文档介绍：气象学与气候学实****教材
of rural drinking water sources, protection of drinking water sources in rural areas by the end of 为了取得气象资料也要建立气象站。建立气象站的工作，除规划气象站网的布局外，还包括观测场地的选择，观测场内仪器的布置，规定观测时间和观测次数，以及观测、发报、记录表报等。
地面观测分为定时观测和不定时观测两类。定时观测包括定时气候观测和定时天气观测，定时气候观测是台站的根本观测，观测的目的是积累资料，了解一地的气候情况，为预报提供实况。一般说一天内观测次数越多，越能反映出一地的气候要素变化情况，但为了节约人力、物力，可以在一天中选几个适当的时间进行观测。统计结果说明，每日选适当时间观测4次与观测24次的日平均值非常接近，所以确定每天进行4次气候观测，根本能满足要求。目前我国确定每日以北京时02、08、14、20时进行四次气候观测，一局部站、哨仅负担08、14、20时三次气候观测任务。
of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities
of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities
of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities
为了获得各气象要素的连续变化和极值，气象站还配有各种自记仪器，连续记录各种气象要素的变化，经过和实测值订正，便能在自记记录上得到任意时间的气象要素值，和一天中出现的极值，这样就弥补了定时气候观测的缺乏。
定时天气观测主要是为了编发天气报告(电报编码按统一规定编成)，满足天气预报进行天气分析的需要而进行的气象观测，由于天气分析预报，必须了解全球各地同一瞬间的气象要素情况，因此要求全球台站按同一时间进行天气观测。
of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities
of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities
of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities
天气系统的移动和变化是