scholarly journals Review of "Multi-variable, multi-configuration testing of ORCHIDEE land surface model water flux and storage estimates across semi-arid sites in the southwestern US"

2019 ◽  
Keyword(s):  
Land Surface ◽  
Water Flux ◽  
Land Surface Model ◽  
Surface Model ◽  
And Storage ◽  
Semi Arid ◽  
Model Water

scholarly journals Observed nighttime conductance alters modeled global hydrology and carbon budgets

2015 ◽  
Vol 8 (12) ◽  
pp. 10339-10363 ◽  
Author(s):  
D. L. Lombardozzi ◽  
M. J. B. Zeppel ◽  
R. A. Fisher ◽  
A. Tawfik
Keyword(s):  
Stomatal Conductance ◽  
Land Surface ◽  
Arid Regions ◽  
Land Surface Model ◽  
Carbon Gain ◽  
Surface Model ◽  
Land Surface Models ◽  
Climate Simulations ◽  
Surface Models ◽  
Semi Arid

Abstract. The terrestrial biosphere regulates climate through carbon, water, and energy exchanges with the atmosphere. Land surface models estimate plant transpiration, which is actively regulated by stomatal pores, and provide projections essential for understanding Earth's carbon and water resources. Empirical evidence from 204 species suggests that significant amounts of water are lost through leaves at night, though land surface models typically reduce stomatal conductance to nearly zero at night. Here, we apply observed nighttime stomatal conductance values to a global land surface model, to better constrain carbon and water budgets. We find that our modifications increase transpiration up to 5 % globally, reduce modeled available soil moisture by up to 50 % in semi-arid regions, and increase the importance of the land surface on modulating energy fluxes. Carbon gain declines up to ~ 4 % globally and > 25 % in semi-arid regions. We advocate for realistic constraints of minimum stomatal conductance in future climate simulations, and widespread field observations to improve parameterizations.

Evaluation of the hydrology of the IBIS land surface model in a semi-arid catchment

2014 ◽  
Vol 29 (5) ◽  
pp. 653-670 ◽  
Author(s):  
Min Chen ◽  
Garry R. Willgoose ◽  
Patricia M. Saco
Keyword(s):  
Land Surface ◽  
Land Surface Model ◽  
Surface Model ◽  
Semi Arid

scholarly journals Translating aboveground cosmic-ray neutron intensity to high-frequency soil moisture profiles at sub-kilometer scale

2014 ◽  
Vol 18 (11) ◽  
pp. 4363-4379 ◽  
Author(s):  
R. Rosolem ◽  
T. Hoar ◽  
A. Arellano ◽  
J. L. Anderson ◽  
W. J. Shuttleworth ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Land Surface ◽  
High Frequency ◽  
Mixed Forest ◽  
Land Surface Model ◽  
Cosmic Ray ◽  
Data Availability ◽  
Surface Model ◽  
Moisture Profiles ◽  
Semi Arid

Abstract. Above-ground cosmic-ray neutron measurements provide an opportunity to infer soil moisture at the sub-kilometer scale. Initial efforts to assimilate those measurements have shown promise. This study expands such analysis by investigating (1) how the information from aboveground cosmic-ray neutrons can constrain the soil moisture at distinct depths simulated by a land surface model, and (2) how changes in data availability (in terms of retrieval frequency) impact the dynamics of simulated soil moisture profiles. We employ ensemble data assimilation techniques in a "nearly-identical twin" experiment applied at semi-arid shrubland, rainfed agricultural field, and mixed forest biomes in the USA. The performance of the Noah land surface model is compared with and without assimilation of observations at hourly intervals, as well as every 2 days. Synthetic observations of aboveground cosmic-ray neutrons better constrain the soil moisture simulated by Noah in root-zone soil layers (0–100cm), despite the limited measurement depth of the sensor (estimated to be 12–20cm). The ability of Noah to reproduce a "true" soil moisture profile is remarkably good, regardless of the frequency of observations at the semi-arid site. However, soil moisture profiles are better constrained when assimilating synthetic cosmic-ray neutron observations hourly rather than every 2 days at the cropland and mixed forest sites. This indicates potential benefits for hydrometeorological modeling when soil moisture measurements are available at a relatively high frequency. Moreover, differences in summertime meteorological forcing between the semi-arid site and the other two sites may indicate a possible controlling factor to soil moisture dynamics in addition to differences in soil and vegetation properties.

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