What is the difference between NLDAS Phase 1 (NLDAS-1) and NLDAS Phase 2 (NLDAS-2)?
A. This is the most popular NLDAS question. We’re developing below an appropriately short yet fully detailed answer! For further information, please refer to the NLDAS-1 Forcing, NLDAS-1 Model, NLDAS-2 Forcing, and NLDAS-2 Model pages. The most significant difference is the time frames of the datasets. NLDAS-1 is available from mid-1996 to the end of December 2007. NLDAS-2 is available from January 1979 to near real-time. Another major difference between the two phases of NLDAS is the sources of model data and observations used to create the respective forcing datasets. NLDAS-1 uses the 40-km NCEP Eta model-based Data Assimilation System (EDAS) for the surface meteorology, while NLDAS-2 uses the 32-km NARR system. For downward shortwave radiation at the surface, NLDAS-1 uses GOES-based satellite retrievals, with EDAS data used when/where not available; NLDAS-2 uses GOES data to bias-correct the NARR shortwave radiation. Both NLDAS-1 and NLDAS-2 use a 1/8th-degree CPC daily gauge analys
A. This is the most popular NLDAS question. We’re developing below an appropriately short yet fully detailed answer! For further information, please refer to the NLDAS-1 Forcing, NLDAS-1 Model, NLDAS-2 Forcing, and NLDAS-2 Model pages. The most significant difference is the time frames of the datasets. NLDAS-1 is available from mid-1996 to the end of December 2007. NLDAS-2 is available from January 1979 to near real-time. Another major difference between the two phases of NLDAS is the sources of model data and observations used to create the respective forcing datasets. NLDAS-1 uses the 40-km NCEP Eta model-based Data Assimilation System (EDAS) for the surface meteorology, while NLDAS-2 uses the 32-km NARR system. For downward shortwave radiation at the surface, NLDAS-1 uses GOES-based satellite retrievals, with EDAS data used when/where not available; NLDAS-2 uses GOES data to bias-correct the NARR shortwave radiation. Both NLDAS-1 and NLDAS-2 use a 1/8th-degree CPC daily gauge analys
