Usage of the Cluster Data in ILWS Studies

Usage of the Cluster Data in ILWS Studies Harri Laakso, Philippe Escoubet, Matt Taylor, and Arnaud Masson European Space Agency (ESA) Science and Robotic Exploration Directorate Noordwijk, The Netherlands Contents: q Introduction to Cluster observations q Introduction to Cluster data archive* * An ESA contribution to the ILWS 2009, Ubatuba, Brazil, 4 -9 October 2009 1

Introduction to the Cluster Mission q Cluster is a four-satellite constellation mission where the satellite separations are controlled and varied between 100 – 10 000 km q The satellites are on a polar-orbit with the orbital period, perigee distance and apogee distance of 55 hours, <4 Re and 19 Re, respectively q The spacecraft were launched in summer 2000 and the science operations started on 1 February 2001. The mission has been extended until December 2012 q The key dayside investigations: solar wind, bow shock, magnetopause and cusp q The key nightside investigations: auroral zone, plasma sheet, radiation belts and plasmasphere q Two Cluster workshops are organized annually: there are usually 100+ participants and are open to all scientists, for details, see http: //caa. estec. esa. int/wksp/cluster_workshop_home. xml 2

Cluster Instruments Particle experiments: Fields & waves experiments: q PEACE Thermal electrons with energies <30 ke. V q FGM DC magnetic fields at 22 Hz (66 Hz in burst mode) q CIS Thermal ions (including composition) below 40 ke. V q EFW DC electric fields at 25 Hz (450 Hz) q q q RAPID High energy electrons and ions below 450 ke. V (Ei>10 ke. V, Ee>20 ke. V) EDI Plasma drift velocity and DC electric fields, with electron beam injection ASPOC Spacecraft potential control, with ion current emission q STAFF Magnetic and electric fluctuations <4 k. Hz (use search coil & EFW sensors) q WHISPER Electron density (0. 1 -80 cc) and plasma waves (2 -80 k. Hz) q WBD Electric field waveforms <500 k. Hz q DWP Wave processor and wave-particle correlator 3

Cluster Orbit in March-April Polar cusp Auroral zone Solar wind Magnetopause 4

Cluster Dayside Observations Auroral region Polar cap Cusp Dayside magnetosphere Magnetosheath Solar wind 5

Cluster Orbit in September-October 6

Cluster Nightside Observations Radiation belts/plasmasphere/ cusp Lobe Plasma sheet 7

Cluster Orbit Evolution 2008 Magnetopause: subsolar point 2001 Auroral zone: Acceleration region Solar wind 2008 -2009 8

Cluster Orbit Evolution 2008 - 2001 Low altitude cusp Near Earth tail: Current disruption Solar wind 2008 -2009 9

What is CAA? q The Cluster Active Archive CAA (http: //caa. estec. esa. int/) aims to ensure that § The CAA will contain all Cluster high-resolution data as well as allied (supporting) data products necessary to the full interpretation of the fullresolution datasets § the entire high- and low-resolution datasets are fully calibrated (to the level achievable within the limited resources available) § the data should be suitable for science use and publication by the worldwide scientific community § all data are provided in a standard format (CEF - Cluster Exchange Format) and with a complete set of metadata in machine readable form § the CAA will provide user friendly services for searching and accessing these data 10

CAA Organigram-2009 Project Manager (H Laakso) Note: names in red color are contractors supported by the CAA project ASPOC CIS EDI PEACE Deputy (A Masson) Technical Manager (C Perry) System Engineer (R Turner) Working Groups (Chairs: C Harvey, A Allen) Cluster Project Scientist (M Taylor) Archive Developers (S Mc. Caffrey, D Herment, J. Kissi) RAPID FGM DWP STAFF JSOC EFW E Georgescu S Walker PI: P Daly PI: H Alleyne PI: M Andre WHISPER WBD C Cully PI: R Torbert PI: K Torkar E Kronberg ESOC PI: J Pickett A Barthe N Doss P French C Burlaud G Facsko PI: I Dandouras PI: A Fazakerley PI: E Lucek PI: N Cornilleau-Wehrlin PI: J-G Trotignon 11

Status of the CAA Data Inventory q The coverage and range of products are being continually improved, currently with over 200 datasets available from each spacecraft, including § high-resolution DC and AC B- & E-fields § full 3 D electron & ion distributions for 0 e. V - 400 ke. V § various ancillary & browse products q Most/many of the teams have provided the data files for years 20012007 § a number of complicated products, mainly due to calibration difficulties, are still partly missing § currently the teams are producing and delivering files for year 2008 12

CAA Access Point q The CAA operational since Feb 2006 q http: //caa. estec. esa. int/ Registration is necessary in order to have an access to the data and graphical products 13

Data Downloading q Two access routes to the data: § xml forms interface on the CAA web site § Command-line interface to automated download requests q Data selection can be based on spacecraft, experiment, measurement type, instrument type and/or time range 14

User Profiles q Request can be stored as user profile to speed up subsequent requests: § provide an easy way to setup and request standard selections from the large number of available CAA datasets. § can be used for machine accessible interface 15

Command-line Request q Simple way of requesting data from the CAA database q Example: requesting a month of full-resolution FGM data from Cluster 1 in February 2001 in daily files in cdf format, one types wget "http: //caa. estec. esa. int/caa_query/? uname=username&pwd=password& dataset_id=C 1_CP_FGM_FULL& time_range=2001 -02 -01 T 00: 00 Z/2001 -02 -28 T 24: 00 Z& file_interval=1 day& file_format=cdf" q one can also download files ingested into the system after a given day: ingestedsince=2008 -01 -01 T 00: 00 Z & q Details/definitions of using the tool are described in a user guide (available under Documentation) 16

CAA User Activity q CAA has ~920 registered users q Every month ~150 different users log in the CAA q Every month CAA gets ~20 new users q The total data volume downloaded is ~0. 5 TB per month 17

CAA Graphics • These plots are produced by CAA using the calibrated CAA data products • User can select and arrange individual panels • Selected set can be saved as a user profile • Plots on screen are in png whereas the downloaded plots are in ps 18

CAA Graphics q Pre-generated CAA plots based on the CAA database q 1 -hr, 6 -hr and 24 -hr plots are available 19

Quick-Look Plots, 1 q provided by the instrument teams and the CSDS (CSDSweb) quick-look system q not well calibrated i. e. not suitable to science § Plots useful for event identifications q links to the database selection interface with the time pre-selected based on the current plot interval 20

Quick-Look Plots, 2 21

New GUI For Downloading 22

New GUI For Downloading 23

CAA Cross-Calibration Workshops q Activity: observations from different Cluster instruments are compared in detail both statistically and on event basis. This is essential to the production of high-quality data products. Minutes and presentations of the past workshops can be found at http: //caa. estec. esa. int/caa/cross-cal. xml q The following workshops have been organized: • Kick-off Cross-Cal Meeting • 1 st Cross-Cal Workshop • 2 nd Cross-Cal Workshop • 3 rd Cross-Cal Workshop • 4 th Cross-Cal Workshop • 5 th Cross-Cal Workshop • 6 th Cross-Cal Workshop • 7 th Cross-Cal Workshop • 8 th Cross-Cal Workshop • 9 th Cross-Cal Workshop • 10 th Cross-Cal Workshop ESTEC, Netherlands MSSL, London, UK LPCE, Orleans, France ESTEC, Netherlands Imperial College, London, UK Tenerife, Spain Kinsale, Ireland Cambridge, UK Paris, France 23 Sep 2005 2 -3 Feb 2006 16 May 2006 26 -27 Oc 2006 12 -13 Feb 2007 14 May 2007 24 -25 Oct 2007 9 Mar 2008 28 -30 Oct 2008 25 -27 Mar 2009 2 -4 Nov 2009 24

Documentation 25

CEF FORMAT q All the science-quality digital data products are provided to the CAA in a standard representation, the Cluster Exchange Format (CEF) q Full descriptions of the data format and meta-data standards used by the CAA can be accessed from the documents area of the CAA web site http: //caa. estec. esa. int/caa/documentation. xml q The CEF § is an ASCII, comma separated, tabular format supporting multi-line records § has a fully self-describing header § offers straightforward long-term accessibility to the Cluster data q On download, products can optionally be converted to the widely used NASA Common Data Format (CDF) 26

Software q MATLAB & IDL tools for reading and displaying data in CEF-format q QSAS for reading & displaying CEF data q Instrument team software for displaying their data q etc 27

Summary q Cluster is a four-satellite constellation mission: § Cluster science: detailed investigations of physical processes in space plasmas around the Earth § Single satellite observations can be very valuable for global magnetospheric studies, e. g. , in the spring-time the spacecraft stays in the solar wind ~24 hours every few days, or in the autumn-time similarly in the plasma sheet § The Cluster observations are available since 1 February 2001 q All full- and spin-resolution Cluster data available to the world-wide science community through the Cluster Active Archive CAA (http: //caa. estec. esa. int/) § All data are aimed to be well calibrated (done with limited resources) § all data are provided in a standard format (CEF - Cluster Exchange Format) with a complete set of metadata in machine readable form § All data can also be downloaded in CDF format § Currently there about 20 -30 TB of data in compressed format § If there any issues on the usability and quality of the data products, one can contact the CAA by sending an e-mail to caateam@rssd. esa. int, or filling in a feedback form at http: //caa. estec. esa. int/caa/feedback_intro. xml 28