Comparison of the surface energy budget between regions of seasonally frozen ground and permafrost on the Tibetan Plateau

Gu, Lianglei; Yao, Jimin; Hu, Zeyong; Zhao, Lin

doi:10.1016/j.atmosres.2014.10.012

Cited by 48 publications

(26 citation statements)

References 59 publications

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“…However, during summer (from April onwards in 2015-16 and from May onwards in 2016-17), after the snowmelt, the H increases significantly. Similar kind of variability in the LE and H is also reported from the seasonally frozen ground and permafrost regions of the Tibetan 760 plateau (Gu et al, 2015;Yao et al, 2011).…”

Section: A Distinction Of Seb Variations During Low and High Snow Yearssupporting

confidence: 80%

The surface energy balance in a cold-arid permafrost environment, Ladakh Himalaya, India

Wani¹,

Thayyen²,

Ojha³

et al. 2020

Preprint

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Abstract. Cryosphere of the cold-arid trans-Himalayan region is unique with its significant permafrost cover. While the information on the permafrost characteristics and its extent started emerging, the governing energy regimes of this cryosphere region is of particular interest. This paper present the results of Surface Energy Balance (SEB) studies carried out in the upper Ganglass catchment in the Ladakh region of India, which feed directly to the River Indus. The point SEB is estimated using the one-dimensional mode of GEOtop model from 1 September 2015 to 31 August 2017 at 4727 m a.s.l elevation. The model is evaluated using field monitored radiation components, snow depth variations and one-year near-surface ground temperatures and showed good agreement with the respective simulated values. The study site has an air temperature range of −23.7 to 18.1 °C with a mean annual average temperature (MAAT) of −2.5 and ground surface temperature range of −9.8 to 19.1 °C. For the study period, the surface energy balance characteristics of the cold-arid site show that the net radiation was the major component with mean value of 28.9 W m−2 followed by sensible heat flux (13.5 W m−2) and latent heat flux (12.8 W m−2), and the ground heat flux was equal to 0.4 W m−2. The partitioning of energy balance during the study period shows that 47 % of Rn was converted into H, 44 % into LE, 1 % into G and 7 % for melting of seasonal snow. Both the study years experienced distinctly different, low and high snow regime. Key differences due to this snow regime change in surface energy balance characteristics were observed during peak summer (July–August). The latent heat flux was higher (lower) during this period with 39 W m−2 (11 W m−2) during high (low) snow years. The study also shows that the sensible heat flux during the early summer season (May, June) of the high (low) snow was much smaller (higher) −3.4 W m−2 (36.1 W m−2). During the study period, snow cover builds up in the catchment initiated by the last week of December facilitating the ground cooling by almost three months (October to December) of sub-zero temperatures up to −20 °C providing a favourable environment for permafrost. It is observed that the Ladakh region have a very low relative humidity in the range of 43 % as compared to, e.g., ~ 70 % in the Alps facilitating lower incoming longwave radiation and strongly negative net longwave radiation averaging ~ −90 W m−2 compared to −40 W m−2 in the Alps. Hence, the high elevation cold-arid region land surfaces could be overall colder than the locations with more RH such as the Alps. Further, it is apprehended that high incoming shortwave radiation in the region may be facilitating enhanced cooling of wet valley bottom surfaces as a result of stronger evaporation.

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Section: A Distinction Of Seb Variations During Low and High Snow Yearssupporting

confidence: 80%

The surface energy balance in a cold-arid permafrost environment, Ladakh Himalaya, India

Wani¹,

Thayyen²,

Ojha³

et al. 2020

Preprint

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show abstract

“…Elevated heating by the Tibetan Plateau (TP) has long been considered the primary driving force for the SASM (Flohn, 1968;Gu et al, 2015;Li and Yanai, 1996;Wu and Zhang, 1998). However, recent studies have shown that heating sources from the southern slopes of the Himalayas (Wu et al, 2012) and non-elevated areas south of the Himalayas (Boos and Kuang, 2013) are equally important for monsoonal circulation.…”

Section: Contents Lists Available At Sciencedirectmentioning

confidence: 98%

Estimation of net radiation flux distribution on the southern slopes of the central Himalayas using MODIS data

Amatya

Han

et al. 2015

Atmospheric Research

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“…Seasonally frozen grounds are widely present in the TP, with the area of 1.46 × 10 6 km 2 over the TP (Zou et al 2017). Because of its effects on water supplies (Guo et al 2011a), energy exchanges (Gu et al 2015), and climatecryosphere interactions in the atmospheric boundary layer (Chen et al 2008), seasonally frozen soil becomes an important portion of hydrologic and climatic variables (Duguay et al 2013;Gu et al 2015).…”

Section: Introductionmentioning

confidence: 99%

The freeze/thaw process and the surface energy budget of the seasonally frozen ground in the source region of the Yellow River

Wang

Luo

et al. 2019

Theor Appl Climatol

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The freeze/thaw process and the surface energy budget of the seasonally frozen ground in the source region of the Yellow River were investigated by using observed soil temperature and moisture and the energy flux from May 12, 2014, to May 11, 2015. Compared with the Maduo site, the starting date of the freezing process was later and the freezing depth was shallower at Maqu site. The maximum frozen depth was about 320 cm at Maduo site and 90 cm at Maqu site. The soil temperature of Maqu site was higher than of Maduo site due to lower latitude and altitude. The soil was the driest under the depth of 40 cm and 80 cm at Maduo and Maqu sites, respectively. The diurnal amplitudes of soil temperature of Maduo site were larger than of Maqu site at four freeze/thaw stages; the amplitudes were the largest in the completely thawed stage (9.19°C and 4.35°C) and minimal in the freezing stage (1.23°C and 0.47°C). The diurnal amplitudes of soil moisture of Maqu site were greater than of Maduo site at all stages. The net radiation Rn's seasonal change was hardly influenced by the freeze/thaw process. The mean ground heat flux (G 0) was negative during the freezing and completely frozen stage and positive during the thawing and completely thawed stage. During the completely thawed and frozen stages, the latent heat flux (LE) and sensible heat flux (H) predominated in the surface energy distribution, respectively. Overall, the variations of fluxes were affected by both the monsoon and freeze/thaw process of the soil layer in seasonally frozen region. The freeze/thaw process had a significant effect on the diurnal change of G 0 during the freezing stage. The annual energy closure status of Maduo and Maqu sites was 0.77 and 0.58, respectively. The energy closure status was the highest during the completely thawed stage at Maduo site and during the thawing stage at Maqu site and lowest during the freezing stage among the four stages, due to the snow cover's impact. Overall, the freeze/thaw process and the high albedo caused by snow cover had effects on the energy closure status.

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Comparison of the surface energy budget between regions of seasonally frozen ground and permafrost on the Tibetan Plateau

Cited by 48 publications

References 59 publications

The surface energy balance in a cold-arid permafrost environment, Ladakh Himalaya, India

The surface energy balance in a cold-arid permafrost environment, Ladakh Himalaya, India

Estimation of net radiation flux distribution on the southern slopes of the central Himalayas using MODIS data

The freeze/thaw process and the surface energy budget of the seasonally frozen ground in the source region of the Yellow River

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