NCRT 2014-2016 News

No announcements in English

User Details

ZerefosChristos S.
First Name:
Christos S.
Last Name:
Member, Academy of Athens
Environment Archive (Observer), Archive NCRT 2014-2016 (Vice-Chair)


NAME: Christos S. Zerefos

BIRTH DATE: April 22, 1943, Cairo


PRESENT AFFILIATION: Member, Academy of Athens

ADDRESS:  Research Center for Atmospheric Physics and Climatology of the Academy of Athens, Panepistimiou 28, 10679 Athens, Greece

PHONE:   +30-210-8832048 (ext. 11)

FAX:   +30-210-8842098


Christos S. Zerefos was born in Cairo, Egypt and graduated in Physics from the University of Athens. MSc in Meteorology and Ph.D. in Physics-Meteorology, University of Athens. Post Doctoral researcher, National Center for Atmospheric Research (NCAR) and other Research Institutions in Greece and abroad. Professor of Atmospheric Physics at the Universities of Thessaloniki and Athens, visiting Professor at the Universities of Boston, Minnesota (USA) and Oslo (Norway).

Member of the Academy of Athens, the Norwegian Academy of Sciences and Letters, the Academia Europaea, the European Academy of Sciences, the Russian Academy of Natural Sciences, the  International Academy of Astronautics and other Academies and research Institutions. Fellow of the Institute of Physics (UK) and Life Member of the American Geophysical Union. His published work in peer reviewed scientific journals has been acknowledged from the scientific community with thousands of citations. Holder of the UNESCO Chair for Natural Disasters, President elect of the International Ozone Commission (IO3C) of IAMAS of ICSU (re-elected in 2012), President elect of the IUGG National Committee for Greece, President of the Mariolopoulos-Kanaginis Foundation for the Environmental Sciences, former President of the National Observatory of Athens and other national and international fora.

Awards and Distinctions

Global Ozone Award from the United Nations Environment Programme (1997), AGU Editors Award for Excellence in Refereeing, (1998), Award of the European Physical Society and the Balkan Physical Union (2006), Honourable Mentions from the United Nations Environmental Program (1995, 1998 and 2012). Has served as Review Editor of Chapter 5, IPCC Aviation Report and reviewer in the IPCC report on natural disasters (2012). Author, reviewer in almost all WMO/UNEP ozone assessments through 2012 and author of the EU report on Ozone-Climate Interactions. His proposal for the Geoastrophysics Museum at the National Observatory has been awarded with the 2010 European Union Prize for Cultural Heritage / Europa Nostra Award. Distinction from the Ministry of Education of Cyprus (2008), Honorary Mention from the Russian Academy of Natural Sciences (2009), Gold Medal of the Municipality of Thessaloniki (2009), City Medal of the Municipality of Athens (2010), Distinction from the Ministry of Education of the Arab Republic of Egypt (2010).

Scientific Achievements

Christos Zerefos started his scientific carrier as atmospheric scientist in the mid1970s. He became known to the scientific community with his studies on the long and short term variability of the ozone layer, the stratosphere 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 and explain the solar activity component in the lower stratosphere. Working with Harry van Loon and other colleagues, he was the first to observe 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 started in the late 70s and peaked in the early 90s with perhaps one of his most important paper with Rich Stolarski and colleagues “Measured trends in stratospheric ozone”, published in Science (1992). In that paper the analysis of combined satellite and ground based total ozone data established the globalization of downward trends in total ozone also in middle latitudes, which 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. The paper became a classic in the field with more than 400 citations.

In the 80s and 90s his papers on the ozone decrease and particularly its inverse relationship with increases in UV-B provided for the first time solid experimental evidence that UV-B has been increasing because of the ozone depletion. Well-cited papers (>50 citations) are: “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 and 90s Zerefos pioneered in establishing in Greece regular well calibrated observations of UV spectral irradiance and ozone. He made use of the first Brewer MKI to be operating outside of Canada and the US (Brewer #5). Also in the 90s has pioneered in the establishment of the European UV-B observing network started from his initiative with Anne Webb, Alkis Bais 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 such as “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 campaigns to study the complex processes of ozone- aerosol-radiation interactions in the Mediterranean (PAUR Campaigns, I, II, MEDCAPHOT Campaign with Ziomas). These campaigns produced well-cited papers, e.g. “The effect of aerosols on solar UV irradiances during the photochemical activity and solar ultraviolet radiation campaign” with Kylling and Bais (>50 citations), “The optical properties of tropospheric aerosols determined by Lidar and spectrophotometric measurements (PAUR Campaign)” with Marenco (>70 citations) 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, with >130 citations).

In the past 20 years has acted as author, contributor or reviewer in almost all WMO/UNEP Scientific Assessments of Ozone Depletion, which produced well-cited papers on ozone and UV-B trends, e.g. with Harris “Trends in stratospheric and free tropospheric ozone, JGR (>80 citations), “Variability of UV-B at four Stations in Europe, GRL, 1997 (>70 citations), “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 with Gerasopoulos (Atm. Chem. & Phys., 2007, 2008). Has quantified the evidence of atmospheric gravity waves following the supersonic transport of moon’s shadow in the ozone layer.

Has served as review Editor of Chapter 5 of the IPCC Aviation Report (1998) and as Reviewer of the IPCC Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (2013). His involvement in the estimates of radiative forcing from aviation resulted to the paper with Sausen and Isaksen “Aviation radiative forcing in 2000: An update on IPCC”, Met. Z., 2005 (>120 citations). Other notable papers that had received attention by the scientific community include the papers “Solar activity-total column ozone relationships: Observations and model studies with heterogeneous chemistry”, JGR, 1997, “Tropospheric ozone changes at unpolluted and semi polluted regions induced by stratospheric ozone changes”, JGR, 2005 with Isaksen, ”Evidence of the impact of aviation on cirrus cloud formation“, Atmos. Chem. Phys., 2003, “Solar dimming and brightening over Thessaloniki, Greece, and Beijing, China”, Tellus B, 2009 and a number of well-received papers as seen in his most cited list of papers. Recently he is analysing data to detect turn around in the ozone and UV-B trends following the phase out of manmade chlorofluorocarbons (e.g. “Evidence of a possible turning point in solar UV-B over Canada, Europe and Japan”, Atmos. Chem. Phys., 2012).

For many years Christos Zerefos has served the stratospheric and ozone scientific community as advisor to the EC Panel of Experts of WMO, to the High Level Group of DG Research of EU for the Stratosphere and by organizing internationally known Symposia which became landmarks in the ozone and atmospheric physics community. Has organized four large international ozone Conferences in one of which (the 1984 Quadrennial Ozone Symposium) winter-spring ozone disturbance in Antarctica was reported by Japanese scientists and subsequently confirmed and explained as an ozone hole by British scientists (Farman et al., Nature, 1985). The second Conference (1995) highlighted the extreme ozone depletion in which Pinatubo and heterogeneous processes at high latitudes have been contributing, the third was the 2004 Quadrennial Ozone Symposium and the fourth was a Symposium organized to celebrate the 20th anniversary of the Montreal Protocol, in which the first data pointing towards a possible recovery of the ozone layer first appeared (Zerefos et al., “Twenty Years of Ozone Decline”, Springer, 2009). More recently has co-authored 2 important reviews on extreme events in Europe (“Extreme Weather Events in Europe: preparing for climate change adaptation”, Norwegian Met. Institute, NILU, ISBN 978-82-7144-100-5 (2013) by Øystein et al. and “Trends in extreme weather events in Europe: implications for national and European Union adaptation strategies”, EASAC Policy Report 22, ISBN 978-3-8047-3239-1 (2013) by Øystein et al.)

Christos Zerefos proposed to WMO the creation of the “WMO Northern Hemisphere Ozone Mapping Center” in 1991 which, in collaboration with the WMO World Ozone and Ultraviolet Radiation Data Center, since then produced and continues producing hundreds of reliable near-to-real time northern hemisphere total ozone maps which served dozens of scientists and international scientific community. This service has been unanimously accepted at the WMO RA-VI Congress (2-13 May 1994) and appreciated by leading organizations such as the European Commission, particularly during the period 1995-1996 during which reliable satellite observations were not available, due to failure of the space instruments ( The Center participated in all European Arctic Stratospheric Ozone campaigns (EASOE, SESAME and THESEO) from which the threat of the possibility for occurrences of ozone-hole atmospheric conditions in the arctic (similar to the Antarctic) in the winter-spring period were discovered. In the past 30 years Christos Zerefos has founded from the very beginning the following Research Centers and Institutions of worldwide reputation:

  1. The Research Center for Atmospheric Physics and Climatology at the Academy of Athens (1978) in collaboration with late Professor E. Mariolopoulos (
  2. The Laboratory of Atmospheric Physics, University of Thessaloniki (1981) (
  3. The World Meteorological Organization Northern Hemisphere Ozone Mapping Center (1991) (
  4. The Graduate Programme on Environmental Physics, at the Physics Department, Aristotle University of Thessaloniki (1991) (
  5. The Laboratory of Atmospheric Environment, Foundation for Biomedical Research, Academy of Athens (2003) (
  6. The UNESCO Chair on Natural Hazards in the Geosphere, the Hydrosphere and the Atmosphere (2006) (
  7. The Geoastrophysics Museum, National Observatory Athens, Greece (2008) (
  8. The Navarino Environmental Observatory (NEO) in Messenia (2009) (

Christos Zerefos has been a life member of AGU and a regular supporter of AGU and its journals (cited for excellence in referring). All these achievements were recognized at the 10th anniversary of the Montreal Protocol by awarding Professor Zerefos with the UNEP Global Ozone Award. The international ozone community, also recognizing his international contributions to science and the scientific society has elected him twice as Secretary of the International Ozone Commission (2000 and 2004) and twice as President of the International Ozone Commission (2008 and 2012). Other distinctions include membership to the Norwegian Academy of Sciences and Letters (1998), the Academy of Athens (2007), the Academia Europaea (2008), the International Academy of Astronautics (2008), the Russian Academy of Natural Sciences (2009), the European Academy of Sciences (2010) and other academies. Fellow, Institute of Physics (UK), various awards and decorations. Also a number of high administrative positions, including State Secretary for the Environment of Greece, President of the National Observatory of Athens and others.

Christos Zerefos is a high level educator, teaching at University level undergraduate and graduate courses of atmospheric and environmental physics. He has taught Atmospheric and Environmental Physics since 1980 at the Universities of Thessaloniki and Athens and as visiting professor at Boston University and the University of Minnesota (Fulbright Fellow) and gave invited lectures at other Universities and scientific bodies, such as the University of Oslo, the Norwegian Academy of Sciences and Letters, the Academia Europaea, the European Physical Union etc. But perhaps most important in his scientific life was the establishment of an esteemed group of former young scientists which started as students of his in the early 80s and today are recognized professors at Universities worldwide (e.g. A. Bais, I. Ziomas, D. Balis, A. Papayannis, K. Tourpali, P. Zanis, E. Gerasopoulos, G. Tselioudis and others). In his career he has supervised 30 PhD theses and 60 MsC theses.

For additional information please visit and