Land Data Assimilation System (LDAS) combines multiple sources of observations (such as precipitation gauge data, satellite data, and radar precipitation measurements) to produce estimates of climatological properties at or near the Earth''s surface.
This dataset is the primary (default) forcing file (File A) for Phase 2 of the North American Land Data Assimilation System (NLDAS-2). The data are in 1/8th-degree grid spacing; the temporal resolution is hourly.
NLDAS is a collaboration project among several groups: NOAA/NCEP''s Environmental Modeling Center (EMC), NASA''s Goddard Space Flight Center (GSFC), Princeton University, the University of Washington, the NOAA/NWS Office of Hydrological Development (OHD), and the NOAA/NCEP Climate Prediction Center (CPC). NLDAS is a core project with support from NOAA''s Climate Prediction Program for the Americas (CPPA).
Documentation:
陆地数据同化系统（LDAS）结合多种来源的观测数据（如降水表数据、卫星数据和雷达降水测量），以产生地球表面或附近的气候学特性估计。
该数据集是北美陆地数据同化系统（NLDAS-2）第二阶段的主要（默认）强迫文件（文件A）。数据的网格间距为1/8度；时间分辨率为每小时。
NLDAS是一个由几个小组合作的项目。NOAA/NCEP的环境模拟中心（EMC）、NASA的戈达德太空飞行中心（GSFC）、普林斯顿大学、华盛顿大学、NOAA/NWS的水文发展办公室（OHD）和NOAA/NCEP的气候预测中心（CPC）。NLDAS是一个核心项目，得到了NOAA's Climate Prediction Program for the Americas（CPPA）的支持。
Dataset Availability
1979-01-01T00:00:00 - 2021-09-25T00:00:00
Dataset Provider
NASA GES DISC at NASA Goddard Space Flight Center
Collection Snippet
ee.ImageCollection("NASA/NLDAS/FORA0125_H002")
Resolution
13915 meters
Bands Table
| Name | Description | Min* | Max* | Units |
| temperature | Air temperature at 2 meters above the surface | -49.79 | 51.2 | °C |
| specific_humidity | Specific humidity at 2 meters above the surface | 0 | 0.02 | kg/kg |
| pressure | Surface pressure | 61847.58 | 105337.62 | Pa |
| wind_u | U wind component at 10 meters above the surface | -27.93 | 27.54 | m/s |
| wind_v | V wind component at 10 meters above the surface | -27.45 | 35.13 | m/s |
| longwave_radiation | Surface downward longwave radiation | 72.18 | 545.11 | W/m^2 |
| convective_fraction | Fraction of total precipitation that is convective: from NARR | 0 | 1 | |
| potential_energy | Convective available potential energy (J/kg): from NARR | 0 | 76666.17 | J/kg |
| potential_evaporation | Potential evaporation: from NARR | 0 | 2.76 | kg/m^2 |
| total_precipitation | Hourly total precipitation | 0 | 124.19 | kg/m^2 |
| shortwave_radiation | Surface downward shortwave radiation - bias corrected | 0 | 1368.54 | W/m^2 |
* = Values are estimated
影像属性：
| Name | Type | Description |
| end_hour | Double | End hour |
| start_hour | Double | Start hour |
数据引用：
The data set source should be properly cited when the data are used. A formal reference of the form: <authors>, 2012, last updated 2013: <dataset name>. NASA/GSFC, Greenbelt, MD, USA, NASA Goddard Earth Sciences Data and Information Services Center (GES DISC). Accessed <enter user data access date> at <DOI> is suggested following Parsons et al. (2010), doi:10.1029/2010EO340001.
代码：
var dataset = ee.ImageCollection('NASA/NLDAS/FORA0125_H002') .filter(ee.Filter.date('2018-07-01', '2018-07-30')); var temperature = dataset.select('temperature'); var temperatureVis = { min: -5.0, max: 40.0, palette: ['3d2bd8', '4e86da', '62c7d8', '91ed90', 'e4f178', 'ed6a4c'], }; Map.setCenter(-110.21, 35.1, 4); Map.addLayer(temperature, temperatureVis, 'Temperature');
