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**Evaluation Report for "Integrated forecasting system for mitigating
adverse space weather effects on the Northern American high-voltage
power transmission system"**

NASA Goddard Space Flight Center in partnership with the Electric Power
Research Institute

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height="0.7965277777777777in"}

Acknowledgments

This work was supported by the NASA Science Mission Directorate, Earth
System Division under the Applied Sciences Program, Energy Management
program element.

+-----------------------------------+-----------------------------------+
| Solar Shield Project Team         |                                   |
+-----------------------------------+-----------------------------------+
| *Michael Hesse-- Principle        |                                   |
| Investigator*                     |                                   |
+-----------------------------------+-----------------------------------+
| [NASA/GSFC]{.underline}           | [EPRI]{.underline}                |
|                                   |                                   |
| Antti Pulkkinen                   | David Fugate                      |
|                                   |                                   |
| Maria Kuznetsova                  | Luke Van der Zel                  |
|                                   |                                   |
| Shahid Habib                      | Ben Damsky                        |
|                                   |                                   |
| Fritz Policelli                   | William Jacobs                    |
+-----------------------------------+-----------------------------------+

**© National Aeronautics and Space Administration**

This document is not a formal publication of NASA, and all rights are
reserved by the Administration. The document may, however, be freely
reviewed, abstracted, reproduced and translated, in part or in whole,
but not for sale nor for use in conjunction with commercial purposes.
The views expressed in documents by named authors are solely the
responsibility of those authors. The mention of specific companies or
specific manufacturers\' products does no imply that they are endorsed
or recommended by the National Aeronautics and Space Administration in
preference to others of a similar nature that are not mentioned.

# Table of Contents {#table-of-contents .Heading-NoTOC}

Table of Contents [iii](#table-of-contents)

Executive Summary [4](#executive-summary)

1.0 Introduction [5](#introduction)

2.0 Overview of enhanced EPRI SUNBURST Decision Support Tool
[6](#overview-of-enhanced-epri-sunburst-decision-support-tool)

3.0 Consideration of NASA inputs [10](#consideration-of-nasa-inputs)

4.0 Gaps in meeting DST needs [13](#gaps-in-meeting-dst-needs)

5.0 Conclusions and recommendations
[13](#conclusions-and-recommendations)

6.0 References [14](#references)

#  {#section .Heading-NoTOC .unnumbered}

# Executive Summary {#executive-summary .Heading-TOC}

The Solar Shield[^1] project responds to the NASA Strategic Goal 3,
Sub-goal 3A: "Study Earth from space to advance scientific understanding
and meet societal needs" as described in the 2006 NASA Strategic Plan.
The project is funded by the NASA Applied Sciences Program, which has
the objective to expand and accelerate the economic and societal
benefits from Earth science, information, and technology. The project is
managed within the NASA Applied Sciences Program's "Energy Management"
program element.

In this project, an enhancement to the Electrical Power Research
Institute's (EPRI) SUNBURST decision support tool used by the U.S.
electric power industry is developed by prototyping a Geomagnetically
Induced Current (GIC) forecasting system for the effects of solar
activity on the North American power grid. The forecasting system will
consist of a chain of state-of-the-art space physics models describing
the coupled Sun-Earth system. Predictions of GIC flowing in the power
transmission system are derived from the model chain output and are used
to create products for the end-user making decisions about possible GIC
mitigation actions.

Models employed by the forecasting system are resident at the Community
Coordinated Modeling Center (CCMC) located at the NASA Goddard Space
Flight Center in Greenbelt, Maryland. These models, which have been
developed using NASA resources by the space research community, have
been provided to the CCMC for research simulation and evaluation of
space weather applications, such as the one discussed in this document.

The model chain will be driven by solar data from NASA missions such as
SOHO, or from ground-based observatories. Additionally, NASA's ACE
spacecraft, which is located upstream from the Earth, will provide a
second source of driver data for the magnetosphere/ionosphere component
of the model chain.

In this document detailed requirements for the GIC forecasting system
are developed. The requirements are designed to take into account both
the basic physics behind GIC and possible mitigation actions available
for power transmission system operators. It will be shown that the model
collection at CCMC together with data feeds generated by NASA missions
can be used to develop a forecasting system meeting the challenging
system requirements. More specifically, the models and the data feeds
enable the required two-level GIC forecasts: Level 1 forecasts driven by
Solar observations with 2-3 day lead time and Level 2 forecasts driven
by L1 solar wind observations with 30-60 minute lead time.

Early advances in this project indicate that the Level 2 forecasts can
be used for successful estimation of GIC during extreme space weather
storms. Together with advances in cost-benefit analysis of large GIC
events and preliminary design of user-relevant output from the system
these advances indicate that the activity has potential for major impact
on future space weather forecasting applications.

# Introduction

The activity discussed in this document seeks to enhance the
capabilities of the Electrical Power Research Institute's (EPRI)
SUNBURST decision support tool used by the U.S. electric power industry
by prototyping a Geomagnetically Induced Current (GIC) forecasting
system for the effects of solar activity on the North American power
grid. The forecasting system will consist of a chain of models, which
transmit plasma and magnetic fields and their dynamics from the solar
surface and heliosphere, to the magnetosphere of the Earth, and then
into the Earth's ionosphere. GIC flowing in the power transmission
system and the geoelectric field driving GIC will be derived from these
ionospheric currents. By using real-time space-based observations
(carried out by NASA) of near-space conditions and the developed model
chain, GIC forecasts can be derived to individual sites of the North
American power transmission system. These forecasts, together with other
real-time information available via SUNBURST network can then be used by
operators of the transmission system to mitigate the potentially harmful
effects of solar activity on the North American grid.

The Solar Shield team has made important advances early in the activity.
More specifically, the coupling of the near-space models to geomagnetic
induction and GIC models has been established (*Pulkkinen et al.,*
2007a) and new tools for optimal usage of GIC observations in generating
the forecasting system have been developed (*Pulkkinen et al.,* 2007b).
First draft versions of the forecasting system have been run for
historical GIC events and the first results indicate that satisfactory
forecasting accuracy is achievable (*Pulkkinen et al.,* 2007a). EPRI
members of the team have carried out analyses of economic impacts of
large GIC events on transmission system and a draft user-relevant output
from the forecasting system has been outlined (See Figure 1). EPRI is
working with power utility representatives of the SUNBURST network to
gain explicit end-user input to the work carried out in the activity so
far.

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height="4.538194444444445in"}

Figure 1: Draft of the control room output from the forecasting system.

# Overview of enhanced EPRI SUNBURST Decision Support Tool

**Overview**

Solar activity is known to cause disturbances in electric power
transmission systems, ranging from minor annoyances to major outages
(*e.g., Boteler et al.*, 1998). In the extreme case, on March 13, 1989,
a geomagnetic disturbance associated with a major solar eruption took
down the entire Canadian Hydro Québec power grid, leaving 6 million
customers without electricity for nine hours. That disturbance occurred
at the peak of Solar Cycle 22. More recent major GIC events include an
electric blackout in Sweden that occurred during the Oct 2003 storm. The
disruptive or destructive effects on the power grid are caused by GIC
induced to the power transmission system (see Figure 2).

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Figure 2: Mechanism for GIC flow in power transmission system.

**Societal Impacts**

A severe GIC event could have the following consequences:

> 1\. Grossly distorted current and voltage waveforms that result in
> poor or non-operation of sensitive equipment.

2.  Misoperation of protective relays resulting in system disturbances
    and possibly a blackout.

3.  Damage to transformers at several sites. This could range from loss
    of operating life at only a few sites to destruction of a
    significant number.

The Northeast Blackout of August 14, 2003 was an example of both the
possibility of a widespread outage and of the cost and consequences of a
blackout to US society. The event was also a demonstration of the
substantial linkages between the US and Canadian grids. Had the event
commenced on Monday afternoon instead of Friday afternoon, the cost
would have been considerably higher.

The most serious possibility by far is the case in which a number of
power transformers are simultaneously damaged or destroyed in a GIC
event. World production capacity for transformers at 345 KV and higher
is estimated at 100 per year with little of the production in the US. A
credible storm might damage as many as several hundred of these in the
US and we could find ourselves vying with other nations also in urgent
need of replacement transformers.

If a city is subjected to a period of several days without power, there
will be severe consequences because of problems relating to several
lifelines. Water supply and sewage systems are essential and are totally
dependant on power. Telephone and other communication systems often have
battery stand-by provisions, but these are seldom viable for days.
Because such system-wide blackouts are possible, it obviously would be
useful to be warned as far in advance as possible of solar disturbances
likely to cause large GIC.

**Decisions in response to GIC expectations/forecasts or GIC
observations**

If GICs are expected or observed on the grid, operators take the
following steps:

1.  Discontinue maintenance work and restore out of service lines to
    service. Avoid any removal of long lines from service.

2.  Be especially careful to maintain system voltage well within the
    acceptable range since voltage swings may occur.

3.  Adjust the flows on HVDC lines so they are between 40% and 90% of
    nominal ratings.

4.  Reduce the loading on any generators operating at full capacity in
    order to provide reserve power and reactive capacity margins.

5.  Consider the possibility that shunt capacitors connected to the grid
    and static VAR compensators may be lost and prepare for such an
    eventuality.

6.  Dispatch reserve generation to manage system voltage and tie line
    loadings to distribute reserve generation.

7.  Bring on line any equipment capable of synchronous condenser
    operation to provide reactive power reserve.

8.  Notify adjacent control areas of GIC problems.

The Solar Shield team seeks to extend the use of NASA Earth-Sun System
data and models to enhance the SUNBURST Decision Support Tool (DST)
owned and operated by EPRI. EPRI was established in 1973 as an
independent, nonprofit center for public interest energy and
environmental research. EPRI brings together member organizations, the
Institute\'s scientists and engineers, and other leading experts to work
collaboratively on solutions to the challenges of electric power. These
solutions span nearly every area of power generation, delivery, and use,
including health, safety, and environment. EPRI\'s members represent
over 90% of the electricity generated in the United States. In addition
to EPRI, end-users for this project include U.S. electrical power
companies, which subscribe to the SUNBURST DST. Currently the SUNBURST
DST provides "now-casting" of elevated GIC in the electric power grid,
by measuring these currents in-situ (Fig. 3). The SUNBURST DST is used
by subscribing electric power companies to provide an indication of when
and where a potentially damaging GIC event has occurred. The Solar
Shield team seeks to enhance the SUNBURST DST through the addition of a
GIC predictive capability, which we believe will for the first time
enable power utilities to take preventative action under certain
circumstances.

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height="3.813888888888889in"}

Figure 3: Snapshot of the current SUNBURST DST.

**System requirements**

To enable the use of the developed forecasting system by the end-user,
the Solar Shield team identified the following technical DST forecasting
requirements to be met by the system:

a\) The system should be able to give advance warnings at two different
levels: Level 1 warnings providing lead time of 1-2 days and Level 2
warnings providing lead time of 30-60 minutes. Level 1 warnings are
based on remote sensing information about solar activity whereas Level 2
warnings are based on in situ L1 observations.

b\) The system should be able to predict the start time of the GIC
activity. Start times are given separately for Level 1 and Level 2
forecasts.

c\) The system should be able to predict the intensity of the GIC
activity. Intensities are given separately for Level 1 and Level 2
forecasts.

d\) The system should be able to indicate the geographic regions or
locations affected by the GIC activity. Affected geographic regions are
given separately for Level 1 and Level 2 forecasts.

e\) The system should be able to predict the end of the GIC activity.
End times are given separately for Level 1 and Level 2 forecasts.

f\) The system should be able to give uncertainty of the prediction.
Uncertainties are given separately for Level 1 and Level 2 forecasts.

g\) The system should be able to give the prediction of the GIC activity
in a form usable for the decision-making process associated with
possible GIC mitigation actions.

It is noted that the determination of the required minimum accuracy of
both the Level 1 and Level 2 forecasts will be part of the output of the
project and thus cannot be specified definitely at this point. The final
accuracy requirement will be based, for example, on the cost-benefit
analysis carried out by EPRI.

The requirements given above will provide the baseline for the system
developed in the activity and the ultimate success of the project will
be measured against the individual components of the list above.

# Consideration of NASA inputs

In the last decade, space weather modeling has undergone a fundamental
transition (see, e.g., The Sun to the Earth --and Beyond, A Decadal
Research Strategy in Solar and Space Physics, 2003). Historically,
modeling has been focused on purely science-driven purposes.
Specifically, models and modelers attempted to reproduce spacecraft and
ground-based observations in a qualitative fashion, with the goal of
obtaining scientific explanations of an entire class of similar
observations. There are many examples -- representative cases are the
successful attempt to explain the generation of current flows into and
out of the Earth's ionosphere from the magnetosphere (e.g., *Hesse and
Birn*, 1991) or present research addressing the formation and
acceleration of Coronal Mass Ejections (e.g., *Antiochos et al*., 1999).
These modeling activities have contributed substantially to scientific
progress, without attempting to reproduce exact details of actual
spacecraft measurements.

Starting with the early 1990s, the growing recognition of the national
and international importance of space weather effects changed this
focus. Akin to terrestrial weather needs and requirements, systems and
users affected by space weather processes have an economic need for
precise forecasts and nowcasts of the space environment and its effects
on their spheres of interest. With the need for precision also arose the
necessity to measure precision through validation and metrics studies --
a requirement recognized by the National Space Weather Program (NSWP,
implementation plan, 2000) by the definition of a set of first line
metrics procedures for space science models.

The new requirement to produce or reproduce the space environment not
only qualitatively, but quantitatively as well, has led to considerable
new model developments over the last ten years. This model development
has been supported by multiple agencies (e.g., the National Science
Foundation), but NASA has been the main supporter. A specific example
for the NASA development support is the Living With a Star program,
which has as one of its major elements the development of advanced space
weather models. Accordingly, there is virtually no space science or
space environment model in existence that is or has not been funded by
NASA in its majority.

The activity will therefore employ a set of modern space research and
space weather models (see Table 2). All models to be utilized in this
endeavor are developed exclusively through NASA investment, or, at a
minimum, through substantial NASA support. Model descriptions can be
found at [http://ccmc.gsfc.nasa.gov](http://ccmc.gsfc.nasa.gov/). Data
sources are obtained from NASA missions such as SOHO, STEREO, ACE, WIND,
and GEOTAIL, in addition to ground-based solar observatories, such as
Mount Wilson or Kitt Peak, who also receive NASA support.

The system requirements as outlined in Section 2.0 above are very
challenging in terms of modeling capability and observational input
needed to drive the models. Community Coordinated Modeling Center (CCMC)
operated at NASA Goddard Space Flight Center with its model collection
and computational resources provides an unique platform for carrying out
extensive modeling from solar surface to the surface of the Earth (see
Figure 4). This capability is unparalleled and it makes CCMC the only
place in the world capable of producing modeling products required by
the specified GIC forecasting system. CCMC also has extensive experience
carrying out the computations in real-time (experimental) operational
fashion. Further, as discussed below, NASA generates the data feeds
required by real-time runs of the appropriate models. It follows that
NASA data input and modeling capabilities do match the system
requirements. The overall quality of the GIC forecasts is a matter of
our present understanding of the Sun-Earth connection and will be
evaluated in detail in the activity.

Although several NASA missions contribute to the activity in terms of
improved general modeling capability via increased understanding of the
near-space phenomena, a more limited list of missions and models playing
central role in the real-time operations of the forecasting tool can be
identified. Tables 1 and 2 provide detailed information about these
missions and models. It is noted that real-time SOHO MDI and LASCO
observations can be replaced, in principle, by ground-based solar
observations and/or by other space-based missions such as STEREO.
However, continuous real-time observations at L1 are at the moment
dependent solely on ACE. From the Level 2 GIC forecast viewpoint this is
a single point of failure in the forecasting system that may need to be
addressed later in the activity.

![](media/image7.jpeg){width="5.993055555555555in" height="3.4125in"}

Figure 4: Sun-GIC modeling chain. The figure illustrates how solar data
(1) are transmitted through the solar atmosphere, heliosphere, and
magnetosphere of the Earth to the Earth's ionosphere. A geomagnetic
induction module generates surface electric fields driving GIC.

**Table 1**. NASA data products considered for inputs to enhanced
SUNBURST DST.

  ----------- ---------- ----------- --------------- -----------------------
  Satellite   Sensors    System      Product         Use in the forecasting
                         Operator                    system

  ACE         MAG,       NASA        Plasma and      To drive magnetospheric
              SWEPAM                 magnetic field  MHD models used for
                                     observations at Level 2 GIC forecasts.
                                     L1.             

  SOHO        MDI, LASCO NASA/ESA    Solar           To drive heliospheric
                                     magnetograms,   MHD models used for
                                     CME             Level 1 GIC forecasts.
                                     observations.   
  ----------- ---------- ----------- --------------- -----------------------

**Table 2**. NASA model products considered for inputs to enhanced
SUNBURST DST.

  -------------------------- -------------------- ---------------- --------------------------
  Model                      Input                Product          Use in the forecasting
                                                                   system

  WSA, potential/empirical   Solar magnetograms.  Plasma           Input to heliospheric MHD
  model of the inner                              parameters and   model used for Level 1 GIC
  heliosphere.                                    the magnetic     forecasts.
                                                  field in the     
                                                  inner            
                                                  heliosphere.     

  ENLIL, MHD model of the    Plasma parameters    Plasma           Input to magnetospheric
  heliosphere.               and the magnetic     parameters and   MHD models used for Level
                             field in the inner   the magnetic     1 GIC forecasts.
                             heliosphere.         field in the     
                                                  heliosphere.     

  BATSRUS, MHD model of the  Plasma parameters    Plasma           Input to the geomagnetic
  magnetosphere-ionosphere   and the magnetic     parameters and   induction and GIC
  system.                    field in the         the magnetic     computations at high
                             vicinity of the      field in the     latitudes. Used for both
                             solar                magnetosphere.   Level 1 and Level 2 GIC
                             wind-magnetosphere   Electrodynamic   forecasts.
                             boundary.            parameters in    
                                                  the ionosphere.  

  OpenGGCM, MHD model of the Plasma parameters    Plasma           Input to the geomagnetic
  magnetosphere-ionosphere   and the magnetic     parameters and   induction and GIC
  system.                    field in the         the magnetic     computations at high
                             vicinity of the      field in the     latitudes. Used for both
                             solar                magnetosphere.   Level 1 and Level 2 GIC
                             wind-magnetosphere   Electrodynamic   forecasts.
                             boundary.            parameters in    
                                                  the ionosphere.  

  CRCM, kinetic model of the Plasma parameters    Plasma           Input to the geomagnetic
  inner magnetosphere.       and the electric     conditions in    induction and GIC
                             field at the outer   the inner        computations at low
                             boundary of the      magnetosphere.   latitudes. Used for both
                             inner magnetosphere. Electrodynamic   Level 1 and Level 2 GIC
                             Magnetic field in    parameters in    forecasts.
                             the inner            the ionosphere.  
                             magnetosphere.                        
  -------------------------- -------------------- ---------------- --------------------------

# Gaps in meeting DST needs

No gaps in meeting the DST requirements have been identified so far.
However, it is emphasized again that continuous real-time observations
at L1 are at the moment dependent solely on the NASA's ACE spacecraft.
From the Level 2 GIC forecast viewpoint this is a single point of
failure in the forecasting system that may need to be addressed later in
the activity.

# Conclusions and recommendations

In this activity, an enhancement to the Electrical Power Research
Institute's SUNBURST decision support tool used by the U.S. electric
power industry is developed by prototyping a Geomagnetically Induced
Current (GIC) forecasting system for the effects of solar activity on
the North American power grid. The forecasting system will consist of a
chain of models, which transmit plasma and magnetic fields and their
dynamics from the solar surface and heliosphere, to the magnetosphere of
the Earth, and then into the Earth's ionosphere. GIC flowing in the
power transmission system and the geoelectric field driving GIC will be
derived from these ionospheric currents. By using real-time space-based
observations of near-space conditions and the developed model chain, GIC
forecasts can be derived to individual sites of the North American power
transmission system. These forecasts, together with other real-time
information available via SUNBURST network can then be used by operators
of the transmission system to mitigate the potentially harmful effects
of solar activity on the North American grid.

Space-based observations carried out by NASA together with
state-of-the-art space physics models hosted at the Community
Coordinated Modeling Center operated at NASA Goddard Space Flight Center
provide an unparalleled platform for the establishment of next
generation GIC forecasting system. Importantly, the challenging system
requirements established above can be met by the considered NASA data
and model input. Further, the early work carried out by the Solar Shield
team indicates that the NASA-based platform can be used for successful
generation of GIC forecasts and it is reasonable to expect that the
activity will have major impact on future strategies used to mitigate
the adverse effects of GIC. The design of the forecasting system
developed in the activity, in  collaboration with end-users, will not
only optimize the GIC modeling  process but will also provide tools for
effectively conveying valuable GIC  forecast results to the people who
operate the North American power  transmission system.

The work in the activity will continue as outlined in the Solar Shield
proposal. As the central part of the work scheduled for year 1 of the
activity has been carried out, the team will proceed with work scheduled
for year 2. Important elements of the future work will include extension
of the model chain used for forecasts, validation of the model output
against the economic impact of GIC and more detailed design of the
end-user output from the system. The team will also use power utility
feedback to further streamline the forecasting system under development.
The progress in the activity will continue to be reported in detail via
scientific peer-reviewed publications and presentations in scientific
conferences. The team will provide V&V and Benchmark reports to NASA as
scheduled by the Applied Sciences Program.

# References

Antiochos, S. K., C. R. DeVore, and J. A. Klimchuk, A model for solar
coronal mass ejections, *Astrophys. J.*, *510*, 485-493, 1999.

Boteler, D.H., Pirjola, R.J., and Nevalinna, H. The Effects of
Geomagnetic Disturbances on Electrical Systems at the Earth's Surface,
*Advances in Space Research*, Vol. 22, No. 1, 1998, pp. 17-27.

Hesse, M., and J. Birn, On dipolarization and its relation to the
substorm current wedge, *J. Geophys. Res., 96*, 19417, 1991.

Pulkkinen, A., M. Hesse, M. Kuznetsova and Lutz Rastätter,
First-principles modeling of geomagnetically induced electromagnetic
fields and currents from upstream solar wind to the surface of the
Earth, *Annales Geophysicae*, 25, 881-893, 2007a.

Pulkkinen, A., R. Pirjola, and A. Viljanen, Determination of ground
conductivity and system parameters for optimal modeling of
geomagnetically induced current flow in technological systems", *Earth,
Planets and Space*, 99, 999-1006, 2007b.

The Sun to the Earth --and Beyond, A Decadal Research Strategy in Solar
and Space Physics, *Solar and Space Physics Survey Committee, National
Research Council*, National Academy Press, Washington, DC, 2003.

The National Space Weather Program, Implementation Program, 2^nd^
Edition, *Office of the Federal Coordinator for Meteorology*,
FCM-P31-2000, Washington, DC, 2000.

[^1]: Throughout the text we will, for brevity, refer to the activity as
    "Solar Shield"