Meteorology of the Red Sea and Cape Guardafui Author(s): R. Strachey Source: Proceedings of the Royal Geographical Society and Monthly Record of Geography, New Monthly Series, Vol. 10, No. 11 (Nov., 1888), pp. 704-708 Published by: Wiley on behalf of The Royal Geographical Society (with the Institute of British Geographers) Stable URL: http://www.jstor.org/stable/1801400 . Accessed: 20/06/2014 14:33 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp . JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. The Royal Geographical Society (with the Institute of British Geographers) and Wiley are collaborating with JSTOR to digitize, preserve and extend access to Proceedings of the Royal Geographical Society and Monthly Record of Geography. http://www.jstor.org This content downloaded from 188.72.126.108 on Fri, 20 Jun 2014 14:33:13 PM All use subject to JSTOR Terms and Conditions 704 METEOROLOGYOF THE RED SEA AND CAPE GUARDAFUI. To the west dwell?or dwelt?the Abchasians and Cherkess (the Circassians of romance), tribes of whose origin, affinities,and customs we have still no fully satisfactory account. Recent enquiries pursued among Circassian exiles in Turkey have led a German investigator to the belief that the leading families at least had connections with Arabia.* " iEschylus, we may remember, wrote of the martial bloom of Arabia, who hold a citadel on lofty crags hard by Caucasus.,, Are the Cir? cassians Semites ? What is their language ? Much remains to be done in investigating the antiquities and origins of these loose confederacies of chivalrous but semi-barbarous tribes, and in clearing up their historical connection with their neighbours on the north, the Tartars of Karatchai and Uruspieh, and the tribes of the Kabardah, who apparently came east- wards from the Crimea.f It is time that I brought to an end this discursive?some may call it, not unjustly, desultory?paper. I shall submit cheerfully to the criticism, if by touching on very various topics I have, perchance, attained my object, to show that it is not only to mountaineers and geographers that this great mountain country is interesting. The Caucasus ought for many years to come to provide ample material for workers in every branch of natural science, as well as for historical and ethnological students; and, last but not least, for the lover of noble scenery and primitive life who views the out ward shows of the world without com- " mitting himself to the special study of any particular branch" of knowledge,? " Contentedif he mayenjoy The thingswhich others understand." Meteorology ofthe Eed Sea and Ga^e Guardafui.% By General B. Stkachey r.e., f.r.s., pbesident b.g.s. Charts, p. 748. Weather Charts of the Bed Sea for January and July.?In these charts,which have been prepared in the Marine Branch of the Meteorological Office,under the supervision of Captain Toynbee and Lieutenant Baillie, the usual system of exhibiting the pressureand temperature,by isobars and isotherms,has not been adopted, as the necessary informationis entirelywanting. The diagrams, * * Petermann'sMitteilungen,' vol. xxxiv. * t For furtherinformation on Caucasian ethnology,see au * Klaproth, Voyage Caucase'; Journalof the Eoyal Asiatic Society,'articles by Mr. E. N, Cust (with list of authorities)and Mr. D. Morgan,vols. xvii, xviii.; 'Petermann's Mitteilungen/ ' vol. xxiii.; V. Miiller's Ossete Studies'; Prof. Kovalevsky's,Uslar's, and Schiefner's works(in Russian); E. Chantre'sfinely illustrated volumes. The above referencesare incomplete,but they may suffice to set a studenton the track. A fineethnological map of the Caucasus has been publishedby the Government. X Read to the GeographicalSection of the BritishAssociation, Bath, Sept. 6th,1888. This content downloaded from 188.72.126.108 on Fri, 20 Jun 2014 14:33:13 PM All use subject to JSTOR Terms and Conditions METEOROLOGYOF THE RED SEA AND CAPE GUARDAFUI. 705 therefore,have been preparedso as to give what may he terrneda sectionalview of the data reeorded,referred to a line supposed to be drawn along the axis of the Red Sea, correspondingto the usual tracks of vessels, and prolongedin like manner throughthe Gulf of Aden. January. North-eastMonsoon Season. Wind.?The northerlywind blows almost uninterruptedlyfrom the Gulf of Suez to about 23? N., and continuesas the prevailingwind to about 19? N., whilst furtherto the southwardthe south-easterly wind prevails. From 23? N. to about 15? N. thereis a minglingof the winds from the principal directionsof north and south-east,and from18? to 20? N. the winds fromthese directionsare of almost equal frequency(this area is shaded darker in the diagram). In the Gulf of Aden the wind is principally easterly, and draws somewhatfrom the northwardin the easternpart. Calms are most frequentbetween Aden and 20? N., hut they forma very small proportionof the observations. The forceof the wind is rather strongerwith the south-easterlywinds than with the northerly,and the strengthof a moderate or freshgale is frequentlymet with betweenPerim and 20? N. * Barometer.?The mean heightof the barometerranges from about 30 10 inches in the Gulf of Suez to 29*97 inches in about 15? N., giving a gradient of 0*13 in about 1100 miles. A second maximum about 30'06 inches is shown in the eastern part of the Gulf of Aden, givinga gradientof a rathersmaller amount,but extend- ing over only about half the distanceor less. The resultsdeduced fromthe several sources(logs in the MeteorologicalOffice, of P. and O. ships,and fromthe Admiralty) agree well among themselves. Air Temperature.?The mean air temperatureranges from about 64? in the Gulf of Suez to 79? in 16? N. In the Gulf of Aden the mean temperatureis generallyabout 77?. Current.?The general driftof the currentis to the westward in the Gulf of Aden and to the N.N.W. in the Red Sea; its strengthis very light, and nowhere does it exceed a knot an hour; as a rule it is less than half a knot an hour. Sea Temperature.?The mean sea temperatureranges from 65? in the Gulf of Suez to 79? in 19? N., and fromthis position southward,as well as in the Gulf of Aden, the temperatureis between 77? and 79?. These temperaturesare somewhat higher?1? or 2??than those of the air. ? SpecificGravity.?The mean specificgravity ranges from1 0314 in the Gulf of Suez to 1*0270 iu the Gulf of Aden, the decreasebeing fairlygradua1. July. South-west Monsoon Season. Wind.?The direction of the wind is generallyfrom the northwardand north-westwardover the whole area of the Red Sea, drawing more westerlyin the southernpart, whilst in the Gulf of Aden the prevailingdirection is westerlyand south-westerly. The mean forceof the wind is about the same in differentparts of the district,but the individual observations show that the forceof a gale is attaincd only in the Gulf of Suez and in the Gulf of Aden, strongestin the latter. Calms are about twice as numerousas in January and now formabout 15 per cent. of the total wind observations. * Barometer.?The mean barometerranges from29 79 inches in the Gulf of Suez to 29' 67 inches offAden, being throughoutabout 0* 30 inches lowerthan in January. The resultsobtained fromthe MeteorologicalOffice and P. and O. observationsare in good agreement. The gradient between the northernand southernends of the sea remainsabout the same, but the minimumin lat. 15? N. is no longerobserved, and with it the relativelyhigh pressureover the Gulf of Aden also disappears. Air Temperature.?The mean air temperatureranges from about 82? in the Gulf of Suez to 90? in the southernpart of the Red Sea. A sharp fall is shown on approachingPerim, and a second minimum of 84? is reached off Aden. These This content downloaded from 188.72.126.108 on Fri, 20 Jun 2014 14:33:13 PM All use subject to JSTOR Terms and Conditions 706 METEOROLOGYOF THE RED SEA AND CAPE GUARDAFUI. temperaturesare higherthan thoseof Januaryby 18? forSuez, 11? forthe southern part of the sea, and 7? forthe Gulf of Aden. Current.?The currentis excessivelyslight in the Red Sea. A tendencyto a south-south-easterlyset is, however,indicated between 17? and 20? N., and thereis also some evidenceof a very weak northerlyset in the northernpart of the district. On approachingPerim there is an indicationof a currentsetting from the Red Sea throughthe straitsof Bab-el-Mandeb. In the Gulf of Aden a strongeasterly eurrent is manifestedon the Arabian side, and a somewhat weaker currentis shown to be settingto the westwardon the Africanside. Sea Temperature.?The temperatureof the sea ranges from77? in the Gulf of Suez to 89? in the southernpart of the Red Sea, and like the air temperatureit tben decreases rapidlyto 84? near Perim, the minimumof 81? being reached offAden; in the easternpart of the gulf it again increasesto 84?*5. These temperaturesare respectivelyhigher than those observed in January, by 12? at Suez, 10? in the southernparts of the sea, and from3? to 5? in the Gulf of Aden. The sea tempera? ture in July in the Gulf of Suez is 5? lower than that of the air, in the southern part of the sea about 1? lower. SpecificGravity.?The specificgravity ranges from1*0310 in the Gulf of Suez to 1*0267 offAden, whilst a slight increase is shown in the eastern part of the gulf. The winds and the currentsat the two seasons obviouslyfollow the pressureand temperature.