On 2 Sept 2010 the Wide-field Imager with NRL researcher Russell Howard as PI was chosen as one of the proposals selected by NASA for financial award. As instrument PI institution, NRL will design and develop the NASA-sponsored Wide-field Imager for the new NASA mission Solar Probe Plus that will plunge directly into the Sun’s atmosphere ~4 million miles from our star’s surface.
On 2 Sept 2010 the Wide-field Imager with NRL researcher Russell Howard as PI was chosen as one of the proposals selected by NASA for financial award. As instrument PI institution, NRL will design and develop the NASA-sponsored Wide-field Imager for the new NASA mission Solar Probe Plus that will plunge directly into the Sun’s atmosphere ~4 million miles from our star’s surface. (Photo: NASA)

Objective: Develop improved heliospace environment understanding, awareness, sensors, forecast capabilities, and monitoring tools that predict operational impacts and enable real-time threat warning; and transition these developments to support the Navy/Marine Corps and other agencies.


S&T Status: Research in solar and heliophysics space-based sensors—most notably coronagraphs, heliospheric imagers, and solar spectrometers—and a steady stream of fundamental discoveries and insights driven by the data that this world-leading instrumentation provides. This research is producing space environmental weather and climatology measurements and models in use by operational forecasting agencies and by inter-governmental scientific assessment bodies.
For more information, please contact nrl.ssd.code7600@nrl.navy.mil.

Selected Research

Solar wind speed and density, respectively, in the solar equatorial plane at 1700UT on August 3, 2010, following a series of Earth-directed CMEs in the preceding three days. Solar Wind Modeling

Objective
Model the evolution of the solar wind from the Sun to the Earth and beyond, using both semi-empirical and advanced 3D MHD numerical modeling techniques. Predict key solar wind plasma and magnetic field parameters throughout the inner heliosphere during both quiet and disturbed solar wind conditions, including disturbances due to coronal mass ejections (CMEs) and co-rotating interaction regions (CIRs) at the boundary between slow and fast wind streams. CMEs and CIRs are the drivers of major geomagnetic storms and solar energetic particle (SEP) space weather events.
MHD simulations of (left) CME generation and (right) 3D magnetic reconnection performed within the HiFi modeling framework. The smallest dynamically relevant scale for reconnection is likely meters and the largest CME-relevant scale is 1000's of megameters. Both reconnection and CME-driven shocks produce non-thermal particle distribution functions that need to be modeled with kinetic simulation methods. HiFi – Numerical Modeling Framework for Laboratory and Heliospheric Plasmas

Objective
Develop, maintain, verify, and validate a state-of-the-art HPC numerical framework for fluid- and particle-based predictive modeling of space weather and plasma confinement devices

To do so, build a computational plasma framework designed to maximize the combined effectiveness of its three core features:

  1. a scalable, efficient, and accurate underlying numerical algorithm;
  2. an easy-to-use flexible interface for achieving basic and applied research objectives;
  3. modular structure that allows to improve and upgrade the framework in-step with the latest computer science and hardware advances
Simulation of magnetic flux rope (twisted fieldlines) emerging through solar photosphere (green plane) into an overlying coronal arcade (high, arching fieldlines). Fieldlines from the emerging rope rise into the corona and reconnect with the overlying field to form an unstable, coronal rope. Ongoing work: Can this coronal rope be made sufficiently robust and unstable that it will form an erupting CME? Leake & Linton (NRL) Coronal Mass Ejection Initiation

Objectives

  • Drive Coronal Mass Ejection (CME) eruptions by self-consistently emerging convection zone magnetic field into pre-existing, coronal magnetic field configurations. Test validity of current CME models.
  • Improve our understanding of how CMEs are driven or destabilized. Enhance the Navy’s ability to develop predictive tools for these solar eruptions and their space weather consequences, by determining how current observations of flux emergence can be incorporated into CME prediction models.
Cartesian projection of the entire solar atmosphere as observed by the NRL SECCHI twin Extreme Ultraviolet Imagers at a temperature of 1.6 million degrees. SECCHI acquires full maps of the Sun every 10-20 min. Sun-Earth Connection Coronal and Heliospheric Investigation (SECCHI)

Objectives
Advance the understanding of the 3-D structure of the Sun’s corona, the origin of Coronal Mass Ejections (CMEs), CME propagation through the heliosphere, and the dynamic coupling between CMEs and Earth.
CMEs, the most energetic phenomena in the solar system, are major drivers of geomagnetic space weather storms that adversely affect ISR, precision engagement, missile detection and intercept, Comms on the Move, spacecraft anomaly assessment, orbital tracking, polar flight activities, and the power grid. CMEs were discovered by NRL with an NRL-built solar coronagraph in 1971.
A composite image showing the expanded field of view of SoloHI compared to the field of SECCHI on the STEREO mission. The Sun is the small light circle inside a red circle. The black and white inset is an example of a CME propagating outward and blowing off the ion tail of Comet Encke. Solar Orbiter Heliospheric Imager (SoloHI)

Objectives
Advance the understanding of the 3-D structure of the Sun’s corona, the origin of Coronal Mass Ejections (CMEs), CME propagation through the heliosphere, and the dynamic coupling between CMEs and Earth.
CMEs, the most energetic phenomena in the solar system, are major drivers of geomagnetic space weather storms that adversely affect ISR, precision engagement, missile detection and intercept, Comms on the Move, spacecraft anomaly assessment, orbital tracking, polar flight activities, and the power grid. CMEs were discovered by NRL, with an NRL-built solar coronagraph, in 1971.
Artist’s impression of the SPP spacecraft at closest approach to the Sun with the WISPR field of view superimposed. The opto-mechanical layout of NRL’s WISPR is shown on the right. Wide-Field Imager for Solar Probe Plus (WISPR)

Objectives

  • Understand the morphology, velocity, acceleration, and density of evolving solar wind structures when they are close to the Sun.
  • Derive the 3D structure of the solar corona through which in-situ measurements are made to determine the sources of the solar wind.
  • Determine the roles of turbulence, waves, and pressure-balanced structures in the solar wind.
  • Measure the physical properties of SEP-producing shocks and their CME drivers as they evolve in the corona and inner heliosphere.
Compact Coronagraph (CCOR)

Objectives

  • Transition basic research on coronal mass ejection imagery technology to operational space weather forecasting of Geomagnetic Storms
  • Develop a low-cost and -mass, small envelope coronagraph for operational satellite
An image of a “halo” type CME surrounding the LASCO C2 occulting disk and a prominence eruption to the South of the Sun. The white circle in the center is the size and location of the Sun, which is obscured by the occulting disk. The bright linear feather to the lower left is a coronal streamer. CMEs were observed to occur up to 6 times per day during the maximum of the solar cycle. The halo is a CME headed toward Earth. Large Angle Spectrometric and Coronagraphic Telescope (LASCO)

Objective
Advance the understanding of the structure of the Sun’s corona, the origin of Coronal Mass Ejections (CMEs), and the dynamic coupling between CMEs and Earth.
CMEs, the most energetic phenomena in the solar system, are major drivers of geomagnetic space weather storms that adversely affect ISR, precision engagement, missile detection and intercept, Comms on the Move, spacecraft anomaly assessment, orbital tracking, polar flight activities, and the power grid. CMEs were discovered by NRL, with an NRL-built solar coronagraph, in 1971.
HYPERION simulation results of (left) temperature isosurfaces and magnetic field lines and (right) loop summit radiation details in a coronal loop, superimposed on an SDO image of coronal loops HYPERION: Modeling Solar Coronal Loops

Objective
Magnetohydrodynamic (MHD) turbulence has long been proposed as a mechanism for the heating of coronal loops in the framework of the Parker scenario for coronal heating. So far most studies have focused on its dynamical properties without considering its thermodynamical and radiative features because of the very demanding computational requirements. We aim to extend this previous research to the compressible regime using HYPERION, a new parallelized, visco-resistive, three-dimensional compressible MHD code.
Monochromatic images of an active region in spectral lines of iron ions formed at different temperatures. EIS can act like a remote sensing thermometer. Extreme-ultraviolet Imaging Spectrometer (EIS) (Solar-B: Hinode)

Objective
Measure the physical conditions such as temperature, density, and dynamics in solar active regions and flares. Determine the physical mechanisms responsible for generating erupting prominences, solar flares, and coronal mass ejections (CMEs).
Solar flares and CMEs are the most energetic phenomena in the solar system and are major drivers of geomagnetic space weather storms that adversely affect ISR, precision engagement, missile detection and intercept, Comms on the Move, spacecraft anomaly assessment, orbital tracking, polar flight activities, the power grid, and ionosphere variations.
The next-generation EUV imaging telescope, proposed for the Solar-C Mission. The instrument would be built by an international consortium. Next Generation EUV High-Resolution Spectroscopic Telescope (for Solar-C)

Objectives
Observe the entire solar atmosphere from the chromosphere into the corona (including flares) with ultra-high spatial and spectral resolution. Determine the flow of energy and dissipation throughout the entire atmosphere. Determine the mechanisms responsible for heating the solar corona.
Understanding how the solar atmosphere is formed and maintained from first principles enables a precision space weather warning system to be developed. The ultimate goal is to predict solar phenomena that are major drivers of geomagnetic disturbances that adversely affect areas such as spacecraft anomaly assessment, orbital tracking, polar flight activities, the power grid, and ionosphere variations.
Sounding Rocket Program (Active Programs: HERSCHEL, VERIS, VAULT)

Objectives

  • Enable cutting-edge scientific research through the development of low-cost, short-schedule, highly advanced suborbital payloads.
  • Provide low-cost, hands-on training experiences for the development of the next generation of SSD scientists and engineers.
  • Provide a low-cost (and accordingly, low-risk) test bed for the technology development for future flight projects for the DoD and other government agencies.
Active-region footpoints (top, red) yield enhanced SEP Fe/O; coronal-hole footpoints (bottom, blue) lead to low SEP Fe/O. NRL researchers have traced the SEP compositional variability back to the nature of the solar region that provides seed particles for shock acceleration. Seed Populations for Large Solar Energetic Particle Events

Objective
To identify sources and to quantify the characteristics of various coronal seed populations that give rise to large solar energetic particle (SEP) events produced by coronal mass ejection (CME)-driven shocks.
At high energies, relevant to spacecraft design and operation, large SEP events are highly variable in their size, duration, spectral shape, and ionic composition. These variable factors determine the nature of the radiation hazard posed to space-based systems. This project focuses on discovering the contribution of seed-particle populations to this variability, as an input for future SEP predictive capability for satellite operations.
Cover page of the C-SPEX proposal to the 2011 NASA Explorer Stand Alone Mission of Opportunity call for mission concepts illustrating the accommodation of the proposed instrument on the International Space Station Coronal Suprathermal Particle Explorer (C-SPEX)

Objective
Develop a mission concept to achieve a new capability for predicting the incidence and severity of solar energetic particle (SEP) events by detecting suprathermal seed particles currently thought to be essential for acceleration of high-energy particles in the solar corona.
SEPs can interrupt satellite-based comms, generate single event effects that destroy even hardened space assets, adversely affect ISR, precision engagement, missile detection and intercept, and polar flight activities.
Comparison of SEP derived abundances (adapted from Ko et al. 2012) with models for closed and open magnetic field regions. Gradual SEPs from an active region footpoint (red triangles) agree very well with the closed field model (red crosses). Open field model and data are shown in blue. Coronal Element Abundances and Enhanced Solar EUV Forecasting

Objective
Advance the understanding of the variable elemental composition of the Sun’s corona; a vital step towards the forecasting of the solar Extreme Ultraviolet (EUV) irradiance. Solar EUV radiation, mainly from ions of iron (Fe), is absorbed in the thermosphere, where it heats the ambient gas causing its scale height to lengthen, thereby increasing the density and associated drag on satellites in the earth’s upper atmosphere. Since the potential exists for debris collisions with operating spacecraft producing further explosions, thereby increasing the debris field in a runaway fashion, mitigation strategies, including forecasting the Solar EUV irradiance, are key.
The variability of the solar Magnesium II index at 279.9 nm as measured by the NRL SUSIM aboard UARS over 14 years. The Mg II solar ultraviolet absorption line core-to-wing ratio index is one of the important metrics of solar activity and is used in connection with applied upper atmospheric models as well as basic solar and atmospheric research. Solar-Spectral Irradiance Monitor (SUSIM)

Objective
Reduce existing major (~30%) absolute and relative 1 hr -11 year solar ultraviolet (115-440 nm) spectro-radiometric measurement discrepancies to the 0.3-3% level in order to achieve sufficient precision of irradiance data for input to models of Earth’s upper atmosphere, including the ionosphere and thermosphere.
Highly variable solar ultraviolet radiation, absorbed by Earth’s upper atmosphere, modulates formation of the ionosphere and heating of the thermosphere thus affecting space based radars, communications, and orbital tracking. SUSIM (and Hinode) data are used to validate solar EUV forecasting models.
Helioseismic Predictions of Solar Flux Emergence

Objective
Give longer warning times for solar geoeffective disturbances via local, very high precision nearside helioseismology to forecast emergence of magnetic flux from below the solar surface that can coalesce into solar active regions and lead to solar geoeffective disturbances. NASA’s Solar Dynamics Observatory (SDO), launched in 2010, enables this objective with high-resolution solar observations at a nearly continuous science data downlink rate of 130 Megabits/sec.