Download Space Weather User Needs Related to Solar Observations

Space Weather User Needs
Related to Solar Observations
Eamonn Daly and Alexi Glover
ESA Space Environments and Effects Section
ESTEC, The Netherlands
Services and associated data collection means
should (eventually) be driven by user requirements
User Requirements
Data Requirements
Measurement Requirements
System Design
User Needs Identification
• Parallel studies for ESA by consortia led by Alcatel (now
Thales Alenia Space) and RAL ~ 2000:
– Intensive study of user requirements, leading to full system
designs;
• More recent updating in context of study of Space
Weather Nanosats (RAL at al.) ~ 2006
• Consolidation in the scope of ILWS Task Group on
“users” (see poster Glover et al., this meeting)
• Presentation of Hochedez et al, “Monitoring capabilities
for solar weather nowcast and forecast”, ESWW 2004
(available esa-spaceweather.net)
esa-spaceweather.net
User Requirements Focus
on End Effects
e.g. RAL study of user requirements:
Solar Sources and Ultimate Effects
Primary Phenomena
Resulting phenomena
Early phase of coronal
mass ejection
(CME)
Prompt acceleration of energetic
particles
Interplanetary shock
preceding CME
Continuing acceleration of
energetic particles
Magnetic structures
associated with
CME
Affect interplanetary propagation
of energetic particles;
Trigger geomagnetic storms on
encountering magnetosphere;
Coronal holes
Solar Flares
High speed streams:
Boundaries are sources of
acceleration;
Boundaries trigger geomagnetic
storms;
Large UV and X emissions affect
ionosphere and
thermosphere
Service Requirements
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Active region identification,
characterisation and tracking
Coronal hole identification
and tracking
Establishment of active
region and coronal hole
magnetic fields
Warnings of potential flaring
and CMEs
Alerts on flaring and CME
occurrence
Event magnitude prediction
“All clear”
Note timescale differences:
– Flare EM in minutes
– SEP: ~ hour
– Shocks and storms: days
Measurement Requirements
esa-spaceweather.net
1 EUV / X-ray solar images
•
Full Sun images in EUV / X-ray wavelengths are required for precursor identification with angular
resolution as good as or better than SOHO EIT, ie. 5 arc seconds. 1–hour resolution is probably
adequate.
2 Visible or UV occulted coronal images
•
Coronal images show the occurrence of Halo CMEs. Angular resolution as good as SOHO
LASCO, ie. 11 arc seconds, is desired. The good spectral resolution of LASCO is not essential for
a Space Weather application.
3 Visible or UV images of Sun-Earth space
•
To spot Earth-directed CMEs, stereo viewing from, for example, Earth and L4 or L5 is preferable,
with angular resolution of around 30 arc seconds.
7 X-ray flux
•
1 minute resolution of total flux is required to capture X-ray flare onset and magnitude. Spectral
measurements like those of GOES, ie. 0.1-0.8 nm and 0.05-0.4 nm, are required. Higher spectral
resolution than the GOES instrument may be useful, eg. 1-20keV spectral measurements which
could be achieved using proportional counters or solid state detectors.
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Detection of solar radio bursts, from the ground in the 10-1000MHz range, is a possible
alternative or complementary measurement.
8 UV flux
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This parameter is required for its effect on the ionosphere and upper atmosphere.
9 F10.7 radio flux
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F10.7cm is radio flux from the Sun, usually measured every day at Dominion in Canada. It is often
equivalent to SSN. Continuous measurements would require several stations around the globe.
17 SSN
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SSN is the optical number of sunspots according to the international index for sunspots algorithm.
This index is routinely maintained by the World Data Center for the Sunspot Index in Brussels.
18 IMF (B-field)
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… work on modelling magnetic structures in the solar wind, such as CMEs, has indicated that
knowledge of the magnetic field structure of the Sun at the point of origin may enable the field
within the structure to be predicted. …
Synthesis of solar measurement
requirements
What is done now?
• ISES services including European ones
– Flare prediction and warnings
– SPE predictions and warnings
– Alert Support
• Independent access to
solar (SOHO, Ground, …)
images by system operators
without support and interpretation
• Access to (e.g.) SIDC, CLS
by sat. operations
• NOAA support to human
spaceflight via JSC SRAG
• …
Solar Observations
in the Context of
Human Space
Exploration
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Future manned missions to Moon/Mars
will have strong requirements for
forecasts and nowcasts
Unpredictability of event timings and
magnitude (helio-propagation)
US National Research Council Report
(2006)
Based on Wintergreen workshop (2005)
“For the average well-connected event,
these methods predict the maximum
intensity within an order of magnitude
and the timing of the maximum within a
couple of hours.
These methods, however, fall apart for
shock-dominated events. Hence,
current forecasting models do badly
in predicting extreme events, and
extreme events represent the greatest
danger to human spaceflight crews.”
Courtesy of Mark Weyland (JSC SRAG)
NASA human spaceflight needs
• Develop forecasting tools giving 30 minutes to 2 hours lead time
(depending on the type of event).
• Free-space/near-Earth measurements or reliable models of higherenergy (~100-1000MeV) proton/ion spectra.
• ACE type data/models on mission termination.
• Be able to predict magnitude / duration / characteristics of SPE from
information received at onset of event
– Corollary: model predictions for 'all-clear' at onset for small events
and/or 'all-clear' forecasting for n day in advance with <~5% probability
of particle activity.
• Improved model correlations/precursors of activity, e.g. electron
signatures.
• Back-side solar imaging/modeling enabling region characterization.
• Better comparison of instrument readings onboard Shuttle/Station
with models transporting simulated or past events through
heliosphere / magnetosphere / vehicle and into onboard detectors.
• Model interpretations allowing correction of GOES particle data to
near free-space values.
Research
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Identify the (reliable) solar surface precursors and indicators of flares and
CMEs
– Solar magnetic field features
– EIT waves and Moreton waves
– Helioseismology
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Magnetic features associated with
CMEs and their coupling to
heliosphere models in real time
• Solar Data driven models of
heliospheric magnetic field
for geoeffectiveness prediction
• Seeding/boundary conditions of
shock and particle models
• Prediction methodologies
(physics based, NN, etc.)
• Coronal hole characteristics
(boundaries, heliospheric extension)
→ SOTERIA will play a
major role in Europe
→ New measurement requirements
will probably emerge
There are Differences between Science
Requirements and Service Requirements
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Data type
Resolution
Coverage (location, target)
Timeliness
Continuity
Quality (calibration)
A science mission
Delay in down-linking data, to
optimise use of
communications;
Delay in processing the data
because of scientific priorities;
Non availability of the
spacecraft due to operational
constraints;
Non-continuity of data stream
or operation – scientific studies
can be “event” or “campaign”
oriented;
A short mission may fulfil
scientific goals
Very high performance
instruments
A service mission
Very little delay permissible
Near real-time data
products are required
High availability of the
spacecraft required
Continuity of data return
needed for near real time
and historical archives
Long duration missions
preferred
Reduced performance may
be acceptable if basic
service requirements are
met
• Solar assets will continue to be Science facilities
in short and medium term
Proba-2
LYRA and SWAP are very good precursors for
space weather “service oriented” instruments:
– Limited resources on a microsat (mass, volume,
power, telemetry);
– Relatively low development cost;
– Demonstrating new technologies (APS, diamond
detectors);
– Low cost orbit (PEO) operations;
– Ground segment aimed to be “rapid, open”
• Both applications and science sides of space
weather look forward to its success
Conclusions
• User requirements have been extensively studied, but
are evolving
• There are on-going UR capture activities in ILWS
• If it goes ahead, the ESA SSA phase 1 will include User
Requirements consolidation
• User requirements vary considerably in terms of
difficulty:
– Among the most challenging is response to fast-onset SPEs
• Important to maintain links to fast-moving research which
are establishing valuable new understanding and
methods (e.g. SIDC NEMO)
• While in the long term service-oriented payloads should
be launched, in the medium and short term, users need
support of science missions.
• We look forward to Proba-2