Phys.org: Earth science

A research team at The Hong Kong University of Science and Technology (HKUST) has analyzed 40 years of data covering about 1,500 tropical cyclones and discovered that average rain rates surge by more than 20% in the 60 hours before landfall. The study is also the first to clearly identify the physical mechanisms behind this increase, showing that rising humidity over coastal areas and enhanced land-sea frictional contrasts strengthen convection, intensifying rainfall ahead of landfall. The results provide valuable insights for improving coastal disaster preparedness and early-warning systems.

Particles in the atmosphere, known as aerosols, cool the climate by acting as cloud condensation nuclei. The more cloud droplets form around these particles, the less sunlight penetrates a cloud. This cools the climate, although this process is outweighed by the much stronger greenhouse effect.

A leading climate scientist has sought to set the record straight over "demonstrably incorrect" claims made in a major U.S. government report that misrepresented his work and downplayed the role of human activity in global warming.

Wildfires in the northern boreal forests of Alaska, Canada, Scandinavia, and Russia may be more damaging to the climate than previously thought, a new UC Berkeley-led study suggests. That's because these fires don't just burn through trees; they can also penetrate deep into the carbon-rich layers of soil underneath many boreal forests, releasing carbon that has been accumulating for hundreds or even thousands of years.

The Cascadia Subduction Zone is unusually quiet for a megathrust fault. Spanning more than 600 miles from Canada to California, the fault marks the convergence of the Juan de Fuca and North American plates. While other subduction zones produce sporadic rumblings as the plates scrape past each other, Cascadia shows very little seismic activity, fueling assumptions that the plates are locked together by friction.

Changes in rainfall within global monsoon regions affect the livelihoods of billions. For years, climate models have suggested that the fingerprint of human-caused climate change on monsoons would become visible by a certain time. But what if that timeline is wrong? A new study published in Advances in Atmospheric Sciences suggests the signal may not emerge until a full decade later than previously estimated.

The South China Sea Throughflow (SCSTF) serves as a critical oceanic conveyor belt for heat and freshwater, mediating water exchanges between the South China Sea (SCS) and the Pacific and Indian oceans while regulating key processes such as heat and salt budgets, eddy activities, and marine biogeochemical cycles. It also plays a pivotal role in modulating the Indonesian Throughflow (ITF) and shaping climate variability across the Indo-Pacific. However, long-term direct observational data of the SCSTF have long been scarce, leaving its long-term changes under climate change and associated driving mechanisms poorly understood.

A research team led by University of Tsukuba has developed a new method to estimate long-term debris supply from steep slopes by measuring debris accumulated on decades-old abandoned roads. Debris supplied by rockfall and related slope processes is a key factor controlling the frequency and magnitude of debris flows. However, estimating the amount of debris supplied over several decades has been technically challenging.

Japan is an archipelago with diverse climate zones and complex topography that is prone to heavy rain and flooding. Add the growing effects of global warming. These disaster risks are heightened with an increased frequency and intensity of extreme precipitation events. Thus, predicting when and where these events might strike is crucial for future-proofing vulnerable infrastructure, especially in rural areas.

Cities are rapidly becoming the defining residential space of human life. Over 55% of the global population lived in urban areas in 2018, a proportion projected to reach nearly 68% by 2050, according to the United Nations (UN).

Greenland's largest glacier, Jakobshavn Glacier, may be edging closer to a critical threshold as meltwater runoff from the Greenland Ice Sheet accelerates in ways not seen in over a century, according to new research published in Climate of the Past. The study reconstructs more than 100 years of freshwater discharge flowing from the ice sheet into Disko Bay in western Greenland, revealing a striking and sustained change that began in the early 2000s.

Sea level can temporarily change for a variety of reasons—atmospheric pressure shifts and water accumulation from wind and storms, for example—which can cause flooding in coastal communities and affect maritime industry operations. The key to mitigating the effects of short-term sea level variation is accurate prediction that provides ample warning time to affected areas.

Cyanobacteria, as they still exist today, were the first organisms to carry out photosynthesis and release oxygen. Produced in primeval oceans about 2.5 billion years ago, this oxygen accumulated in Earth's atmosphere on an immense scale. A research team led by University of Tübingen geomicrobiologist Professor Andreas Kappler has used laboratory experiments to investigate how this process was even possible, given that the iron dissolved in ocean water strongly inhibited the growth of cyanobacteria.

For scientists who study the Southern Ocean, a long-standing silver lining in the gloomy forecast of climate change has been the theory of iron fertilization. As temperatures rise and glaciers in Antarctica melt, ice-trapped iron would feed blooms of microscopic algae, pulling heat-trapping carbon dioxide from the atmosphere as they grow. There's just one problem: The theory doesn't hold water.

We know Aotearoa New Zealand is home to many geographically and biologically special features. Yet few of us know it also has its very own measure of "deep time." Known as the New Zealand Geological Timescale, it has just undergone its most comprehensive revision in 20 years.

Climate change is having a profound impact on the Arctic. We know that the region is warming significantly faster than the global average, resulting in the melting of sea ice and disrupted habitats.

Eastern Canada has seen a rise in the number of hurricane- and near-hurricane strength events battering its maritime areas, with particularly violent storms in 2003 (Hurricane Juan), 2019 (Dorian) and 2022 (Fiona). While this seems to be a recent phenomenon, the region has experienced this kind of surge in activity before, according to a new Concordia University study.

Beaver dams are critical to river health and a source of biodiversity. They create wetlands, slow water and improve water quality. They also reduce flood peaks and delay runoff. But beaver dams are often blamed when extreme rainstorms cause flooding—especially when they fail.

A new study has identified a distinct climate precursor in the Mediterranean Sea that can predict winter precipitation levels in the Levant months in advance. The study, published in Weather and Climate Dynamics, is titled "Mediterranean Sea heat uptake variability as a precursor to winter precipitation in the Levant."

Hike north on the Appalachian Trail and the scenery slowly transforms. Rugged, steep ridgelines in Tennessee and Virginia soften into the broad summits and smooth peaks of Pennsylvania and New Jersey. According to new research from William & Mary Assistant Professor of Geology Joanmarie Del Vecchio, this contrast speaks to an ancient past.