A new study in Proceedings of the National Academy of Sciences (PNAS) reveals that the aerobic nitrogen cycle in the ocean may have occurred about 100 million years before oxygen began to significantly accumulate in the atmosphere, based on nitrogen isotope analysis from ancient South African rock cores.

These findings not only refine the timeline of Earth’s oxygenation but also highlight a critical evolutionary shift, where life began adapting to oxygen-rich conditions—paving the way for the emergence of complex, multicellular organisms like humans.

Earthquakes create ripple effects in Earth's upper atmosphere that can disrupt satellite communications and navigation systems we rely on. Nagoya University scientists and their collaborators have used Japan's extensive network of Global Navigation Satellite System (GNSS) receivers to create the first 3D images of atmospheric disturbances caused by the 2024 Noto Peninsula Earthquake. Their results show sound wave disturbance patterns in unique 3D detail and provide new insights into how earthquakes generate these waves. The results were published in the journal Earth, Planets and Space.

The Satellite Observation Center of the Earth System Division of the National Institute for Environmental Studies (NIES) has been publicly providing global concentrations of greenhouse gases (such as carbon dioxide and methane) and an air pollutant (carbon monoxide) obtained from the Greenhouse Gases Observing Satellite-2 "Ibuki-2" (GOSAT-2, launched in October 2018).

In this study, a research team consisting of Dr. Hirofumi Ohyama (Senior Researcher), Dr. Yukio Yoshida (Senior Researcher), and Dr. Tsuneo Matsunaga (Director of the Satellite Observation Center) of the Earth System Division of the NIES developed a method to calculate the enhancement ratios among carbon dioxide, methane, and carbon monoxide concentrations in megacities, using data from GOSAT-2, the only satellite observing all three gases simultaneously. Furthermore, the team evaluated the accuracy of emission databases and estimated the methane and carbon monoxide emissions for approximately 40 cities around the world by using the calculated four-year average enhancement ratios. The results demonstrated that we could independently evaluate the values in emission databases for megacities using data from satellite observations without relying on complicated calculations of atmospheric transport. With continued observations, we anticipate that annual changes of emissions for certain cities can be captured from satellites. Furthermore, the GOSAT-GW satellite, scheduled for launch in FY2025, will be capable of observing carbon dioxide and methane at a greater number of observation points than GOSAT-2 and will also observe atmospheric concentrations of nitrogen dioxide, most of which is distributed around emission sources. These enhancements are expected to further improve the accuracy of emission estimates. The results of this study were published on 5 November 2024 in Environmental Research Letters, an academic journal in the environmental field.

The El Niño-Southern Oscillation (ENSO) cycle moves between warmer-than-average Pacific Ocean surface water temperatures during El Niño phases to colder-than-average surface water temperatures during La Niña phases. Scientists have observed that the surface temperatures of water in the central and eastern Pacific affect the number and strength of tropical cyclones (TCs) that develop in the North Atlantic Ocean and the probability those TCs will make landfall. Researchers recently investigated the effects of El Niño and La Niña dissipation events on and factors that contribute to TC development in the North Atlantic Ocean.

Experimental studies under atmospheric conditions show two important reaction pathways in the hydroxyl radical-initiated degradation of isoprene, which form highly oxidised peroxy radicals with 8 or 9 oxygen atoms and may be of global importance for the production of organic aerosols.

Highly sensitive detection methods allow ever deeper insights into complex chemical processes in the atmosphere: Researchers at the Leibniz Institute for Tropospheric Research (TROPOS) in Leipzig found a series of new product channels in a detailed product study on the oxidative degradation of isoprene in the gas phase, which allows a better mechanistic understanding of this important process for atmospheric chemistry. The results were published in the journal Nature Communications.

Temperatures around the world continue to rise – and the North Sea is no exception. Yet, in addition to this gradual warming, increasingly frequent and intense heat events also have consequences for marine organisms. Researchers at the Marine Station Helgoland, a research facility of the Alfred Wegener Institute, have quantified the frequency and intensity of these heatwaves along with their repercussions for plankton. They have also conducted an experiment that exposed the North Sea plankton community to different future warmer scenarios, both with and without heatwaves. The researchers found that gradual warming causes significant shifts in the species spectrum. When heatwaves are added, however, these alterations are amplified. The results have been published in three publications, most recently in Limnology and Oceanography.