Estimation of surface energy fluxes in the permafrost region of the Tibetan Plateau based on in situ measurements and the surface energy balance system model

AbstractRoughness height for heat transfer is a crucial parameter in the estimation of sensible heat flux. In this study, the performance of the Surface Energy Balance System (SEBS) has been tested and evaluated for typical land surfaces on the Tibetan Plateau on the basis of time series of observations at four sites with bare soil, sparse canopy, dense canopy, and snow surface, respectively. Both under- and overestimation at low and high sensible heat fluxes by SEBS was discovered. Through sensitivity analyses, it was identified that these biases are related to the SEBS parameterization of bare soil’s excess resistance to heat transfer (kB−1, where k is the von Kármán constant and B−1 is the Stanton number). The kB−1 of bare soil in SEBS was replaced. The results show that the revised model performs better than the original model.

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Evapotranspiration Estimation Using Surface Energy Balance System Model: A Case Study in the Nagqu River Basin

Atmosphere ◽

10.3390/atmos10050268 ◽

2019 ◽

Vol 10 (5) ◽

pp. 268 ◽

Cited By ~ 2

Author(s):

Lei Zhong ◽

Kepiao Xu ◽

Yaoming Ma ◽

Ziyu Huang ◽

Xian Wang ◽

...

Keyword(s):

Energy Balance ◽

Tibetan Plateau ◽

Surface Energy ◽

River Basin ◽

Land Surface ◽

Surface Energy Balance ◽

Hydrological Cycle ◽

The Tibetan Plateau ◽

Balance System ◽

Northern Tibetan Plateau

Calculation of actual evapotranspiration (AET) is of vital importance for the study of climate change, ecosystem carbon cycling, flooding, drought, and agricultural water demand. It is one of the more important components in the hydrological cycle and surface energy balance (SEB). How to accurately estimate AET especially for the Tibetan Plateau (TP) with complex terrain remains a challenge for the scientific community. Using multi-sensor remote sensing data, meteorological forcing data, and field observations, AET was derived for the Nagqu river basin of the Northern Tibetan Plateau from a surface energy balance system (SEBS) model. As inputs for SEBS, improved algorithms and datasets for land surface albedo and a cloud-free normalized difference vegetation index (NDVI) were also constructed. The model-estimated AET were compared with results by using the combinatory method (CM). The validation indicated that the model estimates of AET agreed well with the correlation coefficient, the root mean square error, and the mean percentage error of 0.972, 0.052 mm/h, and −10.4%, respectively. The comparison between SEBS estimation and CM results also proved the feasibility of parameterization schemes for land surface parameters and AET.

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High-resolution modelling of interactions between soil moisture and convection development in mountain enclosed Tibetan basin

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-12-4631-2015 ◽

2015 ◽

Vol 12 (5) ◽

pp. 4631-4675

Author(s):

T. Gerken ◽

W. Babel ◽

M. Herzog ◽

K. Fuchs ◽

F. Sun ◽

...

Keyword(s):

Soil Moisture ◽

Energy Balance ◽

Tibetan Plateau ◽

Surface Energy ◽

Surface Energy Balance ◽

Local Development ◽

Lake Basin ◽

Strong Impact ◽

The Tibetan Plateau ◽

Moist Convection

Abstract. The Tibetan Plateau plays a significant role in the atmospheric circulation and the Asian monsoon system. Turbulent surface fluxes and the evolution of boundary layer clouds to deep and moist convection provide a feedback system that modifies the Plateau's surface energy balance on scales that are currently unresolved in mesoscale models. This work analyses the land surface's role and specifically the influence of soil moisture on the triggering of convection at a cross-section of the Nam Co Lake basin, 150 km north of Lhasa using a cloud resolving atmospheric model with a fully coupled surface. The modelled turbulent fluxes and development of convection compare reasonably well with the observed weather. The simulations span Bowen-ratios of 0.5 to 2.5. It is found that convection development is strongest at intermediate soil moistures. Dry cases with soils close to the permanent wilting point are moisture limited in the convection development, while convection in wet soil moisture cases is limited by cloud cover reducing incoming solar radiation and sensible heat fluxes. This has a strong impact on the surface energy balance. This study also shows that local development of convection is an important mechanism for the upward transport of water vapour that originates from the lake basin that can then be transported to dryer regions of the plateau. Both processes demonstrate the importance of soil moisture and surface–atmosphere interactions on the energy and hydrological cycles of the Tibetan Plateau.

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The impact of the Westerlies on the PBL growth and land surface energy balance on the north of the central Himalaya

10.5194/egusphere-egu2020-1329 ◽

2020 ◽

Author(s):

Xuelong Chen ◽

Yue Lai ◽

Yaoming Ma

Keyword(s):

Energy Balance ◽

Tibetan Plateau ◽

Surface Energy ◽

Land Surface ◽

Surface Energy Balance ◽

The Tibetan Plateau ◽

Central Himalaya ◽

Mountainous Areas ◽

The North ◽

The Impact

<p>The spatial-temporal structure of the Planetary Boundary Layer (PBL) over mountainous areas can be strongly modified by topography. The PBL over the mountainous terrain of the Tibetan Plateau (TP) is more complex than that observed over its flat areas. To date, there have been no detailed analyses which have taken into account the topography effects exerted on PBL growth over the Tibetan Plateau (TP). A clear understanding of the processes involved in the PBL growth and depth over the TP&#8217;s mountainous areas is therefore long overdue.<br>The PBL in the Himalayan region of the Tibetan Plateau (TP) is important to the study of interaction between the area&#8217;s topography and synoptic circulation. This study used radiosonde, in-situ measurements and ECMWF ERA5 reanalysis dataset to investigate the vertical structure of the PBL and the land surface energy balance in the Rongbuk Valley on the north of the central Himalaya, and their association with the Westerlies, which control the climate of the Himalaya in winters. Measurements show that the altitude of the PBL&#8217;s top in November was the highest of three intensive observation periods (i.e., June, August and November). The PBLs in November appeared to have been influenced by the Westerlies which prevails in this region during the non-monsoon season. We discovered that the deep PBLs seen in November correlate with the downward transmission of the Westerlies to the valley floor (DTWTV). It was found that DTWTV happened in the direction of southwest when the synoptic wind above the valley ridges height blow from southwest, which is parallel to the valley axis. DTWTV happened in the direction of southwest promotes a stronger near-surface wind, smaller aerodynamic resistance, and larger sensible heat flux, which cause PBLs grow high.</p>

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Corrigendum to ’Surface energy balance closure at ten sites over the Tibetan Plateau’ Agricultural and Forest Meteorology 259 (2018) 317-328

Agricultural and Forest Meteorology ◽

10.1016/j.agrformet.2021.108754 ◽

2022 ◽

Vol 313 ◽

pp. 108754

Author(s):

Yu-Fei Xin ◽

Fei Chen ◽

Ping Zhao ◽

Michael Barlage ◽

Peter Blanken ◽

...

Keyword(s):

Energy Balance ◽

Tibetan Plateau ◽

Surface Energy ◽

Surface Energy Balance ◽

The Tibetan Plateau ◽

Energy Balance Closure ◽

Forest Meteorology

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Evaluation of the Surface Energy Balance System (SEBS) applied to ASTER imagery with flux-measurements at the SPARC 2004 site (Barrax, Spain)

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-6-1165-2009 ◽

2009 ◽

Vol 6 (1) ◽

pp. 1165-1196 ◽

Cited By ~ 22

Author(s):

J. van der Kwast ◽

W. Timmermans ◽

A. Gieske ◽

Z. Su ◽

A. Olioso ◽

...

Keyword(s):

Energy Balance ◽

Surface Energy ◽

Land Cover ◽

Surface Energy Balance ◽

Sensible Heat Flux ◽

Surface Energy Fluxes ◽

Balance System ◽

Wide Range ◽

Source Models ◽

Flux Measurements

Abstract. Accurate quantification of the amount and spatial variation of evapotranspiration is important in a wide range of disciplines. Remote sensing based surface energy balance models have been developed to estimate turbulent surface energy fluxes at different scales. The objective of this study is to evaluate the Surface Energy Balance System (SEBS) model on a landscape scale, using tower-based flux measurements at different land cover units during an overpass of the ASTER sensor over the SPARC 2004 experimental site in Barrax (Spain). Additionally, the effect of replacement of empirical roughness functions in the model by field estimates or literature values is investigated. Modelled fluxes correspond better with flux measurements over uniform land cover compared to cases where different land covers are mixed in the measurement footprint. Furthermore SEBS underestimates sensible heat flux, which is common in one source models.

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Relating Precipitating Ice Radiative Effects to Surface Energy Balance and Temperature Biases Over the Tibetan Plateau in Winter

Journal of Geophysical Research Atmospheres ◽

10.1029/2018jd030204 ◽

2019 ◽

Vol 124 (23) ◽

pp. 12455-12467

Author(s):

Wei‐Liang Lee ◽

Jui‐Lin Frank Li ◽

Kuan‐Man Xu ◽

Ettamal Suhas ◽

Jonathan H. Jiang ◽

...

Keyword(s):

Energy Balance ◽

Tibetan Plateau ◽

Surface Energy ◽

Surface Energy Balance ◽

The Tibetan Plateau ◽

Radiative Effects

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High-resolution modelling of interactions between soil moisture and convective development in a mountain enclosed Tibetan Basin

Hydrology and Earth System Sciences ◽

10.5194/hess-19-4023-2015 ◽

2015 ◽

Vol 19 (9) ◽

pp. 4023-4040 ◽

Cited By ~ 3

Author(s):

T. Gerken ◽

W. Babel ◽

M. Herzog ◽

K. Fuchs ◽

F. Sun ◽

...

Keyword(s):

Soil Moisture ◽

Energy Balance ◽

Tibetan Plateau ◽

Surface Energy ◽

Surface Energy Balance ◽

Local Development ◽

Lake Basin ◽

Strong Impact ◽

The Tibetan Plateau ◽

Moist Convection

Abstract. The Tibetan Plateau plays a significant role in atmospheric circulation and the Asian monsoon system. Turbulent surface fluxes and the evolution of boundary-layer clouds to deep and moist convection provide a feedback system that modifies the plateau's surface energy balance on scales that are currently unresolved in mesoscale models. This work analyses the land surface's role and specifically the influence of soil moisture on the triggering of convection at a cross section of the Nam Co Lake basin, 150 km north of Lhasa using a cloud-resolving atmospheric model with a fully coupled surface. The modelled turbulent fluxes and development of convection compare reasonably well with the observed weather. The simulations span Bowen ratios of 0.5 to 2.5. It is found that convective development is the strongest at intermediate soil moisture. Dry cases with soils close to the permanent wilting point are moisture limited in convective development, while convection in wet soil moisture cases is limited by cloud cover reducing incoming solar radiation and sensible heat fluxes, which has a strong impact on the surface energy balance. This study also shows that local development of convection is an important mechanism for the upward transport of water vapour, which originates from the lake basin that can then be transported to dryer regions of the plateau. Both processes demonstrate the importance of soil moisture and surface–atmosphere interactions on the energy and hydrological cycles of the Tibetan Plateau.

Download Full-text