RESEARCH ARTICLE


The Relationship between the Mean Surface Air Temperature in Egypt and NAO Index and ENSO



Y.Y. Hafez*, S.M. Robaa
Astronomy & Meteorology Department, Faculty of Science, Cairo University, Giza, Egypt, 12613


© 2008 Hafez and Robaa.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Astronomy & Meteorology Department, Faculty of Science, Cairo University, Giza, Egypt, 12613; E-mail: d_hafez@hotmail.com


Abstract

The relationship between the NAO index and ENSO and the mean surface air temperature over Egypt has been investigated. The NCEP/NCAR reanalysis data of the monthly mean surface air temperature over Egypt for the period (1948-2005) have been used in this study. The corresponding monthly mean values of NAO index, SOI, and El-Nino3 have been also used. Monte Carlo methodology as a linear correlation analysis has been used to obtain the correlation coefficient between the mean surface air temperature over Egypt and NAO, SOI, and El-Nino3 through the period (1948-2005). The results show that surface air temperature in Egypt is significantly correlated with the climatic index NAO and ENSO only for a south western part of Egypt. There is a significant negative correlation (-0.6) between surface air temperature over south west part of Egypt in winter season and NAO index. The relationship between EL-Nino3 and surface air temperature has contradicted the relationship with SOI. Whereas, a significant positive correlation (+0.6) between surface air temperature over south west part of Egypt and EL-Nino3 in autumn season. Surface air temperature correlated with SOI by a significant negative correlation (-0.5) during the same season over south west of Egypt. It is concluded that the surface air temperature is significantly correlated with NAO index and ENSO over the south west part of Egypt.

Keywords: Surface air temperature, NAO index, EL-Nino3, SOI, ENSO.