全校氣象：3風(fēng)及云的觀測

1、風(fēng)力等級表 (bbc視頻),風(fēng)的觀測,海浪（Sea Wave),海浪與海流都是海水運(yùn)動的重要形式，對船舶航行有很大的影響。大風(fēng)浪造成航速下降，舵效降低，甚至停止不前；在狂濤巨浪中還會出現(xiàn)“中垂”或“中拱”使船舶結(jié)構(gòu)變形，嚴(yán)重時造成船體斷裂，導(dǎo)致重大海難事故。,海浪按其形成原因分為：風(fēng)浪、涌浪、近岸浪、內(nèi)波、潮汐波、海嘯、風(fēng)暴潮。,Force 0. Wind Speed less than 1 knot.Sea: Sea like a mirror.,Force 1:Wind Speed 1-3 knots.Sea: Wave height 0.1m; Ripples with appearan

2、ce of scales, no foam crests.,Force 2: Wind Speed 4-6 knots.Sea: Wave height 0.2-0.3m; Small wavelets, crests of glassy appearance, not breaking.,Force 3: Wind Speed 7-10 knots.Sea: Wave height 0.6-1m; Large wavelets, crests begin to break, scattered whitecaps.,Force 4: Wind Speed 11-16 knots.Sea: W

3、ave height 1-1.5m; Small waves becoming longer, numerous whitecaps.,Force 5: Wind Speed 17-21 knots.Sea: Wave height 2-2.5m; Moderate waves, taking longer form, many whitecaps, some spray.,Force 6: Wind Speed 22-27 knots.Sea: Wave height 3-4m; Larger waves forming, whitecaps everywhere, more spray.,

4、Force 7: Wind Speed 28-33 knots.Sea: Wave height 4-5.5m; sea heaps up, white foam from breaking waves begins to be blown in streaks along direction of wind.,Force 8: Wind Speed 34-40 knots.Sea: Wave height 5.5-7.5m; Moderately high waves of greater length, edges of crests begin to break into spindri

5、ft, foam is blown in well marked streaks.,Force 9: Wind Speed 41-47 knots.Sea: Wave height 7-10m; High waves, sea begins to roll, dense streaks of foam along wind direction, spray may reduce visibility.,Force 10: Wind Speed 48-55 knots.Sea: Wave height 9-12.5m; Very high waves with over-hanging cres

6、ts, sea takes white appearance as foam is blown in very dense streaks, rolling is heavy and shock like, visibility is reduced.,Force 11: Wind Speed 56-63 knots.Sea: Wave height 11.5-16m ; Exceptionally high waves, sea covered with white foam patches, visibility still more reduced.,卷云Cirrus (Ci) 絲縷狀，

7、分離散亂，白色無暗影當(dāng)時晴天 天上鉤鉤云，三五日內(nèi)雨淋淋,卷積云Cc：云塊很小，白色細(xì)鱗片狀（魚鱗斑），成行排列，象風(fēng)吹過的水面引起的波紋 當(dāng)時晴天，夏天可能是雷雨的前兆 魚鱗天，不雨也風(fēng)癲,卷層云(Cs)-均勻成層，灰白，日月輪廓清楚，地物有影，常見暈。日暈三更雨，月暈午時風(fēng)日暈不過三，過三天大旱,高層云(As)-灰色或灰白，常布滿天空，有時出現(xiàn) 華 可能有小的降水,高積云 (Ac) 云塊輪廓分明，常呈瓦塊、扁圓、鯉魚片、視寬度1-5最常見的天空,層積云 (Sc) -視寬度5，灰或白，滾軸狀，成群成行出現(xiàn) 間歇性降水,層云St，均勻成層，灰或灰白，象霧不接地 可有毛毛雨,雨層云(Ns)- 低

8、而漫無定形，均勻成層，完全遮蔽日月，伴有連續(xù)性降水 天上灰幕懸，地下雨連綿,積云 (Cu)-云體垂直發(fā)展，底部水平，頂部不規(guī)則隆起 通常晴天，濃積云可伴陣雨,積雨云(Cb)- 垂直發(fā)展極其旺盛 雷陣雨、冰雹、龍卷等強(qiáng)對流天氣,氣象觀測網(wǎng),常規(guī)觀測網(wǎng)。長期穩(wěn)定地進(jìn)行觀測，主要為日常天氣預(yù)報、災(zāi)害性天氣監(jiān)測、氣候監(jiān)測等提供資料的觀測系統(tǒng)。例如由世界各國的地面氣象站（包括常規(guī)地面氣象站、自動氣象站和導(dǎo)航測風(fēng)站）、海上漂浮（固定浮標(biāo)、飄移浮標(biāo)）站、船舶站和研究船、無線電探空站、航線飛機(jī)觀測、火箭探空站、氣象衛(wèi)星及其接收站等組成的世界天氣監(jiān)視網(wǎng)（WWW）,就是一個規(guī)模最大的近代全球氣象觀測網(wǎng)。 專題觀測

9、網(wǎng)。根據(jù)特定的研究課題，只在一定時期內(nèi)開展觀測工作的觀測系統(tǒng)。,船舶海洋水文氣象觀測,1觀測意義：（1）彌補(bǔ)海上測站稀少，資料不足的狀況。（2）對天氣預(yù)報進(jìn)行補(bǔ)充訂正。（3）為氣象導(dǎo)航提供時實(shí)資料。 2觀測項目、時次和程序 項目：溫、壓、風(fēng)、濕、云、能、天、海浪、海溫、 水樣采集、海發(fā)光等。 時次：世界時 00Z 、06Z 、12Z、18 Z共四次。 程序：正點(diǎn)前30分鐘開始到正點(diǎn)結(jié)束，氣象項目觀測應(yīng)安排在正點(diǎn)前15分鐘內(nèi)進(jìn)行，氣壓觀測應(yīng)在接近正點(diǎn)時進(jìn)行。若因特殊原因不能按時觀測，可在正點(diǎn)后30分鐘內(nèi)補(bǔ)測完，記要欄內(nèi)加說明。無法補(bǔ)測時，須注明原因。,Terms and Descriptions

10、 of Weather-1,RAIN: is defined as precipitation of liquid droplets. SNOW: is precipitation, in the form of ice crystals, most of which are branched (sometimes star-shaped). DRIZZLE: is defined as fairly uniform precipitation composed exclusively of fine drops of water of diameter less than 0.5 mm (1

11、150 in.) and very close to one another. Drizzle drops are too small to cause appreciable ripples on the surface of still water. The drops appear almost to float, thus making visible even slight movements of the air. HAIL: is precipitation of small balls or pieces of ice (hailstones) with a diameter

12、ranging from 5 to 50 mm (1/2 to 2 inches) or sometimes more, falling either separately or fused into irregular lumps.,Terms and Descriptions of Weather-2,FOG: is a suspension of very small water droplets in the air reducing the visibility less than 1/2 nautical mile at the earths surface. MIST: is a

13、 suspension in the air of microscopic water droplets or wet hygroscopic particles, reducing the visibility between 1/2 and 5 nautical miles at the earths surface. HAZE: is a suspension in the air of extremely small dry particles invisible to the naked eye and sufficiently numerous to give the air an

14、 opalescent (milky or pearly) appearance. The visibility may be reduced but is always better than 1/2 nautical mile. If the relative humidity of the air is very high (90 - 1 00%), the phenomenon is mist; but if the relative humidity is lower (60-80%), the phenomenon may be classified as haze. ,Terms

15、 and Descriptions of Weather-3,THUNDERSTORMS: is considered to be occurring at the ship when thunder is heard. A thunderstorm is regarded as being heavy when sharp and pronounced thunder and lightning occur almost continuously, accompanied by heavy rain or snow and often by hail, and the peak wind preceding or accompanying the storm is usually in excess of 40 knots. TORNADO: A violently rotating column of air in contact with and extending between a convective cloud and the surface of the earth. It is the most destructive of all storm scale atmospheric phenomena. They can occur anyw