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Research | Polar research | Antarctic research - Aerosols
Antarctic aerosols
In this project the physical and chemical properties and processes and transport of Antarctic tropospheric aerosols are studied. Most of the measurements are conducted in the aerosol research laboratory at the Finnish Antarctic Station Aboa (73°03'S, 13°25'W). Measurements have been conducted during FINNARP-1997, -1999, -2000, and -2003 campaigns. Published results from the campaigns are listed in the references.
Laboratory
A special laboratory container has been installed at Aboa for atmospheric measurements. The laboratory has sampling inlet lines for several instruments and facilities for a clean handling of filters. It was designed by FMI aerosol research group and built by Thermisol Finland in spring 1999.
Instruments
Aerosol physical characterisation, during summer campaigns
Differential mobility particle sizer (DMPS) and aerodynamic particle sizer (APS) for measuring particle number size distributions, 3-wavelength nephelometer (TSI Model 3563) for measuring light scattering coefficient, condensation particle counters, sunphotometer (Microtops II Solar Light Co. Inc, 380, 440, 500, 675, and 800 nm) for measuring aerosol optical depth, aethalometer (Magee Scientific) for measuring light absorption coefficient
Aerosol chemical composition, during summer campaigns
2-stage virtual impactor (sub- and supermicron particles), 12-stage low-pressure impactor, high volume sampler. The samples are analyzed for inorganic and organic ions, elementary and organic carbon, Pb-210, and selectively for trace elements.
Weather station, permanent
A new automatic weather station (Antarktis Aboa, lpnn 9950, wmo 89014, 73 03'S, 13 25'W ) was installed at the aerosol research laboratory in cooperation with SWEDARP in November 2003. The weather sation includes Milos 500 AWS with the following sensors:
Wind direction and velocity: Thies CLIMA Ultrasonic Anemometer 2D, 12m above ground, 489m ASL.
Relative humidity: Vaisala, HMP 45D, 2m above ground, 479m ASL
Temperature: Pentronic Pt-100, 2m above ground, 479m ASL
Pressure: Vaisala PTB220, 1.7m above ground, 478.7m ASL
Global radiation: Kipp&Zonen CM11, heated, 4m above ground, 481m ASL
UVB-radiation: Solar Light CO.inc, model 501A, 4m above ground, 481m ASL
Condensation particle counter: TSI model 3007.
Ground temperature: 4 Pentronic Pt-100 sensors at -2cm, -10cm, -30cm ja -60cm.
Present weather and visibility during summer campaigns: Vaisala FD12P
Present project
In earlier aerosol measurements at Aboa high concentrations of freshly-formed small particles were observed during a few particle formation events. So far only summertime measurements have been conducted at Aboa. The influence of season, weather and solar radiation on particle formation can be studied with year-round measurements. In summer 2003/2004 the first step towards automatic year-round measurements is taken. The FMI aerosol research group has built an automatic system for measuring number concentrations with low power consumption in cooperation with the Aerosol and Environmental Physics Laboratory of University of Helsinki. The system includes two TSI Model 3007 particle counters. The data will be saved in a single-board computer and in the MILOS 500 unit of the automatic weather station. The weather and aerosol data will be transferred to FMI via satellite.
Aerosol deposition to snow
The aerosol research group has studied the chemical composition of snow samples taken from the Queen Maud Land during the FINNARP 1999 and FINNARP 2000 expeditions. The samples were taken by the snow reseach group of the Geophysics Department of University of Helsinki. The chemical composition of the snow samples and aerosol samples taken at Aboa are compared to estimate the contribution of dry deposition to total deposition of various compounds. This cooperation continues in the FINNARP 2003 expedition. In addition, the snow research group will measure aerosol number concentrations from the Weddell Sea coast to 300 km inland using a portable counter of the aerosol research group.
Project group
Dos. Risto Hillamo (project leader)
Dr. Aki Virkkula
Kimmo Teinilä
Finnish Meteorological Institute, Air Quality Research
Sahaajankatu 20E, FIN-00880 Helsinki, Finland
Futher information
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FMI aerosol research
References
Grönlund A., Nilsson D., Koponen I.K., Virkkula A., and Hansson M. (2002) Aerosol dry deposition measured with eddy-covariance technique at Wasa and Aboa, Dronning Maud Land, Antarctica, Ann. Glaciology 35A, 355-361.
Kerminen V.-M., Teinilä K. and Hillamo R. (2000) Chemistry of sea-salt particles in the summer Antarctic atmosphere. Atmos. Environ. 34, 2817-2825.
Teinilä K., Kerminen V.-M. and Hillamo R. (2000) A study of size-segregated aerosol chemistry in the Antarctic atmosphere. J. Geophys. Res. 105, 3893-3904.
Koponen I. K., Virkkula A., Hillamo R., Kerminen V-M, Kulmala M. (2002) Number size distributions and concentrations of marine aerosols: Observations during a cruise between the English Channel and the coast of Antarctica. J. Geophys. Res. 107(D24 ), 4753, DOI: 10.1029/2002JD002533
Koponen I. K., Virkkula A., Hillamo R., Kerminen V-M, Kulmala M. (2003) Number size distributions and concentrations of the continental summer aerosols in Queen Maud Land, Antarctica. J. Geophys. Res. 108(D18), 4587, DOI:10.1029/2003JD003614, 2003.
Virkkula A., Teinilä K., Viidanoja J., Karonen J., Paatero J., Hillamo R., Kerminen V.-M., Koponen I.K., and Kulmala M. (2002) Chemical composition of marine boundary layer aerosol over the Atlantic Ocean between English Channel and Antarctica, during the FINNARP-1999/2000 expedition, Proceedings of 8th European Symposium on the Physico-Chemical Behaviour of Atmospheric Pollutants, 'A Changing Atmosphere', Torino 2001, J. Hjorth, F. Raes and G. Angeletti Eds.,
European Commission, published on CD and in the internet
The Finnish Meteorological Institute (FMI), in collaboration with Servicio Meteorológico Nacional (SMN), Argentina, is constructing a network for aerosol optical depth (AOD) measurements. Measurements are to be started during summer 2003 with three sun photometers, model PFR, Davos. One of them will be sited in Marambio (64.2 °S, 56.7 °W), Antarctica, and the rest two in the Observatory of Jokioinen (60.8 °N, 23.5°E) and Sodankylä GAW station (67.4 °N, 26.6 °E), Finland. Each instrument consists of a precision filter radiometer and a suntracker. AOD measured at Sodankylä GAW station can be compared with estimated aerosol extinction, which is calculated from ground base aerosol properties.
The purpose of the measurements is to establish diurnal, seasonal and annual variation of AOD, and to determine the effect of aerosol to visibility. Furthermore, some closure experiments, e.g. comparisons between measured and calculated AOD, will be carried out. AOD can be determined from surface aerosol properties (scattering and absorption coefficients) and aerosol vertical profile.
Instruments
Each instrument consists of a Precision Filter Radiometer (PFR, manufactured by PMOD/WRC) and a Kipp&Zonen 2AP Gear Drive suntracker. PFR is a research grade instrument to measure direct solar irradiance in 4 narrow spectral bands centered at wavelengths recommended by WMO for the determination of AOD (wavelengths of 862, 500, 412 and 368 nm with 5 nm FWHM bandwidth).
References
Aaltonen V, Koskela T and Lihavainen H 2003. Aerosol Optical Depth Measuring Network - Project Description. Poster presented at the EGS-AGU-EUG Joint Assembly, Nice, France, April 2003.
Further information:
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Precision filter radiometer with suntracker for aerosol optical depth
measurements.
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