SEGH Articles

SEGH Member participated in the Antarctic Circumpolar Expedition

02 July 2017
Francois De Vleeschouwer, researcher at EcoLab, (CNRS, Toulouse France) and SEGH secretary, had the opportunity to embark onboard the RV Akademik Treshnikov to participate in the ACE Expedition


François De Vleeschouwer, researcher at EcoLab, (CNRS, Toulouse France) and SEGH secretary, had the opportunity to embark onboard the RV Akademik Treshnikov to participate in the ACE Expedition. From December 2016 to March 2017, scientific teams from all over the world joined into an unprecedented expedition around Antarctica. From biology to climatology to oceanography, researchers from 22 selected projects worked on a number of interrelated fields revolving around Antarctica.

 

François De Vleeschouwer is involved in a British Antarctic Survey-supervised project dealing with « Measuring the changes in the ocean’s capacity to absorb CO2 ». Concentrations of CO2 in the atmosphere have increased since 1750 AD as a result of human activity. This is linked to warming of the atmosphere and oceans, changes in climate, recession of ice sheets and sea level rise. More than one quarter of this CO2 is absorbed by the oceans; the Southern Ocean accounting for 43%. The capacity of the Southern Ocean to absorb CO2 has recently been limited (according to some models) by an increase in the strength of the Southern Hemisphere Westerly Winds (SHW), which draw CO2 saturated waters back to the surface. This will potentially drive up atmospheric greenhouse gases and accelerate rates of global warming.Reconstructing past changes in the SHW and their impact on the oceanic CO2 sink is therefore a major priority for palaeoclimate science.

 

François De Vleeschouwer participated to the leg 2 of the ACE navigation from Hobart, Tasmania to Punta Arenas, Chile. After an unfortunate storm that obliged the expedition to cancel the sampling at Macquarie Island, the boat navigated throuhgh Antarctic waters to then cross the Drake’s Passage. F. De Vleeschouwer sampled soils, mosses and peatlands on various islands from the Antarctic (Scott, Maher, Lauft, Siple) and sub-Antarctic (Diego Ramirez Archipelago).

 

The main objective of this project is to determine the Holocene (last 12000 yrs) changes in the strength of the SHW over the Southern Ocean by generating records of wind-driven aerosols and other proxies in sediment records from lakes and bogs on the west coasts of sub-Antarctic islands and, These data will be further used in global climate models to test if past changes in the SHW explain past variations in atmospheric CO2.

Further information can be found on : http://spi-ace-expedition.ch/

 

Francois de Vleeschouwer, CNRS, Toulouse, France

Keep up to date

SEGH Events

Submit Content

Members can keep in touch with their colleagues through short news and events articles of interest to the SEGH community.

Science in the News

Latest on-line papers from the SEGH journal: Environmental Geochemistry and Health

  • Characteristics of PM 2.5 , CO 2 and particle-number concentration in mass transit railway carriages in Hong Kong 2017-08-01

    Abstract

    Fine particulate matter (PM2.5) levels, carbon dioxide (CO2) levels and particle-number concentrations (PNC) were monitored in train carriages on seven routes of the mass transit railway in Hong Kong between March and May 2014, using real-time monitoring instruments. The 8-h average PM2.5 levels in carriages on the seven routes ranged from 24.1 to 49.8 µg/m3, higher than levels in Finland and similar to those in New York, and in most cases exceeding the standard set by the World Health Organisation (25 µg/m3). The CO2 concentration ranged from 714 to 1801 ppm on four of the routes, generally exceeding indoor air quality guidelines (1000 ppm over 8 h) and reaching levels as high as those in Beijing. PNC ranged from 1506 to 11,570 particles/cm3, lower than readings in Sydney and higher than readings in Taipei. Correlation analysis indicated that the number of passengers in a given carriage did not affect the PM2.5 concentration or PNC in the carriage. However, a significant positive correlation (p < 0.001, R 2 = 0.834) was observed between passenger numbers and CO2 levels, with each passenger contributing approximately 7.7–9.8 ppm of CO2. The real-time measurements of PM2.5 and PNC varied considerably, rising when carriage doors opened on arrival at a station and when passengers inside the carriage were more active. This suggests that air pollutants outside the train and passenger movements may contribute to PM2.5 levels and PNC. Assessment of the risk associated with PM2.5 exposure revealed that children are most severely affected by PM2.5 pollution, followed in order by juveniles, adults and the elderly. In addition, females were found to be more vulnerable to PM2.5 pollution than males (p < 0.001), and different subway lines were associated with different levels of risk.

  • Comparison of chemical compositions in air particulate matter during summer and winter in Beijing, China 2017-08-01

    Abstract

    The development of industry in Beijing, the capital of China, particularly in last decades, has caused severe environmental pollution including particulate matter (PM), dust–haze, and photochemical smog, which has already caused considerable harm to local ecological environment. Thus, in this study, air particle samples were continuously collected in August and December, 2014. And elements (Si, Al, V, Cr, Mn, Fe, Ni, Cu, Zn, Mo, Cd, Ba, Pb and Ti) and ions ( \({\text{NO}}_{3}^{-}\) , \({\text{SO}}_{4}^{2-}\) , F, Cl, Na+, K+, Mg2+, Ca2+ and \({\text{NH}}_{4}^{+}\) ) were analyzed by inductively coupled plasma mass spectrometer and ion chromatography. According to seasonal changes, discuss the various pollution situations in order to find possible particulate matter sources and then propose appropriate control strategies to local government. The results indicated serious PM and metallic pollution in some sampling days, especially in December. Chemical Mass Balance model revealed central heating activities, road dust and vehicles contribute as main sources, account for 5.84–32.05 % differently to the summer and winter air pollution in 2014.

  • Annual ambient atmospheric mercury speciation measurement from Longjing, a rural site in Taiwan 2017-08-01

    Abstract

    The main purpose of this study was to monitor ambient air particulates and mercury species [RGM, Hg(p), GEM and total mercury] concentrations and dry depositions over rural area at Longjing in central Taiwan during October 2014 to September 2015. In addition, passive air sampler and knife-edge surrogate surface samplers were used to collect the ambient air mercury species concentrations and dry depositions, respectively, in this study. Moreover, direct mercury analyzer was directly used to detect the mercury Hg(p) and RGM concentrations. The result indicated that: (1) The average highest RGM, Hg(p), GEM and total mercury concentrations, and dry depositions were observed in January, prevailing dust storm occurred in winter season was the possible major reason responsible for the above findings. (2) The highest average RGM, Hg(p), GEM and total mercury concentrations, dry depositions and velocities were occurred in winter. This is because that China is the largest atmospheric mercury (Hg) emitter in the world. Its Hg emissions and environmental impacts need to be evaluated. (3) The results indicated that the total mercury ratios of Kaohsiung to that of this study were 5.61. This is because that Kaohsiung has the largest industry density (~60 %) in Taiwan. (4) the USA showed average lower mercury species concentrations when compared to those of the other world countries. The average ratios of China/USA values were 89, 76 and 160 for total mercury, RGM and Hg(p), respectively, during the years of 2000–2012.