Monthly and annual variations in the rainfall pattern alongthe Southern Levantine Coastline

Monthly and annual variations in the rainfall pattern alongthe Southern Levantine Coastline

Tarek M. El-Geziry

طارق محمد الجزيري

Marine Environment Division – Physical Oceanography Lab (NIOF)

Research in Marine Sciences, 2021, 6 (2): 915-925

https://resmarsci.com/

(NotIndexed in Scopus)

Abstract:

Monthly and annual rainfall variations along the southern Levantine Basin were studied using a12-year time data series (2009-2020) from six locations: Marsa Matrouh, Alexandria, Rosetta,Damietta, Port Said, and Arish, from west to east, respectively. The general statistics werecalculated in addition to the coefficients of variations, the seasonal variation index, the precipitationindex, and the cross-correlations. The highest mean monthly rainfall occurred in January (MarasaMatrouh and Rosetta), in November (Alexandria, Damietta and Port Said) and in March (Arish). The lowest mean monthly rainfall for all locations was in September. The highest annual amountof rainfall was 441.1 mm in 2020 in Rosetta, while the minimum was 22.56 mm in 2010 in MarsaMatrouh. The southern border of the Levantine received 8193.61 mm of rainfall over the period2009-2020, with a precipitation rate of 2.28 mm/rainy day. Alexandria had the highest rate (3.33mm/rainy day), while Arish had the lowest rate (1.78 mm/rainy day). On the other hand, Port Saidhad the highest number of rainy days (701 days), while Arish had the lowest number (566 days).

Five locations exhibited seasonal rainfall in 3 months or less with high concentration except MarsaMatrouh where long dry seasons persisted. The indices of seasonal variations and precipitationconcentration showed that rainfall is highly seasonal and highly concentrated in five locationsreceiving rainfall in three months but Marsa Matrouh, which has markedly seasonal rainfall regimewith a long dry season. The cross-correlations suggested two distinct rainfall zones along thesouthern Levantine Basin: zone 1 extends from Marsa Matrouh to Port Said and zone 2 comprisesonly Arish. The rainfall variability along the southern Levantine coastline is substantially higher ona monthly or seasonal basis than on a yearly basis, and its spatial distribution is heavily influencedby local factors such as topography and location.

Keywords: Egypt; Southern Levantine; Rainfall; Seasonal index; Precipitation concentration index; Coefficient of variation

Corresponding author e-mail:[email protected]