海洋气象学：6天气图介绍-美国卫星云图及其他

1、,天气系统：显示大气中天气变化及其分布的独立系统。如冷高压、锋面气旋、副热带高压和台风等系统。 天气形势：大范围环流型与不同类别天气系统分布的概貌（高压、低压、锋、热带气旋的位置、强度、移动等）。,课堂练习1 回答下列问题,1. 只看ASAS图，回答下列问题 A. 图中过台湾海峡的等压线的数值。 B中心位于165E 40N附近的气压系统是个高压还是低压？其中心气压值多少，未来24小时的移动趋势？其后部的风力可达多少？ C 翻译STS的文字说明 2. 结合FSAS图，回答下列问题 A. 解释图题含义 B ASAS图上的大陆高压，24小时后的强度变化 C ASAS图上的热带气旋，24小时后变为什么

2、系统，中心气压值变化 D 预报图上过渤海海峡的等压线的数值,课堂练习2,1. 解释左图任一单站的填图符号意义 2.结合AS图和AW图，说明并比较STS1420和986HPA，978HPA双低压的海浪场的特点,准静止轨道和极地轨道,全球卫星观测系统是由颗地球同步静止卫星和23颗近极地太阳同步极轨卫星组成的。 静止气象卫星：距离地面约35800km，位于经度0o、70oE、140oE、140oW和70oW的赤道上空，分别由美国、俄罗斯、欧盟和日本等负责发射。地球同步卫星的优点是，由于轨道与地球自转同步,卫星能对同一地区进行连续不断的观测。目前每隔30min就可以完成一次观测。观测范围在南北纬600

3、以内，经度横跨1400左右。5颗地球同步卫星的观测覆盖地区形成了以赤道为中心南北纬度各600的一条带，对全球的中、低纬地区进行观测可以取得理想的效果。 我国发射的同步卫星“风云二号B” 位于1100E,极轨气象卫星：在极区地球静止卫星图片畸变很大，观测效果不好。极轨卫星在极区可以得到较理想的观测资料。极轨卫星距地面约8001500km ，由于轨道较低，可以提高图象的空间分辨率和探测资料的精确度。将这两种卫星配合起来是卫星观测的一种理想组合，使观测范围覆盖全球。 全球气象卫星观测系统所取得的资料，对台风、暴雨、洪水、海温和海冰等的监测、预报以及大气运动规律的研究等都具有重要的意义。,可见光云图

4、(Visible Satellite Image,VS),根据物体对阳光的反射率拍摄的。在图片上，表现为黑白色差异，黑白程度（或称亮度）表示云或地面的反照率大小。白色表示反照率大，黑色表示反照率小。通常云层越厚，反照率越大，颜色越白。,红外云图 (IR) -Infrared images,根据物体表面辐射温度的高低拍摄的。在红外云图上，最黑的地区代表最暖的表面，最白的地区代表最冷的表面。根据色调的差异可以判定云顶的高低：色调白，温度就低，表示云顶高度高。色调黑，温度就高，表示云顶高度低。,卫星云图应用一,分析层状与积状云系,卫星云图应用二,定位低压（气旋）及高压（反气旋）中心,台风云系,锢囚锋

5、云系,锋面气旋,暖锋云系,冷锋云系,副高,卫星云图应用三,计算高空风,卫星云图应用四,定位热带气旋，监控天气系统移动,Super-typhoon Haiyan, equivalent to a Category 5 hurricane on the U.S. Saffir-Simpson scale, made landfall as an extremely powerful super typhoon, perhaps the strongest ever recorded at landfall, with sustained winds estimated at 195 mph (31

6、5 kph) by the Joint Typhoon Warning Center.,中尺度（强对流）系统-雷达回波,热带气旋（预）警报图,图中给出了热带气旋当前的实际位置和未来24h、48h和72h的预报位置。并用三种圆来表示。 （1）热带气旋当前的实际位置：圆内风力10级。 （2）预报圆（概率圆）：表示热带气旋中心未来12h、24h、48h、72h可能落入的范围，入圆率为70，风力10级（用虚线表示）。 （3）大风（ 10级）警报区：预计某些地方未来可能被10级大风覆盖，以预报圆外的实线同心圆表示。 当热带气旋实际风力和预报风力均小于级时，只有预报圆（虚线）。,JWTC,中国海洋局提供的

7、海洋预报产品,海流分析及预报图,海冰图,Systems having or expected to have synoptic scale Gale, Storm, or hurricane force conditions are labeled in bold capital letters. Similarly systems expected to develop Gale, Storm or hurricane force conditions in 24 hours have labels of Developing Gale , Developing Storm or Devel

8、oping Hurricane Force. Surface low pressure falls of 24 mb or greater during a 24 hour period are denoted in large capital letters as RAPIDLY INTENSIFYING.,Standard abbreviations,DSIPT DISSIPATE 消亡STNRY - STATIONARYWKNG - WEAKENINGRPDLY - RAPIDLYFRMG - FORMINGMOVG - MOVINGINLD - INLANDDVLPG - DEVELO

9、PINGCOMB - COMBINEDDCRS - DECREASEINCRS - INCREASEINTSFY - INTENSIFYQ-STNRY - QUASI-STATIONARY,A 24-hour tropical cyclone symbol forecast position will be depicted on all surface analyses.,Frontogenesis -The formation of a front occurs when two adjacent air masses with different densities and temper

10、atures meet and strengthen the discontinuity between the air masses. It occurs most frequently over continental land areas such as over the Eastern US when the air mass moves out over the ocean. It is the opposite of frontolysis. Frontolysis -The weakening or dissipation of a front occurs when two a

11、djacent air masses lose contrasting properties such as the density and temperature. It is the opposite of frontogenesis. Squall 飑线 - A sudden wind increase characterized by a duration of minutes and followed by a sudden decrease in winds.,Extratropical Systems,Complex gale/storm -An area in which ga

12、le/storm force winds are forecast or are occurring, but in which more than one center is the generating these winds. Developing gale -Refers to an extratropical low or an area in which gale force winds of 34 knots to 47 knots (8-9级) are expected by a certain time period. On surface analysis charts a

13、 developing gale indicates gale force winds within the next 24 hours. Developing storm -Refers to an extratropical low or an area in which storm force winds of 48 knots (10级) or greater are expected by a certain time period. On surface analysis charts a developing storm indicates storm force winds f

14、orecast within the next 24 hours. Gale - Refers to an extratropical low or an area of sustained surface winds (averaged over a ten minute period, momentary gusts may be higher) of 34 knots to 47 knots. Storm - Refers to an extratropical low or a area of sustained winds (averaged over a ten minute pe

15、riod, momentary gusts may be higher) in excess of 48 knots. Hurricane Force - Refers to an extratropical low or a area of sustained winds (averaged over a ten minute period, momentary gusts may be higher) in excess of 64 knots or higher.,The surface analyses are generated four times per day (00Z, 06

16、Z, 12Z, and 18Z) for each ocean. The analyses consist of isobaric pressure analyses at 4 mb contour interval spacing, labeled every 8 MB. The central pressure mb values of low and high pressure systems are depicted in bold 3 or 4 digits and underlined and placed adjacent to or under the H or L. XXX for an unknown pressure.,P