1. Rescue of retrospective aerosol measurements: a challenge for Estonian Environmental Observatory Rescue of retrospective aerosol measurements: a challenge for Estonian Environmental Observatory hannes.tammet@ut.ee Järvselja 20150615

2. A charged aerosol particle drifting in electric field: Z = electric mobility Charged aerosol particle = air ion Air ions have been measured in Tartu since 1937 + v = Z E E ParticleVelocityMobilityElectric field Common unit

3. Diameter and mobility of a singly charged aerosol particle small ions particles

4. Probability to be neutral or carry few elementary charges 0 e (neutral) 1 e (singly charged) 3 e 2 e

5. Number of elementary charges is to be multiplied with this coefficient to get total number of particles

6. Harrison R.G. and Aplin K.L. (2002) Aerosol variations inferred from historical atmospheric electrical data. Proc. XIIIth Annual Conference The Aerosol Society, Lancaster, April 2002, 113-116. Harrison R.G. (2003) Climate change and long-term variations in the atmospheric electrical system. Proc.12th International Conference on Atmospheric Electricity, Versailles, vol2, 703-706, 2003. Harrison R.G. (2003) Long-term changes in aerosol and the electrical conductivity of oceanic air. Proc. 14th annual conference, The Aerosol Society, Reading, 2nd-3rd April 2003, 22-25. Harrison R.G. and Aplin K.L. (2002) Mid-nineteenth century diurnal smoke concentrations at Kew, London. Atmos Environ 36, 25 4037- 4043. Harrison R.G. and Aplin K.L. (2003) Nineteenth century Parisian smoke variations inferred from Eiffel Tower atmospheric electrical observations. Atmos Environ 37, 5319-5324. Some papers by Giles Harrison:

7. Original instruments and early measurements in Tartu: Jaan Reinet 1951—1955 (Arnold Susi, Hugo Marran) Paul Prüller 1960—1963 (Olev Saks)

10. Tahkuse Tahkuse Air Monitoring Station is located about 27 km from Pärnu. The routine measurements at Tahkuse are carried out by Hilja Iher since 1985. Preliminary measurements were made here at 1984

11. Tahkuse 1985–1994:

12. Tahkuse air ion spectrometer The full range spectrometer was launched at Tahkuse 1988. The air ions are measured using 20 simultaneous electrometric amplifiers. Additional commutation of voltages yields concentrations of 40 fractions in the size range of 0.4 – 80 nm.

13. Tahkuse 2007:

14. EAS = Electrical Aerosol Spectrometer The project EAS was started in seventies. Technically perfect instruments were designed by Aadu Mirme in eighties. Today improved versions of EAS are manufactured by a small company AIREL. The technological solutions achieved during developing the EAS were subsequently used by Aadu Mirme in contemporary universal aerosol and air ion mobility spectrometers NAIS and ANAIS. EAS & NAIS are widely used and well known for everybody who is active in atmospheric aerosol research today.

15. EAS = Electrical Aerosol Spectrometer EASBSMAEAS

16. Measurements by EAS and air ion spectrometer Source : Hõrrak, U., Mirme, A., Salm, J., Tamm, E., and Tammet, H. (1998) Air ion measurements as a source of information about atmospheric aerosols. Atmos. Res. 46, 233–242.

17. Tartu, Tähe 4, measurements of finest nanometer particles

18. Location & instrumentYearsFormats Waldorf (USA) + Vilsandi (EST)1979punched tape Tahkuse AIS + meteo1988–2002txtraw Tahkuse NO2 + meteo1991–2015txt Tahkuse AIS + meteo2003–2015txt, sum Tahkuse EAS2003–2015nc, ncs, vc, vcs, sig, txt Tahkuse weather observations2003–2015paper Tahkuse reports2003–2015xls Tahkuse RM2-B (Rn)2004, 2007xls, paper Tahkuse AlphaGuard + meteo2007–2015dvd, txt Tahkuse Vaisala meteo2006–2015txt Tahkuse BSMA2011txt Tahkuse NAIS2011–2015txt, sum Tõravere EAS2007–2013nc, ncs, vc, vcs, sig, txt Järvselja KAIS2009txt, xls Järvselja BSMA2008–2009txt Järvselja EAS2012–2015block-spectra, sum Järvselja NAIS2012–2015block-spectra, sum Tartu BSMA2004–2014txt Tartu KAIS2006–2014txt Tartu RM2-B (Rn)2007–2008? Tartu NAIS2011–2012block-spectra Tartu SIGMA2011–2014txt Tartu TSI SMPS2014txt Some saved data according to Kaupo Komsaare

19. The DataCite global consortium (https://www.datacite.org) supports archiving of research data and helps to assign to datasets digital object identifiers (DOI).https://www.datacite.org This opportunity is now used uploading few datasets to a safe repository and making the data openly accessible.

20. Dataset ATMEL2007A Access: http://dx.doi.org/10.15155/repo-1http://dx.doi.org/10.15155/repo-1 The dataset provides scientists and students with a collection of data for exploring the correlations and trends in fair-weather atmospheric electricity, air pollution effects, and trends in global climate (Tammet, 2009). It includes hourly averages of digitally available data from 13 stations including 7 stations of the former World Data Centre network. Additional stations are Wank Peak (Germany), Marsta (Sweden), Tahkuse (Estonia), Tartu (Estonia), Hyytiälä (Finland), and Carnegie research ship. The atmospheric electric measurements are accompanied with meteorological and air pollution data. The total amount of included hourly average values is about 12,000,000. New data can easily be imported into the dataset and the excerpts of the data can be exported as traditional tables using the included free software. Introductory presentation of the dataset is available in the included pdf- documents:  Introduction to the ATMEL2007A.  Motivation of the dataset ATMEL2007A.  Sources of ATMEL2007A data.  Explanation of data formats in ATMEL2007A.  Brief overview of the ATMEL2007A data.  Tools for data management in ATMEL2007A.  Manual of ATMEL2007tablemaker. References Dolezalek, H. (1992). The World Data Centre on atmospheric electricity and global change monitoring, Eur. Sci. Notes Inform. Bull., 92-02, 1–32. http://www.dtic.mil/dtic/tr/fulltext/u2/a249486.pdf. http://www.dtic.mil/dtic/tr/fulltext/u2/a249486.pdf Tammet, H. (2009). A joint dataset of fair-weather atmospheric electricity. Atmos. Res., 91, 194–200. http://dx.doi.org/doi:10.1016/j.atmosres.2008.01.012. http://dx.doi.org/doi:10.1016/j.atmosres.2008.01.012

21. Dataset Nanoion2010_11 Access: http://dx.doi.org/10.15155/repo-2http://dx.doi.org/10.15155/repo-2 The positive and negative small and intermediate air ions were routinely measured at Tartu, Estonia (58.373 N, 26.727 E, 70 m a.s.l.) by means of a unique instrument SIGMA (Tammet, 2011). The dataset includes results of a measurement campaign started at 1 April 2010 and finished at 8 November 2011. The dataset presents unique information about nanoparticles up to 7.4 nm in diameter in the atmospheric air (Tammet et al., 2013, 2014). The genesis and subsequent evolution of nanoparticles is a key to understanding the formation of atmospheric aerosols, which is an essential factor of the Earth's climate. The particles are classified according to their size and electric mobility. The full mobility range was logarithmically uniformly divided into 16 fractions. 10 of these fractions include the intermediate ions and 6 include the small ions. Immediately was determined the particle electric mobility while the size was calculated as the mobility equivalent diameter of the particle. The dataset contains files:  nanoion2010_11description.pdf – information about the origin of data and structure of the data files,  nanoion2010_11instrument.pdf – description of the instrument SIGMA used for measuring nanoparticle mobility and size distribution,  nanoion2010_11hours.xls – hourly averages of nanoparticle distribution according to their mobility and size, complemented with meteorological data,  nanoion2010_11records.xls – five minute averages of nanoparticle distribution according to mobility and size,  nanoion2010_11diagrams.ppt – contour plots of nanoparticle size distribution evolution during 147 days,  nanoion2010_11.zip – compressed package of files for download and offline use on a personal computer. References Tammet, H. (2011). Symmetric inclined grid mobility analyzer for the measurement of charged clusters and fine nanoparticles in atmospheric air. Aerosol Sci. Technol., 45, 468–479. http://dx.doi.org/10.1080/02786826.2010.546818.http://dx.doi.org/10.1080/02786826.2010.546818 Tammet, H., Komsaare, K., Hõrrak, U. (2013). Estimating neutral nanoparticle steady-state size distribution and growth according to measurements of intermediate air ions. Atmos. Chem. Phys. 13, 9597–9603. http://dx.doi.org/10.5194/acp-13-9597-2013, http://www.atmos-chem-phys.net/13/9597/2013/.http://dx.doi.org/10.5194/acp-13-9597-2013 http://www.atmos-chem-phys.net/13/9597/2013/ Tammet, H., Komsaare, K., Hõrrak, U. (2014). Intermediate ions in the atmosphere. Atmos. Res., 135–136, 263–273. http://dx.doi.org/10.1016/j.atmosres.2012.09.009. http://dx.doi.org/10.1016/j.atmosres.2012.09.009

22. Dataset Hyytiala08_10aerosol Access: http://dx.doi.org/10.15155/repo-3http://dx.doi.org/10.15155/repo-3 The dataset Hyytiala08_10aerosol contains results of routine measurements of atmospheric aerosols carried on in a well equipped boreal research station during 3 years. The particle size range from 3 nm to 15μm is split into 60 fractions and the records of distribution function are presented for 21682 hours of measurements. The dataset provides scientists with a tool for exploring the structure and dynamics of atmospheric aerosol size distribution. Additionally, it can serve as a basis for data analysis exercises for students in field of environmental sciences. The dataset includes three files:  Data_Hyytiala08_10aerosol.xls – a table, which contains 60 columns of values of the particle size distribution function and 30 columns of complementary variables.  Description_Hyytiala08_10aerosol.pdf – detailed description of origin and structure the data. Additionally includes sample diagrams, which illustrate the data and may provoke new ideas for studies on atmospheric aerosol.  Package_Hyytiala08_10aerosol.zip – a compressed package, which contains both the data file and the description file. The package is to be downloaded to a personal computer, unzipped and used offline. The dataset was compiled in process of studies on coagulation sink of fine nanoparticles and small ions by Tammet and Kulmala (2014) and can be used for examination of air ion balance in the atmosphere. Reference Tammet, H., Kulmala, M. (2014). Empiric equations of coagulation sink of fine nanoparticles on background aerosol optimized for boreal zone. Boreal Environ. Res., 19, 115–126. http://www.borenv.net/BER/pdfs/ber19/ber19-115.pdf. http://www.borenv.net/BER/pdfs/ber19/ber19-115.pdf

23. FACTS:  a lot of old data is lost  some data is saved written or typed on paper  some data is saved on punched tapes  some data is saved on old floppy disks  a lot of data is saved on hard disks of different computers in a disordered state  a limited amount of data is well arranged and saved in DataCite repository

24. CONCLUSIONS We need at least one expert who's full-time job is management and processing both the prospective and retrospective data I guess this would cost about 100000 € per year Otherwise the earlier work of about 10 scientist during about 20 years will be finally lost and the prospects for current work will be problematic

25. Thank you !