Energy partitioning and its biophysical controls above a grazing steppe in central Mongolia

Li, Shenggong; Eugster, Werner; Asanuma, Jun; Kotani, Akio; Davaa, Gombo; Oyunbaatar, Dambaravjaa; Sugita, Michiaki

doi:10.1016/j.agrformet.2006.03.010

Cited by 125 publications

(129 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, whereas we found that a rise in VPD is characterized by a decrease in LE and an increase in H in both periods, their findings show a significant increase in LE and decrease in H with a rise in VPD during the non-drought period, with both components showing slight increases with increase in VPD in dry conditions. Li et al (2006) also investigated the partitioning of surface energy in the grazing lands of Mongolia, and concluded that the energy partitioning was also controlled by vegetation dynamics and soil moisture availability, although soil heat flux is reportedly higher than latent heat flux in most instances. In a temperate mountain grassland in Austria, Hammerle et al (2008) found that the energy partitioning in this climatic region was dominated by latent heat flux, followed by sensible heat flux and lastly soil heat flux.…”

Section: Influence Of Weather Conditions and Seasonalitymentioning

confidence: 99%

“…Bagayoko et al (2007) examined the seasonal variation of the energy balance in West African savannas, and noted that latent heat flux played a major role in the wet season, whereas sensible heat flux was significant in the dry season. In the grassland Mongolian Plateau, Li et al (2006) concluded that sensible heat flux dominated the energy partitioning, followed by ground heat flux, with the rainy season showing slight increase in latent heat flux. Gu et al (2006) used different ratios (Bowen ratio, G / Rn, H / Rn and LE / Rn) to investigate surface energy exchange in the Tibetan Plateau, and showed that during the vegetation growth period, LE was higher than H, and this was reversed during the post-growth period.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Analysing surface energy balance closure and partitioning over a semi-arid savanna FLUXNET site in Skukuza, Kruger National Park, South Africa

Majozi

Mannaerts

Ramoelo

et al. 2017

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. Flux towers provide essential terrestrial climate, water, and radiation budget information needed for environmental monitoring and evaluation of climate change impacts on ecosystems and society in general. They are also intended for calibration and validation of satellite-based Earth observation and monitoring efforts, such as assessment of evapotranspiration from land and vegetation surfaces using surface energy balance approaches.In this paper, 15 years of Skukuza eddy covariance data, i.e. from 2000 to 2014, were analysed for surface energy balance closure (EBC) and partitioning. The surface energy balance closure was evaluated using the ordinary least squares regression (OLS) of turbulent energy fluxes (sensible (H) and latent heat (LE)) against available energy (net radiation (Rn) less soil heat (G)), and the energy balance ratio (EBR). Partitioning of the surface energy during the wet and dry seasons was also investigated, as well as how it is affected by atmospheric vapour pressure deficit (VPD), and net radiation.After filtering years with low-quality data (2004)(2005)(2006)(2007)(2008), our results show an overall mean EBR of 0.93. Seasonal variations of EBR also showed the wet season with 1.17 and spring (1.02) being closest to unity, with the dry season (0.70) having the highest imbalance. Nocturnal surface energy closure was very low at 0.26, and this was linked to low friction velocity during night-time, with results showing an increase in closure with increase in friction velocity.The energy partition analysis showed that sensible heat flux is the dominant portion of net radiation, especially between March and October, followed by latent heat flux, and lastly the soil heat flux, and during the wet season where latent heat flux dominated sensible heat flux. An increase in net radiation was characterized by an increase in both LE and H, with LE showing a higher rate of increase than H in the wet season, and the reverse happening during the dry season. An increase in VPD is correlated with a decrease in LE and increase in H during the wet season, and an increase in both fluxes during the dry season.

show abstract

Section: Influence Of Weather Conditions and Seasonalitymentioning

confidence: 99%

mentioning

confidence: 99%

Analysing surface energy balance closure and partitioning over a semi-arid savanna FLUXNET site in Skukuza, Kruger National Park, South Africa

Majozi

Mannaerts

Ramoelo

et al. 2017

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

show abstract

“…2017 27 da modelagem dos componentes da PA, obtidos através das medições do satélite L8, envolvendo diferentes condições termo hídricas no ano de 2014 na região semiá-rida do município de Juazeiro/BA, Nordeste do Brasil, são apresentadas na Figura 4. Nos agros-ecossistemas mistos da região semiárida brasileira, as superfícies escuras da Caatinga apresentam baixos valores de α 0 , absorvendo mais radiação solar que aquelas mais claras, dependendo ainda das condições de umidade do solo (van Dijk et al, 2004;Li et al, 2006;Teixeira et al, 2008). Os valores mais elevados de α 0 ocorreram na imagem de DJ 265, representativa do período mais seco do ano.…”

Section: Parâmetros Obtidos Por Sensoriamento Remotounclassified

“…Monteith e Unsworth (1990) reportaram α 0 entre 0.15 e 0.26 para vegetações naturais tropicais, entretanto os valores dos ecossistemas mistos do estudo corrente são mais elevados que aqueles encontrados para regiões tropicais mais hú-midas (OGUNTOYINBO, 1970;PINKER;THOMP-SON;ECK, 1980;SHUTTLEWORTH, 1988). A relação de α 0 com as condições ambientais e de umidade está de acordo com outros estudos mais recentes (LOBELL; ASNER, 2002;DIJK;BRUIJNZEEL;SCHELLEKENS, 2004;LI et al, 2006;TEIXEIRA et al, 2014). Através de medições de campo na Caatinga, Teixeira et al (2008) reportaram a dependência de α 0 com as condições das chuvas, variando entre 0.10 e 0.18, similares a várias áreas representativas deste natural ecossistema na Figura 4.…”

Section: Parâmetros Obtidos Por Sensoriamento Remotounclassified

Determinação da Produtividade da Água com Imagens Landsat 8 na Região Semiárida do Brasil

Teixeira

Leivas

2017

cnx

View full text Add to dashboard Cite

Resumo. Considerando o cenário de mudança de uso da terra aliada às alterações climáticas no semiárido brasileiro, a evapotranspiração atual (ET), a produção de biomassa (BIO) e a produtividade da água (PA) baseada na ET, foram quantificadas sob diferentes condições termo hídricas com três imagens Landsat 8 (L8) de 2014 no município de Juazeiro, Estado da Bahia (BA), Nordeste do Brasil. Os valores médios dos pixels para ET, BIO e PA, nas culturas irrigadas, variaram respectivamente de 2.9 ± 1.2 a 3.8 ± 1.6 mm d −1 ; 107 ± 64 a 124 ± 75 kg ha −1 d −1 ; e de 3.0 ± 0.7 a 3.4 ± 0.8 kg m −3 . As faixas correspondentes para a Caatinga foram de 0.1 ± 0.1 a 0.9 ± 0.6 mm d −1 ; 1 ± 2 a 13 ± 11 kg ha −1 d −1 , e 0.5 ± 0.6 a 1.4 ± 0.5 kg m −3 . Os valores incrementais da PA, representativos da substituição da vegetação natural por culturas irrigadas foram de 300%, para o ano estudado. Maior uniformidade nos parâmetros hídricos e de vegetação ocorreu nas espécies da Caatinga, evidenciada pelos menores valores de desvio padrão quando comparados com aqueles para as culturas agrícolas. Os modelos testados no atual estudo podem subsidiar o monitoramento dos agros-ecossistemas, sendo valiosas ferramentas para a sustentabilidade dos recursos hídricos na região semiárida do Brasil.Palavras-chaves: Evapotranspiração. Produção de biomassa. Mudança de uso da terra.Abstract. Considering the climate and land-use change scenario in the Brazilian semi-arid region, actual evapotranspiration (ET), biomass production (BIO), and water productivity (WP) based on ET, were quantified with Landsat 8 images under different thermo-hydrological conditions of 2014, in the Juazeiro municipality, Bahia (BA) state, Northeast Brazil. The mean pixel values for ET, BIO, and PA, for irrigated crops, ranged respectively from 2.9 ± 1.2 to 3.8 ± 1.6 mm d −1 ; 107 ± 64 to 124 ± 75 kg ha −1 d −1 ; and from 3.0 ± 0.7 to 3.4 ± 0.8 kg m −1 . The corresponding ranges for "Caatinga" were 0.1 ± 0.1 to 0.9 ± 0.6 mm d −1 ; 1 ± 2 to 13 ± 11 kg ha −1 d −1 ; and 0.5 ± 0.6 to 1.4 ± 0.5 kg m −3 . The incremental PA values, representing the consequence of replacement of natural vegetation by irrigated crops were 300% for the studied year. Higher uniformity for the water and vegetation parameters happened in "Caatinga" species, evidenced by the lower values of standard deviation, when compared with those for agricultural crops. The models tested in the current study can subsidize the monitoring of the agro-ecosystems, being powerful tools for the sustainability of the water resources in the Brazilian semi-arid region.

show abstract

“…In long-term perspective, increased temperature can exert both negative and positive effects on the lake area by increasing water loss through evapotranspiration (Li et al, 2006) and by enhancing water input through permafrost melting that is widely distributed in the northern part of Tuin river basin (Ishikawa et al, 2005). Rapid increase of livestock populations triggered by livestock privatization since 1992 (Johnson et al, 2006) could be also an important concern of understanding regional water balance.…”

Section: Resultsmentioning

confidence: 99%

Seasonal and Inter-annual Variations of Lake Surface Area of Orog Lake in Gobi, Mongolia During 2000-2010

Lee

et al. 2012

Korean Journal of Remote Sensing

View full text Add to dashboard Cite

Energy partitioning and its biophysical controls above a grazing steppe in central Mongolia

Cited by 125 publications

References 65 publications

Analysing surface energy balance closure and partitioning over a semi-arid savanna FLUXNET site in Skukuza, Kruger National Park, South Africa

Analysing surface energy balance closure and partitioning over a semi-arid savanna FLUXNET site in Skukuza, Kruger National Park, South Africa

Determinação da Produtividade da Água com Imagens Landsat 8 na Região Semiárida do Brasil

Seasonal and Inter-annual Variations of Lake Surface Area of Orog Lake in Gobi, Mongolia During 2000-2010

Contact Info

Product

Resources

About