Surface Weather Observations

Surface weather observations are recorded half hourly, primarily from aerodromes with some additional data coming from unmanned automatic weather stations. In special conditions, observations may be made earlier and for cost savings, some stations may only report hourly. The data show the latest reading at each site over the last 60 minutes.

The following data are recorded:
datetime, id_num (WMO index number, normally a unique id, but can be missing), id_name (abbreviated name, used to identify the observing site), date, time, wdir (wind direction, degrees from N), wspd (wind speed, knots), t_db (temperature dry bulb, degree C), dp (dew point, degree C), qnh (aircraft altimeter setting, hPa), rf9am (rainfall since 9am, mm), rf10m (rainfall last 10 minutes, mm), vic (visibility, m), avis (automatically measured visibility, m), gust (maximum wind gust last 10 minutes, knots), wx1int (first (most important) present weather intensity), wx1dsc (first (most important) present weather qualifier), wx1wx1 (first (most important) present weather type), wx1wx2 (additional weather type for mixed precipitation), wx1wx3 (additional weather type for mixed precipitation), wx2int (second (less important) present weather intensity), wx2dsc (second (less important) present weather qualifier), wx2wx1 (second (less important) present weather type), wx2wx2 (additional weather type for mixed precipitation), wx2wx3 (additional weather type for mixed precipitation), cld1amt (lowest cloud layer amount), cld1typ (lowest cloud layer type), cld1typ (lowest cloud layer base, m), cld2amt (second cloud layer amount), cld1typ (second cloud layer type), cld1base (second cloud layer base, m), cld3amt (third cloud layer amount), cld3typ (third cloud layer type), cld3base (lowest cloud layer base, m), cld4amt (fourth cloud amount), cld4typ (fourth cloud layer type), cld4base (fourth cloud layer base, m), ceil1amt (lowest cloud layer amount measured by ceilometer), ceil1base (lowest cloud layer base measured by ceilometer, m), ceil2amt (second cloud layer amount measured by ceilometer), ceil2base (second cloud layer base measured by ceilometer, m), ceil3amt (third cloud layer amount measured by ceilometer), ceil1base (third cloud layer base measured by ceilometer, m), rotation (required for rotation of wind barbs in MapServer), rh (relative humidity, %), stn_name (full station name).

Information about codes can be found at http://www.bom.gov.au/weather-services/about/IDY03100.doc.

本数据集包含每半小时一次的地面气象观测记录，观测数据主要来源于航空站，另有部分数据取自无人自动气象站。特殊情况下可提前开展观测；部分站点为节约观测成本，仅按每小时频率上报观测数据。数据集将展示各站点过去60分钟内的最新观测读数。

本次记录包含以下数据项：
datetime（日期时间）、id_num（世界气象组织（World Meteorological Organization, WMO）索引编号，通常为唯一标识符，亦可能缺失）、id_name（站点缩写标识名，用于识别观测站点）、date（观测日期）、time（观测时间）、wdir（风向，以正北为基准的角度值）、wspd（风速，单位节）、t_db（干球温度，单位摄氏度）、dp（露点温度，单位摄氏度）、qnh（修正海平面气压，单位百帕）、rf9am（当日9时起累计降雨量，单位毫米）、rf10m（近10分钟降雨量，单位毫米）、vic（能见度，单位米）、avis（自动观测能见度，单位米）、gust（近10分钟最大阵风风速，单位节）、wx1int（首要/核心当前天气现象强度）、wx1dsc（首要当前天气现象修饰词）、wx1wx1（首要当前天气现象类型）、wx1wx2（首要混合型降水附加天气类型1）、wx1wx3（首要混合型降水附加天气类型2）、wx2int（次要当前天气现象强度）、wx2dsc（次要当前天气现象修饰词）、wx2wx1（次要当前天气现象类型）、wx2wx2（次要混合型降水附加天气类型1）、wx2wx3（次要混合型降水附加天气类型2）、cld1amt（最低云量）、cld1typ（最低云型）、cld1base（最低云底高度，单位米，原文此处变量名存在笔误）、cld2amt（第二层层云量）、cld2typ（第二层层云型，原文此处变量名存在笔误）、cld2base（第二层层云底高度，单位米，原文此处变量名存在笔误）、cld3amt（第三层层云量）、cld3typ（第三层层云型）、cld3base（第三层层云底高度，单位米，原文此处说明存在笔误）、cld4amt（第四层层云量）、cld4typ（第四层层云型）、cld4base（第四层层云底高度，单位米）、ceil1amt（云高仪观测的最低云量）、ceil1base（云高仪观测的最低云底高度，单位米）、ceil2amt（云高仪观测的第二层层云量）、ceil2base（云高仪观测的第二层层云底高度，单位米）、ceil3amt（云高仪观测的第三层层云量）、ceil3base（云高仪观测的第三层层云底高度，单位米，原文此处变量名存在笔误）、rotation（MapServer中风向羽饰旋转所需参数）、rh（相对湿度，单位百分比）、stn_name（站点全称）。

各编码的详细说明可通过链接 http://www.bom.gov.au/weather-services/about/IDY03100.doc 查阅。