Improving soil organic carbon parameterization of land surface model for cold regions in the Northeastern Tibetan Plateau, China

Abstract

a b s t r a c tMost current land surface models (LSMs) show poor performance in soil water and temperature simulations for cold regions because of the inappropriate model structures and ill-parameterizations. This study aims to explore how to parameterize soil organic carbon (SOC) in term of soil moisture simulations using the Community Land Model version 4.0 (CLM4.0) model and the Dynamic Land Model version 1.0 (DLM1.0) model. Firstly, we discuss the sensitivities of modeled soil moisture to SOC based on observations. The SOC parameterizations in both CLM4.0 and DLM1.0 were proved poor against the measured SOC through sensitivity analysis for the Heihe River watershed area (cold but with high SOC). A SOC parameterization was developed and tested based on multiple year observations. Our findings are twofold: (i) the soil organic parameterizations in CLM4.0 and DLM1.0 are inappropriate for simulating soil moisture in cold regions with high SOC, and the modified SOC parameterization significantly improves the soil moisture simulations; (ii) the impacts of SOC on soil moisture vary significantly with seasons, which is largest for JJA (June, July and August) followed by SON (September, October and November), MAM (March, April and May) and DJF (December, January and February). This study highlights that the impacts of SOC should be fully considered for LSMs soil moisture simulations, especially for cold areas with high SOC.

Long-Term Lake Area Change and Its Relationship with Climate in the Endorheic Basins of the Tibetan Plateau

“…After comparison, we use the China meteorological forcing dataset [37][38][39] provided by the Qinghai-Tibet Plateau Data Center of the CAS. It is reanalysis data which has a better accuracy than other reanalysis datasets available in the area [37,40]. This gridded dataset has a spatial resolution of 0.1 • × 0.1 • and temporal resolution of 3 h, and includes seven climate elements.…”

“…This gridded dataset has a spatial resolution of 0.1 • × 0.1 • and temporal resolution of 3 h, and includes seven climate elements. The dataset is in NetCDF format and has been validated with good quality and widely applied in long-term climate change analysis in the TP [37,40]. We extracted annual mean temperature and annual precipitation over 1990-2018 for the EBTP from the dataset and calculated the annual mean temperature and annual precipitation for each sub-region for the same time period.…”

Multimodel‐based analyses of evapotranspiration and its controls in China over the last three decades

“…The LSMs-ET was developed by averaging the ET simulations from the Community Land Model (version 4.0, Oleson et al, 2010), Dynamic Land Model (Chen et al, 2013;Sun et al, 2016), and Variable Infiltration Capacity Model (Liang, Lettenmaier, Wood, & Burges, 1994). It has been validated against measurements from eddy covariance towers and from regional water balance analyses and has been compared with the Moderate Resolution Imaging Spectroradiometer (MODIS) ET (Mu, Heinsch, Zhao, & Running, 2007) and the model tree ensembles upscaling ET (Jung et al, 2011).…”

Improving Land Surface Temperature Simulation in CoLM Over the Tibetan Plateau Through Fractional Vegetation Cover Derived From a Remotely Sensed Clumping Index and Model‐Simulated Leaf Area Index

“…In recent years, some efforts have aimed at improving land surface modeling in the TP region. For example, a new soil organic parameterization was applied in CLM4.0 to improve soil moisture simulation in the cold regions of northeastern TP (Sun et al, ). The simulation of daytime ground‐air gradient in the western deserts was improved in the Simple Biosphere model version 2 (SIB2; Sellers et al, ) by using a new excess‐resistance heat transfer scheme (K. Yang et al, ).…”