中国区域高时空分辨率地面气象要素驱动数据集（1979-2015）

中国区域地面气象要素数据集是中国科学院青藏高原研究所开发的一套近地面气象与环境要素再分析数据集。该数据集是以国际上现有的 Princeton 再分析资料、GLDAS 资料、GEWEX-SRB 辐射资料，以及 TRMM 降水资料为背景场，融合了中国气象局常规气象观测数据制作而成。其时间分辨率为 3 小时，水平空间分辨率 0.1°，包含近地面气温、近地面气压、近地面空气比湿、近地面全风速、地面向下短波辐射、地面向下长波辐射、地面降水率，共 7 个要素（变量）。

各变量的物理意义：
| 气象要素||变量名||单位||物理意义
| 近地面气温 ||temp|| K || 瞬时近地面（2m）气温
| 地表气压 || pres|| Pa || 瞬时地表气压
| 近地面空气比湿 || shum || kg/ kg ||瞬时近地面空气比湿
| 近地面全风速 || wind || m /s || 瞬时近地面（风速仪高度）全风速
| 向下短波辐射|| srad || W /平方米 || 3 小时平均 （-1.5hr ～ +1.5hr） 向下短波辐射
| 向下长波辐射||lrad ||W /平方米 ||3 小时平均 （-1.5hr ～ +1.5hr） 向下长波辐射
| 降水率||prec||mm/hr ||3 小时平均 （-3.0hr ～ 0.0hr） 降水率
更多信息，请参见随数据一同发布的《User’s Guide for China Meteorological Forcing Dataset》。

最新版本（01.06.0014）的主要变化有：
1. 将数据延伸到 2015 年 12 月（短波和长波数据例外，只到 2015 年 10 月，2015 年 11-12 月的数据系根据 GLDAS 数据插值得到，误差可能会偏大）；
2. 设定风速最小值为 0.05 m/s；
3. 修正了之前辐射算法中的一个 bug，使我们的短波和长波数据在晨昏时段更合理。
4. 修正了降水数据的 bug，更改涉及的时段是 2011-2015 年。

The China Regional Land Surface Meteorological Element Dataset is a near-surface meteorological and environmental element reanalysis dataset developed by the Institute of Tibetan Plateau Research, Chinese Academy of Sciences. This dataset is produced by fusing routine meteorological observation data from the China Meteorological Administration, using internationally available Princeton reanalysis data, GLDAS data, GEWEX-SRB radiation data, and TRMM precipitation data as background fields. Its temporal resolution is 3 hours, and its horizontal spatial resolution is 0.1°. It contains 7 elements (variables): near-surface air temperature, near-surface air pressure, near-surface air specific humidity, near-surface total wind speed, surface downward shortwave radiation, surface downward longwave radiation, and surface precipitation rate.

Physical meanings of each variable:
| Meteorological Element || Variable Name || Unit || Physical Meaning
| Near-surface Air Temperature || temp || K || Instantaneous near-surface (2m above ground) air temperature
| Surface Air Pressure || pres || Pa || Instantaneous surface air pressure
| Near-surface Air Specific Humidity || shum || kg/kg || Instantaneous near-surface air specific humidity
| Near-surface Total Wind Speed || wind || m/s || Instantaneous near-surface wind speed (at anemometer height)
| Surface Downward Shortwave Radiation || srad || W/m² || 3-hour averaged downward shortwave radiation (-1.5hr ~ +1.5hr)
| Surface Downward Longwave Radiation || lrad || W/m² || 3-hour averaged downward longwave radiation (-1.5hr ~ +1.5hr)
| Precipitation Rate || prec || mm/hr || 3-hour averaged precipitation rate (-3.0hr ~ 0.0hr)

For more information, please refer to the *User’s Guide for China Meteorological Forcing Dataset* released along with the dataset.

The main changes in the latest version (01.06.0014) are as follows:
1. Extended the dataset to December 2015 (except for shortwave and longwave radiation data, which only cover up to October 2015; data for November-December 2015 were interpolated from GLDAS data, and may have relatively large errors);
2. Set the minimum value of wind speed to 0.05 m/s;
3. Fixed a bug in the previous radiation algorithm, making our shortwave and longwave radiation data more reasonable during dawn and dusk periods;
4. Fixed a bug in precipitation data, and the corrected period covers 2011-2015.