The effect of North Atlantic Oscillation (NAO) on the rainfall in Tobruk region. For period: (1985 - 2018)

Abstract

    This research dealt with the effect of the North Atlantic Oscillation on the amounts of rain in the Tobruk region located in the northeastern part of Libya. To identify the relationship between the two variables, the monthly record of the negative NAO indexes and the amounts of rain in Tobruk station for period 1985 - 2018.

    The results indicated that there is a weak positive correlation and a weak positive direct relationship between the amounts of rain and the negative (NAO) periods in most months and a medium positive relationship, especially in the months of April and December. The study showed that most of the months and years in which precipitation decreases or increases in the region are not related to the NAO indexes.

    Although there was a relative increase in the negative indicator of (NAO) during several consecutive months and in separate years, there was no effect on the increase in the amount of rain in Tobruk station, as this clearly showed during 2010, except for a weak effect  on September, October, November and December 2009.

   In general, during the transitional seasons (spring and autumn) there was a weak relationship between the two variables, especially in the months of March, April and November, while the summer season remained without a effect over the past three decades.