Lesson 3 The Global Observing System

课程 3 全球观测系统

The world-wide observing system involves measurements at the earth’s surface, probes carried into the atmosphere by balloons and rockets, and satellite systems looking downwards. The surface-based observations are “synoptic”, taken at the same time in the same manner in all parts of the globe. This network of stations, to which virtually all countries contribute, provides basic measurements of atmospheric pressure, temperature, humidity, wind, precipitation, weather conditions, clouds and visibility every 3 or 6 hours. Some stations, mostly at airports provide hourly observations and special reports of sudden changes. In cooperative agreements developed through WMO, a number of surface synoptic stations are designated for regional and global analyses and predictions. An additional group of stations are designated as required to meet national needs.

全球观测系统包括在地球表面的测量，通过气球和火箭带入大气层的探测器，以及向下观察的卫星系统。基于地面的观测是“天气概要”的，以相同的方式在全球各地同时进行。这个几乎所有国家都参与的站点网络，每 3 小时或 6 小时提供一次基本的大气压力、温度、湿度、风、降水、天气状况、云和能见度的测量。一些站点，主要是在机场，每小时提供一次观测和突变的特别报告。通过世界气象组织（WMO）制定的合作协议，许多地面天气概要站被指定用于区域和全球分析和预测。另有一些站点被指定为满足国家需求所必需的。

Observations of the temperature, wind, humidity, and pressure conditions in the atmosphere above the earth and up to 15 – 20,000 meters, are taken by balloon-carried radiosonde instruments which transmit the data from their sensors back to the base stations. Some 1,000 stations are designated globally to undertake upper-air temperature, humidity and pressure soundings, at least once and sometimes twice (00 and 12 UTC) or four times a day. The instrumented balloons are tracked in a way that permits calculation of the wind speed and direction at various levels in the atmosphere. The internationally agreed global and regional requirements are somewhat greater than presently existing networks. These upper-air data are of direct benefit to aircraft operators in charting their paths and deciding on fuel needs. They are also fundamental to determining the current state of the atmosphere, to initiating computer models for prediction of future conditions, on a regional or global scale.

对地球上空至 15 到 20000 米的温度、风速、湿度和气压条件的观测是通过携带无线电探空仪器的气球进行的，这些仪器将传感器的数据传输回基站。全球大约有 1000 个站点被指定进行高空气温、湿度和气压的探测，每天至少进行一次，有时是两次（00 和 12 协调世界时）或四次。配备仪器的气球被跟踪，以便计算大气不同层次的风速和方向。国际上商定的全球和地区需求略高于目前现有的网络。这些高空数据直接有利于飞机运营商分析航线并决定燃料需求。同时，它们也是确定当前大气状态的基础，并用于启动计算机模型以预测未来的区域或全球气候条件。

Reports from commercial aircraft are a growing source of data contributing to the World Watch Weather (WWW). Currently about 8,000 reports are exchanged per day over the Global Telecommunications Systems (GTS).
来自商用飞机的报告是促进全球天气观察（WWW）数据增加的来源。目前，每天约有 8,000 份报告通过全球电信系统（GTS）交换。

An increasingly important component of the surface sub-system of the WWW involves automatic marine stations and the voluntary ship observing fleets. In December 1992, there were 620 instrumented buoys, launched by many different agencies, drifting with the winds and currents in the world’s ocean. They were sending some 2,400 reports per day into the communications systems. Such drifting buoys provide measurements of atmospheric pressure, air temperature, water temperature and sometimes wind. Moored buoys or fixed platforms, are operated by a number of countries to measure meteorological and oceanographic parameters. Some of these platforms also sample for atmospheric and oceanic pollution. By late 1992, countries reported 195 moored buoys and more than 80 fixed platforms taking observations.

WWW 表面子系统中一个日益重要的组成部分涉及自动海洋站和志愿船只观测队。到 1992 年 12 月，由不同机构投放的 620 个仪器浮标随风和洋流在全球海洋中漂流，每天向通信系统发送大约 2400 条报告。这些漂流浮标提供大气压力、空气温度、水温，有时还包括风力的测量数据。多个国家还操作系泊浮标或固定平台，用于测量气象和海洋参数。这些平台中的一些还对大气和海洋污染进行取样。到 1992 年底，各国报告有 195 个系泊浮标和超过 80 个平台进行观测。

The meteorological community was among the first to make extensive use of satellites. Photographs of storms and cloud systems are used to improve weather predictions and warnings. International cooperation in weather and environmental satellites has grown rapidly since the United Nations General Assembly in 1961 called upon World Meteorological Organization (WMO) in light of developments in outer space to report on the means of developing existing weather forecasting capabilities. It was the 1962 report in response to this request that first introduced the term and concept of the World Weather Watch. Satellites are now essential, especially for tracking storms at sea such as tropical cyclones, hurricanes and typhoons.

气象界是最早广泛使用卫星的领域之一。风暴和云系的照片用于改进天气预报和警报。自 1961 年联合国大会呼吁世界气象组织（WMO）根据外太空的发展报告现有天气预报能力的发展方式以来，国际间在天气和环境卫星方面的合作迅速增长。响应这一请求的 1962 年报告首次引入了世界天气监测的术语和概念。如今，卫星是必不可少的，尤其是在跟踪海上风暴如热带气旋、飓风和台风时。

In hydrology, surface water temperatures, the extent of flood plains and the progress of floods, estimates of soil moisture, sediment transport, the extent of snow and ice cover, and other parameters are often determined by satellite.
在水文学中，地表水温、洪泛平原的范围和洪水的进展、土壤湿度估算、沉积物运输、雪和冰覆盖范围以及其他参数通常通过卫星确定。

The current World Weather Watch satellite system consists of several near polar-orbiting satellites, and four geostationary satellites. These are complementary in purpose. The geostationary satellites are providing effectively continuous surveillance over the tropics and temperate zones from fixed locations over the equator.

当前的世界天气监测卫星系统由几颗近极轨卫星和四颗静止卫星组成。这些卫星的目的互为补充。静止卫星从赤道上的固定位置对热带和温带地区提供有效的连续监测。

Near polar-orbiting satellites are especially important for polar and sub-polar regions, but provide only one image per orbit for a location. Due to westward progression of successive orbits, a particular location is viewed at least twice a day. Measuring systems on board the satellites are programmed to obtain global data (images of clouds, snow and ice cover, sea-surface temperature, temperature profiles) once or twice a day.

近极地轨道卫星对于极地和亚极地地区尤为重要，但每次轨道运行仅为某一地点提供一个图像。由于连续轨道的西向推进，特定地点每天至少被观测两次。卫星上的测量系统被编程为每天获取一次或两次全球数据（云层、积雪和冰层覆盖、海面温度、温度剖面图像）。

Images are made available globally through satellite receiving equipment, some quite inexpensive.

图像通过卫星接收设备在全球范围内提供，有些设备相当便宜。

Due to the efforts of the Coordination Group for Meteorological Satellites (CGMS), the system characteristics are generally similar and compatible for these satellites. Their basic mission is to provide visible and infrared images for cloud presence and cloud top temperature (height of cloud tops), land and sea temperatures, and upper winds estimate from cloud movement. Their communication systems transmit weather facsimile charts, and environmental data from both fixed and moving data collection platforms, such as automatic weather stations and marine observation platforms.

由于气象卫星协调组（CGMS）的努力，这些卫星的系统特性大体相似且兼容。它们的基本任务是提供云层存在情况和云顶温度（云顶高度）、陆地和海洋温度以及通过云层移动估算的高空风速的可见光和红外图像。它们的通信系统传输天气传真图表，以及来自固定和移动数据采集平台（如自动气象站和海洋观测平台）的环境数据。

The ground segment of the satellite program provides for reception of signals and data relays from the satellites. The most complex forms of information are received and processed primarily by the satellite operating countries themselves who in turn encode the data for transmission over the GTS to computer centers for numerical weather prediction. Cloud wind estimates, sea surface temperature and calculated atmospheric temperature profile data are also transmitted through the global system. In addition, there are at present, almost 700 satellite receivers operated by WMO member countries, throughout the world.

卫星计划的地面部分负责接收来自卫星的信号和数据中继。最复杂的信息形式主要由卫星操作国自身接收和处理，这些国家又将数据编码以通过全球通信系统（GTS）传输到数值天气预报的计算中心。云风估计、海表温度和计算的大气温度剖面数据也通过全球系统传输。此外，目前全球有近 700 个由世界气象组织（WMO）成员国操作的卫星接收器。

It must be recognized that the operational satellites designed and used extensively for weather forecasting, are also valuable for many other environmental purposes. A few examples will illustrate. China first detected and tracked the major Northeastern forest fires in 1990 with their environmental weather satellite. The USA has put into effect a Volcanic Hazards Alert Plan using satellite data to determine plume altitudes and ash cloud movements, so dangerous to jet aircraft. WMO’s African Drought Monitoring Center use NOAA satellite images for assessing changes in vegetation affected by drought and rainfall. Many important water management applications are being developed. Coastal zone changes, erosion and sedimentation are monitored by Bangladesh and other countries by satellite. Environmental and hydrological data in addition to meteorological observations are often transmitted from remote areas through the weather satellite communications relay facilities.

必须认识到，专为天气预报设计并广泛使用的操作卫星，对许多其他环境目的也具有重要价值。以下几个例子可以说明这一点。中国在 1990 年首次利用其环境气象卫星检测和追踪东北地区的重大森林火灾。美国已实施火山危险预警计划，利用卫星数据确定烟柱高度和灰云运动，这对喷气式飞机构成危险。世界气象组织的非洲干旱监测中心使用美国国家海洋和大气管理局的卫星图像评估受干旱和降雨影响的植被变化。许多重要的水管理应用正在开发中。孟加拉国和其他国家通过卫星监测沿海地区的变化、侵蚀和沉积。除了气象观测外，环境和水文数据通常通过气象卫星通信中继设施从偏远地区传输。

So far, the surface- and space-based systems together represent a remarkable achievement in scientific cooperation, in many ways a model for the world.

到目前为止，地面和太空系统共同代表了科学合作的一个显著成就，在许多方面成为世界的典范。