A workshop was held in Casablanca, Morocco, in March 2012, to enhance knowledge of climate extremes and their changes in the Arab region. This workshop initiated intensive data compilation activities of daily observational weather station data from the Arab region. After conducting careful control processes to ensure the quality and homogeneity of the data, climate indices for extreme temperatures and precipitation were calculated. This study examines the temporal changes in climate extremes in the Arab region with regard to long-term trends and natural variability related to ENSO and NAO. We find consistent warming trends since the middle of the 20th Century across the region. This is evident in the increased frequencies of warm days and warm nights, higher extreme temperature values, fewer cold days and cold nights and shorter cold spell durations. The warming trends seem to be particularly strong since the early 1970s. Changes in precipitation are generally less consistent and characterised by a higher spatial and temporal variability; the trends are generally less significant. However, in the western part of the Arab region, there is a tendency towards wetter conditions. In contrast, in the eastern part, there are more drying trends, although, these are of low significance. We also find some relationships between climate extremes in the Arab region and certain prominent modes of variability, in particular El Niño-Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO). The relationships of the climate extremes with NAO are stronger, in general, than those with ENSO, and are particularly strong in the western part of the Arab region (closer to the Atlantic Ocean). The relationships with ENSO are found to be more significant towards the eastern part of the area of study.

The urban heat island (UHI) refers to the phenomenon of higher atmospheric 21 and surface temperatures occurring in urban areas than in the surrounding rural areas. Mitigation 22 of the UHI effects via the configuration of green spaces and sustainable design of urban 23 *Manuscript Click here to download Manuscript: ISPRS_Manuscript_final_R1_2013_12_20_final.docx Click here to view linked References 2 environments has become an issue of increasing concern under changing climate. In this paper, 24 the effects of the composition and configuration of green space on land surface temperatures 25 (LST) were explored using landscape metrics including percentage of landscape (PLAND), edge 26 density (ED) and patch density (PD). An oasis city of Aksu in Northwestern China was used as a 27 case study. The metrics were calculated by moving window method based on a green space map 28 derived from Landsat Thematic Mapper (TM) imagery, and LST data were retrieved from 29 Landsat TM thermal band. Normalized mutual information measure was employed to investigate 30 the relationship between LST and the spatial pattern of green space. The results showed that 31 while the PLAND is the most important variable that elicits LST dynamics, spatial configuration 32 of green space also has significant effect on LST. Though, the highest normalized mutual 33 information measure was with the PLAND (0.71), it was found that ED and PD combination is 34 the most deterministic factors of LST than the unique effects of a single variable or the joint 35 effects of PLAND and PD or PLAND and ED. Normalized mutual information measure 36 estimations between LST and PLAND and ED, PLAND and PD and ED and PD were 0.7679, 37 0.7650 and 0.7832, respectively. A combination of the three factors PLAND, PD and ED 38 explained much of the variance of LST with a normalized mutual information measure of 39 0.8694. Results from this study can expand our understanding of the relationship between LST 40 and street trees and vegetation, and provide insights for sustainable urban planning and 41 management under changing climate. 42 43 44 Keywords-urban heat island, urban green space, landscape metrics, configuration, normalized 45 mutual information measure. 46 Remarkable proliferations of studies focusing on the relationship between LST and green space 79 composition has been reported over the last two decades (

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