The abbreviation AEL has on different periods of history stood for somewhat different meanings. Air Ionization and Electroaerosol Laboratory at Tartu State University was officially established in 1964, but the work, resulting in the creation of the laboratory, was begun even earlier. On the suggestions of Prof. Johan Wilip, the teacher of physics of Tartu Hugo Treffner Gymnasium Anatoli Mitt recorded during the whole year of 1937 small air ions, working at Tartu University and gathering material for his master’s degree. The study of aerosol ions grew broader and more intense in the 1950s, mainly under the supervision of senior teacher Jaan Reinet, at the Chair of General and Experimental Physics. In 1956-1957, the first contracts were made to build air ion counters for other research institutions in the Soviet Union. The students of the Department of Physics were encouraged to participate in this work. Until the establishing of the laboratory, AEL could be defined as a research group, which worked at the Chair of General and Experimental Physics, and later at the Chair of General Physics at Tartu State University, the subjects of whose were air ions and electrically charged aerosols.

Air Ionization and Electroaerosol Laboratory at Tartu State University was established by the decree of the Council of Ministers of the Estonian SSR, of March 31, 1964. The Head and the scientific supervisor of the laboratory was docent Jaan Reinet. Such laboratories were subordinated to the Rector’s Office at the university, the research work was co-ordinated by some certain chair of the university, for AEL, this chair was the Chair of General Physics.

In connection with supplementary financing of research in the field of gas discharge, AEL was restructured in 1974. With the Rector’s decree of Sept. 19, 1974, docent Kalju Kudu was appointed the scientific supervisor of AEL, and four sections were created within the laboratory: (1) Section of Air Ion Spectrometry, (2) Section of Aerosols, (3) Section of Gas Discharges and (4) Section of Electrometry. The scientific supervisors of the sections were senior teacher Jaan Salm, senior teacher Eduard Tamm, docent Kalju Kudu and senior teacher Olev Saks, respectively. In 1975, candidate of physics and mathematics Lembit Visnapuu was appointed the Head of the laboratory.

The next change in the structure of AEL occurred in 1983 in relation with the return of doctor of physics and mathematics Hannes Tammet to Tartu State University from Tallinn Pedagogical Institute. With the Rector’s decree of Jan. 31, 1983, AEL was divided into two independent laboratories; the change became effective on Feb. 1, 1983. These laboratories were: Air Electricity Laboratory (AEL) and the Laboratory of Environment Protection Physics (KKFL). Prof. Hannes Tammet was appointed the scientific supervisor and the Head of AEL. Prof. Olev Avaste was appointed the scientific supervisor of KKFL, and senior researcher Lembit Visnapuu became the Head of this laboratory. During the reorganisation of AEL in 1983, its division into sections was discontinued, but in 1984 new sections were created: (1) Section of Mobility Spectrometry, (2) Section of Apparatus Design, and (3) Section of Gas Discharges. During 1989-1993, candidate of chemistry Tiia-Ene Parts was the Head of AEL.

After Estonia regained its independence, the University of Tartu underwent thorough structural reforms in 1992. Resulting from long negotiations, the Learned Council of the university established, with its decree of Nov. 27, 1992, the new structure of the Faculties of Physics and Chemistry, Sports Sciences, Mathematics, and Law, which became effective on Feb. 1, 1993. The structure of the Department of Physics included four institutes and a physical-technical experimental workshop. The Institute of Environmental Physics consisted of three chairs. With the same decree, 12 subdivisions were closed within the department, including the Chair of Geophysics, the Air Electricity Laboratory and the Laboratory of Environment Protection Physics. AEL continued functioning as an informal subdivision within the Institute of Environmental Physics.