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How Buildings Contribute to Urban Heating during Heat Waves

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A bottom-up approach quantifies the contributions of human-caused heating from building energy use during extreme heat events.

The Science

Previous research has found that heat waves and urban heat island effects reinforce each other’s effects. These heat islands are concentrations of buildings, paved areas, and other surfaces that absorb and retain heat. Emissions of heat from buildings are an important part of this heat island effect. Researchers therefore need to understand the interplay of urban microclimates and these building heat emissions. New research developed a method for modeling urban building energy and associated human-caused heat during city-wide heat waves. The researchers used the method to examine the variation over time and space in emissions of waste heat from buildings in Los Angeles. The study incorporated building type, urban microclimate, and large-scale climate conditions.

The Impact

The method provides a high-resolution representation of how buildings contribute to heat islands during heat waves. It details both the magnitude and distribution of these heating effects. The simulation indicates that heat dispersing from buildings to the urban environment increases by as much as 20 percent during a heat wave. Most of this heat is waste heat from air conditioning. The study’s results will serve as a fundamental step in continued investigations of the feedback between changes in building waste heat and urban microclimates during extreme heat events.

Summary

The world is experiencing more frequent and longer-duration heat waves. These heat waves are a serious threat to human health and the stability of electrical grids. Previous studies have identified positive feedbacks between heat waves and urban heat island effects. Heat discharges from buildings and associated energy use have significant effect on the urban environment, and researchers therefore need to understand the interactive effects of urban microclimate and building heat emissions on the urban energy balance. In this study, scientists developed a coupled-simulation approach to quantify these effects, mapping urban environmental data generated by the mesoscale Weather Research and Forecasting (WRF) model, coupled to the Urban Canopy Model (UCM), to simulate urban building energy flows. The scientists conducted a case study in Los Angeles, California, during a five-day heat wave event in September 2009.

The researchers analyzed the surge in city-scale building heat emission and energy use during the extreme heat event. They first simulated the urban microclimate at high resolution (500 by 500 meters) using WRF-UCM. Next, they generated grid-level building heat emission profiles and aggregated them using prototype building energy models informed by spatially disaggregated urban land use and urban building density data. They analyzed the spatial patterns of anthropogenic heat discharge from the building sector. They also assessed the quantitative relationship with weather conditions and urban land-use dynamics at the grid level. The simulation results indicate that during a heat wave, a rise in building energy use follows, and the associated discharge of anthropogenic waste heat from the buildings to the environment increases by as much as 20 percent on average, varying significantly, both in time and space. Notably, air-conditioning use within buildings intensifies, and resulting waste heat discharges outside of the buildings contribute most (86.5 percent) of the total waste heat transferred to the surrounding urban environment. The study also found that the waste heat discharge in inland, dense urban districts is more sensitive to extreme events than it is in coastal or suburban areas. The generated anthropogenic heat profiles can be used in urban microclimate models to provide a more accurate estimation of urban air temperature rises during heat waves.

Funding

This research was supported by the Department of Energy Office of Science as part of research in the MultiSector Dynamics, Earth, and Environmental System Modeling Program.

Rod: A creative force, blending words, images, and flavors. Blogger, writer, filmmaker, and photographer. Cooking enthusiast with a sci-fi vision. Passionate about his upcoming series and dedicated to TNC Network. Partnered with Rebecca Washington for a shared journey of love and art.

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NASA Remembers Trailblazing Astronaut, Scientist Mary Cleave

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NASA Astronaut Mary L. Cleave. April 8, 1985
NASA

Retired NASA astronaut Mary Cleave, a veteran of two NASA spaceflights, died Nov. 27. She was 76. A scientist with training in civil and environmental engineering, as well as biological sciences and microbial ecology, Cleave was the first woman to serve as an associate administrator for NASA’s Science Mission Directorate.

Born in Southampton, New York, Cleave received a Bachelor of Science degree in biological sciences from Colorado State University, Fort Collins, in 1969, and Master of Science in microbial ecology and a doctorate in civil and environmental engineering, both from Utah State University, Logan, in 1975 and 1979, respectively.

“I’m sad we’ve lost trail blazer Dr. Mary Cleave, shuttle astronaut, veteran of two spaceflights, and first woman to lead the Science Mission Directorate as associate administrator,” said NASA Associate Administrator Bob Cabana. “Mary was a force of nature with a passion for science, exploration, and caring for our home planet. She will be missed.”

Cleave was selected as an astronaut in May 1980. Her technical assignments included flight software verification in the SAIL (Shuttle Avionics Integration Laboratory), spacecraft communicator on five space shuttle flights, and malfunctions procedures book and crew equipment design.

Cleave launched on her first mission, STS-61B, aboard space shuttle Atlantis on Nov. 26,1985. During the flight, the crew deployed communications satellites, conducted two six-hour spacewalks to demonstrate space station construction techniques, operated the Continuous Flow Electrophoresis experiment for McDonnell Douglas and a Getaway Special container for Telesat and tested the Orbiter Experiments Digital Autopilot.

Cleave’s second mission, STS-30, which also was on Atlantis, launched May 4, 1989. It was a four-day flight during which the crew successfully deployed the Magellan Venus exploration spacecraft, the first planetary probe to be deployed from a space shuttle. Magellan arrived at Venus in August 1990 and mapped more than 95% of the surface. In addition, the crew also worked on secondary payloads involving indium crystal growth, electrical storms, and Earth observation studies.

Cleave transferred from NASA’s Johnson Space Center in Houston to the agency’s Goddard Space Flight Center in Greenbelt, Maryland in May 1991. There, she worked in the Laboratory for Hydrospheric Processes as the project manager for SeaWiFS (Sea-viewing, Wide-Field-of-view-Sensor), an ocean color sensor which monitored vegetation globally.

In March 2000, she went to serve as deputy associate administrator for advanced planning in the Office of Earth Science at NASA’s Headquarters in Washington. From August 2005 to February 2007, Cleave was the associate administrator for NASA’s Science Mission Directorate where she guided an array of research and scientific exploration programs for planet Earth, space weather, the solar system, and the universe. She also oversaw an assortment of grant-based research programs and a diverse constellation of spacecraft, from small, principal investigator-led missions to large flagship missions.

Cleave’s awards included: two NASA Space Flight medals; two NASA Exceptional Service medals; an American Astronautical Society Flight Achievement Award; a NASA Exceptional Achievement Medal; and NASA Engineer of the Year.

Cleave retired from NASA in February 2007.

https://go.nasa.gov/3uDCykl

Source: NASA

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astronomy

Telescope Array detects second highest-energy cosmic ray ever

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Newswise — In 1991, the University of Utah Fly’s Eye experiment detected the highest-energy cosmic ray ever observed. Later dubbed the Oh-My-God particle, the cosmic ray’s energy shocked astrophysicists. Nothing in our galaxy had the power to produce it, and the particle had more energy than was theoretically possible for cosmic rays traveling to Earth from other galaxies. Simply put, the particle should not exist.

The Telescope Array has since observed more than 30 ultra-high-energy cosmic rays, though none approaching the Oh-My-God-level energy. No observations have yet revealed their origin or how they are able to travel to the Earth.

On May 27, 2021, the Telescope Array experiment detected the second-highest extreme-energy cosmic ray. At 2.4 x 1020eV, the energy of this single subatomic particle is equivalent to dropping a brick on your toe from waist height. Led by the University of Utah (the U) and the University of Tokyo, the Telescope Array consists of 507 surface detector stations arranged in a square grid that covers 700 km(~270 miles2) outside of Delta, Utah in the state’s West Desert. The event triggered 23 detectors at the north-west region of the Telescope Array, splashing across 48 km2 (18.5 mi2). Its arrival direction appeared to be from the Local Void, an empty area of space bordering the Milky Way galaxy.

“The particles are so high energy, they shouldn’t be affected by galactic and extra-galactic magnetic fields. You should be able to point to where they come from in the sky,” said John Matthews, Telescope Array co-spokesperson at the U and co-author of the study. “But in the case of the Oh-My-God particle and this new particle, you trace its trajectory to its source and there’s nothing high energy enough to have produced it. That’s the mystery of this—what the heck is going on?” 

An animation replicating the timing and intensity of secondary particles hitting the Telescope Array surface detection.

In their observation that published on Nov. 24, 2023, in the journal Science, an international collaboration of researchers describe the ultra-high-energy cosmic ray, evaluate its characteristics, and conclude that the rare phenomena might follow particle physics unknown to science. The researchers named it the Amaterasu particle after the sun goddess in Japanese mythology. The Oh-My-God and the Amaterasu particles were detected using different observation techniques, confirming that while rare, these ultra-high energy events are real.

“These events seem like they’re coming from completely different places in the sky. It’s not like there’s one mysterious source,” said John Belz, professor at the U and co-author of the study. “It could be defects in the structure of spacetime, colliding cosmic strings. I mean, I’m just spit-balling crazy ideas that people are coming up with because there’s not a conventional explanation.”

Natural particle accelerators

Cosmic rays are echoes of violent celestial events that have stripped matter to its subatomic structures and hurled it through universe at nearly the speed of light. Essentially cosmic rays are charged particles with a wide range of energies consisting of positive protons, negative electrons, or entire atomic nuclei that travel through space and rain down onto Earth nearly constantly.

Cosmic rays hit Earth’s upper atmosphere and blasts apart the nucleus of oxygen and nitrogen gas, generating many secondary particles. These travel a short distance in the atmosphere and repeat the process, building a shower of billions of secondary particles that scatter to the surface. The footprint of this secondary shower is massive and requires that detectors cover an area as large as the Telescope Array. The surface detectors utilize a suite of instrumentation that gives researchers information about each cosmic ray; the timing of the signal shows its trajectory and the amount of charged particles hitting each detector reveals the primary particle’s energy.


https://stmdailynews.com/unveiling-the-mysteries-of-cosmic-rays-rare-ultra-high-energy-particle-traced-beyond-the-milky-way/

Because particles have a charge, their flight path resembles a ball in a pinball machine as they zigzag against the electromagnetic fields through the cosmic microwave background. It’s nearly impossible to trace the trajectory of most cosmic rays, which lie on the low- to middle-end of the energy spectrum. Even high-energy cosmic rays are distorted by the microwave background. Particles with Oh-My-God and Amaterasu energy blast through intergalactic space relatively unbent. Only the most powerful of celestial events can produce them.   

“Things that people think of as energetic, like supernova, are nowhere near energetic enough for this. You need huge amounts of energy, really high magnetic fields to confine the particle while it gets accelerated,” said Matthews.

Ultra-high-energy cosmic rays must exceed 5 x 1019 eV. This means that a single subatomic particle carries the same kinetic energy as a major league pitcher’s fast ball and has tens of millions of times more energy than any human-made particle accelerator can achieve. Astrophysicists calculated this theoretical limit, known as the Greisen–Zatsepin–Kuzmin (GZK) cutoff, as the maximum energy a proton can hold traveling over long distances before the effect of interactions of the microwave background radiation take their energy. Known source candidates, such as active galactic nuclei or black holes with accretion disks emitting particle jets, tend to be more than 160 million light years away from Earth. The new particle’s 2.4 x 1020 eV and the Oh-My-God particle’s 3.2 x 1020 eV easily surpass the cutoff.

Researchers also analyze cosmic ray composition for clues of its origins. A heavier particle, like iron nuclei, are heavier, have more charge and are more susceptible to bending in a magnetic field than a lighter particle made of protons from a hydrogen atom. The new particle is likely a proton. Particle physics dictates that a cosmic ray with energy beyond the GZK cutoff is too powerful for the microwave background to distort its path, but back tracing its trajectory points towards empty space.

“Maybe magnetic fields are stronger than we thought, but that disagrees with other observations that show they’re not strong enough to produce significant curvature at these ten-to-the-twentieth electron volt energies,” said Belz. “It’s a real mystery.” 

Expanding the footprint 

The Telescope Array is uniquely positioned to detect ultra-high-energy cosmic rays. It sits at about 1,200 m (4,000 ft), the elevation sweet-spot that allows secondary particles maximum development, but before they start to decay. Its location in Utah’s West Desert provides ideal atmospheric conditions in two ways: the dry air is crucial because humidity will absorb the ultraviolet light necessary for detection; and the region’s dark skies are essential, as light pollution will create too much noise and obscure the cosmic rays.

Astrophysicists are still baffled by the mysterious phenomena. The Telescope Array is in the middle of an expansion that that they hope will help crack the case. Once completed, 500 new scintillator detectors will expand the Telescope Array will sample cosmic ray-induced particle showers across 2,900 km (1,100 mi), an area nearly the size of Rhode Island. The larger footprint will hopefully capture more events that will shed light on what’s going on.

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Daily News

Witness the Launch and Docking of Roscosmos Progress 86: A Vital Supply Mission to the International Space Station

Experience live coverage of NASA’s Roscosmos Progress 86 launch to the International Space Station, providing essential supplies. #NASA #ISS #LiveCoverage

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NASA, the renowned space agency, is set to provide live coverage of the highly anticipated launch and docking of the Roscosmos Progress 86 cargo spacecraft. Laden with approximately three tons of crucial supplies, including food, fuel, and other essentials, this unpiloted spacecraft aims to resupply the Expedition 70 crew aboard the International Space Station (ISS). The event, scheduled for Friday, December 1st, will be broadcasted through multiple channels, allowing space enthusiasts to witness this remarkable feat of human ingenuity.

Launch Details:
The Progress 86 cargo spacecraft is slated for launch at 4:25 a.m. EST on December 1st (2:25 p.m. Baikonur time) from the Baikonur Cosmodrome in Kazakhstan. To enable worldwide access, NASA will commence its coverage at 4 a.m. on the NASA+ streaming service, accessible via the web or the NASA app. Additionally, viewers can watch the live coverage on NASA Television, YouTube, and the agency’s official website. NASA has made it convenient for viewers to stream NASA TV through various platforms, including social media, ensuring widespread accessibility.

Journey and Docking:
Following its launch, the Progress spacecraft will embark on a two-day, 34-orbit journey to reach the International Space Station. The spacecraft is set to automatically dock to the Poisk module at 6:14 a.m. on Sunday, December 3rd. NASA will begin coverage of the rendezvous and docking process at 5:30 a.m. on NASA Television and the agency’s website, allowing viewers to witness this intricate maneuver.

Importance of the Mission:
The Progress 86 cargo spacecraft’s arrival at the International Space Station is of great significance. It will deliver vital supplies to support the Expedition 70 crew during their stay aboard the orbiting laboratory. The ISS serves as a unique platform for scientific research, fostering advancements that would be unattainable on Earth. NASA’s continuous support of a human presence on the ISS for over 23 years has contributed to our understanding of long-duration space travel and the development of future space exploration missions.

Future Endeavors:
The International Space Station acts as a springboard for the future of space exploration. It serves as a catalyst for the development of commercial destinations in space and the growth of a low Earth orbit economy. Furthermore, it paves the way for NASA’s ambitious Artemis missions, which aim to return humans to the Moon and eventually expedite the journey to Mars. The progress made aboard the ISS and the knowledge gained by living and working in space for extended periods will be invaluable for these upcoming endeavors.

Stay Connected:
To stay updated with the latest news, captivating images, and intriguing features from the space station, NASA encourages space enthusiasts to follow their Instagram, Facebook, and X accounts. Additionally, one can visit NASA’s official website at https://www.nasa.gov/station to learn more about the International Space Station, ongoing research, and the remarkable crew members who call it home.

The live coverage of the launch and docking of the Roscosmos Progress 86 cargo spacecraft by NASA offers a unique opportunity for space enthusiasts to witness the remarkable supply mission to the International Space Station. As humanity continues to push the boundaries of space exploration, the ISS remains a symbol of scientific progress, technological innovation, and human resilience. Let us join NASA in celebrating this event and eagerly anticipate the exciting future endeavors that lie ahead in our quest for knowledge and discovery beyond our planet.

https://www.nasa.gov/station

Source: NASA

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