خصائص المناخ للفترات النوئية بمدينة خميس مشيط جنوب غربي المملكة العربية السعودية

الملخص EN

Climatologists usually analyze climatological data by classifying them into monthly bases.

Dealing with data for longer periods they group those months into seasons.

Need for more detailed summarized data arise and this stemmed from the fact that the "month" as a base, is considered as a long period and may conceal some important findings in relation to weather phenomena.

In literature, especially in agro meteorology and agro climatology, several studies appeared based on Pentad periods (5 days).

Again many researchers regard this base as so detailed to the extent that it may obscure their results.

Decadal (10 days) period as a base for data arrangement hence appeared and showed strong credibility.

The author of the present paper adopted the mentioned base in a previous study related to Makkah Al Mukarramah climate In this paper a well known, but scarcely looked at, 13 days "Anwaa" base is used.

Astronomically, it is known as "Lunar Arabic Zodiac".

It divides the year into 28 divisions (13 days each) according to the appearance of the moon around its orbit throughout the year Arab knew this movements, perfectly calculated it and gave each division (Nau pl.

Anwaa) a name and noticed its climatic characteristics.

The present study applied the "Anwaa" base for the study of the climatic characteristics of Kamis Musheit.

Data are arranged accordingly.

One of the many interesting findings of this study is that the differences within the same month are discovered.

This enabled the author to perfectly inspect climatic characteristics of the area.

The Anwaa base adopted is found particularly useful in agro meteorology and agro climatology, because of the fact that clarifies, to a high degree, the situation of climatic variables for even short period.

For example, it revealed with great precision the probability of frost incidents as a warning for farmers.

The method and the base adopted here are believed to be useful for different areas of research and studies as the Ministry of Agriculture, transportation, universities and those interested in applied climatology.