scholarly journals Pairing FLUXNET Sites to Validate Model Representations of Land Use/Land Cover Change

2017 ◽  
Author(s):  
Liang Chen ◽  
Paul A. Dirmeyer ◽  
Zhichang Guo ◽  
Natalie M. Schultz
Keyword(s):  
Land Use ◽  
Heat Flux ◽  
Land Cover ◽  
Land Cover Change ◽  
Land Surface ◽  
Surface Fluxes ◽  
Late Winter ◽  
Land Use Land Cover ◽  
Community Land Model ◽  
Ground Heat Flux

Abstract. Land surface energy and water fluxes play an important role in land-atmosphere interactions, especially for the climatic feedback effects driven by land use/land cover change (LULCC). These have long been documented in model-based studies, but the performance of land surface models in representing LULCC-induced responses has not been well investigated. In this study, measurements from proximate paired (open versus forest) flux tower sites are used to represent observed deforestation-induced changes in surface fluxes, which are compared with simulations from the Community Land Model (CLM) and the Noah Multi-Parameterization (Noah-MP) land model. Point-scale simulations suggest CLM can represent the observed diurnal and seasonal changes in net radiation (Rnet) and ground heat flux (G), but difficulties remain in the energy partitioning between latent (LE) and sensible (H) heat flux. CLM does not capture the observed decreased daytime LE, and overestimates the increased H during summer. These biases are mainly associated with deficiencies over forest land-cover types and the parameterization of soil evaporation. Global gridded simulations with CLM show uncertainties in the estimation of LE and H at the grid level for regional and global simulations. Noah-MP exhibits a similar ability to simulate the surface flux changes, but with larger biases in H, G, and Rnet change during late winter and early spring, which are related to a deficiency in estimating albedo. Differences in meteorological conditions between paired sites is not a factor in these results. Attention needs to be devoted to improving the representation of surface heat flux processes in land models to increase confidence in LULCC simulations.

scholarly journals Pairing FLUXNET sites to validate model representations of land-use/land-cover change

2018 ◽  
Vol 22 (1) ◽  
pp. 111-125 ◽  
Author(s):  
Liang Chen ◽  
Paul A. Dirmeyer ◽  
Zhichang Guo ◽  
Natalie M. Schultz
Keyword(s):  
Land Use ◽  
Heat Flux ◽  
Land Cover ◽  
Land Cover Change ◽  
Land Surface ◽  
Surface Fluxes ◽  
Late Winter ◽  
Land Use Land Cover ◽  
Community Land Model ◽  
Ground Heat Flux

Abstract. Land surface energy and water fluxes play an important role in land–atmosphere interactions, especially for the climatic feedback effects driven by land-use/land-cover change (LULCC). These have long been documented in model-based studies, but the performance of land surface models in representing LULCC-induced responses has not been investigated well. In this study, measurements from proximate paired (open versus forest) flux tower sites are used to represent observed deforestation-induced changes in surface fluxes, which are compared with simulations from the Community Land Model (CLM) and the Noah Multi-Parameterization (Noah-MP) land model. Point-scale simulations suggest the CLM can represent the observed diurnal and seasonal changes in net radiation (Rnet) and ground heat flux (G), but difficulties remain in the energy partitioning between latent (LE) and sensible (H) heat flux. The CLM does not capture the observed decreased daytime LE, and overestimates the increased H during summer. These deficiencies are mainly associated with models' greater biases over forest land-cover types and the parameterization of soil evaporation. Global gridded simulations with the CLM show uncertainties in the estimation of LE and H at the grid level for regional and global simulations. Noah-MP exhibits a similar ability to simulate the surface flux changes, but with larger biases in H, G, and Rnet change during late winter and early spring, which are related to a deficiency in estimating albedo. Differences in meteorological conditions between paired sites is not a factor in these results. Attention needs to be devoted to improving the representation of surface heat flux processes in land models to increase confidence in LULCC simulations.

scholarly journals An Urban Parameterization for a Global Climate Model. Part I: Formulation and Evaluation for Two Cities

2008 ◽  
Vol 47 (4) ◽  
pp. 1038-1060 ◽  
Author(s):  
K. W. Oleson ◽  
G. B. Bonan ◽  
J. Feddema ◽  
M. Vertenstein ◽  
C. S. B. Grimmond
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Land Cover Change ◽  
Land Surface ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Surface Model ◽  
Land Use Land Cover ◽  
Community Land Model

Abstract Urbanization, the expansion of built-up areas, is an important yet less-studied aspect of land use/land cover change in climate science. To date, most global climate models used to evaluate effects of land use/land cover change on climate do not include an urban parameterization. Here, the authors describe the formulation and evaluation of a parameterization of urban areas that is incorporated into the Community Land Model, the land surface component of the Community Climate System Model. The model is designed to be simple enough to be compatible with structural and computational constraints of a land surface model coupled to a global climate model yet complex enough to explore physically based processes known to be important in determining urban climatology. The city representation is based upon the “urban canyon” concept, which consists of roofs, sunlit and shaded walls, and canyon floor. The canyon floor is divided into pervious (e.g., residential lawns, parks) and impervious (e.g., roads, parking lots, sidewalks) fractions. Trapping of longwave radiation by canyon surfaces and solar radiation absorption and reflection is determined by accounting for multiple reflections. Separate energy balances and surface temperatures are determined for each canyon facet. A one-dimensional heat conduction equation is solved numerically for a 10-layer column to determine conduction fluxes into and out of canyon surfaces. Model performance is evaluated against measured fluxes and temperatures from two urban sites. Results indicate the model does a reasonable job of simulating the energy balance of cities.

Land use/land cover change dynamics and their effects on land surface temperature in the western region of the state of São Paulo, Brazil

2020 ◽  
Vol 20 (3) ◽  
Author(s):  
Rosana Amaral Carrasco ◽  
Mayara Maezano Faita Pinheiro ◽  
José Marcato Junior ◽  
Rejane Ennes Cicerelli ◽  
Paulo Antônio Silva ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Surface Temperature ◽  
Land Cover Change ◽  
Land Surface Temperature ◽  
Land Surface ◽  
The State ◽  
Western Region ◽  
Land Use Land Cover ◽  
Change Dynamics

scholarly journals Characterizing the relationship between land use land cover change and land surface temperature

2017 ◽  
Vol 124 ◽  
pp. 119-132 ◽  
Author(s):  
Duy X. Tran ◽  
Filiberto Pla ◽  
Pedro Latorre-Carmona ◽  
Soe W. Myint ◽  
Mario Caetano ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Surface Temperature ◽  
Land Cover Change ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Land Use Land Cover ◽  
The Relationship

scholarly journals Impact of urban expansion on continental- to regional-scale warming

2022 ◽  
Author(s):  
TC Chakraborty ◽  
Yun Qian
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Cover ◽  
Land Cover Change ◽  
Land Surface ◽  
Urban Expansion ◽  
Regional Scale ◽  
Land Use Land Cover ◽  
Earth System ◽  
Earth System Models

Abstract Although the influence of land use/land cover change on climate has become increasingly apparent, cities and other built-up areas are usually ignored when estimating large-scale historical climate change or for future projections since cities cover a small fraction of the terrestrial land surface1,2. As such, ground-based observations of urban near-surface meteorology are rare and most earth system models do not represent historical or future urban land cover3–7. Here, by combining global satellite observations of land surface temperature with historical estimates of built-up area, we demonstrate that the urban temperature signal on continental- to regional-scale warming has become non-negligible, especially for rapidly urbanizing regions in Asia. Consequently, expected urban expansion over the next century suggest further increased urban influence on surface climate under all future climate scenarios. Based on these results, we argue that, in line with other forms of land use/land cover change, urbanization should be explicitly included in future climate change assessments. This would require extensive model development to incorporate urban extent and biophysics in current-generation earth system models to quantify potential urban feedbacks on the climate system at multiple scales.

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