CGMS-41, NOAA-WP-21
V1, 24 May 2013
Prepared by NOAA
Agenda Item: III/VI
Discussed in WG III
ANOMALIES FROM SOLAR EVENTS
In response to CGMS Permanent Action 02
This report, on Anomalies from Solar Events, provides examples
of new space weather products under development, the
progression and prediction of the solar cycle, a summary of
recent significant space weather events, and a discussion about
the growth of space weather services and international
cooperation. The Spacecraft Environmental Anomalies Expert
System – Real Time (SEAESRT) at the Space Weather
Prediction Center will provide geosynchronous satellite operators
with information about space weather hazard levels from
energetic particles in the space environment. This information,
along with other tools developed at the National Geophysical
Data Center, will be used to support satellite anomaly
investigation. NOAA is also partnering with the international
community to strengthen the world’s satellite fleet through better
design standards. Predictions are given for the time and
magnitude of Solar Cycle 24 maximum. The consensus
prediction that the new cycle will be smaller than recent cycles is
consistent with current observations; however solar maximum,
based on a running 13-month average of sunspot numbers, may
be later than the predicted May 2013. Although the solar cycle
may be small, we note that historically some of the largest
geomagnetic storms have occurred during small solar cycles. An
update is provided on the levels of recent space weather activity
based on solar and near-Earth observations. Finally, we
describe the increasing international interest in space weather
and activities related to international coordination.
CGMS-41, NOAA-WP-21
V1, 24 May 2013
ANOMALIES FROM SOLAR EVENTS
1
INTRODUCTION
This paper documents significant space weather for the summary period MAY 2012 –
APR 2013. Previous CGMS papers have addressed Solar Cycle 23 and the
extended solar minimum leading into Cycle 24. Now, the report discusses conditions
around the Solar Cycle 24 maximum that was predicted for about May 2013, but now
may occur later in the year. The report also discusses new space weather products,
used both by forecasters and space weather customers, and international space
weather activities. Following is an update of CGMS 40, NOAA-WP-07.
2
SERVING CUSTOMERS WITH NEW PRODUCTS
2.1 New Satellite Anomaly Product – SEAESRT
A new product to support the satellite industry is scheduled to be released to the
public prior to October 1, 2013. The Spacecraft Environmental Anomalies Expert
System – Real Time (SEAESRT) is a set of data-driven algorithms that indicate the
likelihood of an environment-related anomaly on a geosynchronous satellite. The
target customers are operators of geosynchronous satellites who can benefit from
guidance on the hazard levels during active space weather conditions to make
decisions on the operation of their satellites, as well as to assess the possible causes
of anomalies that have occurred.
SEAESRT gives hazard levels at geosynchronous orbit for four common types of
satellite problems: surface charging, internal charging, single event upsets, and total
dose effects. For each of these four hazard types, the software gives a hazard
quotient that represents the probability that the current environmental conditions will
result in a satellite anomaly, relative to the long-term average likelihood of an
anomaly. A hazard quotient of unity indicates the likelihood of an anomaly is equal to
the long-term average. In addition to the hazard quotient, the 95% confidence interval
surrounding the hazard quotient is also given. All of the hazard quotients are derived
from the statistical occurrence of on-orbit anomalies or their proxies. It is assumed
that the probability of future anomalies has the same statistical relationship to the
environmental conditions as the historical anomalies.
The surface-charging hazard quotient is derived from the Kp index of geomagnetic
activity, which is related to the injection of low-energy plasma into the inner
magnetosphere from the magnetotail. Higher values of Kp are correlated with higher
levels of low-energy electrons at geostationary orbit and consequently higher
occurrence of surface-charging anomalies. The internal-charging hazard quotient is
derived from the level of >2 MeV electrons measured by the GOES satellites. High
energy electrons can penetrate into electronic components, and when sufficient
charge builds up, a discharge can occur that may result in an anomaly. The singleevent-upset hazard quotient is derived from the >5 MeV and >30 MeV protons
measured by the GOES satellites. High energy protons can penetrate into electronic
components directly disrupting computer memory and processes that result in
system anomalies. The total-dose hazard quotient is derived from the >5 MeV
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protons measured by the GOES satellites. This hazard quotient quantifies the hazard
to solar power arrays due to short-lived enhancements in the energetic proton flux.
Figure 1: Hazard quotient levels for surface charging and internal charging as
functions of longitude in geostationary orbit. The bar above the equator is colored
differently depending on the level of surface charging and the bar below the equator
indicates the level of internal charging as a function of longitude.
2.2 Satellite Anomaly Information Service Data Portal
Space weather impacts much of our society’s critical technology including satellite
operations. Intense bursts of energetic particles from the Sun and swells of the nearEarth particle radiation environment during geomagnetic storms create a harsh
environment that satellites must endure. These particles can cause sudden
discharges or component bit flips that disable or permanently damage satellite
electronics. NOAA provides a suite of data, services, and products for predicting and
monitoring the space radiation environment and is partnering with the international
community to safeguard the world’s satellite fleet.
To assess the real-time threat from particle radiation, NOAA maintains a constellation
of satellites with monitoring instruments. These include instruments on all 6 current
POES/MetOp low-Earth orbiting satellites and the 2 operational GOES
geosynchronous satellites. These data are provided in real time through the Space
Weather Prediction Center and the National Geophysical Data Center (NGDC). To
aid in interpreting and collating relevant data and information, NOAA is developing an
interactive Satellite Anomaly Information Services data portal. This portal will provide
information organized by the four most common types of space weather related
issues: surface charging, internal charging, single-event upsets and total dose
degradation. The portal will provide real-time data and plots of the particle
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populations most often associated with each type of anomaly as well as flow charts
and steps for quickly assessing whether a recent anomaly is likely related to space
weather. In addition, NOAA is planning for the next generation of GOES satellites by
developing new algorithm to turn the particle radiation data into actionable
information. New data-based products will include densities and temperatures
needed to drive satellite surface-charging models. Additional products will provide
solar proton event fluences shown against large proton events used to test satellite
design resilience giving a quick indication of when the environment has surpassed
design thresholds.
In addition to providing data, NOAA also supports satellite anomaly investigation with
more detailed analysis of the space environment. As an example, the VIIRS
instrument on Suomi NPP suffered several intermittent temporary shut downs.
Engineering analysis of these events suggested the affect was due to a component
vulnerable to particle radiation. A detailed comparison of these events to the space
particle environment reconstructed from the measurements of the 6 POES/MetOp
agreed with the engineering analysis. The data confirmed that the events occurred in
regions where particle radiation is typically highest. Additionally, the data narrowed
down the effect to protons with energies > 35 MeV.
Lastly, NOAA is partnering with the international community to strengthen the world’s
satellite fleet through better design standards. In October 2012, NOAA hosted a
meeting for working group four of the International Standards Organization. The
meeting was combined with two preceding workshops on aspects of the radiation
environment and satellites. One workshop focused on introducing the new AE9/AP9
radiation model that is a comprehensive climatological model of the space
environment to be used to estimate satellite lifetimes and anticipate vulnerabilities.
The second workshop discussed plans for developing a general satellite charging
standard as well as a worst case surface charging environment standard needed to
design robust satellites. A team was defined to continue development of these
standards that included representation from NOAA, commercial satellite builders, and
international partners.
3
SOLAR CYCLE PROGRESSION
Monthly, the Space Weather Prediction Center updates the Solar Cycle Sunspot
Number progression using the latest predictions from the International Space
Environment Services (ISES). The official NOAA, NASA, and ISES Solar Cycle 24
prediction was released by the Solar Cycle 24 Prediction Panel on April 25, 2007 and
updated on May 8, 2009. The Prediction Panel included members from NOAA,
NASA, ISES and other US and international representatives. As shown in Figure 2,
the most recent Panel consensus predicted solar cycle minimum in December 2008
and solar cycle maximum in May 2013. The predicted maximum sunspot number of
90 is below average. The Panel issues this prediction as needed to serve our many
customers who make economic decisions based on the level of solar activity and its
affect on human and technological systems. To date, the observed sunspot number
is coming in below what was predicted, but consistent with the prediction that this
would be a smaller solar cycle than ones in the recent past. In May 2013, activity has
picked up slightly, suggesting that we may be seeing a double peak (not uncommon)
at solar maximum. While Solar Cycle 24 is expected to peak at less than average, it
is worth noting that, historically, some of the largest geomagnetic storms, such as the
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one in 1859 and another in 1921, occurred during weaker solar cycles. Already, this
solar cycle, a large solar coronal mass ejection was observed that would have
caused a major or severe storm had it been directed at Earth. It is also important to
note that different types of space weather occur throughout the solar cycle. For
example, galactic cosmic rays that can affect satellite operations and human space
flight, peak around solar minimum and are unusually strong during this current weak
solar maximum.
Figure 2: Solar Cycle Sunspot Number Progression and Prediction.
4
SIGNIFICANT CYCLE-24 ACTIVITY
Like terrestrial weather, space weather is always present and makes itself apparent
in many forms. This section summarizes significant space weather for the period
May 2012 – April 2013.
Space weather activity showed a modest overall increase as the increasing phase of
Cycle 24 continued. Cycle 24 began in December 2008 and was expected to reach
maximum in May 2013. As noted in the previous section, the observed sunspot
number is coming in below what was predicted, and perhaps later, but consistent
with the prediction that this would be a smaller solar cycle than ones in the recent
past.
Solar flare events: M-class X-ray flares occurred in all but one month (December
2012) of the summary period with a 16% increase in occurrence from the previous
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12-month period. Flare activity increased significantly during July 2012 (see Table 1)
with 45 M-class flares and 2 X-class flares, including the largest of the period: an
X1.8 at 23/0317 UTC (NOAA Scale R3 (Strong) Radio Blackout).
Solar proton events: There were 11 >10 MeV proton events at geosynchronous orbit
during the period, which represented a 10% increase in occurrence vs. the previous
12-month period. The largest >10 MeV event (peak 255 pfu at 17/0430 UTC May
2012) was associated with an M5 flare on 17 March. There was a single >100 MeV
proton event at geosynchronous orbit during the period vs. 7 events during the
previous 12-month period. This event (peak 20 pfu at 17/0230 UTC May 2012) was
also associated with the M5 flare of 17 May.
Geosynchronous electron events: The >2 MeV electron flux at geosynchronous orbit
reached event level (> 1000 pfu) on 113 days of the period, a 9.7% increase from the
previous 12-month period. The vast majority of electron events were in response to
coronal hole high-speed streams.
Geomagnetic field events: There was 1 major storm day (15 July 2012) during the
period, vs. 2 during the preceding 12-month period, due to a coronal mass ejection
(CME) passage at Earth. The 15 July storm caused an AP = 60 with KP=5 and KP=6
observed (NOAA Scale G1 (Minor) and G2 (Moderate), respectively). In addition,
there were 13 major storm (KP=6 (G2)) periods, 3 to 6 hours in duration, observed
during the June 2012 – Mar 2013 timeframe; all associated with CME passages.
There were no severe storm days during the period (no change from the previous 12month period). There was a single 3-hour severe storm (KP=7 (G3 (Strong)) period
observed on 01 October 2012, also associated with a CME passage.
Table 1: Summary of Space Weather Events
X-ray Events
MAY
2012
JUN
JUL
AUG
SEP
OCT
NOV
DEC
JAN
2013
FEB
MAR
APR
5
>2 MeV
Events
Days >
1.0E+03
F10.7
M-class
X-class
12
0
15
11
45
10
4
6
14
0
0
2
0
0
1
0
0
5
1
3
5
Proton Events
Geomagnetic Storms
>10
SPE
>100
SPE
Ap
Major
Severe
121.5
2
1
8
0
0
13
22
8
3
20
5
0
120.5
135.6
115.7
123.2
123.3
120.9
108.4
1
5
0
1
0
0
0
0
0
0
0
0
0
0
10
13
7
8
9
6
3
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
2
127.1
0
0
4
0
0
0
0
0
0
16
9
104.4
111.2
125.0
0
1
1
0
0
1
5
9
5
0
0
0
0
0
0
GROWTH IN SERVICES AND INTERNATIONAL COOPERATION
International interest in space weather continues to grow. The two main
organizations engaged in the coordination and improvement of space weather
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observations and services are the World Meteorological Organization (WMO) and the
International Space Environment Service (ISES). The WMO has a large, global
membership of service providers and users and facilitates a network of observing
systems and information exchange. ISES historically has been the primary
organization for space weather services and consists of 14 nationally designated
service-providing organizations around the world. These two organizations have a
large overlap in their memberships and are working closely to ensure effective
coordination without duplication of effort. NOAA’s Space Weather Prediction Center
is one of the 14 ISES Regional Warning Centers, and NOAA staff participate actively
in the WMO Inter-Programme Coordination Team on Space Weather.
NOAA also participates in the United Nations Committee on Peaceful Uses of Outer
Space (UNCOPUOS) space weather efforts. Within the Science and Technology
Subcommittee of UNCOPUOS, a working group was formed to study and to report
on issues relating to the Long-Term Sustainability of Outer Space Activities (LTSSA).
Within the LTSSA working group, an Expert Team on Space Weather is one of four
working groups that have been formed. This team is working to define guidelines and
recommendations that can safeguard and improve the use of outer space and
mitigate the impacts of space weather. Illustrating the importance of further
international coordination on space weather, space weather has been designated as
a regular agenda item for the Science and Technology Subcommittee Assemblies.
6
CONCLUSIONS
While the current solar cycle appears to be consistent with predictions that it will be
smaller than recent cycles, the interest and demand for space weather services
continues to increase. In part, this is likely due to the increasing use of technologies,
and participation in activities, that are more susceptible to space weather than those
in the past. But, the interest also results from recognizing that large space weather
events can occur during small solar cycles and that different types of space weather
occur throughout the solar cycle. To meet the increasing needs, NOAA is investing in
new observations, products, and models that will serve those impacted by space
weather conditions. A few of these products and recent space weather conditions are
described in this report. Finally, we highlight the increasing international interest in
space weather and activities related to international coordination.
7
REFERENCES
NOAA/NCEP/SWPC Preliminary Report and Forecast of Solar Geophysical Data
(PRF): PRF 1914, 07 MAY 2012 – PRF 1966, 06 MAY 2013.
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