9 航海气象
航海气象学课件

⑤ 近赤道附近存在一个高温带,1月和7月平均气温均高 于25℃,称这个高温带称为“热赤道”(Heat Equator)。 平均在10N左右。
擦作用忽略不计,大气运动规律比较简单和清楚。自由大气 的基本运动形式是层流,气流多波状系统。 对流层顶:厚度约为1-2Km,温度随高度呈等温或逆温状态。
2. 平流层(Stratosphere):厚度:自对流层顶到大约55Km。
特点:空气主要是水平运动垂直运动弱;水汽含量少;(3) 气温随高度升高而递增(最初等温,到20~45Km气温突增, 主要是臭氧吸收太阳紫外线所致);(4)气层稳定利于飞 机飞行。
综上所知,空气与下垫面之间的热量交换是通过多种 途径进行的。
通常,地面与大气之间的热量交换以辐射为主,乱流 和水相变化次之;
各地空气之间的热量交换以平流为主。 上下层空气之间的热量交换以对流和乱流为主。 以上均为非绝热过程。
四、气温随时间的变化
大气的热量主要来自下垫面,所以 气温具有与下垫面温度类似的周期 性变化。如冬寒夏暖、午热晨凉反 映了气温日、年变化的一般规律。
温标
2.温标:温度的数值表示法称温标。常用的温标有三种。
① 摄氏温标 ℃:把水的冰点温度定为0℃,沸点为100℃, 多数非英语国家使用。
② 华氏温标 F:水的冰点温度定为32F,沸点212F。一 些英语国家多使用。
摄氏与华氏的关系: C5(F32) F 9C32
9
5
③ 绝对温标(K氏温标) K:水的冰点温度定为273K,沸点为 373K(由英国物理学家Kelvin提出)。多用于理论计算。
航海气象与海洋学试题九

航海⽓象与海洋学试题九试题九1.就平均状况⽽⾔,在对流层中⾼度每升⾼100m⽓温约降低:A. 1.2℃B. 1.0℃C. 0.65℃D. 0.5℃2.逆温的存在:A. 可以抑制对流的发展B. 有助于对流的发展C. 不利于层状云或雾的形成D. 前三者都不对3.发展旺盛的积⾬云顶部呈砧状,这是由于______造成的。
A. ⾼空风切变B. ⾼空⽓温过低C. 对流层顶存在逆温层D. ⾼空⽓压过低4.稳定性天⽓是指:A. 连续性降⽔⽑⽑⾬雾B. 阵⾬雷阵⾬阵性⼤风冰雹龙卷风C. AB都对D. AB都错5.⼤⽓绝对不稳定的情况多发⽣在夏季局部地区:A. 海洋上的热雷⾬常发⽣在下午到傍晚B. ⼤陆上的热雷⾬多出现在半夜到凌晨C. AB都对D. AB都错6.下列⽓压⽇较差最⼤的海域是:A. 天津B. 连云港C. 海⼝D. 南沙7.当下垫⾯在⽔平⽅向上温度分布不均匀时:A. 在⾼温处空⽓密度⼩,单位⽓压⾼度差⼤,因此上空各等压⾯之间距离增⼤B. 在低温处空⽓密度⼤,单位⽓压⾼度差⼩,因此上空各等压⾯之间距离缩⼩A. 等压线越密集的地⽅,⽔平⽓压梯度越⼩B. 等压线越稀疏的地⽅,⽔平⽓压梯度越⼤C. AB都对D. AB都错9.下列正确的说法是:A. 在低压槽中,等压线弯曲最⼩的那些点的连线称为槽线B. 在⾼压脊中,等压线弯曲最⼩的那些点的连线称为脊线C. AB都对D. AB都错10.通常,在等压⾯图上分析:A.等压线 B.等⾼线 C.等波⾼线 D.地⾯锋线11.热带⽓旋是温度场对称分布的暖性低⽓压:A. 其强度随⾼度的增加⽽减弱B. 由于其地⾯⽓压很低,因此它属于深厚系统C. AB都对D. AB都错12.在海洋上通常⽔汽压e与相对湿度f的⽇变化规律是:A. ⽩天e和f增⼤,夜间e和f减⼩B. ⽩天e和f减⼩,夜间e和f增⼤C. ⽩天e减⼩f增⼤,夜间e增⼤f减⼩D. ⽩天e增⼤f减⼩,夜间e减⼩f增⼤13.E 冰为冰⾯上的饱和⽔汽压,E ⽔为过冷却⽔⾯上的饱和⽔汽压,当温度相同时:A. E 冰> E ⽔B. E 冰< E ⽔C. E 冰 = E ⽔D. E 冰 = E ⽔ = 6.11百帕14.在未饱和空⽓中,⽓温(t)与露点(t d )的关系是:A. t > t dB. t=t dC. t < t dD. ABC都错15.使未饱和空⽓达到饱和或过饱和的途径是:D. AB都错16.在低压中:A. |An|=|Gn|+|C|B. |Gn|=|An|+|C|C. |C|=|Gn|+|An|D. |An|+|Gn|+|C|=017.在开阔洋⾯上,平直等压线⽔平⽓压梯度⼤⼩相等,若较⾼纬度海域风⼒⼩于6级时,则:A. 在较低纬度海域⼀定也⼩于6级B. 在较低纬度海域⼀定有⼤风C. 在较低纬度海域可能⽆⼤风D. 在较低纬度海域风⼒不⼩于7级18.地转风公式适⽤于:A. 龙卷风B. 台风涡旋区C. AB都对D. AB都错19.产⽣⼤⽓环流最基本的因素是:A. 地球表⾯获得的太阳辐射不均匀B. 地转偏向⼒作⽤C. 海陆分布D. 地形差异20.东北信风带位于:A. ⾚道低压带与北半球副热带⾼压带之间B. ⾚道低压带与南半球副热带⾼压带之间C. 北半球副热带⾼压带与北半球副极地低压带之间D. 南半球副热带⾼压带与南半球副极地低压带之间21.属于半永久性⼤⽓活动中⼼的有:A.西伯利亚⾼压 B.南半球副极地低压带 C.夏威夷⾼压 D.亚速尔⾼压22.东亚与南亚季风⽓候特点是:A. 南亚季风的夏季风⼤于冬季风B. 东亚季风的夏季风(除热带⽓旋活动外)⼤于冬季风C. AB都对D. AB都错23.海陆风:A. 在中纬地区,⼀年四季均可出现B. 在低纬度地区主要出现在夏季,冬季很弱;在⾼纬度地区,只有夏季晴朗的⽇⼦⾥才见到微弱的海陆风C. AB都对D. AB都错24.下列正确的说法是:A. 在⼭区,⽩天由⼭顶沿⼭坡吹向⾕底的风称为⾕风B. 在⼭区,夜间由⾕底沿⼭坡吹向⼭顶的风称为⼭风C. AB都对D. AB都错25.皆属于⾼云的是:A. Ci Cs CcB. Ac AsC. Cu Cb ScD. ABC都对26.能产⽣连续性降⽔的云是:A. CiB. CuC. CbD. Ns27.有浓雾时海⾯能见度:A. Vis<0.5 kmB. Vis<1 kmC. Vis<5 kmD. Vis<10 km28.易使平流雾消散的条件是:A. 风⼒增⼤⾄6级以上B. 锋过境C. 风向有较⼤⾓度改变D. 前三者都对29.台湾海峡的雾⽇分布规律为:A. 东部多,西部少B. 东部少,西部多C. 东、西部都少D. 东、西部都多30.波陡 d 是指:(H:波⾼; l :波长;T:周期)A. H/ lB. l /HC. H/TD. T/H31.在波长较短的深⽔波中,相邻⽔质点落后的相⾓。
航海气象

中云族
2,500~5,000m
低云族
<2500m
2004-10
云
低 云 25 00 米 以 下
中云2500-5000m
2004-10
高云5000m以上
第一章 船舶常识
特征 族
云
低云族
中云族
高云族
卷层云(Cs) 卷云(Ci )
层状云 波状云
高层云 雨层云(Ns) (As)
高积云 层积云(Sc) (Ac) 卷积云(Cc ) 淡积云(Cu hum) 浓积云(Cu cong) 积雨云(Cb)
2004-10
第一章 船舶常识
2004-10
第一章 船舶常识
二 主要气象要素
气温:表示空气的冷热程度物理量(摄氏温度,华氏温
度,K氏温度). 气压:单位截面上大气柱的重量(毫巴,毫米汞柱等). 风:空气相对地面或海面的水平运动(信风,季风,海陆 风,山谷风,地转风). 湿度:指大气中含水汽含量的多少(相对湿度,绝对湿 度). 云:由大量的小水滴或小冰晶或两者的混合物组成悬 浮在空中(卷云,积云,层云,碎雨云等). 能见度:正常视力所能见到的最大水平距离(分10个 等级).
1、风的定义
空气相对于地面或海底的水平运动。 风是矢量,既有大小又有方向。
2004-10
第一章 船舶常识
2、风的单位 风速:单位m/s或n mile/h,即节(Kn)。 风向:指来向,常用0º ~360º ,8或16个方 位表示。
2004-10
第一章 船舶常识
风速单位间的关系:
1Kn0.5m.s-1或1m.s-1 2Kn
高积云
像羊群
航海气象与海洋学考试必考知识点

航海气象与海洋学考试知识点总结第一章气象学基础知识第三节气压1.地面气压场分布图:(高压,低压.高压脊.低压槽.鞍型场)第五节空气水平运动---风1.梯度风中三力平衡关系图2.梯度风三力平衡公式梯度风平衡公式:Gn+An+C=0(水平气压梯度力Gn,水平地转偏向力An,惯性离心力C,摩擦力R) 高压中梯度风三力平衡公式:An=Gn+C低压中梯度风三力平衡公式:Gn=An+C2.自由大气层中3.气压场中风向判断5.全球气压带和信风带分布图6.海陆风和山谷风,向岸风和离岸风向岸风,白天,海风+谷风离岸风,夜间,陆风+山风第八节云和降水1.产生连续性降水的云:雨层云Ns 高层云As 层积云Sc2.产生阵性降水的云:积云Cu 积雨云Cb 不稳定的层积云Sc3.间歇性降水的云:层积云Sc 厚薄不均匀的高层云As4.伴随雷暴,阵雨,大风等剧烈天气的云:积雨云Cb5.层状云:高层云As 层云St 卷层云Cs6.波状云:卷积云Cc 高积云Ac 层积云Sc7.积状云:积云Cu 积雨云Cb8.低云:层云St 积云Cu 雨层云Ns 层积云Sc 碎雨云F n第二章海洋学基础知识及应用1.海流北半球:背倾斜流而立,右侧等压面(海面)高,左侧等压面(海面)低;背密度流而立,密度小的(高温)水域在右,密度大的(低温)水域在左。
南半球:背倾斜流而立,右侧等压面(海面)低,左侧等压面(海面)高;背密度流而立,密度小的(高温)水域在左,密度大的(低温)水域在右2.海浪第三章天气系统及其天气特征第一节气团和锋1.北半球槽线和切变线的气流分布图2.北半球几种气流切边分布图3.南北半球冷暖锋面通常走向和气流分布图4.南北半球冷暖锋面通常走向和气流分布图5.锋面附近垂直运动分布图暖锋第一型冷锋第二性冷锋6.锋和云暖锋典型云序:卷云Ci---卷层云Cs---高层云As---雨层云Ns一型冷锋(缓行冷锋)云序:雨层云Ns---高层云As---卷层云Cs---卷云Ci 二型冷锋(急行冷锋)云序:卷云Ci---卷层云Cs---高层云As---雨层云Ns准静止锋云序:雨层云Ns---高层云As---卷层云Cs---卷云Ci第二节锋面气旋南北半球典型锋面气旋图第三节冷高压第四章天气图基础知识第二节地面天气图1.地面图上符号天气:气温降低气温升高降水强度小云层增厚气压升高气压下降时间长降水增强锋后降水,连续降水区域大区域扩大狂风暴雨强度小2.各种填图符号及含义:3.地面天气图填图符号4.第五章.船舶气象信息的获取和应用第二节.船舶分析和应用气象信息.1.锋面气旋发展阶段。
航海气象学(已打印)

一、名词解释天气:指一定区域在较短时间内各种气象要素的综合表现。
天气表示大气运动的瞬时状态。
气候:指某一区域天气的多年平均特征,其中包括各种气象要素的多年平均及极值。
气候表示长时间的统计平均结果。
露点温度:指空气中水汽含量不变且气压一定时,•降低温度使其空气达到饱和时的温度,称为露点温度水平气压梯度力:单位距离内气压的改变量称气压梯度。
在水平方向上称水平气压梯度,方向垂直于等压线,由高压指向低压,即-ΔP/Δn。
其物理意义表示了由于空间水平气压分布不均匀而作用在单位体积空气上的力。
水平地转偏向力:由于地球自转,作用在运动物体上产生使运动物体发生偏转的力,称地转偏向力,又称可科利奥里力(Coriolis force)或科氏力。
地转风;当水平气压梯度力和水平地转偏向力达到平衡时,空气沿等压线(等压面)作无磨擦的直线运动,称地转风。
梯度风:在自由大气中,当水平气压梯度力、地转偏向力和惯性离心力达到平衡时,空气沿等压线作水平、无摩擦、等速作曲线运动。
在自由大气中,空气的水平圆周运动称为梯度风(Gradient Wind)。
梯度风可以看成是水平气压梯度力、水平地转偏向力和惯性离心力三者平衡时的水平运动。
大气稳定度:某一气块受到垂直方向的扰动后,大气层结(周围大气),使其具有返回或远离其平衡位置的趋势和程度,称大气稳定度,又称大气层结稳定度。
海陆风:在海岸附近,由于海陆间热力差异的日变化引起的。
白天:风从海洋吹向陆地称海风;夜间:风从陆地吹向海洋称陆风。
海风≻陆风,主要出现在中低纬度,气温日较差较大,多在夏季晴朗天气条件下。
辐射雾:由下垫面辐射冷却,使低层气温降到露点或以下时所形成的雾。
•多见于陆地上,又称陆地雾。
平流雾:暖湿空气流经冷的下垫面,导致气温下降,水汽凝结所形成的雾。
此雾多形成于冷暖海流交汇处的冷水面一侧。
气团在广大空间里存在着水平方向上物理属性(主要指温度、湿度和稳定度等)相对比较均匀的大块空气,称气团。
航海气象与海洋学知识点重点知识分享

航海气象与海洋学知识点重点航海气象与海洋学第一章重点1.2.1大气在垂直方向上的温度、成分、气流状况和电离现象等有显著差异,根据不同高度气层的特点,特别是气温的垂直分布,可从地面到大气上界将大气层分为五层,依次为对流层、平流层、中间层、热层和逸散层。
对流层(Troposphere):下界为地面,上界随纬度和季节变化,平均厚度10~12 km。
通常在高纬为6~8 km,中纬度10~12 km,低纬度17~18 km。
夏季对流层的厚度比冬季高。
对流层有三个主要特征:(1)气温随高度增加而降低,平均而言,高度每增加100 m,气温则下降约0.65℃,这称为气温直减率。
(2)具有强烈的对流和湍流运动。
对流和湍流运动的强度主要随纬度和季节的变化而不同,一般低纬较强,高纬较弱,夏季较强,冬季较弱。
(3)气象要素水平分布不均匀。
由于地表面有海陆差异、地形起伏等,因此在对流层中,温度、湿度等的水平分布是不均匀的。
一般说来,低纬比中高纬温暖、潮湿,海上比内陆潮湿。
根据大气运动的不同特征又可以将对流层分为行星边界层或摩擦层和自由大气。
摩擦层的范围一般从地面到1~1.5 km高度,其厚度夏季高于冬季,白天高于夜间,大风和扰动强烈的天气高于平稳天气。
湍流输送是该层的基本运动特点,各种气象要素都有明显的日变化。
行星边界层以上的大气层称为自由大气。
在自由大气中,地球表面的摩擦作用可以忽略不计,大气运动规律显得比较简单和清楚。
自由大气的基本运动形式是层流,气流多波状系统。
500hPa等压面最能代表对流层大气的一般运动状况。
空气的增热和冷却主要是非绝热过程引起的,受下垫面的影响很大。
下垫面与空气之间的热量交换途径有以下几种:1.热传导空气与地面之间,空气团与空气团之间,当有温度差异时,就会以分子热传导方式交换热量。
但是地面和大气都是热的不良导体,所以通过这种方式交换的热量很少。
只有在贴近地面几厘米以内,空气密度大,单位距离内的温度差异也较大,热量交换较为明显。
航海科技名词

航海科技名词
航海科技名词如下:
1. 航海:驾驶船舶在海洋上航行。
2. 三维航海图:以三维电子航海图数据库为基础,按照一定比例对海洋环境空间地理信息进行三维表达的航海图。
3. 海洋元数据:描述海洋数据集的名称、目录、内容、质量、位置等基本内容的数据。
4. 航海天文历:船舶航海所用的天文历。
5. 航海仪器:船舶在海上航行时用以测定航向、方位、位置、深度、水深、罗经差等所用的仪器。
6. 航海图:用以标识航道、沿海、海底、岛礁等地貌、地形、水深、助航设施、航行障碍等内容的专题图。
7. 航海图书:包括航路指南、航迹图、海图、沿海灯塔表、地名书、海岸图、船舶图书及其它有关资料。
8. 航迹图:按一定比例尺绘制的船舶航行轨迹图。
9. 航海气象:有关航海气象方面的资料和预报。
10. 航海通信:海上航行通信。
11. 航海无线电:有关航海无线电通信方面的技术和设备。
12. 航海雷达:装在船上能发射雷达信号并接收其反射波的设备。
13. 全球海上遇险和安全系统(GMDSS):为了改善海上人命安全和航行安全而设置的一个包括无线电通信、定位、海上救生和遇险信
号的全球性水上通信系统。
14. 郑和航海图:明代郑和奉命出使下西洋时,为确保海上航行的安全和正确,根据实地测量绘制的一张反映当时世界上海上航路区域划分及沿途山川、岛屿、海洋、商港等地理概况的航海图。
15. 航海学:研究船舶在海洋航行、有关海洋地理学和水文学、航路指南、海图、航海气象学、航海日历、船位确定和无线电航海等问题的一门科学。
航海气象重点知识

填空题1.表征大气状态的物理量和物理现象的气象术语称为气象要素。
2.大气中主要吸收太阳紫外线的气体成分是臭氧。
3.在地气系统的温度和压力条件下,能在气态、液态和固态三者之间互相转化的大气成分是水汽。
4. 气温是用来表示空气冷热程度的物理量。
5.一天中气温的最高值与最低值之差称为气温日较差。
6.一年中月平均气温的最高值与最低值之差称为气温年较差。
7.通常将两个低压之间狭长的区域称为高压带。
8.通常将两个高压之间狭长的区域称为低压带。
9.通常将由两个低压与两个高压交错组成的中间区域称为鞍形气压区。
10.在大气中由于空间气压分布不均匀,作用在单位质量空气上的净空气压力称为气压梯度力。
11.在自由大气中,当水平气压梯度力和水平地转偏向力达到平衡时所吹的风称为地转风。
12.在自由大气中,当水平气压梯度力、水平地转偏向力和惯性摩擦力三者达到平衡时所吹的风称为梯度风。
13.大范围地区的风向随季节而有规律显著改变的盛行风称为季风。
14.通常将海陆热力差异形成的季风称为海陆季风,将行星风带的季节移动形成的季风称为行星季风。
16.表示大气中水汽含量多少或空气潮湿程度的气象要素称为湿度。
17.大气中水汽所引起的那部分压强称为水气压。
18.在空气中水汽含量不变,气压一定时,降低温度使空气达到饱和时的温度称为露点。
19. 海流是指海水大规模的相对稳定的流动,是海水重要的普遍运动形式之一。
20.由风对海面的切应力、地转偏向力、粘滞摩擦力达到平衡时形成的稳定海流是风海流。
21.在东南太平洋沿岸的秘鲁和厄瓜多尔沿海,每隔若干年,在圣诞节前后,发生一种海水异常回暖的现象,当地人称之为厄尔尼诺现象。
22. 拉尼娜现象是赤道附近东太平洋水温反常变化的一种现象,其特征恰好与厄尔尼诺现象相反,指的是洋流水温反常下降。
23.在广大空间里存在着水平方向上物理属性(主要指温度、湿度和稳定度等)相对比较均匀的大块空气称为气团。
24. 天气系统是指具有一定的温度、气压或风等气象要素空间结构特征的大气运动系统。
- 1、下载文档前请自行甄别文档内容的完整性,平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益,请联系客服反馈,我们会尽快为您处理(人工客服工作时间:9:00-18:30)。
9 航海气象9.2 海上气象报告与气象导航951.When winds of force reach 10-11 in Beaufort Scale,usually we call such winds as ______.A. HurricaneB. BreezeC. StormD. GaleKEY: C952.The Routing System which aimed at reducing the risk of casualties is called as ______.A. Traffic Separation SchemesB. Recommended tracksC. Precautionary areasD. Inshore traffic zonesKEY: A953.______ LOW ELY SLWLY WITH COLD FRONT FM CEN TO 12N 179W AND WARM FROM FM CEN TO 11N 171W.A. SHLWB. SCTDC. OBSD. SWKEY: A954.______ moving rather quickly east expected 150 miles south of Cape Farewell 972 by 160000 GMT.A. Developed lowB. Developing lowC. Being developed lowD. Low to be developedKEY: B955.______ rain means it rains in some parts of the area.A. SquallyB. IsolatedC. ScatteredD. Occasional KEY: C956.{On account of} the bad weather,my ETA is amended to read 1830 his on July 15th.A. For the account of B. Because C. Owing to D. For fear of KEY: C957.A cold front moving in from the northwest can produce ______.A. thunderstorms,hail,and then rapid clearingB. increasing cloud cover lasting for several daysC. lengthy wet weatherD. low ceilings with thick cirrus cloudsKEY: A958.A feature of an inflatable raft which helps keep people stationary in rough weather is ______.A. lashings on the floor of the raft for the passenger's feetB. straps from the overheadC. lifelines on the inside of the raftD. ridges in the floor of the raftKEY: C959.A line on a weather chart connecting places which have the same barometric pressure is called an ______.A. isothermB. isallobarC. isobarD. isotopeKEY: C960.A local wind which occurs during the daytime and is caused by the different rates of warming of land and water is a ______.A. foehnB. chinookC. land breezeD. sea breeze KEY: D961.A local wind which occurs during the daytime and is caused by the different rates of warming of land and water is a ______.A. FoehnB. ChinookC. land breezeD. sea breezeKEY: D962.A low,uniform layer of cloud resembling fog,but not resting on the ground,is called______.A. cumulusB. nimbusC. stratusD. cirrus KEY: C963.A mercurial barometer at sea is subject to rapid variations in height (pumping) due to the pitch and roll of the vessel. To avoid this error,measurements of atmospheric pressure at sea are usually measured with a(n) _____.A. syphon barometerB. cistern barometerC. aneroid barometerD. fortin barometerKEY: C964.A microbarograph is a precision instrument that provides a ______.A. charted record of atmospheric temperature over timeB. charted record of atmospheric pressure over timeC. graphic record of combustible gases measured in an atmosphereD. graphic record of vapor pressure from a flammable/combustible liquidKEY: B965.A millibar is a unit of ______.A. humidityB. precipitationC. pressureD. temperature KEY: C966.A sea breeze is a wind ______.A. that blows towards the sea at nightB. that blows towards an island during the dayC. caused by cold air descending a coastal inclineD. caused by the distant approach of a hurricaneKEY: B967.A sylphon cell is a part of a ______.A. maximum thermometerB. barographC. thermographD. hygrometerKEY: B968.A tropical cyclone has recurved and entered temperate latitudes. In the Northern Hemisphere when a large high pressure system lies north of the storm,what situation may occur?A. The low may suddenly deepen,and the cyclone intensify and pick up speed.B. The left semicircle may become the dangerous semicircle.C. The low and the high may merge and cancel out the weather characteristics of each.D. The high may force the cyclone to reverse its track.KEY: B969.A tropical storm is building strength some distance from your ship. Waves are coming from the east,with periods increasing from 5 seconds to 15 seconds. The swell is from the east. Where was the storm when these new swells were generated?A. To the north of youB. To the south of youC. To the east of youD. To the west of youKEY: C970.A tropical wave is located 200 miles due west of your position,which is north of the equator. Where will the wave be in 24 hours?A. Farther away to the westB. Farther away to the eastC. In the same placeD. Closer and to the westKEY: A971.A tropical wave is usually preceded by ______.A. tropical stormsB. good weatherC. heavy rain and cloudinessD. heavy seasKEY: B972.A weather forecast states that the wind will commence backing. In the Northern Hemisphere,this would indicate that it will ______.A. shift in a clockwise mannerB. shift in a counterclockwise mannerC. continue blowing from the same directionD. decrease in velocityKEY: B973.A weather map is a synoptic data because it ______.A. summarizes a great deal of informationB. can be interpreted accuratelyC. appears dailyD. is prepared by the Weather BureauKEY: A974.A WIND BLOWS ROUND ANTICLOCKWISE defines ______.A. Backing (of wind)B. Beach (to)C. Veering (of wind)D. Maintaining direction of the windKEY: A975.After a cold front passes the barometric pressure usually ______.A. fluctuatesB. remains the sameC. remains the same,with clouds forming rapidlyD. rises,often quite rapidly,with clearing skiesKEY: D976.After a cold front passes,the barometric pressure ______.A. drops,and the temperature dropsB. drops,and the temperature risesC. rises,and the temperature dropsD. rises,and the temperature risesKEY: C977.All of the following are associated with cumulonimbus clouds EXCEPT ______.A. steady rainfallB. hail stormsC. thunderstormsD. tornadoes or waterspoutsKEY: A978.An air mass is termed warm if ______.A. it is above 70°FB. the ground over which it moves is cooler than the airC. it originated in a high pressure areaD. it originated in a low pressure area KEY: B979.An aneroid barometer is an instrument ______.A. used to measure the speed of windB. in which the pressure of the air ismeasuredC. that tells which direction a storm is coming fromD. used to measure the height of wavesKEY: B980.An occluded front on a weather map is colored ______.A. blue lineB. purple lineC. dashed blue lineD. alternate red and blue lineKEY: B981.Anticyclones are usually characterized by ______.A. dry,fair weatherB. high winds and cloudinessC. gustiness and continuous precipitationD. overcast skiesKEY: A982.As the temperature for a given mass of air increases,the ______.A. dew point increasesB. dew point decreasesC. relative humidity increasesD. relative humidity decreasesKEY: D983.BASHI:E TO SE 9-10.500M IN HVY SQUALLY SHWRS AND TS.SEA 8-9M.SWELL SE 6-7M.From the above forecast,the wind in Beaufort Scale will be ______.A. STRONG GALE TO STORMB. GALE TO STRONG GALEC. NEAR GALE TO GALED. STRONG BREEZE TO NEAR GALE KEY: A984.CAPE WEST WIND WEST TO SOUTHWEST 15 TO 20 KNOTS WEATHER SHOWERS.This description is likely to be under the heading of ______.A. FORECASTB. STORM WARNINGC. GENERAL SITUATIOND. MAP ANALYSISKEY: A985.During the voyage he encountered boisterous winds and heavy weather during which time the vessel ______ heavily and to such an extent that at times it was necessary to change course.A. moved B. labored C. drove D. wentKEY: B986.During the voyage my ship ______ bad weather in the Pacific Ocean.A. meets withB. has met withC. met withD. meeted withKEY: C987.Especially in adverse weather,risk of collision with an offshore supply vessel increases when the vessel is moored to what side of the unit? ______.A. UpwindB. DownwindC. CrosswindD. DowncurrentKEY: A988.Fleet weather forecast messages are the expected conditions in ______.A. a certain areaB. all ocean areasC. some areasD. important areas KEY: A989.For an accurate barometer check,you would ______.A. check it with a barometer on another vesselB. take readings from several barometers and average themC. check it with the barometer at the ship chandleryD. check it against radio or National Weather Service reports of the immediate vicinity KEY: D990.Gale warnings are usually issued when winds of ______ 8-9 are expected.A. wind SpeedB. Air ForceC. wind VelocityD. Beaufort Force KEY: D991.HIGH WAVES;DENSE STREAKS OF FOAM ALONG THE DIRECTION OF THE WIND;CRESTS OF WAVES BEGIN TO TOPPLE,TUMBLE AND ROLL OVER;SPRAY MAY AFFECT VISIBILITY.This condition is likely to be termed ______.A. strong breezeB. near galeC. galeD. strong gale KEY: D992.If a weather bulletin shows the center of a low pressure system to be 100 miles due east of you,what winds can you expect in the Southern Hemisphere? ______.A. South-southwesterlyB. North-northwesterlyC. South-southeasterlyD. North-northeasterlyKEY: A993.If the sky was clear,with the exception of a few cumulus clouds,it would indicate ______.A. rainB. hurricane weatherC. fair weatherD. fog setting in KEY: C994.If your weather bulletin shows the center of a low pressure area to be 100 miles due east of your position,what winds can you expect in the Northern Hemisphere? ______.A. East to northeastB. East to southeastC. North to northwestD. South to southeastKEY: C995.In Beaufort Scale,the wind force 7 with speed of 28-33 knots is defined as ______.A. Moderate galeB. Near galeC. Strong galeD. Whole galeKEY: B996.INTERTROPICAL CONVERGENCE ZONE OVER SOUTH PHILIPPINE PASSING OVER MINDANAO NORTHERN SULU AND PALAWAN.This paragraph is likely to be under the heading of ______.A. GALE WARNINGB. 24 HOURS FORECASTC. SYNOPSISD. STORM WARNINGKEY: C997.It is predicted that heavy rains are ______ to flood the harbor and its vicinity in a few days.A. frightening B. threatening C. scattering D. warning KEY: B998.Mechanical lifting of air by the upslope slant of the terrain is called ______.A. vertical liftingB. convective liftingC. advective liftingD. topographic liftingKEY: D999.Of the following,______ is not a wind.A. boraB. gustC. gregaleD. floeKEY: D1000.OWING TROPICAL STORM9706 CROSSING OUR/COURSE PLSPERMIT SHELTERING KAGOSHIMA KAIWAN. This cable indicates that ______.A. she requested shelter permissionB. she intended to berth at port of KAGOSHIMAC. she intended to change her courseD. she was reporting to the port that a tropical storm is comingKEY: A9.3 海上天气现象1001.When a wind blows round clockwise,it is ______.A. VariableB. ChangingC. BackingD. VeeringKEY: D1002.Isobars on a synoptic chart are useful in predicting ______.A. temperatureB. dew pointC. wind velocityD. relative humidity KEY: C1003.______ causing strong winds and rough sea north west Bay of Biscay.A. Strong low pressureB. Strong high pressureC. Steep pressure gradientD. Steep gradient pressureKEY: C1004.A hurricane moving northeast out of the Gulf passes west of your position. You could expect all of the following EXCEPT ______.A. higher than normal swellsB. high windsC. winds veering from south,through west,to northwestD. light showers KEY: D1005.A katabatic wind blows ______.A. up an incline due to surface heatingB. in a circular patternC. down an incline due to cooling of the airD. horizontally between a high and a low pressure areaKEY: C1006.A steep barometric gradient indicates ______.A. calmsB. light windsC. strong windsD. precipitationKEY: C1007.A storm is forecast for the area where your vessel is moored. For its safety you should put ______.A. more slack in the mooring linesB. a strain on the mooring linesC. chafing gear on the mooring linesD. grease on the mooring linesKEY: C1008.A strong,often violent,northerly wind occurring on the Pacific coast of Mexico,particularly during the colder months,is called ______.A. Tehuan tepecerB. PapagayoC. NortherD. PamperoKEY: B1009.A strong,often violent,northerly wind occurring on the Pacific coast of Mexico,particularly during the colder months,is a ______.A. PapagayoB. fall windC. foehnD. williwawKEY: B1010.A thin,whitish,high cloud popularly known as mares tails is ______.A. altostratusB. stratusC. cumulusD. cirrusKEY: D1011.A very light breeze that causes ripples on a small area of still water is a ______.A. cat's pawB. hog's breathC. williwawD. chinook KEY: A1012.Above-normal tides near the center of a hurricane maybe caused by the ______.A. high barometric pressureB. jet streamC. storm surgeD. torrential rainsKEY: C1013.Altocumulus clouds are defined as ______.A. high cloudsB. middle cloudsC. low cloudsD. vertical development cloudsKEY: B1014.An anemometer on a moving vessel measures ______.A. apparent wind speed onlyB. true wind speed and true wind directionC. true wind speed onlyD. apparent wind speed and true wind direction KEY: A1015.An aneroid barometer reading should be corrected for differences in ______.A. elevationB. temperatureC. wind speedD. latitudeKEY: A1016.Cirrus clouds are composed primarily of ______.A. ice crystalsB. water dropletsC. snow crystalsD. nitrogenKEY: A1017.Early indications of the approach of a hurricane may be all of the following EXCEPT______.A. short confused swellsB. gradually increasing white clouds (mare's tails)C. pumping barometerD. continuous fine mist-like rain KEY: A1018.Especially in adverse weather,risk of collision with an offshore supply vessel increases when the vessel is moored to what side of the unit? ______.A. UpwindB. DownwindC. CrosswindD. DowncurrentKEY: A1019.Fetch is the ______.A. distance a wave travels between formation and decayB. stretch of water over which a wave-forming wind blowsC. time in seconds required for two crests to pass a given pointD. measurement of a wave's steepnessKEY: B1020.Fleet weather forecast messages are the expected conditions in ______.A. a certain areaB. all ocean areasC. some areasD. important areasKEY: A1021.Fog is likely to occur when there is little difference between the dew point and the ______.A. relative humidityB. air temperatureC. barometric pressureD. absolute humidityKEY: B1022.For an accurate barometer check,you would ______.A. check it with a barometer on another vesselB. take readings from several barometers and average themC. check it with the barometer at the ship chandleryD. check it against radio or National Weather Service reports of the immediate vicinity KEY: D1023.Gasoline tank vent lines on board small passenger vesselsmust be fitted with removable flame screens ____.A. and 30 square inches of louversB. three inches in diameter with a check valve to prevent water from entering in heavy weatherC. three inches in circumference inside the fill pipeD. consisting of a single screen of at least 30 X 30 mesh,corrosion resistant wireKEY: D1024.Generally speaking,with ______ the weather becomes cloudy or overcast with strong winds.A. high pressuresB. low pressuresC. weak pressuresD. strong pressuresKEY: B1025.Good weather is usually associated with a region of ______.A. low barometric pressureB. high barometric pressureC. falling barometric pressureD. pumping barometric pressureKEY: B1026.High clouds,composed of small white flakes or scaly globular masses,and often banded together to form a mackerel sky,would be classified as ______.A. cirrusB. cirrocumulusC. altostratusD. cumulonimbusKEY: B1027.High pressure ridge ______ from Sevastopol to eastern Libya.A. reachingB. extendingC. increasingD. upgradingKEY: B1028.Hurricane warnings are issued ______ when winds of force 12 or above are expected.A. in all parts of the world B. in some parts of the worldC. from all corners of the worldD. from every corner of the world KEY: B1029.If you are caught in the left semicircle of a tropical storm,in the Southern Hemisphere,you should bring the wind ______.A. on the starboard quarter,hold course and make as much way as possibleB. 2 points on the port quarter,and make as much way as possibleC. on the port bow,and make as much way as possibleD. dead ahead and heave toKEY: C1030.In a storm,the leeward lines of a ship's mooring system will ______.A. pull the unit in the same direction that the weather is pushing itB. pull the unit in the opposite direction that the weather is pushing itC. tend to keep the unit on its original location over the well headD. affect the unit's draft and inclination as maximum mooring tensions are reachedKEY: A1031.In bad weather,what length of chain should be used with a single anchor?A. 3 times the depth of waterB. 6 times the depth of waterC. 10 times the depth of waterD. 15 times the depth of waterKEY: C1032.In North America the majority of the weather systems move from ______.A. north to southB. south to northC. east to westD. west to eastKEY: D1033.In reading a weather map,closely spaced pressure gradient lines would indicate ______.A. high windsB. high overcast cloudsC. calm or light windsD. fog or steady rainKEY: A1034.In the doldrums you can expect ______.A. steady,constant windsB. frequent rain showers and thunderstormsC. steep pressure gradientsD. low relative humidityKEY: B1035.In the doldrums you will NOT have ______.A. high relative humidityB. frequent showers and thunderstormsC. steep pressure gradientsD. frequent calmsKEY: C1036.In the relatively calm area near the hurricane center,the seas are ______.A. moderate but easily navigatedB. calmC. mountainous and confusedD. mountainous but fairly regular as far as direction is concernedKEY: C1037.Little or no change in the barometric reading over a twelve hour period indicates ______.A. stormy weather is imminentB. that present weather conditions will continueC. a defect in the barometerD. increasing wind strengthKEY: B1038.MAINLY GOOD BECOMING MODERATE.This forecast probably refers to ______ in a certain area.A. visibilityB. windsC. seaD. fogKEY: A1039.MAINLY VARIABLE 3 to 4 VEERING NELY 5 TOMORROW MORNING.This forecast refers to ______ in the designated area.A. visibilityB. windsC. seaD. fog KEY: B1040.Most high pressure areas are accompanied by ______.A. precipitationB. clear,cool weatherC. humid,sticky weatherD. cool fogsKEY: B1041.NASHA VERELLA ST JACQUES ZENMU ANSHA REEF CLOUDY TO OVERCAST WITH SHOWERS WIND SW 17 TO 21 SEA MOD VIS GOOD TO MOD.The abovementioned forecast is probably from ______.A. Radio DalianB. Radio GuangzhouC. Radio SingaporeD. Radio BangkokKEY: B1042.Navigational warnings and weather bulletins for shipping ______ from Singapore Radio.A. broadcast B. broadcasted C. are broadcast D. are broadcastedKEY: C1043.On a working copy of a weather map,a cold front is represented by what color line?A. RedB. BlueC. Alternating red and blueD. PurpleKEY: B1044.On the pole side of the high pressure belt in each hemisphere,the pressure diminishes. The winds along these gradients are diverted by the Earth's rotation toward the east and are known as the ______.A. geostrophic windsB. doldrumsC. horse latitudesD. prevailing westerliesKEY: D1045.Plain language is usually used on marine weather ______.A. forecastsB. observationsC. analysesD. reports KEY: A1046.Prevailing winds between 30°N and 60°N latitude are from the ______.A. northB. southC. eastD. westKEY: D1047.Recurvature of a hurricane's track usually results in the forward speed ______.A. increasingB. decreasingC. remaining the sameD. varying during the dayKEY: A1048.Relative humidity is the percentage of water vapor that is in the air as compared to the maximum amount it can hold at ______.A. a specific barometric pressureB. a specific temperatureC. a specific wind speedD. any timeKEY: B1049.Snow has obliterated surface features and the sky is covered with uniform,altostratus clouds. There are no shadows and the horizon has disappeared. What is this condition called?A. Ice blinkB. WhiteoutC. Water skyD.Aurora reflectionKEY: B1050.Steady precipitation is typical of ______.A. coming cold weather conditionsB. a warm front weather conditionC. high pressure conditionsD. scattered cumulus cloudsKEY: B。