Contribution draft: The Urban Heat Island of Athens

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Here is a draft of my contribution about Athens, which is conceived as a paragraph for the "Urban Heat Island" article. I am still working around it, some term may be improved. The title will be "The Case of Athens, Greece".

The Urban Heat Island of Athens, Greece

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"The city of Athens is characterized by a strong heat island effect, mainly caused by the accelerated industrialization and urbanization during recent years." (Giannakopoulos et al. 2010:746).[1] The urban heat island of Athens is studied within the framework of the campaign "Thermopolis 2009" by the Democritus University of Thrace with the support of ESA[2] and several other studies. Satellite measurements of surface temperature revealed that "In the case of Athens [...], mixed urban areas are hot spots and appear to be 3.5–4°C warmer than the surrounding rural areas, during daytime, a fact that can be attributed to intense human and industrial activities".[3] Kassomenos and Katsoulis (2006) detect strong urban heat island affecting Athens for 1/3 of the days, switching on in the afternoon and being stronger with low humidity and clear sky conditions.[4] Santamouris et al. (2001) by the use of 30 meteorological stations and specific measurements detect levels of urban heat island as strong as exceeding 10°C in extreme cases in central Athens during daytime and up to 5°C during the night.[5] A daytime negative urban heat island may be detected in Athens under some synoptic conditions.[6][7][8] The urban heat island effect in Athens is not homogeneous inside the city: it is more intense in some western parts, and less intense in green areas; it is more intense in open-surrounded positions in presence of asphalt and intense traffic circulation.[9] The urban heat island of Athens is also variable according to the season, and winter is the period of less intense effect.[10] According to Livada et al. (2002) some green areas that are protected by greenery such as the National Gardens inside metropolitan Athens are less or not affected by the UHI.[11] The urban heat islands have implications also for climate change analysis. A early detection of Athens urban heat island effect over the temperatures measured by the NOA meteorological station at Thiseio was reported by Katsoulis (1987:75-76): "[...] the differences in the maximum and minimum temperature trends may be interpreted as a long-term variation due to che city's growth and the result of increasing urban temperature due to human causes".[12] An effect of +1/+2°C on its summertime maximum temperatures due to urban heat island is reported by different studies.[13][14][15] The warming observed in annual and summer air temperature times-series of the National Observatory of Athens weather station at Thiseio between 1970 till mid 1990s compared to reference non-urban stations "[...] must be attributed to the urban effect of Athens city as has been demonstrated by many scientists" (Repapis et al. 2007:110).[16] The effect of the urban heat island on the maximum temperatures measured by the meteorological station of the National Observatory of Athens at Thiseio is variable across the year: it amounts about +2°C in spring and summer, less in fall, while no clear urbanization effect is detected in winter.[17]

References

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  1. ^ Giannakopoulos C., Hatzai M., Kostopoulou E., McCarty M., Goodess C. (2010). "The impact of climate change and urban heat islands on the occurrence of extreme events in cities. The Athens case". Proc. of the 10th International Conference on Meteorology, Climatology and Atmospheric Physics, Patras, Greece, May 25th-28th, 2010, pp. 745-752.
  2. ^ "European Space Agency ESA helps make summer in the city more bearable". Retrieved 7 November 2010.
  3. ^ Stathopoulou M., Cartalis C., Andritsos A. (2005). "Assessing the thermal environment of major cities in Greece". International Conference "Passive and Low Energy Cooling for the Built Environment", May 2005, Santorini, Greece, pp. 108-112.
  4. ^ Kassomenos P.A. and Katsoulis B.D. (2006). "Mesoscale and macroscale aspects of the morning Urban Heat Island around Athens, Greece", Meteorology and Atmospheric Physics, 94, pp. 209-218.
  5. ^ Santamouris M., Papanikolaou N., Livada I., Koronakis I., Georgakis A., Assimakopoulos D.N. (2001). "On the impact of urban climate on the energy consumption of buildings". Solar Energy, 70 (3): pp. 201-216.
  6. ^ Kassomenos P.A. and Katsoulis B.D. (2006). "Mesoscale and macroscale aspects of the morning Urban Heat Island around Athens, Greese", Meteorology and Atmospheric Physics, 94, pp. 209-218.
  7. ^ Marina S., Constantinos C. (2007). "Study of the urban heat island of Athens, Greece during daytime and night-time". Urban Remote Sensing, 11-13 April 2007, pp. 1-7.
  8. ^ Stathopoulou A., Synnefa C., Cartalis C., Santamouris M. (2007). "A heat island study of Athens using high-resolution satellite imagery and measurements of the optical and thermal properties of commonly used building and paving materials". Conference Proceedings of the 2nd PALENC Conference and 28th AIVC Conference on Building Low Energy Cooling and Advanced Ventilation Technologies in the 21st Century, Crete Island, Greece, September 2007, pp. 1016-2020.
  9. ^ Livada I., Santamouris M., Niachou K., Papanikolaou N., Mihalakakou G. (2002). "Determination of places in the Great Athens area where the heat island effect is observed". Theoretical and Applied Climatology, 71, Numbers 3-4, 219-230.
  10. ^ Livada I., Santamouris M., Niachou K., Papanikolaou N., Mihalakakou G. (2002). "Determination of places in the Great Athens area where the heat island effect is observed". Theoretical and Applied Climatology, 71, Numbers 3-4, 219-230.
  11. ^ Livada I., Santamouris M., Niachou K., Papanikolaou N., Mihalakakou G. (2002). "Determination of places in the Great Athens area where the heat island effect is observed". Theoretical and Applied Climatology, 71, Numbers 3-4, 219-230.
  12. ^ Katsoulis B. (1987). "Indications of change of climate from the Analysis of air temperature time series in Athens, Greece". Climatic Change, 10, 1, pp- 67-79.
  13. ^ Repapis C. C, Metaxas D. A. (1985). "The Possible influence of the urbanization in Athens city on the air temperature climatic fluctuations at the National Observatory". Proc. of the 3rd Hellenic-British Climatological Congress, Athens, Greece 17–21 April 1985, pp.188-195.
  14. ^ Philandras C.M, Metaxas D.A., Nastos P.T. (1999). "Climate variability and Urbanization in Athens". Theoretical and Applied Climatology, vol. 63, Issue 1-2, pp.65-72.
  15. ^ Philandras C.M, Nastos P.T. (2002). "The Athens urban effect on the air temperature time series of the National Observatory of Athens and New Philadelphia stations". Proc. of the 6th Hellenic Conference on Meteorology, Climatology and Atmospheric Physics, Ioannina Greece, 25–28 September 2002, pp.501-506.
  16. ^ Repapis C.C., Philandras C.M., Kalabokas P.D., Zerefos C.S. (2007). "Is the last years abrupt warming in the National Observatory of Athens records a Climate Change Manifestation?". Global NEST Journal, Vol 9, No 2, pp. 107-116.
  17. ^ Philandras C.M, Metaxas D.A., Nastos P.T. (1999). "Climate variability and Urbanization in Athens". Theoretical and Applied Climatology, vol. 63, Issue 1-2, pp.65-72.