Space Weather Difficult to Explain, But Accurate Forecasting is Critical

Space weather happens every day not just when auroras light up the sky, but intense solar flares can disrupt our technological societies making forecasts of space weather just as critical as terrestrial weather.  That was the message at a seminar on Thursday (November 20) on Capitol Hill that explained why space weather is important and why satellites are needed to enable forecasters to warn of impending events.  A new satellite, DSCOVR, is about to join the effort.

Representatives of NASA, NOAA, the Air Force, the State Department and a regional electricity transmission organization laid out the science behind space weather, forecasting efforts by NOAA and the Air Force, practical effects on the electrical power grid, and international efforts to better understand and mitigate it.  The panel was sponsored by the Secure World Foundation (SWF) and American Astronautical Society (AAS).

Laura Delgado López, SWF project manager and AAS Board member, summed up space weather as “complex, international, and routine.”  It is indeed complex and several panelists pointed out that the topic simply is not conducive to “sound bite” explanations.

Lika Guhathakurta, Living with a Star and STEREO program scientist in NASA’s heliophysics division, stressed that space weather happens not just when the Sun is most active at solar maximum “but all the time.”   It is severe space weather events that attract media attention, however, and explaining the nuances between events that pose differing levels of potential damage can be a challenge.

Thomas Berger, Director of NOAA’s Space Weather Prediction Center (SWPC), pointed out that extreme space weather events are rare, but can have a considerable impact on technology.   An array of space- and ground-based sensors is used to collect data that allows SWPC to make operational forecasts and issue watches, warnings or alerts to stakeholders that could be negatively affected.  Satellites in earth orbit are particularly vulnerable to space weather impacts, but Berger identified other customers for SWPC’s forecasts as ranging from banking to shipping to oil drilling to utilities to the Federal Emergency Management Agency (FEMA) and many more.

Though they are not the only satellites used for operational space weather forecasting, spacecraft at the Sun-Earth L1 Lagrange point are critical for providing early warning of the intensity and polarity of particles emitted by eruptions on the Sun.   NASA and the European Space Agency (ESA) currently have spacecraft positioned at the Sun-Earth L1 point that are used by SWPC.  They were designed for research, not operations, however, and are quite old.   In two months, the Air Force will launch the NASA-NOAA Deep Space Climate Observatory (DSCOVR, once known as Triana) to satisfy the highest priority space weather operational requirements.

The electric utility sector is one of those customers.  Frank Koza, Executive Director of Infrastructure Planning Support at PJM Interconnection, explained the challenges of managing the electric power grid during severe solar weather events.  The Sun’s charged particles can cause geomagnetically induced currents (GICs) that knock out transformers, for example.  While his company has generators that can go from zero to full load in 10 minutes to add capacity and blunt the impact, adequate warning is needed.  SWPC issues warnings 1-3 days in advance based on solar activity, but critical data from the L1 satellites on intensity and polarity provide only about 20-40 minutes of warning, he said.  PJM is a wholesale electricity provider, managing the high-voltage electricity grid in all or parts of 13 states and the District of Columbia and selling that electricity to local power companies.

Space weather forecasting begins with observations, continues with modeling, and ends with watches, warnings, or alerts, Berger explained.  In that regard, it is similar to terrestrial weather forecasting.  SPWC is, in fact, part of the National Weather Service (NWS) and has its own system of designations from minor to extreme events for radio blackouts, solar radiation storms, or geomagnetic storms.

Asked what Congress can do to help in understanding, forecasting and coping with space weather, Chris Cannizzaro from the State Department’s Office of Space and Advanced Technology and Col. Robert Swanson from the Air Force’s Directorate of Weather both mentioned the need for budget certainty.   Swanson said it is critical to know how much money his office will have for training and other activities in order to spend it wisely.  Cannizzaro said budget uncertainty complicates efforts to enter into partnerships with other countries.  The United States is active in international forums like the U.N. Committee on Peaceful Uses of Outer Space (COPOUS), for example, to coordinate efforts to predict and mitigate space weather.

Swanson pointed out the capability to respond to space weather events is evolving and the White House Office of Science and Technology Policy (OSTP) has created an interagency space weather operations and mitigation task force to address the issue.

OSTP’s July 2014 National Plan for Civil Earth Observations directs NOAA, in consultation with NASA, to provide observations using its geostationary weather satellites (GOES) and DSCOVR to enable the forecasting of space weather and to study options and explore working with international and interagency partners to provide such data beyond the design lifetime of DSCOVR.

DSCOVR is scheduled for launch in January 2015 and will join NASA’s Advanced Composition Explorer (ACE) and ESA’s Solar Heliophysics Observatory (SOHO) spacecraft at Sun-Earth L1, which is 1.5 million kilometers (932,000 miles) from Earth.  SOHO has been operating since 1996 and ACE since 1997.

NASA has 17 other heliophysics spacecraft, Guhathakurta said.  Of them, she identified STEREO, SDO, and the Van Allen Probes as contributing to operational space weather forecasting.   STEREO is a pair of satellites, one ahead of Earth in its orbit and the other behind it.  The Van Allen probes are another pair in nearly identical elliptical Earth orbits.  The Solar Dynamics Observatory (SDO) is an inclined geosynchronous Earth orbit.

Like space weather, heliophysics is difficult to explain.  Guhathakurta referred to it as a “concocted” word that represents an environmental science that has an “applied branch” – space weather, and a “pure branch” – studying fundamental physical processes.  The phrase “solar and space physics” was commonly used before heliophysics became the term of art and is still used today in some quarters.

DSCOVR is intended to support operational space weather forecasting rather than research, which is NASA’s focus.  Scientists hope to launch future research spacecraft in accordance with the priorities set out in the most recent National Research Council Decadal Survey for Solar and Space Physics.

PowerPoint presentations from Thursday’s seminar are posted on SWF’s website.