Taxonomy term

atmospheric chemistry

Reconstructing ancient oxidant levels and their climatic effects

Oxidants in the troposphere, such as ozone and hydroxyl radicals, influence the life spans of other atmospheric components, including pollutants and greenhouse gases like carbon monoxide and methane. But how the abundance of tropospheric oxidants varies as climate changes is poorly understood. Part of the challenge is that these oxidants are too reactive to be preserved in paleo-records, such as ice cores.

29 Aug 2017

"Blob"-related warming contributed to Pacific Northwest ozone spike

In June 2015, instruments on Oregon’s Mount Bachelor recorded mean ozone for the month at 56 parts per billion, more than 20 percent higher than the average level for the 11 years prior. Other stations around the West noted similarly high readings, puzzling scientists over the cause of the rise. In a new study in Geophysical Research Letters, researchers describe a confluence of meteorological conditions that appear to have driven the phenomenon.

18 May 2017

Fossil fuels diluting atmospheric radiocarbon

Radioactive carbon-14, or radiocarbon, is used to date fossils and artifacts and study ecosystems, as well as to solve crimes and run medical tests. But these applications could be in jeopardy, according to new research illustrating how atmospheric radiocarbon will be diluted by fossil fuel emissions in the coming century.  
 
05 Nov 2015

Hydrogen chloride on the rise in Northern Hemisphere skies

Levels of the atmospheric pollutant hydrogen chloride have increased substantially in the lower stratosphere over the Northern Hemisphere since 2007, according to a new study. The increase, however, is not due to an influx of chlorine, but rather to a side effect of the recent slowing of stratospheric circulation that was first reported in 2005.
 
02 Jul 2015

Thank subduction for Earth's nitrogen-rich air

Plate tectonics underlies many of Earth’s distinctive features, from its ever-shifting continents to its colliding mountain ranges and continuously forming crust at mid-ocean ridges. According to a new study, the process might also explain another of our planet’s peculiarities: its nitrogen-rich atmosphere.

 
08 Mar 2015

Carbon tet still offensive to ozone layer

Earth’s ultraviolet light-shielding ozone layer is recovering, according to a report released in September by the World Meteorological Organization and the United Nations Environment Programme. The findings, authored by more than 250 scientists and presented as part of the latest Scientific Assessment of Ozone Depletion (SAOD), suggest the ongoing success of the 1987 Montreal Protocol and its amendments in cutting atmospheric levels of chlorofluorocarbons (CFCs) and other ozone-depleting substances (ODS’s), which have fallen by about 10 to 15 percent overall since peaking in the late 1990s.

22 Dec 2014

Link between volcanoes and drought cools geoengineering prospects

The realization that large volcanic eruptions can trigger climatic cooling has inspired some to call for stratospheric geoengineering projects, which mimic volcanic eruptions, to combat the effects of global warming. But the approach is not without risks. And a new study looking at the effects of volcanic eruptions on monsoon cycles in China over the past 700 years elucidates one: Eruptions can also cause profound drought in some regions. The finding suggests that although artificially induced cooling may have benefits in some places, it could backfire in others.

14 Dec 2014

Sudden gas eruption shakes the ground near Rome's airport

On Aug. 24, 2013, visitors arriving at Rome’s Leonardo da Vinci International Airport, located in the Fiumicino municipality, flew over a surprising hazard: a gas emission that suddenly exploded from the ground a few meters outside the airport compound. The expulsion, referred to as the Fiumicino Gas Vent (FGV), occurred about 15 kilometers southwest of Rome and was first noticed by passing motorists. Shortly after the explosion, scientists sought  to determine the gas’ makeup and whether it posed a continuing danger.

03 Mar 2014

Lofted by hurricanes, bacteria live the high life

With cold temperatures, low humidity and high levels of ultraviolet (UV) radiation, conditions 10 kilometers above Earth’s surface may seem inhospitable. But next time you’re flying, consider this: The air outside your airplane window might be filled with an array of microscopic life that affects everything from weather and climate to the distribution of pathogens around the planet.

05 May 2013

AGU: Colorado ski industry owes Great Salt Lake thank you note

SAN FRANCISCO — Colorado skiers have long suspected that snowfall is fluffiest when winds blow salt and dust eastward from the Great Salt Lake in Utah. Now that wisdom is confirmed by science.

After measuring cloud particles from plane flights over Colorado, atmospheric chemist Kim Prather of Scripps Institution of Oceanography in La Jolla and colleagues determined that nascent snow largely formed as a result of suspended Utah salt.

In order for snow and rain droplets to form, water needs a particle base on which to accumulate. This process is called nucleation.

20 Dec 2008