NASA: Day to Night and Back Again: Earth’s Ionosphere During the Total Solar Eclipse
PRESS RELEASE ISSUED 8/ 10/ 18
On Aug. 21, 2017, the Moon will slide in front of the Sun and for a brief moment, day will melt into a dusky night. Moving across the country, the Moon’s shadow will block the Sun’s light, and weather permitting, those within the path of totality will be treated to a view of the Sun’s outer atmosphere, called the corona.
But the total solar eclipse will also have imperceptible effects, such as the sudden loss of extreme ultraviolet radiation from the Sun, which generates the ionized layer of Earth’s atmosphere, called the ionosphere. This ever-changing region grows and shrinks based on solar conditions, and is the focus of several NASA-funded science teams that will use the eclipse as a ready-made experiment, courtesy of nature.
NASA is taking advantage of the Aug. 21 eclipse by funding 11 ground-based science investigations across the United States. Three of these will look to the ionosphere in order to improve our understanding of the Sun’s relationship to this region, where satellites orbit and radio signals are reflected back toward the Earth.
“The eclipse turns off the ionosphere’s source of high-energy radiation,” said Bob Marshall, a space scientist at University of Colorado Boulder and principal investigator for one of the studies. “Without ionizing radiation, the ionosphere will relax, going from daytime conditions to nighttime conditions and then back again after the eclipse.”
Stretching from roughly 50 to 400 miles above Earth’s surface, the tenuous ionosphere is an electrified layer of the atmosphere that reacts to changes from both Earth below and space above. Such changes in the lower atmosphere or space weather can manifest as disruptions in the ionosphere that can interfere with communication and navigation signals.
“In our lifetime, this is the best eclipse to see,” said Greg Earle, an electrical and computer engineer at Virginia Tech in Blacksburg, Virginia, who is leading another of the studies. “But we’ve also got a denser network of satellites, GPS and radio traffic than ever before. It’s the first time we’ll have such a wealth of information to study the effects of this eclipse; we’ll be drowning in data.”
Pinning down ionospheric dynamics can be tricky. “Compared to visible light, the Sun’s extreme ultraviolet output is highly variable,” said Phil Erickson, a principal investigator of a third study and space scientist at Massachusetts Institute of Technology’s Haystack Observatory in Westford, Massachusetts. “That creates variability in ionospheric weather. Because our planet has a strong magnetic field, charged particles are also affected along magnetic field lines all over the planet — all of this means the ionosphere is complicated.”
But when totality hits on Aug. 21, scientists will know exactly how much solar radiation is blocked, the area of land it’s blocked over and for how long. Combined with measurements of the ionosphere during the eclipse, they’ll have information on both the solar input and corresponding ionosphere response, enabling them to study the mechanisms underlying ionospheric changes better than ever before.
Tying the three studies together is the use of automated communication or navigation signals to probe the ionosphere’s behavior during the eclipse. During typical day-night cycles, the concentration of charged atmospheric particles, or plasma, waxes and wanes with the Sun.
“In the daytime, ionospheric plasma is dense,” Earle said. “When the Sun sets, production goes away, charged particles recombine gradually through the night and density drops. During the eclipse, we’re expecting that process in a much shorter interval.”
The denser the plasma, the more likely these signals are to bump into charged particles along their way from the signal transmitter to receiver. These interactions refract, or bend, the path taken by the signals. In the eclipse-induced artificial night the scientists expect stronger signals, since the atmosphere and ionosphere will absorb less of the transmitted energy.
“If we set up a receiver somewhere, measurements at that location provide information on the part of the ionosphere between the transmitter and receiver,” Marshall said. “We use the receivers to monitor the phase and amplitude of the signal. When the signal wiggles up and down, that’s entirely produced by changes in the ionosphere.”
Using a range of different electromagnetic signals, each of the teams will send signals back and forth across the path of totality. By monitoring how their signals propagate from transmitter to receiver, they can map out changes in ionospheric density. The teams will also use these techniques to collect data before and after the eclipse, so they can compare the well-defined eclipse response to the region’s baseline behavior, allowing them to discern the eclipse-related effects.
The ionosphere is roughly divided into three regions in altitude based on what wavelength of solar radiation is absorbed: the D, E and F, with D being the lowermost region and F, the uppermost. In combination, the three experiment teams will study the entirety of the ionosphere.
Marshall and his team, from the University of Colorado Boulder, will probe the D-region’s response to the eclipse with very low frequency, or VLF, radio signals. This is the lowest and least dense part of the ionosphere — and because of that, the least understood.
“Just because the density is low, doesn’t mean it’s unimportant,” Marshall said. “The D-region has implications for communications systems actively used by many military, naval and engineering operations.”
Marshall’s team will take advantage of the U.S. Navy’s existing network of powerful VLF transmitters to examine the D-region’s response to changes in solar output. Radio wave transmissions sent from Lamoure, North Dakota, will be monitored at receiving stations across the eclipse path in Boulder, Colorado, and Bear Lake, Utah. They plan to combine their data with observations from several space-based missions, including NOAA’s Geostationary Operational Environmental Satellite, NASA’s Solar Dynamics Observatory and NASA’s Ramaty High Energy Solar Spectroscopic Imager, to characterize the effect of the Sun’s radiation on this particular region of the ionosphere.
Erickson and team will look further up, to the E- and F-regions of the ionosphere. Using over 6,000 ground-based GPS sensors alongside powerful radar systems at MIT’s Haystack Observatory and Arecibo Observatory in Puerto Rico, along with data from several NASA space-based missions, the MIT-based team will also work with citizen radio scientists who will send radio signals back and forth over long distances across the path.
MIT’s science team will use their data to track travelling ionospheric disturbances — which are sometimes responsible for space weather patterns in the upper atmosphere — and their large-scale effects. These disturbances in the ionosphere are often linked to a phenomenon known as atmospheric gravity waves, which can also be triggered by eclipses.
“We may even see global-scale effects,” Erickson said. “Earth’s magnetic field is like a wire that connects two different hemispheres together. Whenever electrical variations happen in one hemisphere, they show up in the other.”
Earle and his Virginia Tech-based team will station themselves across the country in Bend, Oregon; Holton, Kansas; and Shaw Air Force Base in Sumter, South Carolina. Using state-of-the-art transceiver instruments called ionosondes, they will measure the ionosphere’s height and density, and combine their measurements with data from a nation-wide GPS network and signals from the ham radio Reverse Beacon Network. The team will also utilize data from SuperDARN high frequency radars, two of which lie along the eclipse path in Christmas Valley, Oregon, and Hays, Kansas.
“We’re looking at the bottom side of the F-region, and how it changes during the eclipse,” Earle said. “This is the part of the ionosphere where changes in signal propagation are strong.” Their work could one day help mitigate disturbances to radio signal propagation, which can affect AM broadcasts, ham radio and GPS signals.
Ultimately, the scientists plan to use their data to improve models of ionospheric dynamics. With these unprecedented data sets, they hope to better our understanding of this perplexing region.
“Others have studied eclipses throughout the years, but with more instrumentation, we keep getting better at our ability to measure the ionosphere,” Erickson said. “It usually uncovers questions we never thought to ask.”
WASH. Sec. of State: Washington State Library to host Eclipse Event Aug. 21
PRESS RELEASE ISSUED 8/ 14/ 17
OLYMPIA…For those who aren’t headed south for a total view of the solar eclipse on Aug. 21, the Washington State Library is offering an alternative to watch the rarely seen astronomical phenomenon much closer to home.
The State Library is hosting an Eclipse Event at its Tumwater location from 8:30 a.m. to noon on Aug. 21. The event, which is free to the public, will be held on the south side of the library building, located at 6880 Capitol Blvd. SE in Tumwater.
“We invite everyone throughout the Olympia area to join us at our Eclipse Event on the 21st,” said State Librarian Cindy Aden. “This is a rare, amazing natural occurrence that the South Sound area won’t experience again until 2044, so we hope others will join us to observe and celebrate this incredible moment.”
The State Library will hand out 200 pairs of eclipse glasses on a first-come, first-served basis. A reflective projection area will be set up outside so that those who don’t receive the safety glasses can still watch and enjoy the eclipse. Because parking is very limited, people are asked to use public transportation to reach the library. Intercity Transit’s Bus #13 drops off passengers right outside the main library entrance.
A speaker from the Tacoma Astronomical Society will be on hand to talk about the science behind the eclipse and answer questions. People can use the special hashtag, #WSL_Eclipse, on social media posts to get in on the fun!
The Olympia area will experience about a 94 percent eclipse starting around 9:07 a.m. as the moon moves east. The optimal viewing time will be at 10:19 a.m. as the moon blocks nearly all of the sun. The eclipse will end around 11:38 a.m.
The State Library has distributed nearly 4,000 eclipse glasses to 44 libraries across the state for safe viewing of the eclipse.
Secretary DeVos Announces Approval of Nevada, New Jersey and New Mexico's ESSA Plans
PRESS RELEASE ISSUED 8/ 9/ 17
WASHINGTON – U.S. Secretary of Education Betsy DeVos today announced the approval of Nevada, New Jersey and New Mexico's respective consolidated state plans under the Every Student Succeeds Act (ESSA).
"Throughout this approval process, it has been exciting to see how each state has chosen to serve its students through the flexibility afforded to them under ESSA," said Secretary DeVos. "Nevada, New Jersey and New Mexico's plans meet the statutory requirements of ESSA and these plans will provide a solid framework for educating students in ways that meet each individual state's needs."
"The efforts put into these plans by chief state school officers, governors and others is evident, and I look forward to continuing to collaborate with each of them as we work to expand and improve educational opportunities for all students."
Allowing states more flexibility in how they deliver education to students is at the core of ESSA. Each state crafted a plan that it feels will best offer educational opportunities to meet the needs of the state and its students. The following are some of the unique elements from each state's approved plan as highlighted by each state:
Nevada
Creates pre-approved evidence-based intervention lists to streamline district identification, review and approval processes.
Implements strategies that will target rural districts that typically struggle to provide a wide variety of advanced course offerings and CTE courses to students, as well as urban schools with low participation rates of underrepresented subgroups.
Supports college and career readiness through a competitive grant process focused on science, technology, engineering and math (STEM) for middle and high school students, an increase in AP enrollment and support for AP success and an increase and expansion of dual enrollment for students enrolled simultaneously in high school and college courses.
New Jersey
Implements the New Jersey Tiered System of Supports, which is an evidence-based framework for implementing academic and behavioral supports and interventions to improve achievement for all students.
Supports LEAs in offering greater opportunities for middle school students to enroll in advanced-level math coursework by designing, implementing and evaluating research-based technical support around math literacy; designing and disseminating guidance to LEAs on the use of Title I to support preparation for advanced math; and designing multiple, model course pathways for middle schools that allow eighth-grade students to complete Algebra I.
Aims for at least 80 percent of all students and at least 80 percent of each subgroup of students in each tested grade to meet or exceed grade-level expectations on the statewide ELA and mathematics assessments by 2030.
New Mexico
Provides clear measurements of interim progress and targets for all subgroups for ELA and math through 2020, including targets for all subgroups for four-, five- and six-year adjusted cohort graduation rates through 2020.
Utilizes an A-F "School Grades" accountability system, with grades tied to a school's identification for comprehensive support and improvement.
Implements the Principals Pursuing Excellence and Teachers Pursuing Excellence programs, which embed mentors for educators in struggling schools.
WASH. STATE BOARD OF EDUCATION CALLS FOR SPECIAL MEETING AUG. 16th
Amara, Elephant Room 5907 Martin Luther King Jr. Way S
Seattle, WA 98118 August 16, 2017
Agenda highlight: Approval of Letter Regarding ESSA Plan Components Pursuant to Statutory Authority of the State Board of Education
WORLD & NATIONAL NEWS BRIEFS
NEWS FROM THE UN NEWS CENTER:
Amid soaring food insecurity in DR Congo, UN agencies call for food aid, supplies
14 August 2017 – More than one in ten people living in rural areas of the Democratic Republic of the Congo (DRC) are hungry due to escalating and prolonged conflict and displacement, United Nations agencies today reported, warning that the situation will worsen unless urgent support comes in time.
Yemen's cholera epidemic surpasses half-million suspected cases, UN agency says
14 August 2017 – More than 500,000 people in Yemen are suspected of having cholera, the United Nations health agency today said, warning that the disease is spreading quickly due to a lack of clean water or health access.
NATIONAL
AP: Trump speaks on Charlottesville: 'Racism is evil'WASHINGTON (AP) — Under pressure all weekend, President Donald Trump on Monday named and condemned hate groups as "repugnant" and declared "racism is evil" in an updated, more forceful statement on the deadly, race-fueled clashes in Charlottesville, Virginia.
NYT: Heather Heyer, Charlottesville Victim, Is Recalled as ‘a Strong Woman’
Heather D. Heyer died standing up for what she believed in.
Friends described her as a passionate advocate for the disenfranchised who was often moved to tears by the world’s injustices. That sense of conviction led her to join demonstrators protesting a rally of white nationalists in Charlottesville, Va., on Saturday.
Reaction from Olympia on Charlotteville
Inslee statement on violence in Charlottesville, Va.
PRESS RELEASE ISSUED 8/ 12/ 17
"No American can ignore the disgusting hate and violence we’ve seen in Charlottesville over the last two days.
"Trudi and I hold the victims of today’s attack in our thoughts, and we know that all Washingtonians who believe in freedom, peace, and justice for all will do the same.
"It is on all of us, from me, to you, and all the way to the President, to denounce and decry the horror we’ve seen today in Virginia.
"But speaking out against this hate is not enough. Our actions as a nation in response to racist, nationalist bigotry will speak louder.
"We can not let anyone stoke racism for political gain. We can’t ignore an attack on our people. And we will not tolerate hate in any form, anywhere, in the United States of America."
Daily Bible Verse: [ The Lukewarm Church ] “And to the angel of the church of the Laodiceans write, ‘These things says the Amen, the Faithful and True Witness, the Beginning of the creation of God: Behold, I stand at the door and knock. If anyone hears My voice and opens the door, I will come in to him and dine with him, and he with Me.
Revelation 3:14,20 NKJV
Free bible studies (WBS)
Learn english using the bible as text (WEI)
No comments:
Post a Comment