Comparative trends and seasonal variation of 7Be, 210Pb and 137Cs at two altitude sites in the central part of France

Bourcier, L.; Masson, Olivier; Laj, Paolo; Pichon, J. M.; Paulat, P.; Freney, Evelyn; Sellegri, Karine

doi:10.1016/j.jenvrad.2010.12.005

Cited by 53 publications

(18 citation statements)

References 64 publications

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“…Hence, we also test the hypothesis of a constant aerosol profile within the ML. Moreover, other bias between the two measurements may be due to the fact that on some occasions such as during dust episodes, high concentrations of aerosols are preferentially transported at high altitudes, as evidenced in Bourcier et al (2011). In some cases, dust or sea salt aerosols may be transported above the PUY station and hence captured by the sun photometer but not detected by the PUY in situ instrumentation.…”

Section: Cloud-free Conditionsmentioning

confidence: 99%

Comparison of the aerosol optical properties and size distribution retrieved by sun photometer with in situ measurements at midlatitude

Chauvigné¹,

Sellegri²,

Hervo

et al. 2016

Atmos. Meas. Tech.

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Abstract. Aerosols influence the Earth radiative budget through scattering and absorption of solar radiation. Several methods are used to investigate aerosol properties and thus quantify their direct and indirect impacts on climate. At the Puy de Dôme station, continuous high-altitude near-surface in situ measurements and low-altitude ground-based remote sensing atmospheric column measurements give the opportunity to compare the aerosol extinction measured with both methods over a 1-year period. To our knowledge, it is the first time that such a comparison is realised with continuous measurements of a high-altitude site during a long-term period. This comparison addresses to which extent near-surface in situ measurements are representative of the whole atmospheric column, the aerosol mixing layer (ML) or the free troposphere (FT). In particular, the impact of multi-aerosol layers events detected using lidar backscatter profiles is analysed. A good correlation between in situ aerosol extinction coefficient and aerosol optical depth (AOD) measured by the Aerosol Robotic Network (AERONET) sun photometer is observed with a correlation coefficient around 0.80, indicating that the in situ measurements station is representative of the overall atmospheric column. After filtering for multilayer cases and correcting for each layer optical contribution (ML and FT), the atmospheric structure seems to be the main factor influencing the comparison between the two measurement techniques. When the site lies in the ML, the in situ extinction represents 45 % of the sun photometer ML extinction while when the site lies within the FT, the in situ extinction is more than 2 times higher than the FT sun photometer extinction. Moreover, the assumption of a decreasing linear vertical aerosol profile in the whole atmosphere has been tested, significantly improving the instrumental agreement. Remote sensing retrievals of the aerosol particle size distributions (PSDs) from the sun photometer observations are then compared to the near-surface in situ measurements, at dry and at ambient relative humidities. When in situ measurements are considered at dry state, the in situ fine mode diameters are 44 % higher than the sun-photometer-retrieved diameters and in situ volume concentrations are 20 % lower than those of the sun-photometer-retrieved fine mode concentration. Using a parameterised hygroscopic growth factor applied to aerosol diameters, the difference between in situ and retrieved diameters grows larger. Coarse mode in situ diameters and concentrations show a good correlation with retrieved PSDs from remote sensing.

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Section: Cloud-free Conditionsmentioning

confidence: 99%

Comparison of the aerosol optical properties and size distribution retrieved by sun photometer with in situ measurements at midlatitude

Chauvigné¹,

Sellegri²,

Hervo

et al. 2016

Atmos. Meas. Tech.

View full text Add to dashboard Cite

show abstract

“…The 137 Cs is presently found mainly in soils and vegetation, and it can get back into the atmosphere by soil resuspension (Pham et al, 2011;Povinec et al, 2012a;Sýkora et al, 2012) and by biomass burning (Bourcier et al, 2010;Hirose and Povinec, 2015). Seasonal variations of the 137 Cs concentration in the atmosphere, associated with local meteorological conditions (like winds, air temperature, pressure and precipitations) were observed in post-Chernobyl period by several authors (Rosner et al, 1996;Lee et al, 2002;Pham et al, 2011;Bourcier et al, 2011;Povinec et al, 2012a). In the ground-level air, the size distribution of 137 Cs carrying aerosols from the post-Chernobyl period was found to be 0.3e1.4 mm (Lujanien e et al, 1997).…”

Section: Introductionmentioning

confidence: 98%

Long-term variations of radionuclides in the Bratislava air

Sýkora

Holý

Ješkovský

et al. 2017

Journal of Environmental Radioactivity

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“…with k a being the reload rate, t representing time (days) between the last rainfall event and sampling date, and r max being a maximum dry deposition rate, which is a step function that reflects seasonal variability in the density of aerosol particles, as shown by satellite aerosol optical depth from the wet winter season to the dry summer season (NASA, 2014), and the reported 7 Be concentration in marine air masses (Bourcier et al, 2011;Al-Azmi et al, 2001). We use an r max of 50 dpm m −2 d −1 in January and February, 100 dpm m −2 d −1 in March, April, and early May, 120 dpm m −2 d −1 in late May and June (the maximum value being half of the atmospheric production rate of 240 dpm m −2 d −1 ; Nagai et al, 2000).…”

Section: Atmospheric 7 Be Inputmentioning

confidence: 99%

A dual-tracer approach to estimate upwelling velocity in coastal Southern California

Haskell

Hammond

Prokopenko

2015

Earth and Planetary Science Letters

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Comparative trends and seasonal variation of 7Be, 210Pb and 137Cs at two altitude sites in the central part of France

Cited by 53 publications

References 64 publications

Comparison of the aerosol optical properties and size distribution retrieved by sun photometer with in situ measurements at midlatitude

Comparison of the aerosol optical properties and size distribution retrieved by sun photometer with in situ measurements at midlatitude

Long-term variations of radionuclides in the Bratislava air

A dual-tracer approach to estimate upwelling velocity in coastal Southern California

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