Advances in Geosciences
www.adv-geosci.net
1680-7340
1680-7359
12
Mediterranean storms and extreme events in an era of climate change
2007
10.5194/adgeo-12-137-2007
http://www.adv-geosci.net/12/137/2007/
http://www.adv-geosci.net/12/137/2007/adgeo-12-137-2007.html
http://www.adv-geosci.net/12/137/2007/adgeo-12-137-2007.pdf
137
143
2007-10-15
Synoptic climatological analysis of Red Sea Trough and non-Red Sea Trough rain situations over Israel
Y. Tsvieli
A. Zangvil
zangvil@bgu.ac.il
The Blaustein Institute for Desert Research, Ben Gurion University, Sde Boker Campus, Israel
Winter (October to April) rainfall in Israel is caused mostly by migrating
Mediterranean cyclones but certain rain situations are accompanied by a low
pressure trough extending northward from the southern Red Sea towards the
Eastern Mediterranean (EM) and the Levant. This system, the Red Sea Trough
(RST) is one of the most frequent surface atmospheric circulation patterns
over the southeastern Mediterranean, but most of the RSTs are not
accompanied by rain. This paper presents a synoptic climatological
comparative analysis between rain situations associated with RSTs, and those
not connected with RSTs (non-RST rain, NRR). The RST situations were
identified objectively with the aid of a new algorithm applied to the GEOS-1
reanalysis gridded data set from NASA, for the period of March 1985–November 1995.
<br><br>
Results show that RST rain is accompanied by a relatively narrow 500-hPa
trough, located west of the Israeli coast-line and characterized by a deep
southward penetration, while Non-RST-associated rain (NRR) is accompanied by
a wider upper trough, located over the Israeli coast-line with a shallower
southward penetration. We found a south-southwesterly wind vector anomaly at
200 hPa over Israel during RST rains, while during NRRs a similar wind
vector anomaly pattern is observed east of Israel. There is a divergence
center over, or a few degrees east of Israel during RST rains, while NRR is
associated with a divergence value of nearly zero over Israel and a maximum
divergence center located east of Israel. The moisture flux during NRR at
700 and 900 hPa is from the Mediterranean, while during RST rain there is a
south-westerly moisture flux at 700 hPa from equatorial Africa to Israel and
vicinity. A steeper temperature lapse-rate between 950–500 hPa was found
during RST rain compared with NRR, resulting from a combination of cooling
aloft together with heating near the surface.
Air Ministry, Meteorological Office: Weather in the Mediterranean, Vol. I, London, HMSO, 362 pp., 1962.
Alpert, P. and Shay-El, Y.: The moisture source for the winter cyclones in the Eastern Mediterranean, Israel Meteorological Research Papers, 5, 20–27, 1994.
DaSilva, A. and Alpert, P.: Documentation of the multi-year GEOS-1 assimilation data subset for Northern Africa, the Mediterranean and the Middle East. NASA, Goddard Space Flight Center, DAO Office Note 96-05, 24~pp., Feb. 1996.
Dayan, U. and Sharon, D.: Meteorological parameters for discrimination between widespread and spotty storms in the Negev, Israel J. Earth Sci., 29, 253–256, 1980.
Doty, B. E.: Grid Analysis and Display System (GrADS), Center for Ocean-Land-Atmosphere Interaction, Institute for Global Environment and Society, Calverton, MD, 1988.
Fengjun, J.: The connection between water vapor budget components and rainfall in the Eastern Mediterranean, M.S. Thesis, Blaustein International School for Desert Studies, Ben Gurion University, 63 pp., 2005.
Goldreich, Y.: The Climate of Israel: Observation, Research and Applications, Kluwer Academic/Plenum Publishers, New York, 298 pp., 2003.
Itzigsohn, D.: Dynamical and climatological analysis of interactions between the tropics and mid-latitudes in the Red Sea area, MSc Thesis, Department of Geophysics and Planetary Sciences, Tel Aviv University (in Hebrew), 137 pp., 1995.
Kahana, R., Ziv, B., Enzel, Y., and Dayan, U.: Synoptic climatology of major floods in the Negev Desert, Israel, Int. J. Climatol., 22, 867–882, 2002.
Karas, S. and Zangvil, A.:. A preliminary analysis of disturbance tracks over the Mediterranean Basin, Theor. Appl. Climatol., 64, 239–248, 1999.
Kidron, G. J. and Pick, K.: The limited role of localized convective storms in runoff production in the western Negev Desert, J. Hydrol., 229, 281–289, 2000.
Krichak, S. O, Alpert, P., and Krishnamurti, T. N.: Interaction of topography and tropospheric flow – a possible generator for the Red Sea Trough?, Meteorol. Atmos. Phys., 63(3–4), 149–158, 1997a.
Krichak, S. O., Alpert, P., and Krishnamurti, T. N.: Red Sea Trough/cyclone development – numerical investigation, Meteorol. Atmos. Phys., 63(3–4), 159–169, 1997b.
Leguy, C., Rindsberger, M., Zangvil, A., Issar, A., and Gat, J. R.: The relation between the oxygen-18 and deuterium contents of rainwater in the Negev desert and air mass trajectories, Chem. Geol. (Isotope Geoscience Sec.), 1, 205–218, 1983.
Malka, S.: Analysis of the water vapor field and synoptic characteristics in relation to temporal and regional variation of precipitation in Israel, M.S. Thesis, Blaustein International School for Desert Studies, Ben Gurion University, 99 pp., 2006 (in Hebrew).
Saaroni, H., Ziv, B., Bitan, A., and Alpert, P.: Easterly wind storms over Israel, Theor. Appl. Climatol., 59, 61–77, 1998.
Sasson, A.: Connection between synoptic characteristics and atmospheric moisture field and major rain storms over Israel, Masters Thesis, Dept of Geography and Institute for Desert Research, Ben Gurion University, 115 pp., 1990 (in Hebrew).
Sasson, A. and Zangvil, A.: Preliminary report on the connection between the atmospheric moisture field measured by the METEOSAT-2 satellite and precipitation in Israel, Israel Meteorological Research Papers, 5, 79–82, 1994.
Tsvieli, Y. and Zangvil, A.: Synoptic climatological analysis of "wet" and "dry" Red Sea Troughs over Israel, Int. J. Climatol., 25, 1997–2015, 2005.
Tsvieli, Y.: Synoptic climatological analysis of "wet" and "dry" Red Sea Troughs over Israelm Ph.D thesis, Department of Geography and Environmental Development, Ben-Gurion University of the Negev, Israel, 98 pp., 2006 (in Hebrew).
Yakir, D., Lev-Yadun, S, and Zangvil, A.: El Nino and tree growth near Jerusalem over the last 20 yearsm Global Change Biol., 2, 97–101, 1996.
Zangvil, A. and Shemer, D.: The climate of the Negev, in: Atlas of the Negev, edited by: Stern, E., Gradus, Y., Meir, A., Krakover, S., and Tsoar, H., Department of Geography, and the Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Beer-Sheva, 1986 (in Hebrew).
Zangvil, A. and Druian, P.: Upper air trough axis orientation and the spatial distribution of rainfall over Israel, Int. J. Climatol., 10, 57–62, 1990.
Zangvil, A. and Isakson, A.: Structure of the water vapor field associated with an early spring rainstorm over the eastern Mediterranean, Israel J. Earth Sci., 44, 159–168, 1995.
Zangvil, A., Karas, S., and Sasson, A.: Connection between Eastern Mediterranean seasonal mean 500 hPa height and sea-level pressure patterns and the spatial rainfall distribution over Israel, Int. J. Climatol., 23, 1567–1576, 2003.
Ziv, B.: The weather in Israel, in: Introduction to Meteorology, edited by: Ziv, B., and Yair, Y., The Open University Press, Tel Aviv, Israel, Unit 5, 8–59, 1994 (in Hebrew).