Phys.org September 24, 2024 Researchers in Australia used a theoretical model to study water waves propagating into and through a region containing thin floating ice, for ice covers transitioning from consolidated (large floe sizes) to fully broken (small floe sizes). The degree of breaking was simulated by a mean floe length. The model predicted deterministic limits for consolidated and fully broken ice covers where the wave fields do not depend on the realization of the ice cover for a given mean floe length. The consolidated ice limit was consistent with classic flexural-gravity wave theory, and the fully broken limit was […]
Category Archives: Climatology
Extreme weather to strengthen rapidly over next two decades, research suggests
Phys.org September 2024 While the magnitude of changes in mean and extreme climate are broadly studied, regional rates of change, a key driver of climate risk, have received less attention. Using large ensembles of climate model simulations an international team of researchers (Norway, UK) showed that nearly three quarters of the global population can expect strong and rapid changes in extreme temperatures and rainfall in the next 20 years unless greenhouse gas emissions are cut dramatically. Their research showed that 20% of the population could face extreme weather risks if emissions are cut enough to reach the aims of the […]
Earth’s oldest, tiniest creatures are poised to be climate change winners—and the repercussions could be huge
Phys.org August 14, 2024 Heterotrophic Bacteria and Archaea (prokaryotes) are a major component of marine food webs and global biogeochemical cycles. Yet, there is limited understanding about how prokaryotes vary across global environmental gradients, and how their global abundance and metabolic activity (production and respiration) may be affected by climate change. An international team of researchers (Australia, Spain, Austria, the Netherlands, Canada) used global datasets of prokaryotic abundance, cell carbon and metabolic activity to show that mean prokaryotic biomass varies by just under 3-fold across the global surface ocean, while total prokaryotic metabolic activity increases by more than one order […]
First-of-its-kind analysis reveals importance of storms in air–sea carbon exchange in Southern Ocean
Phys.org August 14, 2024 The strength and variability of the Southern Ocean carbon sink is a significant source of uncertainty in the global carbon budget. One barrier to reconciling observations and models is understanding how synoptic weather patterns modulate air-sea carbon exchange. An international team of researchers (USA – Monterey Bay Aquarium Research Institute, NCAR, Pacific Marine Environmental Laboratory, University of Arizona, Canada, South Africa) identified and tracked storms using atmospheric sea level pressure fields from reanalysis data to assess the role that storms play in driving air-sea CO2 exchange. They examined the main drivers of CO2 fluxes under storm […]
New study unveils 16,000 years of climate history in the tropical Andes
Phys.org August 12, 2024 Understanding tropical South America’s climate history can provide valuable insight into the water cycle, ecosystems, and future climate change, yet past temperature changes are not well-known. An international team of researchers (USA – Brown University, Florida Institute of Technology, the Netherlands) reconstructed temperature and rainfall since ~16,800 y ago in the tropical Andes Mountains. In addition to warming driven by rising atmospheric CO2 concentrations, they observed rapid temperature changes linked to changes in the deep ocean circulation. Their findings suggested that Amazonia’s ecosystems may be challenged by rapid temperature changes superposed on warming from sharply increasing […]
Hidden players in climate change: How microscopic proteins could shape our future
Phys.org August, 1, 2024 Extremes in the magnitude and frequency of temperature changes are increasing across the planet, raising questions as to how the biosphere will respond. An international team of researchers (USA – Duke University, University of North Carolina, Germany) examined mechanisms of adaptation to temperature in the fungus Ashbya gossypii. They found that control of the nuclear division cycle and polarized morphogenesis, both critical processes for fungal growth, were temperature sensitive and varied among the isolates. The phenotypes were associated with naturally varying sequences of an RNA-binding protein called Whi3 which regulated both nuclear division and polarized growth. […]
New tipping point discovered beneath the Antarctic ice sheet
Phys.org June 25, 2024 Recently published studies of the complex hydrography of grounding zones suggest that warm ocean water can intrude large distances beneath the ice sheet, with dramatic consequences for ice dynamics. Researchers in the UK developed a model to capture the feedback between intruded ocean water, the melting it induces and the resulting changes in ice geometry showing a sensitive dependence of the grounding-zone dynamics on this feedback: as the grounding zone widens in response to melting, both temperature and flow velocity in the region increase, further enhancing melting. They found that increases in ocean temperature could lead […]
Scientists suggest causes behind one of the most significant climate catastrophes
Phys.org June 17, 2024 Anoxic events are prolonged periods where large expanses of the Earth’s oceans are depleted of dissolved oxygen, which creates toxic waters and leads to mass extinction and habitat loss. The cause of this anoxic event which lasted >500,000 years has been a source of debate among experts. Researchers in the UK used basin sedimentary mercury (Hg) concentrations to determine the timing of volcanism, and neodymium (Nd) and strontium (Sr) isotopes for sedimentary provenance. High Hg concentrations compared to Northern Hemisphere records, and a shift to radiogenic Nd isotopes, indicated Kerguelen LIP volcanic activity and plateau uplift […]
Researcher: Climate models can run for months on supercomputers—but my new algorithm can make them ten times faster
Phys.org May 4, 2024 Marine and terrestrial biogeochemical models are key components of the Earth System Models (ESMs) used to project future environmental changes, but their slow adjustment time also hinders effective use of ESMs because of the enormous computational resources required to integrate them to a pre-industrial equilibrium. Researchers in the UK developed a process based on “sequence acceleration” to accelerate equilibration of state-of-the-art marine biogeochemical models by over an order of magnitude. The technique could be applied in a “black box” fashion to existing models. Even under the challenging spin-up protocols used for Intergovernmental Panel on Climate Change […]
Long-term satellite observations show climatological characteristics of isolated deep convection over the Tibetan Plateau
EurekAlert April 10, 2024 Researchers in China investigated isolated deep convections (IDCs), which have a smaller spatial and temporal size than mesoscale convective systems (MCSs), over the TP in the rainy season during 2001–2020. They showed that IDCs mainly concentrated over the southern Tibetan plateau (TP). The larger IDC had intense precipitation contributing 20 %–30 % to total precipitation, with a larger percentage in July and August than in June and September. IDCs contribute more to both total precipitation and extreme precipitation over the TP compared to the surrounding plain regions. IDCs over the TP account for a larger fraction […]