers have been a key science target for many satellite missions. They have been sampled, at the same time, either locally by a maximum of 4 to 5 closely spaced spacecraft (from the Cluster constellation and the Double Star TC-1 satellite) or on larger scales by missions such as Geotail, Cluster and THEMIS. Unfortunately none of the spacecraft configurations has so far permitted to track the "evolution" of perturbations in their main direction of propagation. The study of the evolution of plasma perturbations, such as Kelvin-Helmholtz (KH) waves or Flux Transfer Events (FTEs), together with the (associated or not) generation of Kinetic Alfvén Waves (KAWs) and the turbulence developing at the flank magnetopause boundary layer, is important for our understanding of the mechanisms that mediate solar wind plasma entry into the magnetosphere, i.e. magnetic reconnection and diffusive processes. The Cluster Guest Investigator (GI) proposal implemented in November 2012 on the Dusk flank targeted inter-spacecraft separations of about 1 RE necessary to relate disturbances and deduce their evolution. It resulted in separations of up to 36 000 km across the constellation at the magnetopause and was the largest separation ever for the Cluster mission. One of the events studied allows us to study changes to the magnetopause boundary layer properties during the passage of an Interplanetary Coronal Mass Ejection (ICME). We would like to repeat the November 2012 GI operation on the Dawn flank, to increase the probability to have phenomena of interest travelling roughly parallel to the alignment, and to provide a study of asymmetries between the two flanks.
Implementation
10 orbits with around 10h NM1 + 5h of BM1 + 10h NM1 centred on the dawn flank of the magnetopause have been selected in June 2016. The spacecraft follow each other with around 1 RE separation distance along their orbit.
Orbit | Timing | NM1 start | NM1 end | BM1 start | BM1 end |
2500 | C1,C4 | 03/06/2016 23:30 | 05/06/2016 03:16 | 05/06/2016 03:16 | 05/06/2016 07:16 |
2500 | C2,C3 | 04/06/2016 01:23 | 05/06/2016 03:16 | 05/06/2016 03:16 | 05/06/2016 07:16 |
2501 | MP in | 06/06/2016 07:00 | 07/06/2016 08:27 | 07/06/2016 08:27 | 07/06/2016 12:57 |
2502 | MP in | 08/06/2016 15:00 | 09/06/2016 13:34 | 09/06/2016 13:34 | 09/06/2016 18:34 |
2505 | MP in | 15/06/2016 08:00 | 16/06/2016 05:08 | 16/06/2016 05:08 | 16/06/2016 10:08 |
2506 | MP out | 17/06/2016 13:30 | 18/06/2016 14:30 | 17/06/2016 15:35 | 17/06/2016 20:36 |
2507 | MP in | 19/06/2016 19:30 | 20/06/2016 20:30 | 20/06/2016 14:30 | 20/06/2016 19:30 |
2508 | MP out | 22/06/2016 00:30 | 23/06/2016 01:30 | 22/06/2016 04:55 | 22/06/2016 09:55 |
2509 | Apogee | 24/06/2016 07:15 | 25/06/2016 08:15 | 24/06/2016 17:45 | 24/06/2016 22:45 |
2510 | Apogee | 26/06/2016 16:32 | 27/06/2016 17:32 | 26/06/2016 23:15 | 27/06/2016 04:15 |
Cluster 3rd Early Career Scientist and Guest Investigator Operations
Following the successful Cluster Guest Investigator (GI) announcements of opportunity in 2010 and 2014, and their implementation in 2011-2013 and 2015-2016 respectively, the European Space Agency (ESA) issued a 3rd Announcement of Opportunity (AO) on 27 February 2019. This time it was open to Early Career Scientist (ECS) and GI Programme of any nationality. Selected Proposals were supported by their national or other funding agencies. The deadline for submission was 29 May 2019.
Following a review in Summer/Autumn 2019, by the Cluster Science Operations Working Group, and by a Peer Review Committee with members from the Solar System and Exploration Working Group, three ECS proposals were selected. These are as follows:
Early Career Scientist Proposal title Laboratory Implementation period
Patrik Krcelic
North-south asymmetries in the polar cusps and its influence on ion outflow: experimental determination of mirror forces Max Planck, Germany and University of Zagreb, Croatia, January and May 2020
Pavel I. Shustov Investigation of sub-ion magnetic holes in the dipolarized plasma sheet: ion-electron energy exchange and magnetosphere-ionosphere interaction on small scales Space Science Institute, Russian Academy of Sciences, Moscow, Russia Aug-Sept 2020
S. Toledo-Redondo Constraining the meso-scale of magnetic reconnection at the Earth’s magnetopause using MMS – Cluster conjunctions IRAP/CNRS, France Dec 2020-Mar 2021
Information on specific operations is detailed below (once in the planning), including periods of enhanced/extended BM periods, in the order in which they were or will implemented.
The proprietary data period for the ECS was to be at least 6 months after measurements were made. During this period data access is limited to the ECSs and the PI teams. After at most 9 months the PI teams will deliver the data to CSA where it will be publicly accessible. This will enable the PI teams to keep to their agreed CSA delivery schedule and provide ECSs time to carry out their analysis.
Early Career Scientist: Patrik Krcelic
Proposal title: North-south asymmetries in the polar cusps and its influence on ion outflow: experimental determination of mirror forces
Abstract
This proposal addressed north-south asymmetries in the polar cusps and their influence on ion outflow. Observations were proposed during each hemisphere winter period, where illumination effects are low, and processes are mainly driven by the mirror force. The Cluster satellites will pass through the north hemisphere cusp around January 2020, and through the southern cusp around May 2020. In order to get good spatial gradients, the constellation should be similar. The inter-spacecraft distances required for the investigation is between 0.5 and 2 Earth radii or RE. In order to get accurate magnetic field gradients, observations from the FGM instrument are required from all four spacecraft. The FGM instrument offers sufficient resolution in normal mode for this study, but other instruments are requested to operate in burst mode. Observations from the CIS and PEACE instruments are required, to calculate energisation of ions due to heating. CIS observations are available on C1 and C4. Hence, Krcelic's ECS suggests to use CODIF on C4 to estimate the ratio between H+ and O+ ions, and energies obtained from both CODIF (C4) and HIA (C1) to estimate the change of energisation as a function of radial distance. The PEACE instruments will also be used to estimate heating on C1 and C4. Finally, Krcelic's ECS proposes to estimate the loss of outflow ions in both hemispheres separately. In order to get convection velocities, EDI measurements are requested in electric field mode (available on C1 and C3). Since the cusp magnetic field is typically weak (around 60 nT or less), EDI data quality is expected to be limited. Hence, burst mode on C1 and C3, to get higher sampling of EDI is requested to potentially improve data quality, no guarantee however can be given by the instrument team. The research will provide better understanding of physical processes and differences in the north and south cusps. Comparison of north hemisphere and south hemisphere cusps would require similar solar wind conditions, which may not happen on such limited number of orbits.
Implementation
A preliminary schedule indicated that it could be carried out in January and May 2020, with three crossings in each cusp dedicated to this ECS proposal. Due to the time needed to achieve the configuration required, it was proposed to postpone the January observations by one week and it was accepted by the ECS. An extra orbital drift of 2h in December 2019 along the orbit of C1 would enable to compute magnetic gradients in the cusps.
The periods identified for this investigation were:
- 20200108 09:50 UT
- 20200110 15:00 UT
- 20200112 20:00 UT
- 20200521 10:50 UT
- 20200523 18:30 UT
- 20200526 01:00 UT
4h BM were allocated for each period centered on the times above.
____________________________________
Early Career Scientist: Pavel I. Shustov
Proposal title: Investigation of sub-ion magnetic holes in the dipolarized plasma sheet: ion-electron energy exchange and magnetosphere-ionosphere interaction on small scales
Abstract
This proposal targets investigation of sub-ion magnetic holes in the dipolarized plasma sheet. Previous single spacecraft observations and multispacecraft observations by MMS (<10 km) and THEMIS (around a few RE) only provide estimates of the magnetic hole gradients in the equatorial plane, but are unable to clarify the hole configuration along magnetic field lines (i.e., along Bz field around the equatorial plasma sheet). This significantly limits the calculation of gradients of off-equatorial magnetic field components, mostly contributing to the field-aligned currents originating at the magnetic holes and projecting these holes to the aurora. Such measurements, together with important electron measurements, can be performed by the Cluster tetrahedron (or, even by two closely located Cluster spacecraft) crossing the plasma sheet along its highly inclined orbit. The data collection for this ECS could be executed in August and September 2020 before and after the long eclipse season. These two months (especially September) are characterized by good coverage of the nightside aurora region by the THEMIS all-sky imagers. Therefore, a comparison is foreseen between small-scale aurora observations and equatorial Cluster observations of field-aligned currents, originating from the sub-ion magnetic holes. Sub-ion hole investigation requires sub-second magnetic field measurements and electron measurements from the PEACE instruments. For each Cluster orbit in the midnight magnetotail (e.g., summer 2020), spacecraft may observe several dipolarizations, and thus 10 orbits would allow to collect several events with multiple hole observations. The main important change of the spacecraft configuration required, for Z-gradient estimates, is to reduce GSM X and Y separation (GSM: Geocentric Solar Magnetospheric coordinate system). In other words, observations from two/three spacecraft are needed where spacecraft can probe magnetic hole structures along Z (along the background magnetic field in the dipolarized plasma sheet). More precisely, C1/C2 spacecraft are requested to be separated along Z by ~0.2-0.5 RE (1000-3000 km) and be quite close in XY (<500 km), because the maximum observed hole cross-section (its size in the equatorial plane) is 500 km.
Implementation
After some interactions between P. Shustov and the Cluster project scientist, a possible configuration was identified where C1/C2 would be separated by around 1500 km around the plasmasheet in the Zgsm direction, close to 0 km in the Ygsm direction and around 1000 km in the Xgsm direction. The separation in X of 1000 km is acceptable since the sub-ion holes propagate along X and have a longer lifetime than the time to travel 1000 km. Simultaneous MMS observations in the magnetotail region during this time period on top of THEMIS all-sky cameras would allow comparison of in-situ and auroral small-scale perturbations behind dipolarization fronts.
The periods identified are:
- 20200822 1725 UT
- 20200825 0013 UT
- 20200827 0545 UT
- 20200829 1130 UT
- 20200831 1845 UT
- 20200914 0736 UT
- 20200916 1349 UT
- 20200918 2127 UT
- 20200921 0318 UT
- 20200923 0840 UT.
4h BM were allocated for each period centred on the times above.
____________________________________
Guest Investigator: S. Toledo-Redondo
Proposal title: Constraining the meso-scale of magnetic reconnection at the Earth’s magnetopause using MMS – Cluster conjunctions
Abstract
This proposal is targeted at constraining the meso-scale of magnetic reconnection at the Earth’s magnetopause using MMS and Cluster conjunctions. Burst mode 1 (or BM1) is requested during the time of the conjunctions at the dayside magnetopause. At least magnetic field and ion velocities are required to identify the reconnection jets. Electron and electric field data would be an asset. C1 and C4 are currently the only ones that can measure ion moments, which are the best measurements to identify reconnection jets. A separation by a few thousand km is suggested to increase the probability of simultaneous crossings between any of the MMS and either C1 or C4 (availability of ion measurements). The location of C2 and C3 is less important but having them in tandem is recommended, i.e., C1 close to C2 and C3 close to C4 (tens to hundreds of km). This would complement the observations and enable some basic two-spacecraft techniques such as time differencing to infer the magnetopause motion.
Implementation
C1 and C4 distance could not be decreased down to a few 1000s km and it was around 10000 km, the spacecraft were however crossing the magnetopause around the same time. This was accepted by S. Toledo. A number of conjunctions have been identified and could be executed late 2020 and early 2021. C3 and C4 separation was be reduced from 200-400 km to 100-200 km at the dayside magnetopause. Other conjunctions exist in winter and spring 2020 and burst mode will be planned as much as possible but Krcelic’s cusp events (see above) will have priority. The data collected for these (additional conjunctions) periods will not be reserved for ECS and will be open to everybody. This was accepted by S. Toledo. The MMS-Cluster conjunctions prediction was based on models and there was no guarantee that conjunctions were really observed.
The periods identified:
2020/12/01 00:00 - 04:00 UT Distance between missions: 17.3 RE
2020/12/11 13:26 - 17:26 UT Distance between missions: 5.6 RE
2020/12/19 05:01 - 09:31 UT Distance between missions: 6.8 RE
2020/12/22 16:56 - 20:56 UT Distance between missions: 16.6 RE
2021/01/05 03:48 - 07:48 UT Distance between missions: 2.3 RE
2021/01/26 17:46 - 21:46 UT Distance between missions: 6.4 RE
2021/02/09 06:53 - 10:53 UT Distance between missions: 18.2 RE
2021/03/30 23:20 - 03:50 UT Distance between missions: 7.1 RE
Burst mode was assigned on these intervals.
8 July 2010
This Announcement of Opportunity solicits special operation proposals for participation in the Guest Investigator (GI) Programme of the Cluster extended mission from the European Space Agency (ESA). The aim of the GI Programme is to open future spacecraft science operations to the scientific community. Investigations are solicited which identify compelling utilization of the Cluster spacecraft payload for scientific study. The deadline for proposal submissions is 1 October 2010.Eligibility to propose for the GI Programme covered by this AO is open to all scientists of any nationality. Selected proposals will have to obtain funding for their research from their national or other funding agencies.
Shortcut to this AO page:
http://sci.esa.int/Cluster_AO
This AO solicits proposals for new payload operations utilizing the Cluster mission through participation in the Cluster Guest Investigator Programme.
Proposals to exploit Cluster data along with other satellites data (e.g. THEMIS), or proposals for theoretical and/or modelling studies focused on the goals and objectives of the mission, are encouraged. Principal and co-investigators on experiments on the Cluster mission are also eligible to propose under this AO.
Investigators are encouraged to propose the acquisition of data from more than one instrument. Inter-spacecraft separation can be changed but is limited to phasing manoeuvres due to limited available fuel.
Proposers are strongly encouraged to examine the information available via the documentation section of the Cluster Active Archive (http://caa.estec.esa.int/caa/), which also accompanies this AO as part of the Proposal Information Package (see below). In particular proposers are directed towards the instrument user guides, to obtain information on spacecraft payload specifications. In addition, proposers may contact the Cluster Project Scientist, Mission Manager and also instrument PIs directly for further information on instrument limitations and spacecraft limitations that may be pertinent to their proposal.
Full details of this AO and the guidelines for the Letters of Intent and Proposals in response to this AO can be found in the Cluster AO document, which is included in the documentation package for this AO.
AO documentation: Proposal Information Package
The Proposal Information Package (PIP) for this Cluster AO contains, in addition to the complete Cluster AO document, the following documents:
- The User Guide (UG) and the Calibration Report (CR) for each of the 11 Cluster instruments (ASPOC, CIS, DWP, EDI, EFW, FGM, PEACE, RAPID, STAFF, WBD, WHISPER)
- Eclipse times Cluster 1, 2, 3 and 4
- Cluster JSOC System Specification DS-JSO-SS-0001
The above documents can be downloaded as a single zip file (35 MB) from the right-hand menu, under "Documentation".
Timetable of the AO
Issue date of the AO: | 8 July 2010 |
Deadline for submission of Letter of Intent: | 15 August 2010 |
Deadline for submission of Proposal: | 1 October 2010 |
Evaluation phase: | |
Selection: | February 2011 |
Letter of Intent
A Letter of Intent from prospective Guest Investigator programme proposers should reach ESA by 15 August 2010. The letter should be sent by email to M.G.G.T. Taylor (ESTEC) at: Matthew.Tayloresa.int.
The Letter of Intent should be concise (not more than 3 pages), and should provide the following information:
- A descriptive title for the proposal.
- Name, affiliation, mailing address, telephone and fax numbers, and e-mail address of the Principal Investigator of the proposal. If the proposal is from a team, the name, affiliation and email of each member of the team should be included. A Principal Investigator should be identified from that team, with their full details provided.
- A brief abstract (1 page maximum) indicating: scientific rationale; data set(s) required; duration of operations (this should not be more than 3 orbits); region of space for observations; relation to other missions/ground based instruments where applicable.
- Intended source for funding.
Contact with ESA
Any requests for further information and clarification before submitting your proposal should be addressed to:
C.P. Escoubet
ESA/ESTEC (SRE)
Postbus 299
2200 AG Noordwijk
The Netherlands
Phone: (31) 71 5658009
Telefax: (31) 71 5654697
Email: Philippe.Escoubetesa.int
M.G.G.T. Taylor
ESA/ESTEC (SRE)
Postbus 299
2200 AG Noordwijk
The Netherlands
Phone: (31) 71 5658009
Telefax: (31) 71 5654697
Email: Matthew.Tayloresa.int
Proposal submission
The proposal should be submitted electronically using the dedicated submission form, which can be accessed through the link below or in the right-hand menu (the form will open in a new window). ESA will confirm by e-mail the reception of the proposal.
Deadline has passed
NOTE: The page limit for a proposal (page size A4, font size 12), including references and figures, is 6 pages: 1 cover page; scientific objectives (including the abstract and data requirements): 3 pages. Management plan: 1 page and funding statement: 1 page.