Improved NLDAS‐2 Noah‐simulated hydrometeorological products with an interim run |
| |
| Authors: | Youlong Xia Christa D Peter‐Lidard Maoyi Huang Helin Wei Mike Ek |
| |
| Affiliation: | 1. Environmental Modeling Center (EMC), National Centers for Environmental Prediction (NCEP), College Park, National Oceanic and Atmospheric Administration (NOAA), College Park, MD, USA;2. IMSG at NOAA/NCEP/EMC, College Park, MD, USA;3. Hydrological Science Laboratory, Goddard Fight Space Center, National Aeronautics and Space Administration (NASA), Green Belt, MD, USA;4. Pacific Northwest National Laboratory (PNNL), Richland, WA, USA |
| |
| Abstract: | In North American Land Data Assimilation System Phase 2 (NLDAS‐2) Noah simulation, the NLDAS team introduced an intermediate ‘fix’ to constrain the surface exchange coefficient when the atmospheric boundary layer is stable. In the current NLDAS‐2 Noah version, this fix is used for all stable cases including snow‐free grid cells. In this study, we simply apply this fix to the grid cells in which both stable atmospheric boundary layer and snow exist simultaneously, excluding the snow‐free grid cells as we recognize that the fix in NLDAS‐2 is too strong. We conduct a 31‐year (1979–2009) NLDAS‐2 Noah interim (Noah‐I) run and use observed streamflow, evapotranspiration, land surface temperature, soil temperature, and ground heat flux to evaluate the results, including comparisons with the original NLDAS‐2 Noah run. The results show that Noah‐I has the same performance as NLDAS‐2 Noah for snow water equivalent; however, Noah‐I significantly improved the simulation of other hydrometeorological products as noted earlier when compared with NLDAS‐2 Noah and the observations. This simple modification is being included in the next Noah version used in NLDAS. The hydrometeorological products from the improved NLDAS‐2 Noah‐I are being staged on the National Centers for Environmental Prediction public server. Copyright © 2014 John Wiley & Sons, Ltd. |
| |
| Keywords: | NLDAS‐2 Noah land surface model hydrometeorological products snow hydrology |
|
|
