Determination of annual and seasonal daytime and nighttime trends of MODIS LST over Greece - climate change implications

摘要

AbstractClimate change is one of the most challenging research topics during the last few decades, as temperature rise has already posed a significant impact on the earth's functions thus affecting all life of the planet. Land Surface Temperature (LST) is identified as a key variable in environmental and climate studies. The present study investigates the distribution of daytime and nighttime LST trends over Greece, a country in the Mediterranean area which is identified as one of the main “hot-spots” of climate change projections. Remotely sensed LST data were obtained from MODerate Resolution Imaging Spectroradiometer (MODIS) sensor in the form of 8-day composites of day and night values at a resolution of 1km for a 17-year period, i.e. from 2000 to 2017. Spatial aggregates of 10km×10km were computed and the annual and seasonal temporal trends were determined for each one of those sub-areas. Results showed that annual trends of daily LST in the majority of areas demonstrated decrease ranging from −1∗10–2°C to −1.3∗10−3°C, with some sporadic parts showing a slight increase. A totally different outcome is observed in the fate of night LST, with all areas over Greece demonstrating increasing annual trends ranging from 4.6∗10−5°C to 3.1∗10–3°C, with highest values in the South-East parts of the country. Seasonal trends in day and night LST showed the same pattern, i.e., a general decrease in the day LST and a definite increase in night. An interesting finding is the increase in winter LST trends observed both for day and night LST, indicating that the absolute minimum annual LST observed during winter in Greece increases. Our results also indicate that the annual diurnal LST range is decreasing.Graphical abstractDisplay OmittedHighlights•Daytime and nighttime MODIS LST data all over Greece were obtained for 2000–2017.•Annual and seasonal trends of daytime and nighttime LST were computed.•Spatial trends were also highlighted.•Diurnal LST range trends were also evaluated on an annual and seasonal basis.•Climate change is expressed as increase in LSTminand decrease in diurnal range.