Meteorological Conditions
|
What the weather is like, right now, in an area of North Africa where the real Rat Patrol might have been (Jalo, Libya). |
|
|
|
[][][][][]
Khamseen
(Chamsia,
Chamsin, Kamseen, Khamsin)
Chase of Fire Raid (pilot)
|
The
episode mission
briefing |
|
There are times during the year when the prevailing winds of Libya, the area over which the Rat Patrol travelled, shift significantly from their usual direction. Then comes a time when life for the desert inhabitants becomes considerably more difficult. The winds drive up from the south, drawing super-heated, very dry air across the massive deserts - air so dry that all in its path are in danger of serious dehydration. These southern winds can force local temperatures up by as much as 50 degrees C (122 F) in the span of just a few hours and transport masses of sand and dust in the form of immense dust and sand storms.
Easterly is the direction of travel for the low pressure cells across the Mediterranean Sea that give rise to these annual southerly winds. One name for this weather phenomenon is the Sirocco, which is the Arab word for ‘easterly'.
Between late March and mid May, there are approximately fifty days when this wind may blow. Sometimes it is just a terribly hot dry dusty wind, but other times it is much more ferocious and carries great quantities of sand and dust. The Egyptian name for this wind is 'Khamseen' and it is derived from the Arabic word for fifty ("rih al khamsin" or 'wind of fifty days'). There are a number of alternate spellings of the name - Chamsia, Chamsin, Kamseen, Khamsin - but they all refer to the same hot, very dry, dusty wind blowing out of the Sahara that can bring violent sandstorms with them.
These are the winds that Moffitt speaks of in The Chase of Fire Raid (pilot). For more about what he said, see here on the Quotes page.
[][][][][]
The Ghibli, or El-ghibli, is a dry dessicating wind that blows from the desert and carries towers of dust. It is evil and feared by the desert dwellers of North Africa. The camel-masters of southwestern Libya say that during the ghibli a camel can become pregnant without the intervention of the male. It may be that Ghibli and Khamseen are the same phenomenon and are regional names for the fierce winds that blow from the south bringing sandstorms. Reference was found where not just the winds, but that the sandstorms themselves were called Ghiblis.
|
|
The Ghibli can have profound effect on the landscape by moving vast quantities of sand from one place to another. As demonstrated most clearly through photos in The Chase of Fire Raid, the desert, like a lady, can change her face daily. The Ghibli is indeed a major desert ‘face'-altering force. The term Ghibli is applied in The Rat Patrol to something other than wind or sandstorm. See where. |
(from
Chase of Fire Raid)Sahara - a Natural History by Marq de Villiers and Sheila Hirtle, McClelland and Stewart, 2003.
[][][][][]
Some odds and ends about the Ghibli (Chibli)
In 1936 an Italian engineer (Cesare Pallavicino) designed a prototype of a two-engined aircraft for use at the Italian colonies in Africa (Libya was one). It was called Ca 309 Chibli (Desert Wind).
[][][][][]
Sandstorms
|
Although sandstorms can happen any time during the year in North Africa, the most fierce occur in the spring and the autumn. A sandstorm will usually last from one to four days, but one reference mentioned a claim by some natives that five days in a sandstorm was a reasonable excuse for murder so it would appear that a sandstorm can occasionally last longer. |
|
The winds of a sandstorm can reach 144 kph (90 mph) and overturn light vehicles and bring a halt to offensives. Despite the power of the winds, grains of sand (as opposed to dust-sized particles) whipped up by winds rarely reach more than two meters (2 yards) above the ground. Dust, however, may be carried to great heights of 5,000 metres (16,000 feet) and be seen 100 kilometres (62 miles) out to sea and be carried to other continents.
|
|
The sandstorms of North Africa are described as being huge clouds of a reddish hue. Depending on the colour settings of your monitor, this scan of real Saharan desert sand will have a pinkish hue. The sand in the sample is very well sorted and fine grained with a pinkish tinge.
|
personal
account about war time desert conditions http://web.archive.org/web/20021011024849/http://freepages.family.rootsweb.com/~sarker/Sound/Sound_AppendixB.html
[note:
the above url is only currently accessible through the facilities of
archive.org. The page may be slow to load.]
[][][][][]
Will that be hot tea or iced tea?
|
The world's hottest offical temperature was recorded in Azizia Libya in September of 1922. 58 degrees C (136 F) and that was in the shade! The temperature range in the desert can be considerable. With the lack of moisture in the air, there can be a rapid loss of heat come nightfall, giving a daily range of 30 degrees C (86 F) . It is not uncommon for there to be night time freezing temperatures between December and February.
No wonder Moffitt was 'bloody cold' and wanted a cup of hot tea in Chase of Fire Raid.
When it was really cold they might have consumed something other than tea. See what here. |
|
[][][][][]
Water, water everywhere.
|
|
No, that isn't really a band of Arab horsemen riding out of an inland desert sea to attack the Rat Patrol although it looks like it. It's a mirage. Mirages, of the sort the Rat Patrol saw here, arise because of the way light travelling through air can be 'bent'. Suncompass does not intend to get into detailed physics here (not that she'd be totally comfortable with doing so anyway) but in simplest terms here is how it is that you (or the Rat Patrol) might see a mirage in the desert or elsewhere. |
|
Light travels in a straight line through a medium (air, water, beer, glass, whatever) of consistent density, but when the light travels from one medium to another with a different density, it bends (refracts). (if you don't believe Suncompass, just put a straw into a glass of water or beer or Ghibli and see that it looks bent.) The greater the change in density, the greater the amount of 'bending' of the light. Air does not everywhere have the same density. Heated air is less dense than cooler air. In the desert (or over a hot bit of pavement) air can become very hot just above the heated surface. This creates a thin layer of less dense air - considerably less dense than the air higher up. The light travelling from the sky bends upward through the ultra heated air layer next to the ground so our eye thinks there is a patch of water on the ground reflecting the sky above it.
There
are many good sites to learn about mirages but here's one where you
can find a good explanation of the Inferior Mirage: |