18
19
Very low clouds in a typhoon move with the wind, but if the clouds are higher they move romture, if the typhoons that recurve in the China Sea are not taken into account.
A vessel having the centre in front and to either side, but more in towards the centre in rear. A heavy nimbus cxpericuced a typhoon is not likely to fall in with it again after it has recurved, but it happens to passing to leeward causes heavy squalls, veering or backing regularly; and to windward it has tessels in the Pacific, especially to such as have suffered damage and been carried all round the centre opposite effect. The cause of this is obvious.
then they first met the typhoon.
0.08 to 10, 0.09, 0.10 and 0.11 to 11, 0.12 and above this to 12.
he
336
The wind blows from a region where the air pressure is higher towards one where it is lo Typhoons cease to exist, except as minor depressions, as soon as the centre euters the mainland. It is, however, deflected towards the right in the northern hemisphere. The force of the wind depent centres of different typhoons often enter the coast in the same place: where it is low, as for upon the difference of pressure between one place and another situated in the direction where the stance, the Lien-chau peninsula; near Hailingsan; the Canton river, etc. The typhoons originate barometric slope or gradient is greatest. The gradient is measured in hundredths of an inch per ring squalls in hot and damp places near sea-level and over the sea. Storias in N China originate nautical miles. The force of the wind corresponding to a certain gradient is greater the hotter the higher up in the air on the mainland across which they move, and they do not appear to increase in is, and is different in a typhoon from what it is in the trade, owing to the path of the air partice strength so quickly as the typhoons, when the centro reaches the sea. Islands-even Formosa with is high mountains-do not affect a typhoon's path much though they tend to break the typhoon up, being curved. They are almost logarithmic spirals, but somewhat different from such curves. gradient of 0.01 corresponds to force 4, 0.02 to 6. 0.03 to 7, 0.04 to 8, 0.05 to 9, 0.06 to 91, 0.07 as some extent, as is particularly noticeable in case of typhoons remaining long over the southern
The steepest gradient usually hiippines or crossing Formosa moving from S towards "N.
On the contrary, open channels such with is a third of an inch in 15 nautical miles. Gradients above this are rare, but sometimes they are the Balingtang Channel, the Formosa aud Korea Chanuels, have much greater effect on the path. much greater. The steepest gradient (1 inch in 15 miles) ever met with occurred in a low latitulat has already been remarked that the progression of a typhoon is the effect of the wind prevailing at the Pacific. That corresponds to a wind velocity of perhaps about 160 miles per hour at sea to be time at or near the earth's surface. Now, the wind rushes with such force through open channels, Such velocities are not common at an altitude of 2,000 feet in severe typhoons. Anything aborth more or less high mountains on both sides, as to deflect the typhoons and accelerate their speed. 80 miles per hour is called a typhoon. It is seen that there is as great difference between the fore this is sometimes seen in the China Sea, when the centre of a typhoon is moving slowly northwards. As soon as the centre approaches the latitude of the Balingtang Channel, the centre bends its way one typhoon and another as between a calm and a storm which nearly reaches typhoon force.
uddenly to the Westward, and rushes towards Hainan perhaps thrice as quickly as it moved before. When a typhoon is blowing it is of great importance to have a house well shut-up. Window typhoons entering the Formosa Channel and at times the Korea Channel are deflected to the West- and doors should be firmly locked, bolted and barred. Damage is frequently caused by shutters beard and have their speed accelerated by the strong NE winds in those Channels. As long as the out of repair. Once the wind enters a broken window, it begins to blow through and its force is the monsoon is strong, the typhoons move in some Northerly direction. It is only late in the year As long as all apertures are thoroughly shut on both sides a fearful howling a hen the NE monsoon happens to blow very fresh that typhoons move South-westward in the China quickly felt. whistling is heard, the rain blows in through the smallest openings and the house may shake, ba damage is seldom done. Should a fierce squall get the chance to blow into a house, the roof is ofte the first part to give way. It is believed that pressure falls so quickly outside that the air confine in the house bursts through the roof like an explosion, but there is no foundation for that belief; it more likely that a fierce squall would break through the windows and doors and through the roofs well. But if any fear is entertained of the air being confined inside, it is merely necessary to las the chimneys open so that pressure inside will be nearly the same as on the outside.
In many typhoons the barometer, reduced to the temperature of freezing water and to sea-lerd does not fall below 28.80 inches. In others it falls as low as 28.50. Lower readings are rare, sometimes it falls much lower,
Most off
No typhoon ever stands still. As soon as it is formed, it is carried forward by the prevail wind. That is why the isobars are elongated, except near the centre where the force of the prevai ing wind is of no account. The isobars could be circular only in a stationary typhoon. The also why typhoons move so as to keep the areas of high baroneter on their right, and so as to rece from areas where the barometer is high, and so as to approach low-pressure areas. typhoons that originate in the Pacific to the East of the Philippines or Formosa move Westward first, then NW. then N., then they recurve to the NE, and beyond Japan they move Eastward. is under the influence of the high-pressure area in the Northern Pacific, which they rotate around the same direction as the hands of a watch. When there are two typhoons about at the same they rotate round each other in the opposite direction, that is, abstracting from the influence of high-pressure areas, which may cause them to move somewhat differently from this simple rak. the China Sea there is sometimes a low-pressure channel between high pressures in China and in Southern part of the China Sea. A typhoon in the Pacific at such times is attracted towards i China Sea and passes along the low-pressure channel, because the winds blowing to either side off channel agree with the winds round the centre of a typhoon, and they move according to the prosj of least action. During the typhoon season typhoons follow each other quickly, and there are several at one time raging in different parts of the Far East. Then they cease, and there are maybe for several weeks; but during the height of the season in August and September that is unusual.
As explained above, the paths of typhoons in the Pacific look often like parabolas, but those the China Sea are quite different and the difference must be due to the distribution and land ands The latter do not as a rule recurve, ie., move North-eastward after having moved North-westwards Northward. Some of them, in fact, disappear in the China Sea after turning to the SW. recurve between 20 deg. N and 40 deg. N, and between 115 deg. E and 180 deg. E. Dog lighthouse at the Northern entrance to the Formosa Chunnel is the centre of the region of ret
The 3
* Curved lines drawn on a map through places from which the same height (corrected and reduced) of the barometer is repor between those that report a slightly higher and lower pressure are called isobars. The gradient lies at a right-angle to the isobar. 1 the most important elements for Forecasting the weather. The curvature of isobars indicates the existence of depressions beyond the ar the telegraphic reporting stations are situate, but it is of course impossible to lay down the centre accurately from such data. rg, wik the sea its position and motion can only be guessed at, not known with certainty.
W
5
29.50
29.59
N
6
10
E
29.40
2930
5
9
Typhoon in the Formosa Channel
1884 August 21-22.
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10
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