Eclipse Science Showcase - Attendees & Experiments

Optical and Radio Studies of Coronal Plasma at the 2017 Eclipse (NSF)Jay Pasachoff, Williams College

The main goal of this 3-year project is to enable a unique observational campaign during the 21 August 2017 total solar eclipse across the North America. The eclipse observations are unique because they provide a rare opportunity to discover new types of solar phenomena that may be linked to the solar cycle and space weather. The project's high-resolution studies of flaring and active regions at long radio wavelengths should provide information that is potentially useful for space weather predictions. Studies of the solar corona at eclipses have been a major part of the success of the Williams College department in attracting and training students. Undergraduate students, increasingly including members of underrepresented groups through Williams' need-blind admissions policy, have been intimately connected with the eclipse expeditions in the past and the associated data reduction and analysis. This project would enable the active involvement and training of students at the Williams College to continue. Furthermore, since total solar eclipses are of widespread public interest in the countries from which they are visible, they provide an excellent opportunity for public education in the United States about astronomy in general. Therefore, this project directly supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research. 

This 3-year project is to take advantage of the 21 August 2017 total solar eclipse, especially to observe the white-light corona and work with highly processed images that bring out detail and extreme contrast, allowing improved measurements of dynamics of coronal plumes and other coronal features, especially coronal mass ejections (CMEs), and to observe the green-line (Fe XIV), and red-line (Fe X) coronas to contrast regions of different temperatures. The solar observations include exquisitely high resolution observations with a Fabry-Perot. Also, high-frequency (>1 Hz) power spectra of coronal loops will be used to compare mechanisms of coronal heating. Spectrographic observations will allow the project team to investigate changes of the spectral-line ratios over the solar-activity cycle as the cycle, now past a low maximum, declines toward. Radio telescopes, including the Jansky Very Large Array, will provide the best-ever mapping of active regions to pinpoint the different locations of radio and EUV eruption origins.

The scientific program is supported by grants from the Solar Terrestrial Program of the Atmospheric and Geospace Sciences Division of the National Science Foundation and from the Committee for Research and Exploration of the National Geographic Society. Additional support for students comes from the NSF, the Sigma Xi Society, the NASA Massachusetts Space Grant Consortium, and the Clare Booth Luce Foundation as well as from Williams College.

ARTSE: Atmospheric Response to a Total Solar Eclipse (NSF) Scott Gunter, Columbus State University, Georgia

The Earth and Space Sciences Department at Columbus State University (CSU), in cooperation with the Coca-Cola Space Science Center (CCSSC), is deploying several teams armed with high resolution (4K) video equipment to the path of totality to document the evolution of the eclipse for research objectives and the creation of a planetarium video. The ARTSE project seeks to added to the scientific merit of the deployment and provide educational opportunities for CSU students (as well as K-12 students and members of the community at large) through the inclusion of two surface flux stations provided by NCAR’s Integrated Surface Flux System facility and the educational deployment loan program. These stations will record changes in solar radiation and surface layer fluxes during the eclipse that can be used to characterize the boundary layer response to the total eclipse. Each station will include a high resolution sonic anemometer, pyranometer, pyrgeometer, gas analyzer, and soil probes as well as other instrumentation to measure standard atmospheric variables. The flux stations will be deployed in Grand Island, Nebraska. One station will be located at the Central Nebraska Regional Airport where it will be able to collect undisturbed data in relatively uniform exposure. The second station will be deployed at the Stuhr Museum (also in Grand Island), where CSU students participating the in the experiment can engage with members of the community attending an eclipse event at the museum. Attendees will be able to learn about the expected response of the surface layer during the eclipse and will be able to “tour” the instrumentation. A monitor displaying the real time changes in the meteorological data at the site will be also be running during the event. Both stations will be operating at least 24 hours prior to the eclipse and will remain operational at their respective locations for at least 24 hours after the eclipse. By collecting data on either side of the event, the evolution of the surface layer fluxes during the event can be compared to those of a typical diurnal cycle. 

A primary component of this project is the educational opportunities it affords. Students participating in the project are also enrolled in a class for the Fall 2017 semester in which the meteorological data will be analyzed. The analyzed data will then be developed into educational materials for CSU courses and the CCSSC (e.g. Lab Manual exercises, interactive exhibits, etc.). Finally, time histories of meteorological variables measured by the stations during the eclipse will be merged with the 4K video also collected in Grand Island to produce an informative and entertaining planetarium video to be shown at the CCSSC. Overall, the ARTSE project offers a diverse department at CSU the chance to bring students to the field to participate in cutting-edge, hand-on research.

Solar Eclipse Observations with a Dense Network of Single-frequency GNSS Receivers (NSF) Josh Semeter & Sebastijan Mrak, Boston University 

This award would use off-the-shelf cell phone technology just recently made available on the market to construct a single frequency GPS array of sensors that would be applied to study the ionospheric effects of the solar eclipse happening on 21 August 2017. This event would provide the opportunity to study the ionospheric response to a well-characterized modification of the solar influx. The path of total obscuration crosses the central continental United States and deployment of the networked instrumentation to Tennessee is planned for the proposed measurements. The proposed project would deploy a regional network of dual-frequency and single-frequency Global Navigation Satelite System (GNSS) receivers with the goal of monitoring total electron content (TEC), ionospheric drifts, and signal scintillation effects induced by the eclipse. The proposed project lays the foundation for the use of consumer smartphones to augment the current GNSS-TEC receiver network to produce a greatly enhanced space weather monitoring capability. The August eclipse provides an outstanding opportunity for a proof-of-concept data capture. The project will partially sponsor one full-time Ph.D. student with the eventual objective of making this his Ph.D. project, and this project will employ six undergraduates for the proposed observing campaign. 

TEC estimation from single-frequency GNSS measurements requires resolving carrier-phase ambiguity problem and mitigating the higher uncertainty introduced by using code delay in the TEC estimation process. Clusters of such receivers, analyzed collaboratively with surrounding dual frequency receivers, will enable a value-added enhancement standard TEC maps. Moreover, the phase information from the single frequency receivers allows the tracking of irregularity drifts (through a correlation analysis), and also the tracking of incidents of signal scintillation. This data fusion approach will be evaluated experimentally in the proposed investigation.\ 

EclipseMob, Crowdsourcing for Radio Propagation in the Ionosphere (NSF) Jill Nelson, Laura Lukes, Janet Oputa & Jennifer Henry, George Mason University; Kiersten Kerby-Patel, Univ. Mass

For centuries, total solar eclipses have provided unique opportunities to study the Sun and the Earths atmosphere. They rarely occur across the continental United States. In August of 2017, an eclipse will travel through the heart of the nation and across the entire continent. Eclipses provide a period of relative quiet in the atmosphere as the radiation from the sun is blocked by the moon. This project will take full advantage of crowdsourcing techniques and inexpensive modern technologies to measure the response of the upper atmosphere (the ionosphere) to low frequency radio waves, thus giving new insight into characteristics of the atmosphere that are not well understood. This project is important to national interests as disturbances to the ionosphere are known to modulate radio waves and in some extreme cases, block them entirely. This project also broadens scientific participation through its involvement of students from high school through graduate school and the general public. Additionally, the project is led by an interdisciplinary team of scientists from underrepresented minorities. 

Transmitters in two locations (Dixon Naval Radio Transmitter Facility in Sacramento, CA and National Institute of Standards and Technology in Fort Collins, CO) will broadcast at low frequencies (LF), probing the D and E regions of the ionosphere. Receivers across the continental US installed and manned by students and the general public will collect the amplitude data at the given frequencies. A subset of these receivers will also collect phase change data. The goal of this project is to use the collected date to examine how the amplitude and phase changes are affected by eclipse path and the relative distance/locations of the transmitter-receiver pairs. The data collected will be processed in collaboration with the LF Radio Lab at the Georgia Institute of Technology for ionization and recombination behavior of the D and E layers. The results and the data collected will be publicly available through the EclipseMob web presence. 

Effects of the 2017 Total Solar Eclipse on Earth's Ionosphere (NSF) Greg Earle & Lee Kordella, Virginia Tech 

The ionosphere — a region of Earth’s atmosphere made of both charged and neutral particles — is a dynamic region of space that begins ~50 miles overhead and encompasses the altitude range where low-Earth-Orbit satellites and the space station fly.  The total eclipse provides our team at Virginia Tech the opportunity to understand how the ionosphere reacts when the eclipse temporarily dims the sunlight in a confined region of space. The team will use a network of radio transmitters and receivers across the country, which will be configured to function as radars observing the ionosphere at frequencies from 2-25 MHz.  Their measurements will be combined with data from a nation-wide network of GPS receivers and signals from the Ham Radio Reverse Beacon Network, both of which are sensitive to the state of the ionosphere. The team will also utilize data from Virginia Tech’s SuperDARN radars, two of which are located along the eclipse path in Christmas Valley, Oregon, and Hays, Kansas. By combining all the data, the Virginia Tech team will be able to compare the observations with modeling results over most of the US.  Modeling efforts will support the data analysis to reveal how the eclipse changes the physics of the near-Earth space environment. 

CAREER: Exploiting the Low/Medium Frequency (LF/MF) Radio Band for Ionospheric Remote Sensing (NSF) Morris Cohen & Nick Gross, Georgia Tech 

Cohen and his team will study the border between the Earth’s atmosphere and the surrounding space environment, which is a layer called the “D-region ionosphere”, 70-100 km altitude. This region is traditionally difficult to study, since it’s too high to reach with balloons, and too low for satellites to orbit. On the other hand, it has significant impacts on satellite-to-ground and long range ground-to-ground communications, and navigation systems such as GPS and others. So while the ionosphere is disturbed by a huge number of phenomena such as lightning, solar and space weather, and earthquakes, scientists have a poor ability to predict or even track what’s happening. 

Certain radio waves are known to reflect off the D-region, since the D-region consists of an electrically charged plasma similar to what is in fluorescent light bulbs or plasma TVs. This capability allows scientists to diagnose what is happening, because as the D-region changes, so too does the reflection of these radio waves, a little bit like radar. Unfortunately, these techniques are generally difficult to use in practice for a number of reasons. In Cohen’s NSF program, he and his team will explore a radio band around 300 kHz which has not previously been used to sense the ionosphere, but may, due to some specific properties at this frequency, allow more direct and simpler observations over a large region. 

Cohen and his team will also prepare a full set of observations for the upcoming “Great American Solar Eclipse”, taking place on August 21, 2017, which is known to have a very remarkable impact on the ionosphere. Not only will the eclipse be a great test case for the new analysis technique that he and his team are developing, but it is also the focus of his group's educational outreach efforts. Cohen and his team will make many observations with instruments hosted at high schools and educational centers, and engage with these students to drive up enthusiasm in STEM careers. 

Citizen CATE/ Know Your Sun: Eclipse Webcasts (NSF/NASA)Matt Penn & Claire Raftery, NSO & Adriana Mitchell, Univ. of Arizona, Tucson 

The Citizen Continental-America Telescopic Eclipse (CATE) Experiment is a collaborative effort of volunteer members from 27 universities, 22 high schools, 8 informal education groups and 5 national labs.  With CATE, 68 identical telescope and digital camera systems will be distributed along the path of totality for the 2017 total eclipse and will be used to capture high quality images of the inner solar corona. The volunteer site coordinators have been rigorously preparing and training, with coordinated practices using the Sun and the Moon. CATE has been funded with support from a combination of federal, corporate and private sources.  Dozens of education and public outreach events have already been held, and many more are scheduled as part of the CATE initiative.

From any one CATE location, the inner corona will be visible for only about two minutes. Citizen CATE will conduct an eclipse “relay race” by having observers spaced along the path so as the shadow passes over the horizon for one observer, another will be ready to start observing. Each site will collect a series of high dynamic range images every 2.1 seconds (so approximately 60 HDR images per site), with exposure times varying from 0.4 msec to 1.3 sec per image. Combining all the images from the CATE network will result in a coordinated, calibrated dataset spanning 93 minutes of totality. 

CATE data will sample the region of the solar atmosphere from 1.0 to about 2 solar radii (i.e. from the solar surface to 864,000 miles above the surface) in visible, or white light in the range from 480-680nm (red/yellow/green part of the spectrum). That part of the atmosphere continues to evade solar scientists as it is inherently difficult to observe. With the HDR images down to the solar surface, Citizen CATE’s students and scientists will be seeking to observe the highly dynamic processes that occur in the corona, including the acceleration of the solar wind – the ubiquitous flow of particles that stream out from the sun into the solar system. The solar wind accelerates from 1 to 150 km/s in the CATE field of view, but little is known why. We anticipate that studying this flow in polar plumes – the region of open magnetic field close to the north and south solar poles – will shed light on this ongoing mystery. 

Eclipse Megamovie Project (NSF) Laura Peticolas & Juan Carlos Martinez Oliveros, UC Berkeley 

Since 2011, a team of solar scientists, eclipse chasers, education and outreach professionals, and filmmakers have been working to explore the possibility of gathering images from the public during the 2017 eclipse across the United States, to be used for scientific research, education, and enhancing the public’s experience of the eclipse. After years of testing the initial ideas, engaging new organizations, and exploring new technologies, our team has developed a blueprint for this project. There are four main goals for this effort: 1. to learn more about the dynamic non-­equilibrium processes in the corona and lower atmosphere of the Sun, 2. to educate the public about space physics, 3. provide different levels of engagement opportunities for an interested public, and 4. to understand how these various levels of engagement with a major scientific phenomena allow people to develop deeper personal connections to Science, Technology, Engineering, and Mathematics (STEM). We will meet these goals by training 1000 volunteers to take scientifically valid images and donate the images to this project, while also allowing the general public to share their images as well.

During the Aug 21, 2017 eclipse, we will stitch together images using an automated script to produce public­-generated videos and movies showing the corona of the Sun during totality from over a thousand people. These videos will be disseminated in the afternoon of Aug 21st to other eclipse programs, news organizations, and to the general public. Meanwhile, images collected during and after the eclipse will be available to scientists and the public for research purposes. The team plans to use the images to better understand plasma wave propagation related especially waves causing density perturbations; and variability in the Sun’s size over time. To further engage the public, video clips, film, and a documentary will be produced prior and after the event.

Citizen Science Approach to Measuring Polarization of the Inner Solar Corona During Eclipse 2017 (NASA) Padma Yanamandra-Fisher, Space Science Institute, David Elmore, NSO, & Adriana Mitchell, Univ. of Arizona, Tucson

Padma Yanamandra-Fisher of the Space Science Insitute in Rancho Cucamonga, California, will lead an effort to take images of part of the sun’s atmosphere, the solar inner corona – visible only during total solar eclipses – in polarized light. Light becomes polarized as it passes through some kind of medium. The experiment will map the two-dimensional electron distribution in the inner solar corona, which will provide input for models that address the question of why the sun’s atmosphere, the corona, is so much hotter than its surface. The experiment, PACA_PolNet, builds on the work of a citizen science project known as Citizen CATE and will be conducted from two sites: Tetonia, Idaho and Carbondale, Illinois. 

Solar Eclipse Induced Changes in the Ionosphere over the Continental US (NASA) Phil Erickson & Nancy Wolfe Kotary, MIT / Haystack Observatory 

The ionosphere, an electrically charged outer shell of Earth’s atmosphere, is affected by processes in deeper levels of the atmosphere, as well as by incoming sunlight and particles. Electrons and atoms in the region are constantly being shaken by travelling ionospheric disturbances, which move in ripples through the charged gas, ionized by the sun’s ultraviolet light. These disturbances in the ionosphere are often caused by a phenomenon known as atmospheric gravity waves, which can be triggered by eclipses. A team, led by Phil Erickson of MIT’s Haystack Observatory in Westford, Massachusetts, will use an extended network of sensors to monitor the ionosphere as it crosses America, in order to understand the large-scale effects of these disturbances. 

Using over 6,000 ground-based sensors along with data from NASA’s space-based Thermosphere Ionosphere Mesosphere Energetics and Dynamics, or TIMED, mission, the team will monitor the changes in the ionosphere in real-time. The data will be publicly available during the eclipse and available online afterwards. 

Chasing the 2017 Eclipse: Interdisciplinary Airborne Science from NASA's WB-57 (NASA)Amir Caspi, Con Tsang, Craig DeForest, Southwest Research Institute; Dan Seaton, NOAA; Paul Bryans, NCAR/HAO; Laura Lukes & Jill Nelson, George Mason University; K.C. Kerby-Patel, Univ. Massachusette; Bill Liles, Extra Class Radio Amateur

Amir Caspi and Constantine Tsang of the Southwest Research Institute in Boulder, Colorado, will use the DyNAMITE visible and infrared telescopes on NASA’s twin WB-57 airplanes to get a unique look at both the sun and Mercury during the total solar eclipse. Flying in the stratosphere at 50,000 feet above the ground at up to 470 miles per hour, the two planes will tag- team to provide the researchers with a total of about 8 minutes of data during totality – a useful increase over the 2 minutes and 40 seconds afforded a single, stationary instrument on the ground. These observations are obtained at an altitude above 90% of Earth’s atmosphere, enabling exceptionally accurate measurements of the solar corona in visible and infrared light in order to better understand how energy moves throughout the sun’s atmosphere. Just after totality, when light is still low enough to allow the telescope to get a good look at Mercury, the instruments will turn their gaze from the solar corona to our solar system’s smallest planet for unprecedented observations of its surface in infrared light, which can be otherwise hindered by infrared radiation from the sun. Scientists hope these measurements will give new information about how Mercury’s surface temperature changes as its day turns to night, shedding light on the surface composition and properties. The planes, which are operated out of NASA’s Johnston Space Center, will take off from Houston, Texas, and fly over Carbondale, Illinois and surrounding areas. 

Quantifying the Contributions of Ionization Sources on the Formation of the D-region Ionosphere during the 2017 Solar Eclipse (NASA) Bob Marshall & Wei Xu, University of Colorado, Boulder 

The upper reaches of Earth’s atmosphere — a region ionized by solar and cosmic radiation — is a superhighway for long-range, very low frequency, or VLF, telecommunications transmissions. Known as the ionosphere, this layer of the atmosphere is used for sending VLF transmissions all around the world. A research project, led by Bob Marshall at the University of Colorado, Boulder, will use the unique conditions created by the eclipse to study the ionosphere in hopes of improving models of the region’s dynamics. 

Radio wave transmissions sent from Lamoure, North Dakota, will be monitored at receiving stations across the eclipse path in Colorado and Utah. The data will be compared with several space-based missions, such as NOAA’s Geostationary Operational Environmental Satellite, NASA’s Solar Dynamics Observatory and NASA’s Ramaty High Energy Solar Spectroscopic Imager, to precisely characterize the effect of the sun’s radiation on the ionosphere. 

Rosetta Stone (NASA)Steve Tomczyk, Phil Judge & Paul Bryans, NCAR/HAO 

We propose to deploy two unique experiments during the 21st August 2017 total solar eclipse to learn about magnetism and thermal structure of the solar corona with the goal of understanding how the Sun generates weather in space. Additionally, we will test a new technology for solar and stellar polarimetry. First, a FLIR thermal imager will provide narrow-bandpass images at infrared wavelengths of the magnetically sensitive coronal emission lines of Si X 1430 nm, Si XI 1920 nm, Fe IX 2855 nm and Si IX 3935 nm. Information on the brightness of these lines is important for identifying the optimal lines for coronal magnetometry. The second novel experiment will provide instantaneous measurements of the polarization of four selected coronal lines from visible to near infrared wavelengths, at high frame rates.  An innovative commercial sensor coated with arrays of special linear micro-polarizers oriented at four different angles will be used to produce polarization measurements of coronal light. This data will provide information on the orientation of magnetic fields in the solar corona, which is important since coronal magnetism is the source of solar eruptions that can impact the earth. This new technology is simple and compact enough for future potential deployment on spacecraft. This work is supported by a grant from NASA, through NSF base funding of HAO/NCAR and by generous loans of equipment from our corporate partners, FLIR, 4D Technologies and Avantes.

FTIR (Fourier Transform Infrared Spectrometer) (NASA) – Phil Judge & Paul Bryans, NCAR/HAO 

This project aims to measure, for the first time, the spectrally resolved infrared (IR) corona over the range of 1.6-5.5 microns. This region of the solar spectrum is extremely important for diagnosing the coronal magnetic field because it contains several lines that are magnetically sensitive. However, the intensity of the emission from the corona in this spectral range is typically overwhelmed by the far brighter solar disk. For this reason, the total solar eclipse of 2017 provides an excellent opportunity to measure the IR spectrum of the corona under pristine conditions.  

We will observe the corona using a Michelson interferometer that will be deployed atop Casper Mountain in Wyoming. This experiment will provide the first moderate resolution spectral survey of the entire corona from 1.6 to 5.5 μm. Because the instrument is a Fourier Transform Interferometer, the entire spectral range is sampled simultaneously, without the need for a diffraction grating. We will explore, for the first time, magnetically sensitive emission lines with complete temperature coverage of the solar corona. 

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