Sample MERRA analysis

Sample analysis file from MERRA (Modern-Era Retrospective analysis for Research and Applications), produced by NASA (http://gmao.gsfc.nasa.gov/merra/). This contains historical analysed fields (i.e. output from data assimilation) from this global numerical weather prediction modeling system.<br>- Dimensions: 144×288 grid-points in the horizontal with a global coverage on a 1.25 x 1.25 degree geographical grid. There are 42 vertical levels from 1000hPa to 0.1hPa. <br>- There are 8 time-points, representing regular three-hourly snapshots from 2013-06-01 00:00:00 UTC.<br>- There 11 variables with these four dimensions, including dynamical fields (wind components, pressure, temperature, vorticity, geopotential height) and composition (relative humidity, liquid water and ice mixing ratios, ozone mixing ratio). <br><br>

本文件为美国国家航空航天局（NASA）研发的现代时代回顾性研究与应用分析（Modern-Era Retrospective analysis for Research and Applications，简称MERRA）的样本分析文件，数据来源网址为http://gmao.gsfc.nasa.gov/merra/。该数据集包含该全球数值天气预报模式系统生成的历史分析场（即数据同化输出结果）。<br>- 维度参数：水平方向采用1.25°×1.25°的地理网格实现全球覆盖，包含144×288个水平网格点；垂直方向共设42层，气压范围覆盖1000百帕至0.1百帕。<br>- 时间维度：包含8个时间点，为2013年6月1日00:00:00 协调世界时（UTC）起每隔3小时采集的常规快照数据。<br>- 变量维度：共包含11个适配上述四维（水平、垂直、时间）的变量，涵盖动力场变量（风分量、气压、气温、涡度、位势高度）以及大气成分变量（相对湿度、液态水与冰混合比、臭氧混合比）。