#icesat-2

[icy-saturday]

Tried new brushes and made another icy drawing. I like this one a lot ~^w^~

[michaelgabrill]

ICESat-2 Hosts Third Applications Workshop

Introduction The NASA Ice, Cloud, and land Elevation Satellite-2 mission (ICESat-2), launched September 15, 2018, continues the first ICESat mission, delivering invaluable global altimetry data. Notwithstanding its icy acronym, ICESat-2 can do more than measure ice – in fact, the expanded acronym hints at these wider applications. From vegetation to inland surface water to bathymetry, […] from NASA https://ift.tt/6klCFzc

[spacetimewithstuartgary]

Arctic and Antarctic Sea Ice Approached Historic Lows

Arctic sea ice retreated to near-historic lows in the Northern Hemisphere this summer, likely melting to its minimum extent for the year on September 11, 2024, according to researchers at NASA and the National Snow and Ice Data Center (NSIDC). The decline continues the decades-long trend of shrinking and thinning ice cover in the Arctic Ocean.

The amount of frozen seawater in the Arctic fluctuates during the year as the ice thaws and regrows between seasons. Scientists chart these swings to construct a picture of how the Arctic responds over time to rising air and sea temperatures and longer melting seasons. Over the past 46 years, satellites have observed persistent trends of more melting in the summer and less ice formation in the winter.

Tracking sea ice changes in real time has revealed wide-ranging impacts, from losses and changes in polar wildlife habitat to impacts on local communities in the Arctic and international trade routes.

This year, Arctic sea ice shrank to a minimum extent of 4.28 million square kilometers (1.65 million square miles), as shown on the map above. That’s about 1.94 million square kilometers (750,000 square miles) below the 1981 to 2010 end-of-summer average of 6.22 million square kilometers (2.4 million square miles). The difference in ice cover spans an area larger than the state of Alaska. Sea ice extent is defined as the total area of the ocean with at least 15 percent ice concentration.

This year’s minimum—the seventh lowest in the satellite record—remained above the all-time low of 3.39 million square kilometers (1.31 million square miles) set in September 2012. While sea ice coverage can fluctuate from year to year, it has trended downward since the start of the satellite record for ice in the late 1970s. Since then, the loss of sea ice has been about 77,800 square kilometers (30,000 square miles) per year, according to NSIDC.

Scientists currently measure sea ice extent using data from passive microwave sensors aboard satellites in the Defense Meteorological Satellite Program, with additional historical data from the Nimbus-7 satellite, jointly operated by NASA and the National Oceanic and Atmospheric Administration (NOAA).

Sea ice is not only shrinking, it’s also getting younger, noted Nathan Kurtz, chief of the Cryospheric Sciences Laboratory at NASA’s Goddard Space Flight Center. “Today, the overwhelming majority of ice in the Arctic Ocean is thinner, first-year ice, which is less able to survive the warmer months. There is far, far less ice that is three years or older now,” Kurtz said.

Ice thickness measurements collected with spaceborne altimeters, including NASA’s ICESat and ICESat-2 satellites, have found that much of the oldest, thickest ice has already been lost. New research out of NASA’s Jet Propulsion Laboratory shows that in the central Arctic, away from the coasts, fall sea ice now hovers around 1.3 meters (4.2 feet) thick, down from a peak of 2.7 meters (8.8 feet) in 1980.

Another Meager Winter Around Antarctica

Sea ice in the southern polar regions of the planet was also low in 2024. Around Antarctica, scientists tracked near-record-low sea ice at a time when it should have been growing extensively during the Southern Hemisphere’s darkest and coldest months.

Ice around the continent likely reached its maximum extent for the year on September 19, 2024, when growth stalled out at 17.16 million square kilometers (6.63 million square miles). This year’s maximum, shown on the map above, was the second lowest in the satellite record and remained above the record winter low of 16.96 million square kilometers (6.55 million square miles) set in September 2023. The average maximum extent between 1981 and 2010 was 18.71 million square kilometers (7.22 million square miles).

The meager growth in 2024 prolongs a recent downward trend. Prior to 2014, sea ice in the Antarctic was increasing slightly by about 1 percent per decade. Following a spike in 2014, ice growth has fallen dramatically. Scientists are working to understand the cause of this reversal. The recurring loss hints at a long-term shift in conditions in the Southern Ocean, likely resulting from global climate change.

“While changes in sea ice have been dramatic in the Arctic over several decades, Antarctic sea ice was relatively stable. But that has changed,” said Walt Meier, a sea ice scientist at NSIDC. “It appears that global warming has come to the Southern Ocean.”

In both the Arctic and Antarctic, ice loss compounds ice loss. This is because while bright sea ice reflects most of the Sun’s energy back to space, open ocean water absorbs 90 percent of it. With more of the ocean exposed to sunlight, water temperatures rise, further delaying sea ice growth. This cycle of reinforced warming is called ice-albedo feedback.

Overall, the loss of sea ice increases heat in the Arctic, where temperatures have risen about four times the global average, Kurtz said.

NASA Earth Observatory images by Lauren Dauphin, using data from the National Snow and Ice Data Center. Story by Sally Younger, NASA’s Earth Science News Team, updated and adapted for Earth Observatory by Kathryn Hansen.

[slaparoonie]

What’s your opinion on these guys ? I wanna know if I’m not the only one >///<

The top is the ICESat-2 Satellite, the bottom is the Opportunity Rover. Both are from NASA ^w^ ~

very cute lil guys. my heart aches for opportunity rover

[controversial-blorbo-bracket]

SO SO SO glad Jaiden made it in. thank you, mx split, for allowing OCs because i am ECSTATIC seeing her here

i forget what i actually put as propaganda when i submitted her but like. she absolutely sucks. shes so interesting. there is so much wrong with her. she used to be a nurse before humans stopped being able to die of natural causes and one day SPACE PROBES started waking up and yknow. being People and so JAIDEN decided "hey what if i tried waking one up myself" and proceeded to. try doing that for awhile and, in her own words (this was written by her mun, Rusty): > "None of the machines had survived so far. But all of them were worthy sacrifices in her eyes. If they did not survive, they would have contributed to the next machine’s progress. Each failed subject was a lesson for the woman, a lesson of what not to do next time."

So she's a little fucked up. Anyways one day she finally manages to wake Chip up successfully and. uh. Well she succeeded at that! She doesn't tell Chip her actual name, saying he can give her one instead and so thats where she gets the alias "Dani" from

Anyways. I'm not going to attempt to sum up every event involving her ever cause we'd be here all day, but some major points include: 1 - Emotional manipulation 2 - At one point, hacking of MULTIPLE sentient probes (icesat-1, MESSENGER, and.. C h i p) 3 - The entire arc with her and Chip. Hey isnt it fun when somebody gives themselves up for everyone? Isnt it fun when somebody puts their life in the hands of someone else, says to do anything - dissect them, burn them up in the atmosphere, whatever, just stop hurting their friends (Colors added to make intent clear here: green is dani, red is chip) When their sibling learns what they did and is forced to watch as they experience frequent overheating and memory lapses When she's finally gone, but what she did has left a lasting impact and sure they can try to stay silly but now theyre haunted by the memory of someone who loved them. someone who hurt them. jesus christ. yeah shes fucked up

Anyways check the reblogs on the Jaiden poll if you want to see a video mimi made with her in it!

.

[techtired]

Laser Scanning: An In-Depth Guide to the Technology, Its Types, and Importance

Laser scanning is a revolutionary technology that enables the precise measurement and mapping of objects, environments, and surfaces by using laser beams. It plays a key role in a wide variety of fields, such as architecture, engineering, construction, environmental science, archaeology, and even filmmaking. This technology works by emitting laser beams from a scanner, which reflect off surfaces, with the time it takes for the light to return being recorded. This data is then used to generate accurate, detailed 3D models or maps. In this article, we will explore the concept of laser scanning, the different types of laser scanning, and its importance across industries. What Is Laser Scanning? Laser scanning, often referred to as LiDAR (Light Detection and Ranging) or 3D scanning, is a technique that utilizes laser beams to collect data points from the surface of objects. These data points represent the distance between the scanner and the object, calculated based on the time it takes for the laser to hit the object and reflect. This results in a "point cloud," which is essentially a collection of millions of data points that can be processed to create a precise 3D digital model. The primary advantage of laser scanning is its ability to capture complex geometries and large environments with a high degree of accuracy and detail in a relatively short amount of time. Compared to traditional measurement methods, laser scanning can be exponentially faster while also reducing human error. Types of Laser Scanning There are three main types of laser scanning technologies: satellite laser scanning, airborne laser scanning, and terrestrial laser scanning. Each type serves a unique purpose depending on the scope and the area that needs to be scanned. 1. Satellite Laser Scanning Satellite laser scanning, also known as spaceborne laser scanning, involves lasers mounted on satellites orbiting the Earth. These lasers are used to measure the Earth’s surface and can map large-scale environments, from vast landscapes to urban areas. This technology has become instrumental in climate studies, topography, forest management, and disaster response. Applications of Satellite Laser Scanning: - Climate Change and Environmental Monitoring: Satellite laser scanning helps scientists monitor deforestation, glacier movements, and sea-level changes. By comparing scans taken over time, researchers can observe environmental changes on a global scale, making this an essential tool for studying climate change. - Urban Planning and Development: The ability to collect data on cities and urban areas from space allows for large-scale infrastructure planning and population growth studies. - Disaster Management: Satellite laser scanning can be used to assess damage caused by natural disasters such as earthquakes, floods, and hurricanes. It provides real-time data for emergency responses and recovery planning. One of the best-known examples of this technology is NASA’s ICESat-2 (Ice, Cloud, and Land Elevation Satellite), which measures ice sheet elevations, forest canopy heights, and more. 2. Airborne Laser Scanning Airborne laser scanning, often referred to as LiDAR when applied in this context, is performed by mounting a laser scanner on an aircraft, helicopter, or drone. As the aircraft flies over a target area, the laser scanner emits thousands of laser pulses per second towards the ground. These pulses then reflect to the scanner, and the time-of-flight (ToF) is used to calculate distances, which can be converted into topographical maps or 3D models. Applications of Airborne Laser Scanning: - Geographical Information Systems (GIS): Airborne laser scanning is widely used in GIS to generate accurate digital elevation models (DEMs) and 3D topographical maps. This data is crucial for floodplain mapping, land-use planning, and environmental conservation. - Forestry Management: LiDAR is used to analyze forest structures by calculating tree heights, canopy density, and forest biomass. This helps in forest monitoring, resource management, and wildfire risk assessment. - Infrastructure and Urban Mapping: Municipalities use airborne laser scanning to map cities and urban regions, helping with planning for new infrastructure projects, monitoring traffic patterns, and managing utilities. One advantage of airborne scanning is its ability to cover vast areas quickly, making it ideal for surveying inaccessible regions such as dense forests, mountains, and large river systems. 3. Terrestrial Laser Scanning Terrestrial laser scanning involves the use of stationary ground-based scanners that are typically mounted on tripods or other platforms. These scanners rotate around a fixed point and capture the environment in 360 degrees. Unlike airborne or satellite scanning, terrestrial laser scanning provides highly detailed and accurate scans of objects within a smaller range. Applications of Terrestrial Laser Scanning: - Architecture and Construction: Terrestrial laser scanning is widely used in the construction industry for surveying buildings, bridges, and other infrastructure. Scans can help identify structural issues, monitor progress, and create precise as-built models. - Heritage Preservation: This technology is often used to create digital replicas of historical monuments, ancient buildings, and archaeological sites. These digital replicas help preserve and restore cultural heritage. - Industrial Inspections: Terrestrial laser scanning is used to inspect manufacturing facilities, pipelines, and machinery. It allows engineers to detect potential wear and tear or damage, making maintenance more efficient. The detailed and accurate data provided by terrestrial laser scanning is essential for professionals working in fields that require precise measurements, such as civil engineering, architecture, and construction. The Importance of Laser Scanning Laser scanning has become an invaluable tool in modern industries due to its unparalleled precision, speed, and versatility. Below are some key reasons why laser scanning is important: 1. High Accuracy and Precision Laser scanning produces data with a level of accuracy that traditional surveying methods cannot match. The technology can capture details down to millimeter-level precision, making it ideal for industries where even the smallest measurement errors can have significant consequences, such as construction, engineering, and manufacturing. 2. Time-Efficiency Laser scanning drastically reduces the amount of time needed for surveying and data collection. Traditional surveying techniques may take days or weeks to complete large-scale projects, whereas laser scanning can collect data in hours. This saves time and resources, allowing projects to be completed faster. 3. Comprehensive Data Collection Laser scanning captures millions of data points in a short period, resulting in a highly detailed point cloud that can be processed into a 3D model or map. These models are not only accurate but also rich in detail, providing comprehensive information that can be analyzed and manipulated for various purposes. 4. Non-Contact Measurement Laser scanning is a non-invasive technology, which means there is no need for physical contact with the object being scanned. This is particularly useful when working with delicate or hazardous materials, such as historical artefacts, contaminated areas, or dangerous construction sites. 5. Versatility Across Multiple Industries Laser scanning is versatile enough to be used in a wide range of industries, including: - Construction: For as-built models and progress tracking. - Archaeology: To digitally preserve and analyze historical sites. - Automotive and Aerospace: To inspect components and detect manufacturing defects. - Environmental Science: To monitor natural ecosystems and study changes in landscapes. - Healthcare: For creating accurate prosthetics and detailed imaging of the human body. Conclusion Laser scanning is an essential technology that is transforming the way we measure, map, and analyze the world around us. With its ability to generate highly accurate 3D models in a fraction of the time required by traditional methods, it has found applications in numerous industries, from construction and environmental monitoring to archaeology and industrial inspections. The future of laser scanning looks even more promising with the continued advancement of the technology. As laser scanning becomes more affordable and accessible, its potential applications are expected to expand, bringing unprecedented precision and efficiency to various fields. Whether you’re planning a new infrastructure project, preserving a historical site, or conducting environmental studies, laser scanning is likely to play a critical role in your work. Read the full article

[sunaleisocial]

Bente Eegholm: Ensuring Space Telescopes Have Stellar Vision - NASA

New Post has been published on https://sunalei.org/news/bente-eegholm-ensuring-space-telescopes-have-stellar-vision-nasa/

Bente Eegholm: Ensuring Space Telescopes Have Stellar Vision - NASA

Bente Eegholm is an optical engineer working to ensure missions like the Nancy Grace Roman Space Telescope have stellar vision. When it launches by May 2027, the Roman mission will shed light on many astrophysics topics, like dark energy, which are currently shrouded in mystery. Bente’s past work has included Earth-observing missions and the James Webb Space Telescope.

Name: Bente Eegholm Title: Goddard Optics Lead for Roman Space Telescope OTA (Optical Telescope Assembly) Formal Job Classification: Optical Engineer Organization: Optics Branch (Code 551)

What do you do and what is most interesting about your role at Goddard?

I am an optical engineer, and I work on the Nancy Grace Roman Space Telescope as the Goddard optics lead on the observatory’s OTA (Optical Telescope Assembly). My work is a combination of optical systems work, technical meetings, and hands-on work in the labs and integration facilities. The most interesting part is that we are creating unique, one-of-a-kind instruments, which enable NASA, as well as anyone around the world, to become more knowledgeable about our universe, including our own planet.

How will your current work influence the Nancy Grace Roman Space Telescope’s future observations?

The quality of Roman’s future observations is directly tied to the telescope’s optical quality. As an optical engineer I am involved with providing the best imaging possible for the telescope and its science instruments. I work closely with the OTA management, and optical and system engineers at Goddard and at L3Harris in Rochester, New York, a mission partner that is building the OTA. The OTA consists of a series of total 10 mirrors. I am frequently on site in Rochester, most recently for the very important first light test and ensuing alignment process of the telescope. We are striving to get every photon possible delivered to Roman’s two instruments, the WFI (Wide Field Instrument) and coronagraph technology demonstration.

What motivates you as an engineer? And what was your path to your current role?

It motivates me to support a great purpose, pioneer technology for spaceflight, and to conquer the challenges that inevitably occur along the way. I also enjoy being a mentor for newer engineers, as well as giving Roman tours and presentations to Goddard visitors.

I received my M.Sc. and Ph.D. degrees in my native Denmark. The path to my current role really started in 2004 after I had obtained my green card and gotten a position with Swales Aerospace, supporting NASA Goddard’s Optics Branch, Code 551. I was a contractor for eight years, supporting the James Webb Space Telescope. This was a magnificent project to work on; it was very rewarding in terms of the optical technology to accomplish this mission, as well as the amazing and talented people with whom I was working. I supported the development and test of a speckle interferometer which we used to prove the stability of the backplane structure for Webb’s primary mirror.

After becoming a U.S. citizen, I obtained a civil servant position in 2012. I was appointed the ATLAS (Asteroid Terrestrial-impact Last Alert System) telescope product development lead for the ICESat-2 mission, an Earth-observing mission to measure sea ice thickness from space. Both a flight and a spare telescope were built, and after successful testing and delivery of the ATLAS flight telescope, the ATLAS spare telescope was a perfect match for GEDI (the Global Ecosystem Dynamics Investigation), a mission to measure forest canopies from the International Space Station. That naturally led to me to continue to GEDI, where I was the alignment lead. GEDI launched in December 2018.

In 2019 I started working on the Roman Space Telescope and was thrilled to work on a large astronomy mission again, and in two capacities to boot. Concurrently with my role on the telescope I was optics lead on the prism assembly (a slitless spectrometer which helps enable the WFI’s study of dark energy) from 2019 until its completion and delivery to the WFI in September 2022.

I feel very fortunate to have experience from both astronomy and Earth-observing missions! It definitely widens your technical experience. Often, the telescopes and science instruments for astronomy missions typically take longer to develop and implement than the ones for Earth-observing missions. With the shorter time to launch, you have the opportunity to see the fruits of your labor fly into space within a few years, and it is beneficial to go through the steps of an entire development and launch cycle.

How do you stay updated on the latest technological advancements? How do you apply that knowledge to your work?

I enjoy learning something new every day, either by individual research or via professional organizations. I use it in my own work and in working with many optics vendors, and being a reviewer on projects and proposals. Bringing new technology to Goddard is important, and we must approve each technology for space flight before we can use it in our next missions.

What is your favorite project or challenge you’ve worked on so far in your career?

That is a really hard question. Just like you can’t choose between your children! All four of the missions I have worked on have been awesome experiences. A recent amazing event, though, was on Roman, watching the first fringes emerge on the OTA interferometer screen at the “first light” session in the integration facility. This was the result of several years of hard work for many people, and it indicated that all the 10 telescope mirrors were well-positioned, boding well for the successful final alignment, which we achieved.

What do you like best about working for NASA?

I enjoy working on unique projects, always reaching for the stars, and using new technology and methods. NASA is a unique organization, known by everyone around the globe. For example, it has been a great honor to hear from many people who follow our work how much they appreciate Webb. NASA’s work is very visible, and that commits us and holds us accountable. And we are up to the challenge!

What hobbies fill your time outside of work?

I love yoga, and hiking in nature. I also love singing in choir, especially classical music. The magnificent sound we can achieve with 75 singers, and how the different types of voices merge to convey the music, is an example of collaboration that is a bit like succeeding in a flight mission. All the different people, tasks and parts synchronized and coming together to make it work!

What advice do you have for others who are interested in working in engineering?

Maybe I am a bit biased, since both my husband and I are engineers, my son is in grad school for engineering, and my daughter is in grad school for ocean science. In my opinion, an engineering degree offers highly transferable skills, and is a great path for everyone who enjoys math and physics. People skills are also important in engineering, as most projects are performed in teams. Make sure to select math and science classes in high school, and aim for internships in college. An engineering degree requires effort and dedication, but it’s worth it!

By Ashley Balzer NASA’s Goddard Space Flight Center, Greenbelt, Md.

Conversations With Goddard is a collection of Q&A profiles highlighting the breadth and depth of NASA’s Goddard Space Flight Center’s talented and diverse workforce. The Conversations have been published twice a month on average since May 2011. Read past editions on Goddard’s “Our People” webpage.

[ricmlm]

PhyTon Phrightday: PACE and ICESat-2 Mess with Mesodinium

[jaspersboy]

Around the world, communities are bracing for sea level rise: the Netherlands is stabilizing its dikes, Senegal is relocating neighborhoods, and Indonesia is moving its entire capital city. These projects are hefty, expensive, and slow.

But they may need to pick up the pace. As new research shows, in many places, sea level rise will cause coastal flooding and other disruptions much sooner than anyone realized. It’s not that the water is rising faster; it’s that the land was lower to begin with.

Calculating when a rising sea will flood any one place involves a lot of math: you need to know the height of the water, the range of the tide, the elevation and slope of the land, the pace of sea level rise, and how much the land itself is rising or falling, among myriad other factors. As with all of science, the accuracy of these predictions is only as good as the data flowing into them.

The problem, according to the new study by Ronald Vernimmen and Aljosja Hooijer, two data analysts working on flood risk in Southeast Asia, is that time after time, the measurements of coastal elevation that scientists feed into their models have been wildly inaccurate. In tropical forests, says Vernimmen, these misinterpretations can be off by 20 meters or more. “Obviously, you can’t use that,” he says.

The problem stems from limitations in the technology typically used to measure elevation: radar. Radar blankets an area in radio waves, then measures how long it takes the waves to bounce back. But radar isn’t precise enough to separate treetops from terra firma, and a patch of pines or cluster of condos can easily exaggerate the elevation. Many studies of sea level rise still use radar elevation data collected by the space shuttle in 2000.

Lidar is a lot like radar, but it uses lasers instead of radio waves. A lidar detector like the one on the ICESat-2 satellite, which NASA launched in 2018, can send up to one million pulses each second, firing lasers that can pinpoint the gaps between buildings and trees to more accurately gauge the elevation of the land underneath. Analysts still need algorithms to filter that barrage of information into a functional map, but the results are far more precise.

Vernimmen and Hooijer spent the past few years filtering the new satellite data for Earth’s immense coastline, comparing elevation estimates gathered from radar with the newer lidar-based measurements. It wasn’t pretty.

The scientists’ big finding is that forests and buildings along the coast have skewed radar maps, presenting planners with inaccurate elevation data. Lidar showed coastlines often lower than first realized. This has two important implications: the same amount of sea level rise will be able to reach much farther inland, and it’s going to happen a lot sooner than expected.

The scientists’ new lidar-based estimate predicts that roughly 482,000 square kilometers of land will be submerged with one meter of sea level rise, nearly triple the 123,000 square kilometers predicted by radar-based projections. That’s an extra Cameroon-sized chunk of Earth, currently home to roughly 132 million people, that will be underwater by 2100 under a high-emissions scenario.

[icy-saturday]

Me after finding out ICESat-2 and Aqua are literally the same person

[noneofthisisreal]

The beams were synchronized with a tiny green dot that was briefly visible between the clouds. He guessed it was a satellite, so he investigated orbital data and got a match. NASA’s Ice, Cloud and Land Elevation Satellite 2, or ICESat-2, had flown overhead that night. Fujii posted his findings on social media, which eventually got the attention of the NASA team.

Mysterious Green Lasers Near Mount Fuji, Japan Have a “Chilling” Explanation

[angelsalcedo]

Un Venezolano en la misión del ICESat-2, Expresó: Este año me uní al equipo de artistas y amantes del espacio que comunican la misión del ICESat-2, el satélite que mide el deshielo y su impacto global. Jamás me imaginé que podría formar parte de un proyecto de la Nasa y que representaría a Venezuela. Honestamente, ya ni sé a donde voy. Solo me dejo llevar, confiado en lo que Dios programó y sus maravillas en mi tiempo terrenal. De mi parte, Ángel Salcedo le desea éxito y que es un orgullo que nos represente en ese proyecto en la #NASA (en Venezuela) https://www.instagram.com/p/Co5B-ucOG5h/?igshid=NGJjMDIxMWI=

[spacetimewithstuartgary]

Water for a Desert Lake in Algeria

Roughly 11,000 to 5,000 years ago, during the African Humid Period, the Sahara Desert was likely far wetter and greener. Geologic and archaeological evidence indicates that vegetation, wetlands, and perhaps even large lakes covered areas that are now oceans of sand.

In September 2024, hints of this more watery past emerged after an extratropical cyclone dropped a deluge of rainfall on parts of northern Africa. Runoff from the storm has partially filled several ephemeral desert lakes in normally dry areas.

The OLI-2 (Operational Land Imager-2) on Landsat 9 (lower) captured this image of Sebkha el Melah, an ephemeral lake in Algeria, on September 29, 2024. The lake is situated along a ridge of the Ougarta Range and fed by the Oued Saoura, an ephemeral river (sometimes called a wadi) that enters from the southeast. The other image (left) shows the salt-encrusted lakebed on August 12, before the rain event. NASA satellites observed the lake beginning to fill in mid-September.

As of October 16, water covered 191 square kilometers (74 square miles) to a depth of 2.2 meters (7.2 feet), and Sebkha el Melah was roughly one-third full, said Moshe Armon, a senior lecturer at the Hebrew University of Jerusalem. Armon calculated these values using satellite images of the water’s extent, like the one above, along with a three-dimensional map of the lake’s bathymetry based on ICESat-2 observations. Since June 2000, only two other rain events have resulted in larger lake volumes—one in 2008 and one in 2014, Armon said.

The filling of a Sahara Desert lake is a “rare, largely undocumented, transient phenomenon,” noted Joëlle Rieder, a colleague of Armon’s, in a 2024 study that detailed the frequency of refilling events at the lake since 2000. This part of Algeria has few ground-based weather stations, so the researchers used rainfall data from NASA’s Integrated Multi-satellite Retrievals (IMERG) and ERA5 weather reanalysis data from the European Center for Medium-range Weather Forecasts (EMCWF) to study the meteorological conditions required to fill the lake.

Of the hundreds of rainfall events that affected Sebkha el Melah’s watershed since 2000, only six delivered enough water to start filling it. All of these involved long-lasting extratropical cyclones that produced especially heavy rainfall as moist tropical air was pushed up and over mountains, a process called orographic lift.

Satellite observations indicate that when Sebkha el Melah fills, the water can stick around. After it filled in 2008, it took until 2012 to dry completely. “If we don’t get any more rain events, a 2.2-meter depth, like we have now, would take about a year to evaporate completely,” Armon said.

Armon and other scientists track lake-filling episodes in part because questions remain about both the region’s past and future. Despite evidence indicating that the Sahara was wetter during the African Humid Period, just how wet remains a matter of scientific debate. To help resolve it, scientists look to desert lakes, like Sebkha el Melah, because they function a bit like giant “rain gauges” that provide clues about past precipitation patterns, explained Armon.

One of the challenges for researchers who study this topic is that models that simulate prior climate conditions struggle to reproduce the rainfall required to fill as many Saharan lakes as geologists believe were present during the African Humid Period. This has led some researchers to suggest that either the Sahara wasn’t actually as rainy and verdant as paleoclimate experts think or that the models are missing something, explained Armon.

“We’re proposing a third option: that extreme rain events, like the one in September in the northwestern Sahara, might have been more frequent in the past,” said Armon. “Given how long it takes lakes to dry up, these events could have been common enough to keep lakes partially filled over long periods—even years or decades—without frequent rainfall.”

It’s generally accepted by paleoclimatologists that small orbital variations called Milankovitch cycles were key drivers of the African Humid Period because they would have caused slight changes in the distribution of solar radiation and shifts in the strength and position of the North African monsoon. Less clear is whether and how much the Sahara might green and support long-lasting lakes in future centuries and millennia as the impacts of greenhouse gas emissions and climate change are layered onto the cyclical effects of the Milankovitch cycles.

Projections from the Intergovernmental Panel on Climate Change (IPCC) indicate that while parts of the Sahara may receive more rainfall as global temperatures increase, other parts may receive less. “But the uncertainties in these projections are larger than the projected changes,” said Armon. “What’s going to happen in the Sahara remains very unclear, but we hope that we’ll eventually develop a better understanding of the Sahara’s future by studying these lake-filling events.”

NASA Earth Observatory images by Michala Garrison, using Landsat data from the U.S. Geological Survey. Story by Adam Voiland.

[parttimereporter]

The new normal: Military fighters taking down UFOs..

Think about this.. it was science fiction to predict government officials would orders militaries to take down unidentified aerial objects, of unidentified craft.

But for the third time *that we know of* the United States military took one down.

On Saturday night February 11, there was a long strange odyssey over Montana. The FAA restricted airspace and all eyes were on tanker jets on Flight Aware refueling fighters.. However, we were told in public statements that the military would continue to monitor the object and reconsider in the morning..

So here is the fact that we know, from public official releases from the White House and Pentagon: The US and Canada brought down three high-altitude airborne objects this month, including one Washington said was sent deliberately by China for surveillance. Beijing countered that it was a harmless weather-monitoring device that blew off course...

And now this spicy news from China: They apparently say they have seen an object flying and THEY intend on taking it down over their nation..

WE assume the military knows a bit more than they would tell us, of course, but people are clamoring to know what in the world, or other world, they are. With the silence comes conspiracies.. On one hand we have been worried about World War III, but maybe we missed the beginning of War of the Worlds in the process!

Talking about these objects being anything other than mannade is speculative .. people would slam it as conspiracy. But consider the fact, as we mentioned opening up this post, we have been hearing of the military spotting UAPs for years.. Pentagon officials have silently warned Congress that they did not know what the objects were. Now, after spotting and taking down the Chinese spy balloon, the new objects being shot down apparently don't completely match that M.O.

From news accounts in Canada: The object was “cylindrical” and smaller than the suspected Chinese balloon shot down last weekend, Canadian Defense Minister Anita Anand said on Saturday evening. It is not clear what the object shot down over Canada is or whether it is related to the spy balloon shot down last week or the unidentified object shot down over Alaska on Friday.

But it is not just objects. It is lights in the sky as well.

Late last month, mysterious green laser beams were spotted from Hawaii's tallest peak. Experts initially said the burst of laser beams was emitted by a NASA spacecraft though that was proven incorrect this week -- with evidence pointing to a Chinese satellite. 

Space experts at the National Astronomical Observatory of Japan (NAOJ) initially tweeted on Jan. 30 that the Subaru-Asahi Star Camera "captured green laser lights in the cloudy sky over Maunakea, Hawai'i. The lights are thought to be from a remote-sensing altimeter satellite ICESAT-2/43613." 

Yes indeed... some may call some conspiracy theorists. But right now, we all maybe just became honorary members in 2023.

[conptyusa]

Green lasers fired at Hawaii by a Chinese satellite occurred in same area as unusual Chinese real estate activity Guest post by Lawrence Sellin, Ph.D.  Citing a Zerohedge report, The Gateway Pundit noted that the Chinese altimeter satellite ICESAT-2/43613, fired green laser bursts over Maunakea, Hawaii on January 28, 2023. That Chinese military operation occurred…

[astroimages]

O QUE ERAM OS FEIXES DE LASERS VERDES QUE CURZARAM O CÉU DO HAVAÍ?

ASSINE JÁ O SPACE TODAY PLUS E TENHA ACESSO A CENTENAS DE CONTEÚDOS INÉDITOS E EM PORTUGUÊS SOBRE ASTRONOMIA E ASTRONÁUTICA POR APENAS R$29,90 POR MÊS!!! https://quero.plus OUÇA O PODCAST HORIZONTE DE EVENTOS: https://www.spreaker.com/episode/52441779 Sobre as ilhas do Havaí , em 28 de janeiro, um laser verde foi visto perfurando o céu noturno, traçando silenciosamente um caminho em direção ao horizonte como uma gagueira no código da Matrix. A cena foi capturada por uma câmera de um telescópio no topo do pico mais alto do Havaí. Felizmente, não era uma espaçonave alienígena escaneando a Terra em busca de sinais de vida. Parece que os misteriosos feixes verdes realmente vieram de um satélite em órbita. Mas não o que esperávamos. Originalmente, especialistas do Observatório Astronômico Nacional do Japão (NAOJ), coproprietário da câmera, anunciaram no Twitter que a luz verde provavelmente veio de um dispositivo de radar em um satélite em órbita, conhecido como ICESat-2 . O ICESat-2 é de propriedade da NASA e é usado para monitorar a espessura do gelo marinho, mantos de gelo e florestas da Terra. Mas em 6 de fevereiro de 2022, o NAOJ atualizou suas imagens do feixe de laser dizendo que, com base na trajetória, era improvável que fosse a NASA, afinal. "De acordo com o Dr. Martino, Anthony J., um cientista da NASA trabalhando no ICESat-2 ATLAS, não é por seu instrumento, mas por outros", explica uma nota no vídeo do YouTube. "Seus colegas, Dr. Alvaro Ivanoff et al., fizeram uma simulação da trajetória de satélites que possuem um instrumento semelhante e encontraram um candidato mais provável como o instrumento ACDL do satélite chinês Daqi-1/AEMS. "Nós realmente apreciamos seus esforços na identificação da luz. Lamentamos nossa confusão relacionada a este evento e seu potencial impacto na equipe ICESat-2." O satélite chinês Daqi-1 foi lançado em abril do ano passado e semelhante ao ICESat-2, é um satélite de monitoramento do ambiente atmosférico. Isso significa que está em órbita ao redor da Terra para monitorar os níveis globais de carbono, bem como a poluição atmosférica. O Daqi-1 contém cinco instrumentos para ajudá-lo a fazer isso, incluindo ACDL, que significa Lidar de Detecção de Aerosol e Dióxido de Carbono. Lidar é um acrônimo para imagem a laser, detecção e alcance, e funciona um pouco como um sonar. Mas, em vez de enviar ondas sonoras para mapear uma área, ele envia raios laser. E acredita-se que esses lasers iluminaram o céu do Havaí no final de janeiro. No caso do ACDL, ele pode enviar lasers de comprimento de onda duplo em comprimentos de onda específicos para detectar várias moléculas na atmosfera da Terra. O tempo que leva para esses feixes de laser se recuperarem fornece informações sobre a composição da atmosfera e do solo abaixo. Por exemplo, ACDL pode descobrir quanto CO2 está na atmosfera da Terra emitindo dois lasers alternados em torno da faixa de comprimento de onda de 1572 nanômetros. O Daqi-1 pode monitorar a poluição por partículas finas como PM2.5, gases poluentes, incluindo dióxido de nitrogênio, dióxido de enxofre e ozônio, bem como a concentração de dióxido de carbono", um comunicado de imprensa de março de 2021 da China Aerospace Science and Technology Corporation, que desenvolveu o Daqi -1, explicou. Ainda é cedo para o Daqi-1, então ainda estamos esperando os resultados das varreduras. Mas se tudo correr como planejado, o satélite é apenas o começo dos planos da China para controlar a poluição do ar. " A China produzirá uma série de satélites Daqi no futuro, que serão usados ​​para monitorar a poluição atmosférica, fornecer suporte de dados de sensoriamento remoto para autoridades ambientais e também apoiar pesquisas científicas sobre mudanças climáticas globais", explicou o comunicado à imprensa de março de 2021 . “O Daqi-1 será conectado em rede com outros satélites, incluindo o Daqi-2, para realizar o monitoramento de gases de efeito estufa e ajudar a China a reduzir as emissões de carbono”. Ainda está para ser visto se esses lasers verdes de detecção atmosférica podem se tornar mais comuns à medida que a China atinge esse objetivo. FONTE: https://www.sciencealert.com/ominous-green-lasers-shot-over-hawaii-didnt-come-from-nasa-satellite-after-all #LASER #LIFE #UNIVERSE