ISTP NEWSLETTER Vol 6, No. 3. December, 1996
Figure shows a schematic representation of the geometry suggested
by the preliminary analysis of an ISTP Correlative Science Event.
IN THIS ISSUE
Title Author
ISTP moves to CDF V2.5 - Mona Kessel
ISTP Shines at the Fall 96 AGU Meeting - Mauricio Peredo
New NSSDC User Survey - Joe King
A multispacecraft ISTP Study: substorm evolution from the solar wind to the magnetosphere and ionosphere - T. I. Pulkkinen,D. N. Baker, N. Turner, H. J. Singer, J. B. Blake, H. Spence L. A. Frank, J. B. Sigwarth, T. Mukai, S. Kokubun, R. Nakamura C. T. Russell, H. Kawano, F. Mozer, J. A. Slavin, R. Lepping R. Anderson, G. Reeves, L. M. Zelenyi
Case Study for Theory-Data Closure - Mauricio Peredo
ISTP Correlative Science Event - Mauricio Peredo
New Release of the ISTP Key Parameter Visualization Tool (KPVT), (Version 2.1 will be officially released on 12-2-96) - Syau-Yun Hsieh, Mauricio Peredo, Bill Mish
Polar/ISTP Science Coordination - Nicola J. Fox, Robert A. Hoffman
Editor:
Michael Cassidy
CASSIDY@ISTP1.GSFC.NASA.GOV
Contributing Editors:
Steven Curtis - Science Editor
U5SAC@LEPVAX.GSFC.NASA.GOV
Doug Newlon - Data Distribution Facility
NEWLON@IPDGW1.NASCOM.NASA.GOV
Kevin Mangum - Central Data Handling Facility
MANGUM@ISTP1.GSFC.NASA.GOV
Dr. Mauricio Peredo - Science Planning and Operations Facility
PEREDO@ISTP1.GSFC.NASA.GOV
Dick Schneider - ISTP Project Office
SCHNEIDER@ISTP1.GSFC.NASA.GOV
Jim Willett - NASA Headquarters
WILLETT@USRA.EDU
ISTP moves to CDF V2.5
Mona Kessel
ISTP has adopted CDF V2.5 as the official project version; the previous official version was CDF V2.4. With the installation of CDHF software version 6.4 (approximately December 1996), CDF V2.5 will be producing the Key Parameter files from Geotail, Wind, and Polar. It will be necessary to upgrade your system to CDF V2.5 in order to read the newly created KP files.
ISTP has tried to minimize software changes to lessen the impact on the PI/CoI community. This change is necessary in order to verify externally generated CDFs, many of which are using CDF V2.5.
CDF V2.6 has been released by NSSDC, however at this time IDL is not supporting this version and so it's use is not yet recommended. (CDF V2.6 has a number of enhancements which are highly desired, for example: compression. These will be discussed in a future newsletter article.) IDL support for CDF V2.6 is expected with one of their upcoming releases next year. After that time ISTP will adopt CDF V2.6
as the official version and use it for producing Key Parameter files.
There is a user support office for CDF that you should contact when you need assistance.
For Email requests send to:
Internet CDFSUPPORT@NSSDCA.GSFC.NASA.GOV (128.183.36.23)
cdfsupport@nssdca.gsfc.nasa.gov
DECnet NCF::CDFSUPPORT (15578::CDFSUPPORT)
Mona Kessel
Goddard Space Flight Center
Code 632.0
Greenbelt, Md. 20771
kessel@nssdca.gsfc.hasa.gov
ISTP Shines at the Fall 96 AGU Meeting
Mauricio Peredo
Over the last few years, several special sessions have been organized at AGU meetings with the purpose of highlighting ISTP activities. Initially, these sessions described the ISTP data system as well as existing or planned data products of interest to the wider space physics community. More recently, the special sessions have focused on presentation of early ISTP results; primarly those involving correlative studies between different spacecraft observations, ground-based measurements, or theoretical investigations.
This December, the tradition continues with a series of ISTP sessions at the Fall 96 AGU. In fact, following the successful launches of SOHO, POLAR, FAST and Interball-Aurora, many collaborations have ensued, resulting in in overwhelming number of ISTP-related papers to be presented. The
specific sessions focusing on ISTP correlative results this year span the entire spectrum of solar, interplanetary, magnetospheric and ionospheric physics. Specifically, the follwing sessions have been
scheduled:
SM71A Sun-Earth Connections: ISTP/GGS Correlative Results I: MagnetosheathPosters (joint with SA,SH)
SM72F Sun-Earth Connections: ISTP/GGS Correlative Results I: Magnetosheath (joint with SA,SH
SM11A Sun-Earth Connections: ISTP/GGS Correlative Results II:Polar Cap and LobesPosters (joint with SA,SH)
SM12C Sun-Earth Connections: ISTP/GGS Correlative Studies II:Polar Cap and Lobes (joint with SA,SH)
SM21D Sun-Earth Connections: ISTP/GGS/POLAR Initial Results I (joint with SA,SH)
SM22B Sun-Earth Connections: ISTP/GGS/POLAR Initial Results II Posters
SM21A Sun-Earth Connections: ISTP/GGS Correlative Results III: Plasma Sheet and AuroraPosters (joint with SA,SH)
SM22D Sun-Earth Connections: ISTP/GGS Correlative Results III: Plasma Sheet and Aurora (joint with SA,SH)
SM31A Sun-Earth Connections: ISTP/GGS Correlative Results IV: Inner Magnetosphere and FAST Posters (joint with SA,SH)
SM32D Sun-Earth Connections: ISTP/GGS Correlative Results IV: Inner Magnetosphere and FAST (joint with SA,SH)
SM41A Sun-Earth Connections: ISTP/GGS Correlative Results V: Theory and Ground Based Observations Posters (joint with SA,SH)
SM42C Sun-Earth Connections: ISTP/GGS Correlative Results V: Theory and Ground Based Observations (joint with SA,SH)
SH71B Global Coronal Disturbances and Mass Ejections I
SH72B Global Coronal Disturbances and Mass Ejections II
SH11A Global Coronal Disturbances and Mass Ejections II Posters
SH21D Helioseismology I
SH22A Helioseismology II
SM41A Sun-Earth Connections: ISTP/GGS Correlative Results V: Theory and Ground Based
Observations Posters (joint with SA,SH)
SM42C Sun-Earth Connections: ISTP/GGS Correlative Results V: Theory and Ground Based Observations (joint with SA,SH)
SH71B Global Coronal Disturbances and Mass Ejections I
SH72B Global Coronal Disturbances and Mass Ejections II
SH11A Global Coronal Disturbances and Mass Ejections II Posters
SH21D Helioseismology I
SH22A Helioseismology II
The full program for the FALL 96 AGU Meeting, including session descriptions and paper titles for each session is available from the AGU world wide web site at URL: http://www.agu.org/meetings/fm96top.html/"
In addition to these 17 sessions, a large number of papers involving ISTP studies are scheduled for other sessions. All together, the FALL 96 AGU will see well over 250 presentations reporting results from the ISTP initiative.
Mauricio Peredo
ISTP Science Planning and Operations Facility,
Raytheon STX Corporation
Goddard Space Flight Center
Greenbelt, Md. 20771
peredo@istp1.gsfc.nasa.gov
New NSSDC User Survey
Joe King
The National Space Science Data Center has initiated a new survey of present and potential users of NSSDC data and services. The survey solicits both user satisfaction levels and suggestions for changes in its services and interfaces which would make NSSDC more effective and useful. This announcement earnestly solicits your input. The survey is at URL: http://nssdc.gsfc.nasa.gov/nssdc/survey.html/
Joseph H. King
Goddard Space Flight Center
Code 633.0, NSSDC
Greenbelt, Md. 20771
king@nssdca.gsfc.nasa.gov
A multispacecraft ISTP Study: substorm evolution from the solar wind to the magnetosphere and ionosphere
T. I. Pulkkinen(1,2), D. N. Baker(1), N. Turner(1), H. J. Singer(3),
(1)Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO
Abstract
An isolated substorm event on May 15, 1996, was recorded by an unprecedented suite of satellites both
in the solar wind and in the magnetosphere. We show data from various instruments onboard several
ISTP satellites to discuss both the prompt response of the dayside magnetosphere to the changes in the
interplanetary magnetic field and the following substorm evolution in the nightside tail.
1. Introduction
Exploration of the Earth's space environment has revealed a dynamic and complex system of
interacting plasmas, magnetic fields and electrical currents. The near-Earth environment has traditionally
been explored and studied as a system of independent component parts - the interplanetary region, the
magnetosphere, the ionosphere, and the upper atmosphere. From these early explorations, it was
known that geospace is a complex system of highly interactive parts. One of the key objectives of the
International Solar Terrestrial Physics program is to understand how the individual parts of the closely
coupled, highly time-dependent geospace systems work together [e.g., Acuna et al., 1995] (see
references therein for the instrumentation used here).
Magnetospheric substorms represent a basic form of interaction between the solar wind, the
magnetosphere, and the ionosphere. One of the key open questions in magnetospheric dynamics is the
coupling of the various plasma regions; how important it is for the dynamics and through what
mechanisms is the information passed from the solar wind to the magnetosphere or between the
magnetosphere and the ionosphere. Early case studies and statistical analyses led to the understanding
that substorms occurred when the interplanetary magnetic field turned southward: that allowed a more
direct energy input from the solar wind into the magnetosphere, which later led to the explosive energy
release during the substorm expansion phase. However, the mechanism which initiates the energy
release is still debated upon: both internal instabilities and external (solar wind and/or IMF induced)
triggers have been suggested.
A key problem in substorm studies has been the lack of simultaneous observations from all the key
regions: Early and mid 1980's hosted a variety of magnetospheric satellites, which led to a wealth of
new information of the inner magnetosphere dynamics, but during that period the solar wind and IMF
observations were not continuously available. Furthermore, the more advanced instrumentation
onboard the presently operative satellites have revealed processes that were not
possible to detect with previous spacecraft. Here we present data from
one particularly well-observed substorm event using
a multitude of satellites in the solar wind and in the magnetosphere together with
ground-based observations of the ionospheric current systems.
Figure 1 Satellite locations in the GSM X-Y plane: (left)
Larger view showing the upstream satellites. (right)
Detailed view of the inner magnetosphere. The statistical location of the
magnetopause is shown with the black line, the solar
wind is indicated with blue, and magnetosphere with
green.
The extensive set of observations here allows detailed study of the magnetospheric effects of changes
in the interplanetary magnetic field (IMF), with three satellites (WIND, IMP-8, and INTERBALL Tail
Probe) upstream and POLAR in the dayside high-latitude polar region. Furthermore, we show the time
evolution of the instability growth in the nightside magnetosphere using geostationary satellites and
GEOTAIL at about 10 Re radial distance.
2. Observations
2.1 Solar wind - magnetosphere coupling
The top panel of Figure 2 shows the IMF Bz measured by IMP-8, WIND, and INTERBALL, all
upstream of the Earth. Using magnetic field and solar wind speed measurements allowed us to infer
that the southward turning, which is a sign of enhanced coupling between the solar wind and the
magnetosphere, arrived at the magnetopause at about 0548 UT. Similarly, the northward turning
recorded by WIND at about 0652 UT arrived at the magnetopause at about 0705-0707 UT.
POLAR was located near local noon, moving poleward through the auroral region. Figure 3 shows the
energetic electron and ion data from the CEPPAD instrument from 0500 UT until 0700 UT.
Interestingly, the higher-energy electrons (top panel) disappear from the detector at
about the time of the southward turning of the IMF. (The lower-energy
portion of the electron data shown as white and
red should be considered as a low energy threshold of the instrument.) Between 0600 and 0610 UT
the satellite was at the dayside auroral oval region, moving from the closed field lines to the open field
line environment.
Immediately upon the arrival of the southward turning of the IMF, the POLAR electric field instrument
(EFI) showed a significant enhancement of the fluctuations in the DC electric field (third panel of
Figure 2). The data indicate an increased level of activity throughout the period of negative IMF Bz,
after which the field quieted substantially. The wave instrument (PWI) onboard POLAR (Figure 4)
also detected increased electrostatic wave power at low frequencies (peak intensity below 100 Hz)
beginning immediately after the southward turning of the IMF; the power level was enhanced until the
IMF turned northward again.
The magnetic field measured by POLAR reveal that after 0550 UT POLAR crossed the auroral current
systems. The field differences shown in the fourth panel of Figure 2 (model field values have been
subtracted from the actual measurements) indicate that the field lines became more vertical. We
interpret this change to be caused by the arrival of the front carrying the southward IMF at the dayside
magnetopause. Note also that the field disturbances begin to decrease at the time of the northward
turning of the IMF shortly after 0700 UT.
In summary, at the estimated time when the southward IMF arrived at the dayside magnetopause,
several instruments onboard POLAR recorded an almost instantaneous response to the changed
external conditions.
Figure 2 Panels from top to bottom: Interplanetary magnetic field Bz and Bx
from WIND (blue), IMP 8 (green), INTERBALL (red) in GSM coordinates.
Electric field from POLAR. Magnetic field from POLAR (in nT), the data are in
GSM coordinates, and model field values have been subtracted from the
observations.
Figure 3 Energetic electron and ion data from the POLAR CEPPAD instrument. The
electron measurements below about 80 keV have not yet been calibrated, and the
monoenergetic band at low energies should be considered as the low energy cutoff. The
bottom panel shows POLAR L-value (solid line, scale on the left) and MLT (dashed line,
scale on the right).
The solar wind and magnetosphere interact also in a slower time scale, of the order of few days. The
top panel of Figure 5 shows an auroral image taken during the time interval discussed here. The
continental outline has been added to the figure in order to help locating the band of auroral luminosity
over the northern polar region and the auroral brightening occurring over North America. The bottom
panel of Figure 5 shows the global extent of the outer radiation belt on 15 May 1996 in a northern
hemisphere projection map. This map shows the count rate of electrons with E>1 MeV measured by
SAMPEX as a function of geographic longitude and latitude. The bright red and yellow collar around
the northern polar region shows that the outer radiation belt was rather intense as a result of a small
solar wind stream that peaked on 13 May 1996. (Note that the bright red pattern near the bottom of the
image is relatively constant and is due to the South Atlantic Anomaly). We are in the process of
comparing the auroral luminosity pattern of location and intensity with the related pattern of radiation
belt features for this period.
2.2 Substorm evolution
The GOES-8 and GOES-9 satellites at geostationary orbit [Singer et al., 1996] started recording
substorm growth phase-associated signatures at 0600 UT: the field configuration became gradually
more stretched (top two panels of Figure 6). Magnetic field and convective electric field values
observed at GEOTAIL (bottom three panels of Figure 6) at about 10 Re distance reveal a similar
picture, growth phase signatures began at about 0600 UT, and no prior disturbances
that could be associated with the IMF southward turning were
seen. Thus, it took about 10 min for the information
of the dayside changes to penetrate to the nightside plasma sheet.
The auroral pictures taken by the UVI imager onboard POLAR give a global view of the substorm evolution. Figure 5 shows a sample
image taken during the second substorm activation at 0713 UT.
The Los Alamos National Laboratory satellite 1990-095 was in the local dawn sector at about 0500
MLT. It recorded dispersed electron signatures of three distinct activations (top panel of Figure 7). The
two GOES satellites were in the nightside tail, GOES-8 in the morning sector and GOES-9 in the
evening sector; the actual substorm onset meridian was located between the spacecraft. Thus, we are
able to follow the azimuthal expansion of the substorm-associated current systems in the nightside tail.
The GEOTAIL plasma moments (bottom panels of Figure 7) show the onset of Earthward flow and
large electric field fluctuations at 0639 UT, a few minutes after a weak field dipolarization was seen
at GOES-8 somewhat closer to midnight.
3. Discussion
With this complex set of data, we have examined three distinct events: a southward turning of the IMF;
a substorm onset caused by an internal tail instability; and a substorm intensification occurring
simultaneously with an IMF northward turning. The results, when fully analyzed, can reveal important
facts about the solar wind - magnetosphere coupling and on the various substorm onset mechanisms.
The southward turning of the IMF caused an immediate response at the dayside auroral oval region.
The nightside magnetosphere between 6 and 10 Re responded to the IMF turning within 10 minutes.
Figure 4 Wave measurements from POLAR PWI instrument showing the electric field wave power.
Figure 5a Auroral image taken by the FUV camera of
the VIS imager onboard POLAR at 0713 UT, during the second substorm activation.
Figure 5b Radiation belts as measured by SAMPEX. The
image shows a composite of measurements over one day (16
orbits), flux of electrons over 1 MeV energy are shown.
The observations suggest that some signature of the substorm onset is rapidly seen at various locations
in the nightside tail: The geostationary orbit satellites remotely sensed the current wedge currents
poleward of the s/c locations immediately after their formation. GEOTAIL toward dawn from the
onset longitude recorded fluctuations in the magnetic and electric fields also within a minute of the
onset, several minutes before Earthward flow and actual magnetic field dipolarization were observed
at the satellite location. Thus, this demonstrates the truly global nature of the substorm process and the
rapid way the magnetosphere transfers information from one location to another.
This article presents initial results of an ongoing study involving multiple spacecraft and ground-based
observations: In the analysis, we have used observations from ten spacecraft:
Furthermore, ground-based magnetograms were studied from the 14 CANOPUS chain magnetometers,
the 13 Greenland chain magnetometers, and several other locations in Eastern Canada (obtained
through the online facility at NGDC), which was the key location of activity. Obviously, the results
shown here represent only a very minor portion of the data gathered.
This study is a very positive demonstration of the capabilities of the ISTP Key Parameter and other
WWW-based data search tools: These make it possible to take a quick initial
look at the data and its availability. Furthermore, identifying key
observations and dynamical events is much easier when the
various data can be analyzed together in the key parameter format.
Already the initial results reveal the importance of having several spacecraft upstream of the
magnetosphere for detailed investigation of the solar wind and IMF conditions before and during the
substorm activity. Similarly, good coverage is necessary both in the dayside magnetosphere as well
as in the magnetotail in order to address questions related to the channels of information transfer from
the solar wind to the magnetosphere. It is necessary that these processes be understood before detailed
mechanisms for the substorm onset can be conclusively evaluated.
Figure 6 Panels from top to bottom: Magnetic field Bz from GOES-8 and
GOES-9. Magnetic field By from GOES-8 and GOES-9. Total magnetic field,
and magnetic field Bz and Bx components from GEOTAIL. Convection electric
field (computed from magnetic field and plasma measurements) Ey component.
Figure 7 Panels from top to bottom: Electron differential fluxes from s/c 1990
-095. Plasma velocity Vx and Vy components measured by GEOTAIL LEP
instrument. Convection electric field Ex and Ez components as computed from
plasma and magnetic field measurements.
Acknowledgments
We thank the NSSDC personnel for maintaining the online ISTP key parameter facility. The work of
TP was supported by the Finnish Fulbright Commission. We are thankful for the ISTP teams for their
support for this study. The plasma wave data from POLAR PWI instrument was kindly provided by
D. Gurnett (instrument PI). We thank Y. Saito for evaluation of the GEOTAIL LEP data, and ISAS
for successful and continuing operations of GEOTAIL. We thank S. Romanof for providing the
INTERBALL magnetometer data to the key parameter facility, and the IKI group for maintaining the
INTERBALL key parameter data set. We thank Terry Raytheon and the Canadian Space Agency for
providing the CANOPUS data and Eigil Friis-Christensen for providing the Greenland magnetometer
data.
References
Case Study for Theory-Data Closure
Background
A key goal of the ISTP initiative is to understand the flow of mass, momentum and energy across the
solar wind-magnetosphere-ionosphere system in a global sense.
What?
Following the successful launch of POLAR on February 24, 1996, a detailed end-to-end test
involving the spaceborne, theory and ground-based investigations comprising ISTP became
possible.
Who?
The ISTP Science Planning adn Operations Facility was chartered by the Science Working Team to
identify candidate intervals for such an end-to-end test.
How?
The desired selection constraints, in approximate priority order, were:
When?
Several candidate periods were identified, and upon iteration with the science teams, the interval from
May 19, 1996 17:30 UT to May 20, 1996 02:30 UT was selected.
Why?
During this interval, a large fraction of the criteria outlined above were met, and nature provided
several substorms. WIND observed the oncoming solar wind ~110 Re upsteam from Earth, and
detected a southward turning of the IMF between May 19, 21:00 UT and May 20, 01:00 UT, with a
a few, very brief northward excursions. The Sondrestrom rad was operated from May 19, 22:39 to May
20, 05:00, providing excellent overlap with the substorm activity evident from the POLAR/UVI
images, and from the CANOPUS Auroral Electrojet indices which show a dip of Cl to -800 nT and
an envelope Cu-Cl of 1200 nT around 00:40 UT on May 20. The UVI images suggest the substorm
expanded both westward and eastward during this period.
So what?
Because of the intrinsic integration of spaceborne and ground-based observations, and theoretical
tools, this study will allow us to obtain the first quantitative assessment of our progress toward meeting
the key goal of the ISTP initiative: understandign the global flow of mass, energy and momentum
across the sun-earth system.
Initial results from this study will be presented at the Fall 1996 AGU meeting, where multiple papers
will address the elements of the complete end-to-end test, with emphasis on the global implications
for mapping of auroral features to the magnetotail, and the dependence of such mappings on the
upstream solar wind and IMF conditions.
Mauricio Peredo
ISTP Correlative Science Event
With the successful launch of the POLAR spacecraft on February 24, 1996;
a new stage of collaborative ISTP research began. Early results from
the POLAR science teams are extremely exciting, and in particular
two intervals were extensively discussed during the August 27-28, 1996
Polar Science Operations Team meeting. The observations in question
are all within the period from May 26-29, 1996, and have resulted in
the kind of multi-instrument, multi-mission collaborations that ISTP
is intended to address.
There are two primary science thrusts within the period. First of all,
a POLAR perigee pass on May 27, 1996, centered at
about 12:30 UT, in which the satellite crossed the southern auroral zone
from near midnight to near noon. Bright and active aurora were observed
by all three POLAR imaging systems simultaneously with comprehensive
measurements by the POLAR particles and fields instruments. This pass
was the first opportunity in the POLAR mission for coordinated imaging,
particles, and fields measurements on auroral field lines, that included
all three POLAR imagers. During this period two DMSP satellites crossed
the auroral zone within the view from POLAR, providing low altitude
measurements of precipitating particles as well as auroral images in
visible light. Just before and just after the pass, TIROS satellites
also crossed through the region, providing a longer baseline of
precipitating particle observations. WIND data indicate that these
aurorae were associated with a density enhancement just upstream of a
large magnetic cloud, which continued to pass by Earth for the next two
days. In addition to WIND, GEOTAIL, INTERBALL-TAIL and IMP-8 are all
upstream of the bow shock during the perigee pass, providing an
opportunity to study this period with multiple solar wind monitors. The
excellent auroral views provided by the POLAR orbit, together with the
comprehensive datasets available for this time provide an optimum
opportunity for detailed study of this event. Initial work will focus
on intercallibration of imaging and precipitating particle observations
to validate instrument responses and auroral emission models. The
period has been proposed by Dave Chenette as a GGS Event, and in
accordance with the GGS Event process, he is maintaining a web page to
provide access to information regarding this study; the event URL is:
ftp://klamath.spasci.com/pixie/www/27_May_GGS_Event/27_May.html
The second science thrust is associated with observations made
on May 28-29, 1996, when we observed an excellent configuration of the
ISTP constellation of satellites, both in terms of their relative
locations, as well as their conjunctions with ground-based
observatories. In addition, because of the magnetic cloud passing
through Earth at the time (as mentioned above in connection with the May
27 observations), the magnetosphere was compressed well inside its
nominal position, and as POLAR was traversing the dayside, it crossed
the magnetopause and encountered intense magnetosheath-like plasmas.
This interval is also receiving considerable attention from the ISTP and
GEM scientific communities; Bill Peterson is coordinating the analysis,
and is maintaining a web page to disseminate information, at URL:
ftp://sierra.spasci.com/DATA/timas/GEM/may29.html
Preliminary work suggests extremely high plasma densities and
substantial He++ fluxes present. Furthermore, HYDRA observations appear to
be consistent with POLAR crossing through a reconnection region at high
latitude. Figure 1 shows a schematic representation of the geometry
suggested by the preliminary analysis. Alan Rodger has reported excellent
ground-based coverage from the Southern Hemisphere stations, starting on
May 28th and lasting throughout the 29th. The event web page has further
detail, and identifies over a dozen groups, both experimental and
theoretical, already working on the event analysis. Furthermore, Bill
Peterson has argued that a control interval is essential to place this
observations in proper context, and has selected May 26, 1996 from 3:00 to
11:00 as the control period.
It has been proposed that the entire period of May 26-29, 1996 be
identified as an Inter Agency Consultative Group (IACG) interval, and that all
agencies cooperate to assemble the largest possible quantity of relevant data.
The proposal will be considered at a future IACG meeting.
Mauricio Peredo
New Release of the ISTP Key Parameter Visualization Tool (KPVT)
(Version 2.1 will be officially released on 12-2-96)
Syau-Yun Hsieh, Mauricio Peredo, and Bill Mish
The Key Parameter Visualization Tool (KPVT), developed at the ISTP Science
Planning and Operations Facility (SPOF), is a generic software package to visualize the key parameter
data produced from ISTP missions, interactively and simultaneously. The tool is designed to facilitate
correlative displays of ISTP data, and thus the selection of candidate events, data quality control.
The software, written in IDL, includes a graphical user interface, and runs on many platforms including
multiple UNIX workstations, VAX/Open VMS, PC/Windows 95, and Macintosh. The full package
of the tool including the source code, installation instructions, and other important materials can be
obtained via anonymous FTP from the directory SYS$PUBLIC:[TOOLS.KP_PLOT] on
ISTP1.GSFC.NASA.GOV or from ISTP website
here
Version 2.1 of the KPVT will be publicly available to the ISTP community starting 12-2-1996. It
supports various plot types such as time series, spectrograms, and images. The user interface is flexible
and easy to use.
The basic requirement for users is to select the data to be displayed. For new data selections, the plot
will be generated automatically with default settings. Many options are available for users to
customize the plots if desired. All data and plot parameters can be saved into a Plot File template and
retrieved later for reuse.
Specific features provided in this version include:
(1) System Setup: quick and flexible access to a user's local environment.
(2) Select Data: flexible data selection procedures to accommodate versatile choices for users.
(3) Plot Control: flexibility and capability for from interactive plot manipulation to on-line custom plot making.
(5) Browser:
Any GIF or ASCII file can be selected to display with hardcopy option.
(6) Modularized Tools:
Tool of Generating CDFskeleton tables is currently available.
(7) On-Line Help:
of the tool also provides a framework the community can for easy comparisons or analyses. We hope
that the improvements we have made to the tool are useful and that many scientific collaborations are
facilitated by its use. The on-line quick reference provides an ISTP web site address which serves as
a generic pointer to the links of investigators. As always, user feedback is essential to guide further
improvements of the tool. For comments or questions, please contact:
Syau-Yun Hsieh,
Polar/ISTP Science Coordination
Nicola J. Fox, Robert A. Hoffman
The Polar satellite, launched February 24, 1996, is the second of the two NASA spacecraft in
the Global Geospace Science (GGS) initiative, a part of the International Solar Terrestrial Physics
(ISTP) program. This program combines resources and scientific communities on an international
scale using multiple spacecraft missions, augmented with complementary ground facilities and
theoretical efforts, to obtain coordinated, simultaneous investigations of Sun-Earth connections.
The primary science objectives of the ISTP Science Initiative are as follows:
1. Determining structure and dynamics in the solar interior and their role in driving solar activity;
2. Identifying processes responsible for heating the solar corona and its acceleration outward as the
solar wind;
3. Determining the flow of mass, momentum and energy through geospace;
4. Gaining a better understanding of the turbulent plasma phenomena that mediate the flow of energy
through geospace;
5. Implementing a systematic approach to the development of the first global solar-terrestrial model,
which will lead to a better understanding of the chain of cause-effect relationships that begins with
solar activity and ends with the deposition of energy in the upper atmosphere.
The ISTP Science Initiative uses simultaneous and closely coordinated measurements from
POLAR, WIND, GEOTAIL and SOHO, in collaboration with INTERBALL and FAST. These
measurements in the key regions of geospace are supplemented by data from equatorial missions and
ground-based investigations. The equatorial missions include: the Geosynchronous Operational
Environmental Spacecraft (GOES) Program of the National Oceanic and Atmospheric Administration
(NOAA) and the Los Alamos National Laboratory (LANL) spacecraft from the Department of Energy
(DOE). The ground-based investigations include the SuperDARN and SESAME coherent radar
networks, Sondrestromfjord incoherent scatter radar and the CANOPUS array. Additional data from
other satellites such as NASA's IMP-8 satellite are used to supplement the data from these missions.
These missions and investigations provide a measurement network to determine the local state of
several key magnetospheric regions.
In order for the POLAR spacecraft to support the ISTP science objectives, the location of the
collaborating satellite and ground-based instruments is taken into account when scheduling the
operations and pointing direction of the de-spun platform which contains the auroral imagers. The
priority for Polar science scheduling is listed below in table 1. Time intervals when the deployment
of the GGS spacecraft offers a unique opportunity for the pursuit of coordinated correlative studies
using GGS/ISTP resources, collaborating spacecraft and ground-based facilities are called GGS
Special Operations Periods (GSOPs). An example of a GSOP would be a period when POLAR is
performing auroral imaging, GEOTAIL is near the tail axis, WIND is in the solar wind, and the
SuperDARN radar array covers the nightside. The generation of GSOPs is the responsibility of the
GGS spacecraft project scientists, the GGS coordinator and members of the Spacecraft Planning and
Operations Facility (ISTP/SPOF). A GSOP is generated via a GSOP Form, which will contain a
description of the opportunity. The forms are accessed from the web via the ISTP SPOF homepage.
Each GSOP is listed in the GSOP catalogue, from which the completed forms may be accessed.
POLAR OPERATIONS PRIORITIES
PRIORITISED SPOTs
PRIORITISED GSOPs
ROUTINE OPERATIONS
Table 1. Polar Operations Priorities
In addition to the GSOPs, GGS Science Priority Operation Topics (SPOTs) may be generated
by any member of the space science community. The SPOTs are more general than the GSOPs as their
emphasis should be on science rather than operations. It is the job of the GGS coordinator and ISTP
/SPOF to decide when the optimum scheduling time for the science operation topics occurs. SPOTs
are submitted using a form similar to that for GSOPs, also accessed from the SPOF homepage.
The science planning for Polar is completed six weeks prior to the operation. This entails
ascertaining the position of each of the collaborating spacecraft and radar using the variety of orbit
plots and ground-based maps available on the web. The GSOPs and SPOTs are also reviewed in order
to determine the best direction for Polar to be pointed. Some examples are, when one of the ISTP
satellites is crossing through the tail axis, the platform will be pointed towards midnight to compliment
substorm studies; if FAST is crossing through the cusp region while Polar is near apogee, the platform
will be directed so that the cusp can simultaneously be imaged by Polar, or when the Polar footprint
crosses through a radar field-of-view as the radar moves through the cusp or midnight region, Polar will
image the radar location. The science plans are then posted on the web in the Master Operations
Catalogue for comment by any members of the community. Once the science plans have been approved,
the pointing plans and spacecraft maneuvers are submitted to the Flight Operations Team.
All members of the space science community are invited to contribute to the ISTP/Polar science
collaboration effort either by submitting science priority operations topics (SPOTs) or commenting on
the plans on the Master Operations Catalogue. In this way, the Polar science and operations teams can
be sure that they are achieving the best results from the ISTP mission.
Nicola J. Fox
Robert A. Hoffman
SPOF Homepage URL
ISTP Homepage URL
J. B. Blake(4), H. Spence(5), L. A. Frank(6), J. B. Sigwarth(6),
T. Mukai(7), S. Kokubun(8), R. Nakamura(8) C. T. Russell(9),
H. Kawano(9), F. Mozer(10), J. A. Slavin(11), R. Lepping(11),
R. Anderson(6), G. Reeves(12), and L. M. Zelenyi(13)
(2)Permanently at: Finnish Meteorological Institute, Helsinki, Finland
(3)NOAA Space Environment Center, Boulder, CO
(4)The Aerospace Corporation, Los Angeles, CA
(5)Department of Astronomy, Boston University, Boston, MA
(6)Department of Physics and Astronomy, The University of Iowa, Iowa City, IA
(7)Institute of Space and Astronautical Science, Sagamihara, Japan
(8)Solar Terrestrial Environment Laboratory, Nagoya University, Toyokawa, Japan
(9)Institute of Geophysics and Planetary Physics, UCLA, Los Angeles, CA
(10)Space Science Laboratory, University of California Berkeley, Berkeley, CA
(11)NASA Goddard Space Flight Center, Greenbelt, MD
(12)Los Alamos National Laboratory, Los Alamos, NM
(13)Space Research Institute (IKI), Moscow, Russia
Acuna, M. H., K. W. Ogilvie, D. N. Baker, S. A. Curtis,
D. H. Fairfield, and W. H. Mish, The global geospace science program
and its investigations, in: C. T. Russell (ed.), The global geospace
mission, Kluwer Academic Publishers, Dordrecht, the Netherlands, p. 5,
1995.
Singer, H. J., L. Matheson, R. Grubb, A Newman, and S. D. Bouwer,
Monitoring space weather with the GOES magnetometers, SPIE Conference
Proceedings, Volume 2812, 4-9, August 1996, in press.
Mauricio Peredo
ISTP Science Planning and Operations Facility,
Raytheon STX Corporation
Goddard Space Flight Center
Greenbelt, Md. 20771
peredo@istp1.gsfc.nasa.gov
Mauricio Peredo
Figure 1 shows a schematic representation of the geometry
suggested by the preliminary analysis.
ISTP Science Planning and Operations Facility,
Raytheon STX Corporation
Goddard Space Flight Center
Greenbelt, Md. 20771
peredo@istp1.gsfc.nasa.gov
ISTP Science Planning and Operations Facility
The directory paths of a user's local database and print commands for various
printing facilities can be interactively stored in the tool's
system for easy access to files and printers. User options such as
variable choices for the default color table, file path, printer, and the
size of the plot display window on the computer screen are also available.
Once a desired file and key parameter are selected, the KPVT will
analytically determine and provide all the possible selection choices for
a user to select. For non-image data, the data can be plotted in multiple
panels up to a maximum of 15 panels. Each panel may contain one or two
variables. Data may be selected from multiple files, corresponding to
one or multiple investigations. For image data, only one type of image
can be selected at a time.
Many options are available for plot manipulation. The plot controls
panel provides access to the most frequently used IDL plotting settings.
All user-defined plot parameters can be saved into a Plot File and
retrieved later for reuse.
For visualization of images, two different displays are available and
the options also include color scale, color table, and plot format
manipulations. (examples next pages)
For non-image displays, various plot characteristics can be customized,
including:
1. overall plot settings such as font size, thickness of characters,
and the style of plot panels;
2. axis settings such that every axis in every plot panel can be
customized independently. The options consist of labels, character
size, scale ranges, scalings, tick marks, the length of tick marks
(inwards, outwards, or a grid), color bar scales, etc..
An interface is also provided for easy time range adjustments;
3. ability to save customized plot styles in the users' individual
preferred setting;
4. plot layout, panel locations and spacing between panels that a user
can specify;
5. user-specified color bars;
6. adding custom vertical or horizontal lines to the plots such as a
zero line or a pair of vertical guide lines. Each panel can have 10
line additions in either orientation;
7. annotating the plots with text in user-preferred styles. The tool
allows 30 text additions to the plot.
The tool supports various output formats, including PostScript files for
hardcopy printing, as well as GIF files for easy import into world wide
web documents.
(4) Plot File and Viewing Loop: painless, cost-effective and efficient
approach in interactive data visualization over huge and rich collections
of ISTP key Parameters in a regular basis.
Once a user has decided what to plot and how to plot, all the necessary
data and plot parameters can be saved into a Plot File, a reusable
plotting template. At a later time, a user only needs to open a desired
Plot File and select the appropriate data files. The data will be
immediately displayed according to the preset preferences. After a Plot
File is created, a user doesn't need to repeat the interactive selections
over the same data and plot parameters again. A user can take advantage
of viewing loop to continuously view different data files with the same
set of data selections in preferred plot formats.
The on-line help is available to guide users through step by step
instructions. Plot examples and tutorial instructions are also provided.
The combined use of Plot File, plot manipulation features, and the Viewing Loop represents an easy
and powerful data visualization method over the ISTP Key Parameter data collections. The flexibility
Raytheon STX Corporation
ISTP Science Planning and Operations Facility
Phone: (301)-286-4981 Fax: (301) 286-1683
xrswh@istp1.gsfc.nasa.gov
Cusp passes with good footprint
Recurrent event
Routine Wideband
GGS Operations Coordinator
Goddard Space Flight Center
Mailstop 696.0, NRC
Greenbelt, MD 20771
fox@lepmfs.gsfc.nasa.gov
Polar Project Scientist
Goddard Space Flight Center
Mailstop 696.0
Greenbelt, MD 20771
hoffman@eldyn2.gsfc.nasa.gov
Newsletter HTML Author: Michael Cassidy - RMS Technologies, Inc.
cassidy@istp1.gsfc.nasa.gov
