Hydrological evaluation of the Noah‐MP land surface model for the Mississippi River Basin

Abstract

This study evaluates regional‐scale hydrological simulations of the newly developed community Noah land surface model (LSM) with multiparameterization options (Noah‐MP). The model is configured for the Mississippi River Basin and driven by the North American Land Data Assimilation System Phase 2 atmospheric forcing at 1/8° resolution. The simulations are compared with various observational data sets, including the U.S. Geological Survey streamflow and groundwater data, the AmeriFlux tower micrometeorological evapotranspiration (ET) measurements, the Soil Climate Analysis Network (SCAN)‐observed soil moisture data, and the Gravity Recovery and Climate Experiment satellite‐derived terrestrial water storage (TWS) anomaly data. Compared with these observations and to the baseline Noah LSM simulations, Noah‐MP shows significant improvement in hydrological modeling for major hydrological variables (runoff, groundwater, ET, soil moisture, and TWS), which is very likely due to the incorporation of some major improvements into Noah‐MP, particularly an unconfined aquifer storage layer for groundwater dynamics and an interactive vegetation canopy for dynamic leaf phenology. Noah‐MP produces soil moisture values consistent with the SCAN observations for the top two soil layers (0–10 cm and 10–40 cm), indicating its great potential to be used in studying land‐atmosphere coupling. In addition, the simulated groundwater spatial patterns are comparable to observations; however, the inclusion of groundwater in Noah‐MP requires a longer spin‐up time (34 years for the entire study domain). Runoff simulation is highly sensitive to three parameters: the surface dryness factor (α), the saturated hydraulic conductivity (k), and the saturated soil moisture (θmax).

The incorporation of an organic soil layer in the Noah-MP land surface model and its evaluation over a boreal aspen forest

“…To initialize LSMs properly, the spin-up time required for LSMs to reach the equilibrium stage needs to be examined first (Chen and Mitchell, 1999;Cosgrove et al, 2003). In this study, model runs for the year 1998 were performed repeatedly until all the soil-state variables reached the equilibrium state, defined as when the difference between two consecutive 1-year simulations becomes less than 0.1 % for the annual means (Cai et al, 2014; L a te n t h e a t fl u x S e n s ib le h e a t fl u Yang et al, 1995). Yang et al (1995) discussed the spin-up processes by comparing results from 22 LSMs for grass and forest sites, and showed a wide range of spin-up timescales (from 1 to 20 years), depending on the model, state variable, and vegetation type.…”

“…When using the groundwater component of Noah-MP, it might take at least 250 years to spin up the water table depth in arid regions (Niu et al, 2007). Cai et al (2014) found that water table depth requires less than 10 years to spin up in a wet region, but more than 72 years for a dry region. For this boreal forest site where the water table depth is shallower (less than 2.5 m), it takes ∼ 7 years for water table depth to reach equilibrium.…”

“…Noah-MP has been implemented in the community Weather Research and Forecasting (WRF) model , which is widely used as a numerical weather prediction and regional climate model for dynamical downscaling in many regions worldwide (Chotamonsak et al, 2012). The performance of Noah-MP was previously evaluated using in situ and satellite data Yang et al, 2011;Cai et al, 2014;Pilotto et al, 2015;Chen et al, 2014). Those evaluation results showed significant improvements in modeling runoff, snow, surface heat fluxes, soil moisture, and surface skin temperature compared to the Noah LSM (Chen et al, 1996;Ek et al, 2003).…”

Assessing optimal set of implemented physical parameterization schemes in a multi-physics land surface model using genetic algorithm

“…Model runs for 2001 were repeatedly performed for all scheme combinations until the variables reached equilibrium. The criterion for the equilibrium is defined as the time when the difference in annual means between two consecutive one-year simulations is less than 0.1 % of the means (Cai et al, 2014;Yang et al, 1995). The spin-up periods of the all scheme combinations were no more than two years, and their differences were quite small among the scheme choices even though the scheme choices in RUN showed the greatest differences.…”

Study of the Spatiotemporal Characteristics of Meltwater Contribution to the Total Runoff in the Upper Changjiang River Basin

“…Additionally, Noah-MP has different parameterizations for several key land surface processes (Table 2); therefore, it can be used to conduct ensemble model simulations. Various studies have confirmed the performance of Noah-MP in reproducing energy and water fluxes at various scales and under different hydrometeorological conditions [41][42][43].…”