Better measurements reveal seasonal changes in sulfur

October 07, 2005

Researchers from the University of Maryland (UMD) and the National Institute of Standards and Technology (NIST) have developed a new and improved technique for the simultaneous measurement of sulfur isotopic ratios and concentrations of atmospheric sulfate using snow samples from Greenland and Kyrgyzstan.

Sulfur plays an important role in the Earth's climate. Sulfate particles in the atmosphere scatter and absorb sunlight, provide "seeds" for cloud formation, and affect the reflectivity and radiance of clouds, and thus the temperatures at the Earth's surface. Atmospheric sulfate comes from natural sources, including oceans and volcanoes, but a large fraction comes from the burning of fossil fuels. Researchers can distinguish between various natural and anthropogenic sources in snow by measuring sulfur isotopes--forms of the element with different numbers of neutrons.

To study how these particulates have changed over time, scientists dig holes in snow that provide an archive of atmospheric particles deposited on the Earth's surface. The standard analysis technique, gas-source isotope ratio mass spectroscopy (GIRMS), requires relatively large samples--up to four kilograms (about 9 pounds) of snow and ice, but the cycling of sulfur in the atmosphere is dynamic and variable, so samples this large blur seasonal changes.

To solve this problem, the UMD/NIST team developed a new analytical tool based on thermal ionization mass spectrometry (TIMS), which requires much smaller samples. The researchers used an advanced calibration technique known as double isotopic spiking to correct measurement drift and obtain isotope ratio measurements comparable to or better than GIRMS. The smaller snow samples required for TIMS make it possible to distinguish seasonal changes in sulfur particulate composition. The technique also can be used for making highly precise and accurate measurements of sulfur in low-sulfur fossil fuels, and similar applications.
-end-
The new technique was presented in a poster* at the 230th National Meeting of the American Chemical Society (2005). A description of the technique has been accepted for publication in Rapid Communications in Mass Spectrometry.

* J. Mann and W.R. Kelly. Measurement of sulfur isotopic signatures in two high elevation snow pits. American Chemical Society Annual Meeting (2005).

National Institute of Standards and Technology (NIST)

Related Atmosphere Articles from Brightsurf:

ALMA shows volcanic impact on Io's atmosphere
New radio images from ALMA show for the first time the direct effect of volcanic activity on the atmosphere of Jupiter's moon Io.

New study detects ringing of the global atmosphere
A ringing bell vibrates simultaneously at a low-pitched fundamental tone and at many higher-pitched overtones, producing a pleasant musical sound. A recent study, just published in the Journal of the Atmospheric Sciences by scientists at Kyoto University and the University of Hawai'i at Mānoa, shows that the Earth's entire atmosphere vibrates in an analogous manner, in a striking confirmation of theories developed by physicists over the last two centuries.

Estuaries are warming at twice the rate of oceans and atmosphere
A 12-year study of 166 estuaries in south-east Australia shows that the waters of lakes, creeks, rivers and lagoons increased 2.16 degrees in temperature and increased acidity.

What makes Saturn's atmosphere so hot
New analysis of data from NASA's Cassini spacecraft found that electric currents, triggered by interactions between solar winds and charged particles from Saturn's moons, spark the auroras and heat the planet's upper atmosphere.

Galactic cosmic rays affect Titan's atmosphere
Planetary scientists using the Atacama Large Millimeter/submillimeter Array (ALMA) revealed the secrets of the atmosphere of Titan, the largest moon of Saturn.

Physics: An ultrafast glimpse of the photochemistry of the atmosphere
Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.

Using lasers to visualize molecular mysteries in our atmosphere
Molecular interactions between gases and liquids underpin much of our lives, but difficulties in measuring gas-liquid collisions have so far prevented the fundamental exploration of these processes.

The atmosphere of a new ultra hot Jupiter is analyzed
The combination of observations made with the CARMENES spectrograph on the 3.5m telescope at Calar Alto Observatory (Almería), and the HARPS-N spectrograph on the National Galileo Telescope (TNG) at the Roque de los Muchachos Observatory (Garafía, La Palma) has enabled a team from the Instituto de Astrofísica de Canarias (IAC) and from the University of La Laguna (ULL) to reveal new details about this extrasolar planet, which has a surface temperature of around 2000 K.

An exoplanet loses its atmosphere in the form of a tail
A new study, led by scientists from the Instituto de Astrofísica de Canarias (IAC), reveals that the giant exoplanet WASP-69b carries a comet-like tail made up of helium particles escaping from its gravitational field propelled by the ultraviolet radiation of its star.

Iron and titanium in the atmosphere of an exoplanet
Exoplanets can orbit close to their host star. When the host star is much hotter than our sun, then the exoplanet becomes as hot as a star.

Read More: Atmosphere News and Atmosphere Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.