Professor Christos S. Zerefos 

Professor Christos S. Zerefos is Member of the Academy of Athens (since 2007) and Head of the Research Centre for Atmospheric Physics and Climatology of the Academy of Athens.

He has been Professor of Atmospheric Physics, National and Kapodistrian University of Athens, Scientific Collaborator, University of Oslo, Honorary Fellow (Fulbright Scholar), University of Minnesota, Visiting Professor, Physics and Astronomy Department, Boston University, Professor of Atmospheric Physics, Physics Department, Aristotle University of Thessaloniki, Greece (1979-2002).

 Professor Zerefos has received a number of internationally recognized awards, among which the title of Emeritus Professor of the Physics Department of the Aristotle University of Thessaloniki (2018), the “IoanUrsu” Medal of Honor of the Balkan Physical Union (2018), “Honorary Member” of the International Ozone Commission (2016), the Honorary Doctorate Degree, University of Patras (2016), the Yoram Kaufman Award of the American Geophysical Union (2015), the French Government Decoration “Commandeurdansl’ordre de Palmesacadémiques“ (2015), the Blaise Pascal Medal, European Academy of Sciences (2015), Award of the Balkan Physical Union (2015), Medal of the City of Athens (2010), Professor Emeritus of the National and Kapodistrian University of Athens (2010), the Gold Medal of the City of Thessaloniki (2008),  the Honorary Degree of Doctor of Humane Letters, University Division of the American College ANATOLIA, Thessaloniki (2008), Award Certificate and Letter from UNEP and from IPCC for his substantial contribution to the reports of IPCC, which shared the 2007 Nobel Peace Prize with the former Vice President of USA, Al Gore (2008), Fellow, Institute of Physics (2002), UNEP Honourable Mentions (2013, 1999, 1995), Editors Award for Excellence in Refereeing, American Geophysical Union (1998), Global Ozone Award, UNEP on the 10th Anniversary of the Montreal Protocol (1997). Reviewer, IPCC “Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX)”, Field et al., Cambridge, UK, 582 pp. (2012).Review Editor, Chapter 5: Solar Ultraviolet Irradiance at the Ground, IPCC “Aviation & the Global Atmosphere” Report, Switzerland (1998). In the past 20 years has acted as author, contributor or reviewer in almost all WMO/UNEP Scientific Assessments of Ozone Depletion (Montreal Protocol Who’s. He is member of many scientific societies.

Professor Christos Zerefos became known in the 70s for his studies on the long and short term variability of the ozone layer and related geophysical signals in a global perspective. The relation between solar activity and the lower stratosphere, e.g. his paper with Paul Crutzen “Stratospheric thickness variation over the northern hemisphere ….” (JGR, 1975) was one of the first studies to model the solar activity component in the stratosphere. Working with Harry van Loon, they first observed the El Nino signals in the lower stratosphere (“The southern oscillation in the stratosphere”, Mon. Weather Rev., 1982) and in the columnar ozone (“On the relative importance of QBO and El Nino in the revised Dobson total ozone records”, JGR, 1992). His early papers on long term trends in stratospheric temperatures and total ozone include one of his most important papers with Stolarski “Measured trends in stratospheric ozone”, Science (1992). That paper provided the scientific basis for the strengthening of the phase out of halocarbons. In this work Zerefos played a key role in analyzing ground based data. Recently long-term trends from the lower troposphere to the lower stratosphere have been revisited in Zerefos et al. in ACP (2014).

His papers on the inverse relationship between ozone and UV-B, provided for the first time evidence that UV-B had significant positive trends. “A note on the recent increase of solar UV-B over northern mid latitudes”, GRL, 1995, “Optical properties of tropospheric aerosols …, Appl. Optics, 1997, “Spectral measurements of solar UVB radiation and its relations to total ozone, SO2, and clouds”, JGR, 1993 as well as his papers on record low total ozone anomalies and the effects of volcanic eruptions (e.g. with Bojkov “Record low total ozone during northern winters of 1992 and 1993″, GRL 1993). In the 80s Zerefos pioneered in establishing in Greece regular well calibrated observations of UV spectral irradiance and ozone. In the 90s has pioneered in the establishment of the European UV-B observing network started from his initiative with Anne Webb, AlkisBais and late Heinz Ott. He has also supported the use of the Brewer spectroradiometer, which became a model instrument to measure not only columnar ozone and SO2 but also UV spectral irradiances. Notable are papers with Bais and McElroy “Solar UV-B with the double and single Brewer ozone spectrophotometers”, GRL, 1996 and “Correcting global solar ultraviolet spectra recorded by a Brewer spectroradiometer for its angular response error”, Appl. Optics, 1998. In the 90s Zerefos has organized large EU-funded campaigns to study the processes of ozone- aerosol-radiation interactions in the Mediterranean (PAUR Campaigns, I, II, MEDCAPHOT Campaign with Ziomas): “The effect of aerosols on solar UV irradiances during the photochemical activity and solar ultraviolet radiation campaign” with Kylling “The optical properties of tropospheric aerosols determined by Lidar and spectrophotometric measurements (PAUR Campaign)” with Marenco and others. In the 2000s has participated in the MATCH Campaigns joining the European group led by Rex, Schultz and others which studied ozone loss rates inside and outside of the polar vortex (JGR, 2001; GRL, 2000, 2006). On another collaborative project with Stohl et al., studied and reviewed mechanisms of stratosphere-troposphere exchange (JGR, 2003) and with Harris “Trends in stratospheric and free tropospheric ozone, JGR “Variability of UV-B at four Stations in Europe, GRL, 1997, “Quasi-biennial and longer-term changes in clear sky UV-B solar irradiance”, GRL, 1998, “Further studies on possible volcanic signal to the ozone layer”, JGR, 1994. He has discovered with his colleagues the effects in the stratosphere of the solar eclipses of 1999 (JGR, 2000) and 2006 (ACP, 2007, 2008) presenting evidence of atmospheric gravity waves following the supersonic transport of the moon’s shadow in the ozone layer.