The gloomy arguments in favor of solar geoengineering are compelling; so are the even gloomier counter-arguments. Stardust is the name of a small startup with enormous ambitions. The company, which is based in Israel and registered in Delaware, proposes to do nothing less than dim the sun. Its business plan is modelled on volcanoes. In a major eruption, millions of tons of sulfur dioxide get thrown up into the stratosphere.

This drone's wingspan rivals a 737--but it's lighter than a NFL linebacker It could deliver internet to remote areas...or quietly watch us from the stratosphere. Radical's Evenstar solar-powered drone has a 120-foot wing span and weighs just 240 pounds. Breakthroughs, discoveries, and DIY tips sent every weekday. Back in the mid-2010s, some of the world's biggest tech companies were racing to launch lightweight, solar-powered drones to hover above remote areas and beam down internet connectivity. Meta (then called Facebook) and Google, the two companies most heavily investing in the technology at the time, abruptly exited the space following a series of mishaps.

Thinking LLMs solve complex tasks at the expense of increased compute and overthinking on simpler problems, while non-thinking LLMs are faster and cheaper but underthink on harder reasoning problems. This has led to the development of separate thinking and non-thinking LLM variants, leaving the onus of selecting the optimal model for each query on the end user. We introduce OptimalThinkingBench, a unified benchmark that jointly evaluates overthinking and underthinking in LLMs and also encourages the development of optimally-thinking models that balance performance and efficiency. Our benchmark comprises two sub-benchmarks: OverthinkingBench, featuring simple math and general queries in 72 domains, and UnderthinkingBench, containing 11 challenging reasoning tasks along with harder math problems. Using novel thinking-adjusted accuracy metrics, we extensively evaluate 33 different thinking and non-thinking models and show that no model is able to optimally think on our benchmark. Thinking models often overthink for hundreds of tokens on the simplest user queries without improving performance. In contrast, large non-thinking models underthink, often falling short of much smaller thinking models. We further explore several methods to encourage optimal thinking, but find that these approaches often improve on one sub-benchmark at the expense of the other, highlighting the need for better unified and optimal models in the future.

Atmospheric ozone is a crucial absorber of solar radiation and an important greenhouse gas. However, most climate models participating in the Coupled Model Intercomparison Project (CMIP) still lack an interactive representation of ozone due to the high computational costs of atmospheric chemistry schemes. Here, we introduce a machine learning parameterization (mloz) to interactively model daily ozone variability and trends across the troposphere and stratosphere in standard climate sensitivity simulations, including two-way interactions of ozone with the Quasi-Biennial Oscillation. We demonstrate its high fidelity on decadal timescales and its flexible use online across two different climate models -- the UK Earth System Model (UKESM) and the German ICOsahedral Nonhydrostatic (ICON) model. With atmospheric temperature profile information as the only input, mloz produces stable ozone predictions around 31 times faster than the chemistry scheme in UKESM, contributing less than 4 percent of the respective total climate model runtimes. In particular, we also demonstrate its transferability to different climate models without chemistry schemes by transferring the parameterization from UKESM to ICON. This highlights the potential for widespread adoption in CMIP-level climate models that lack interactive chemistry for future climate change assessments, particularly when focusing on climate sensitivity simulations, where ozone trends and variability are known to significantly modulate atmospheric feedback processes.

Global climate models parameterize a range of atmospheric-oceanic processes like gravity waves, clouds, moist convection, and turbulence that cannot be sufficiently resolved. These subgrid-scale closures for unresolved processes are a leading source of model uncertainty. Here, we present a new approach to developing machine learning parameterizations of small-scale climate processes by fine-tuning a pre-trained AI foundation model (FM). FMs are largely unexplored in climate research. A pre-trained encoder-decoder from a 2.3 billion parameter FM (NASA and IBM Research's Prithvi WxC) -- which contains a latent probabilistic representation of atmospheric evolution -- is fine-tuned (or reused) to create a deep learning parameterization for atmospheric gravity waves (GWs). The parameterization captures GW effects for a coarse-resolution climate model by learning the fluxes from an atmospheric reanalysis with 10 times finer resolution. A comparison of monthly averages and instantaneous evolution with a machine learning model baseline (an Attention U-Net) reveals superior predictive performance of the FM parameterization throughout the atmosphere, even in regions excluded from pre-training. This performance boost is quantified using the Hellinger distance, which is 0.11 for the baseline and 0.06 for the fine-tuned model. Our findings emphasize the versatility and reusability of FMs, which could be used to accomplish a range of atmosphere- and climate-related applications, leading the way for the creation of observations-driven and physically accurate parameterizations for more earth-system processes.

It looks like a cross between a toy airplane and a drone, but this British solar-powered aircraft could be the future of aerial surveillance. PHASA-35, built by British company BAE Systems, is a 150kg solar-electric aircraft that can quietly cruise through the stratosphere for months at a time. Named after its 35-metre wingspan, the unmanned aerial vehicle (UAV) travels at a maximum height of 70,000 feet, at a leisurely speed of 55mph. Designed as a cheaper and lighter alternative to satellites, it can be used for Earth observation and surveillance, border control, communications and disaster relief. Now, BAE Systems reveals that PHASA-35 has just completed a second round of test flights into the stratosphere – the second layer of Earth's atmosphere.

However, it is or flows. Where a dataset does not contain both of these also a challenge when trying to compare them and choose the formats, adapting it into the form expected by a given IDS is best one for your needs, because there is no standardisation non-trivial, where the expected format is not the one provided due to the complexity of the environment that these IDSs by the dataset authors. This discrepancy presents challenges were designed for. In order to determine to what degree in obtaining satisfactory results when an IDS and dataset are IDSs can be adapted to different environments, we compare incompatible without significant processing [1]. Our evaluation their performance across common Network Intrusion process was further complicated by the necessity of converting Detection Systems (NIDS) datasets. This approach aims to these datasets into formats compatible with various IDS provide a more standardized basis for comparison, taking into solutions. This data wrangling could amplify the errors and account different variables such as attack types, networking inconsistencies inherent in the datasets.

Solar-powered balloons floating in the stratosphere have recorded low-frequency sounds of mysterious origin. "When we started flying balloons years ago, we didn't really know what we'd hear," says Daniel Bowman at Sandia National Laboratories in New Mexico. "We learned how to identify sounds from explosions, meteor crashes, aircraft, thunderstorms and cities. But virtually every time we send balloons up, we find sounds that we cannot identify." Bowman and his colleagues measured infrasound signals – sounds with a frequency so low they are inaudible to human ears – using solar-powered balloons floating 20 kilometres high.

Taipei, Taiwan – At opposite ends of Southeast Asia, researchers Pornampai Narenpitak and Heri Kuswanto are both working on the same problem: Is it possible to mimic the cooling effects of volcanic eruptions to halt global warming? Using computer modelling and analysis, Narenpitak and Kuswanto are separately studying whether shooting large quantities of sulphur dioxide into the earth's stratosphere could have a similar effect on global temperatures as the eruption of Indonesia's Mount Tambora in 1815. The eruption, the most powerful in recorded history, spewed an estimated 150 cubic kilometres (150,000 gigalitres) of exploded rock and ash into the air, causing global temperatures to fall as much as 3 degrees Celsius (5.4 degrees Fahrenheit) in what became known as the "year without a summer". Stratospheric aerosol injection is among a number of nascent – and controversial – technologies in the field of solar geoengineering (SRM) that have been touted as potential solutions to mitigating the effects of climate change. Other proposed strategies include brightening marine clouds to reflect the sun or breaking up cirrus clouds that capture heat.

Zephyr, a solar-powered unmanned aerial vehicle (UAV) built by Airbus, was used to deliver next generation wireless internet, as part of a test flight over Arizona. Airbus was testing the'High Altitude Platform Station' (HAPS), onboard the British-built UAV, as part of an 18-day flight in the stratosphere, 76,100ft above the surface. The test was in partnership with Japanese mobile operator, NTT DOCOMO, and could one day lead to super-fast broadband in remote areas, without the need to send a fleet of satellites into low Earth orbit, according to Airbus. It carried an onboard radio transmitter that let it provide a datalink to simulate future systems that would send internet signals between the UAV and a computer. The successful test could pave the way for a fleet of Zephyr aircraft delivering 5G and 6G mobile internet to the most remote parts of the planet, or providing a short-term signal boost during a major event in a densely populated area, Airbus says.