Events

The resulting atmospheric chemistry of the enhanced soil nitrous acid emissions has aggravated global ozone pollution in the last decades.

Soil microbial nitrous acid (HONO) production is an important source of atmospheric reactive nitrogen that affects air quality and climate. In this work, we propose that climate change (through changing soil temperature and soil water content) and the increased fertilizer use have enhanced soil HONO emissions since the 1980s. Model simulations suggest that the resulting atmospheric chemistry of increased soil HONO emissions has contributed to aggravate tropospheric ozone pollution at a global scale, although with marked regional differences.

From these results, we suggest the need for more efficient use of fertilizers in agriculture and recommend consideration of soil HONO emissions in strategies for mitigating global…

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The study quantifies for the first time the global emission of methanethiol, a sulfur gas produced by marine life, and its contribution to the formation of airborne particles and clouds with cooling effects on the climate.

Almost 40 years ago, one of the most ground-breaking hypotheses about the role of the ocean in regulating the Earth's climate was put forward. The hypothesis proposed that microscopic plankton living on the surface of the seas produce sulphur in the form of a gas which, once in the atmosphere, is oxidised and forms tiny particles called aerosols. Aerosols reflect part of the solar radiation back into space and therefore reduce the heat retained by the Earth, with an effect opposite to that of the well-known greenhouse gases. The cooling effect of aerosols is amplified because these particles are essential for the condensation of water…

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Using multi-configurational quantum chemistry, a mercury photoreduction mechanism is proposed to explain the measurements of mercury re-emission from ice to the atmosphere, which have been poorly understood for decades.

An international research team co-led by the IQF-CSIC and the University of Valencia has discovered the mechanism by which almost all mercury deposited in polar ice returns to the atmosphere with the arrival of spring in the Arctic. The discovery, achieved using computational chemistry techniques and published in the journal ‘PNAS’, provides new information for understanding the biogeochemical cycle of mercury, a global pollutant and a toxic element for the nervous system of living beings.

The collaborative team has been trying for years to understand the mercury cycle in the atmosphere, adding to atmospheric and climatic representations…

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During polar front intrusion episodes, air masses from the Arctic not only reduce the temperature but also the ozone concentration in the mid-latitudes.

We find that the inclusion of polar halogens (chlorine, bromine, iodine) in our climate model is necessary to reproduce ozone levels and seasonality in the Arctic, particularly in spring. When cold Arctic air masses descend to mid-latitudes, they are halogen-enriched and ozone-depleted. In addition, halogen-mediated catalytic ozone-destroying reactions continue to operate within the cold air mass during southward transport. This phenomenon causes significant reductions in background ozone over large regions of Canada, the United States, and Europe.

These results have been published in the journal PNAS:

Rafael P. Fernandez, Lucas Berná, Orlando Tomazzeli, Anoop Sharad Mahajan, Qinyi Li, Douglas E. Kinnison,…

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The study indicates that a significant portion of the mercury entering terrestrial ecosystems is chemically activated and transported globally in the stratosphere.

So far, both the chemical reactivity and the global transport of mercury have been considered to occur in the troposphere, the lower layer of the atmosphere in contact with the surface. However, this work shows that this is not the case, revealing that nearly a third of the mercury that enters the terrestrial ecosystem has reacted in the stratosphere (from 12 to 40 km high), due to the unique characteristics of the stratospheric photochemical environment that accelerate the oxidation processes of mercury, leading to the formation of a ring of oxidized mercury that would surround the planet.

In addition, the study shows for the first time that the circulation of air in this layer of the atmosphere…

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This work shows the potential of iodine to increase the sulphuric acid- and dimethylamine-driven nucleation rates through coupled chemical cycles.

Iodic acid is a well-known driver for marine new particle formation (NPF), showing high efficiency in nucleation. Despite its recent detection over land and rapid global increase, its role in continental NPF and the resulting current and future atmospheric impacts remain unknown. Here, we present molecular-level evidence that iodic acid can substantially facilitate particle formation (1.5 to 50 times by 2060) by its synergistic nucleation with the typical land-based pollutants, sulfuric acid and amine, thus effectively capturing the observed inland NPF events in China. These findings highlight the significance of considering iodine-involved nucleation in accurately modelling continental particle formation and the…

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