Premium
Factors affecting isotopic composition of the rainwater in the Negev Desert, Israel
Author(s) -
Dody Avraham,
Ziv Baruch
Publication year - 2013
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/jgrd.50592
Subject(s) - rainwater harvesting , entrainment (biomusicology) , middle latitudes , environmental science , mediterranean climate , atmospheric sciences , climatology , geology , geography , ecology , philosophy , archaeology , rhythm , biology , aesthetics
Abstract The study examines the δ 18 O of rain observed in the middle of the Negev Desert, Israel, based on seven rainstorms, associated with convective clouds resulting from midlatitude cyclones found over Trans‐Jordan. The analysis is based on synoptic maps, vertical atmospheric cross sections, and air back trajectories. The rainwater sampling was done in temporal scale of hours. Four known factors were addressed here: the temperature effect, the amount effect, and two geographical effects: the marine and continental effects. The temperature effect is expressed by a positive relation between the lower level temperature and the isotopic composition. The amount effect, related to rainfall, is negative. The marine effect, expressed by a relation between the time the rain‐producing air spends above the Mediterranean Sea, is positive and the continental effect, associated with the passage over land is negative. The linear relationships found in this study met the expectations, although only the amount effect was statistically significant. A fifth effect, entitled cloud top effect proposed here, relates to the height of the convective cloud layer top. It assumes that lower top prevents entrainment of upper cold air into the clouds, so the isotopic composition is enriched. The cloud top effect was found most statistically significant.