中国气象局数据虽然也公开，相对其它部门做得要稍好些，但设置的门槛也不少，服务水平且不说不高，还有故意刁难的意思。如下载个50年的日数据，居然形成6000多个单独文件，要一个一个下载，服务人员说是系统需要？？？？？？。要想下小时数据更是门儿都找不到。气象数据更新还要要延迟3个月，我们不是网络时代吗？？？？？？。科学界的人大代表是不是应该提案质询一下！！！！！产出比和效益？

不得不吐槽，国人的小肚与官僚，还是美国人有国际范，有科学无国界的意思。不像中国报个科学奖都得自己申报，真是奇观？？？

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来到美国国家气候数据中心（national climate data center),世界最大的气象气候数据提供机构：http://www.ncdc.noaa.gov/

地面站点观测数据介绍如下：http://www.ncdc.noaa.gov/data-access/land-based-station-data 

地面站点观测的数据参数包括：temperature, dew point,  relative humidity,precipitation, wind speed and  direction, visibility, atmospheric pressure, and types of weather occurrences such as hail, fog, and thunder.等

数据发布的时间尺度多种，包括： sub-hourly, hourly, daily, monthly, annual, and multiyear timescales 等。

不同标准数据的所记录的气象观测数据和时间尺度各有不同，详见各个数据说明。数据多种标准类型如下：http://www.ncdc.noaa.gov/cdo-web/datasets

本人选择了：Global Surface Summary of the Day数据集作为工作对象，如下：

https://gis.ncdc.noaa.gov/geoportal/catalog/search/resource/details.page?id=gov.noaa.ncdc:C00516 

数据说明：

Global Surface Summary of the Day is derived from The Integrated Surface Hourly (ISH) dataset. The ISH dataset includes global data obtained from the USAF Climatology Center, located in the Federal Climate Complex with NCDC. The latest daily summary data are normally available 1-2 days after the date-time of the observations used in the daily summaries. The online data files begin with 1929 and are at the time of this writing at the Version 8 software level. Over 9000 stations' data are typically available. The daily elements included in the dataset (as available from each station) are: Mean temperature (.1 Fahrenheit) Mean dew point (.1 Fahrenheit) Mean sea level pressure (.1 mb) Mean station pressure (.1 mb) Mean visibility (.1 miles) Mean wind speed (.1 knots) Maximum sustained wind speed (.1 knots) Maximum wind gust (.1 knots) Maximum temperature (.1 Fahrenheit) Minimum temperature (.1 Fahrenheit) Precipitation amount (.01 inches) Snow depth (.1 inches) Indicator for occurrence of: Fog, Rain or Drizzle, Snow or Ice Pellets, Hail, Thunder, Tornado/Funnel Cloud Global summary of day data for 18 surface meteorological elements are derived from the synoptic/hourly observations contained in USAF DATSAV3 Surface data and Federal Climate Complex Integrated Surface Hourly (ISH). Historical data are generally available for 1929 to the present, with data from 1973 to the present being the most complete. For some periods, one or more countries' data may not be available due to data restrictions or communications problems. In deriving the summary of day data, a minimum of 4 observations for the day must be present (allows for stations which report 4 synoptic observations/day). Since the data are converted to constant units (e.g, knots), slight rounding error from the originally reported values may occur (e.g, 9.9 instead of 10.0). The mean daily values described below are based on the hours of operation for the station. For some stations/countries, the visibility will sometimes 'cluster' around a value (such as 10 miles) due to the practice of not reporting visibilities greater than certain distances. The daily extremes and totals--maximum wind gust, precipitation amount, and snow depth--will only appear if the station reports the data sufficiently to provide a valid value. Therefore, these three elements will appear less frequently than other values. Also, these elements are derived from the stations' reports during the day, and may comprise a 24-hour period which includes a portion of the previous day. The data are reported and summarized based on Greenwich Mean Time (GMT, 0000Z - 2359Z) since the original synoptic/hourly data are reported and based on GMT.