NLDAS Noah Land Surface Model L4 Monthly 0.125 x 0.125 degree V002 (NLDAS_NOAH0125_M) at GES DISC

This data set contains a series of land surface parameters simulated from the Noah land-surface model (LSM) for Phase 2 of the North American Land Data Assimilation System (NLDAS-2). The data are in 1/8th degree grid spacing and range from Jan 1979 to the present. The temporal resolution is monthly. The file format is WMO GRIB-1. The NLDAS-2 monthly Noah model data were generated from the NLDAS-2 hourly Noah model data, as monthly accumulation for rainfall, snowfall, subsurface runoff, surface runoff, total evapotranspiration, snow melt, and monthly averages for other variables. The monthly period of each month is from 00Z at start of the month to 23:59Z at end of the month, with the exception of the very first month in the data set (Jan 1979) which starts at 00Z 02 Jan 1979. Also for the first month (Jan 1979), because the variables listed as instantaneous in the README file do not have valid data exactly on 00Z 02 Jan 1979, and this one hour is not included in the average for this month only.

A brief description about the NLDAS-2 monthly Noah model can be found from the dataset landing page for NLDAS_NOAH0125_H_002 and the NLDAS-2 README document.

Details about the NLDAS-2 configuration of the Noah LSM can be found in Xia et al. (2012).

The NLDAS-2 Noah monthly data contain fifty-two fields. The data set applies a user-defined parameter table to indicate the contents and parameter number. The GRIBTAB file shows a list of parameters for this data set, along with their Product Definition Section (PDS) IDs and units.

For information about the vertical layers of the Soil Moisture Content (PDS 086), Soil Temperature (PDS 085), and Liquid Soil Moisture Content (PDS 151) please see the README Document or the GrADS ctl file.

本数据集收录了北美陆地数据同化系统第二阶段（NLDAS-2）的Noah陆地表面模型（LSM）模拟的一系列陆地表面参数。数据以1/8度网格间距呈现，时间跨度自1979年1月至今。时间分辨率以月为单位。数据文件格式遵循世界气象组织（WMO）的GRIB-1标准。NLDAS-2的月度Noah模型数据由NLDAS-2的时度Noah模型数据生成，包括降雨、降雪、地下径流、地表径流、总蒸散量、积雪融化等变量的月累积值，以及其他变量的月平均值。每月的周期从每月00Z时开始至当月23:59Z时结束，数据集中最早的月份（1979年1月）则从1979年1月2日的00Z时开始。由于在README文件中标记为瞬时的变量在1979年1月2日的00Z时没有有效数据，因此此小时数据未包含在当月的平均值中。关于NLDAS-2的月度Noah模型的简要描述，可参考NLDAS_NOAH0125_H_002数据集的着陆页以及NLDAS-2的README文档。关于Noah LSM在NLDAS-2中的配置细节，可参见Xia等（2012）的研究。NLDAS-2的Noah月度数据包含五十二个字段。数据集应用用户定义的参数表以标识数据内容及其参数编号。GRIBTAB文件展示了该数据集的参数列表，包括其产品定义部分（PDS）标识符和单位。关于土壤含水量（PDS 086）、土壤温度（PDS 085）和液态土壤含水量（PDS 151）的垂直层信息，请参阅README文档或GrADS ctl文件。