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As a major parameter in the energy balance of the ground surface, temperature represents the level of exchange of energy and moisture between the ground and air. The Qinghai-Tibet Plateau (QTP) has the permafrost region with the highest altitude and the largest area in low–middle latitude of the world. The variation in ground surface temperature has an impact on the existence and development of the permafrost. Therefore, the analysis of the ground surface temperature in the QTP is significant to reflect the energy exchange in permafrost regions. This paper collected solar radiation data and calculated the conversion coefficient from total solar radiation to long-wave radiation of the ground surface on different underlying surfaces. The ground surface temperature was inversely calculated and modified based on the reception of solar radiation on different underlying surfaces. A simplified calculation model of ground surface temperature was built to reflect the ground surface temperature on different underlying surfaces of the QTP. The calculation results were compared with MODIS and showed good fitness, providing a systematic and reliable method for calculating the ground surface temperature on the QTP. The above model plays a significant role in the estimation of soil moisture, ground surface energy and water balance. [ABSTRACT FROM AUTHOR]

Taking only the mean value of cover transmittance and cover absorbance would lead to a large error in estimating the thermal performance of a greenhouse. This paper discusses an innovative dynamic energy balance model of a glass greenhouse, incorporating dynamic cover absorbance and transmittance. Different cover absorbances and transmittances for diffuse, beam, and ground-reflected radiation are used. The model primarily comprises nine differential energy conservation equations for indoor air, seven layers of soil, and the greenhouse's cover. Greenhouse temperature trends are acquired by solving the unsteady-state equations with MATLAB. The model was verified using experimental data recorded during three non-continuous periods of 15 days each in northern China (36.08°N, 116.95°E), during which the daily maximum outdoor solar radiation flux intensity fell between 191 and 894 Wm-2, the outdoor air temperature fell between −12.3 °C and 24.5 °C, the ground surface temperature fell between 0.6°C and 44.3 °C, and the indoor air temperature fell between −9.0 °C and 51.8 °C. The estimates agree well with the measurements, suggesting that the dynamic model is valid. Meanwhile, the dynamic cover absorbance and transmittance, the solar radiation absorbed by the cover, the solar radiation transmitted into the glass greenhouse and the proportion of solar radiation from each surface are discussed. • The model considers dynamic cover absorbance and transmittance with an improved performance. • Use of a sub-model of seven-layer soil resulted in an improved performance. • The solar radiation transmitted into the greenhouse from side walls was studied. • Study of the dynamic absorbance and transmittance of various greenhouse surfaces. • Analysis of solar radiation absorbed by cover and solar radiation transmitted into the greenhouse. [ABSTRACT FROM AUTHOR]

Complex interactions between the land surface and atmosphere and the exchange of water and energy have a significant impact on climate. The Tibetan Plateau is the highest plateau in the world and is known as 'Earth's third pole'. Because of its unique natural geographical and climatic characteristics, it directly affects China's climate, as well as the world's climate, through its thermal and dynamic roles. In this study, the BCCCSM1.1 model for the simulation results of CMIP5 is used to analyze the variation of the land surface processes of the Tibetan Plateau and the possible linkages with temperature change. The analysis showed that, from 1850 to 2005, as temperature increases, the model shows surface downward short-wave radiation, upward short-wave radiation, and net radiation to decrease, and long-wave radiation to increase. Meanwhile, latent heat flux increases, whereas sensible heat flux decreases. Except for sensible heat flux, the correlation coefficients of land surface fluxes with surface air temperature are all significant at the 99 % significance level. The model results indicate rising temperature to cause the ablation of ice (or snow) cover and increasing leaf area index, with reduced snowfall, together with a series of other changes, resulting in increasing upward and downward long-wave radiation and changes in soil moisture, evaporation, latent heat flux, and water vapor in the air. However, rising temperature also reduces the difference between the surface and air temperature and the surface albedo, which lead to further reductions of downward and upward short-wave radiation. The surface air temperature in winter increases by 0.93 °C/100 years, whereas the change is at a minimum (0.66 °C/100 years) during the summer. Downward short-wave and net radiation demonstrate the largest decline in the summer, whereas upward short-wave radiation demonstrates its largest decline during the spring. Downward short-wave radiation is predominantly affected by air humidity, followed by the impact of total cloud fraction. The average downward short-wave and net radiation attain their maxima in May, whereas for upward short-wave radiation the maximum is in March. The model predicts surface temperature to increase under all the different representative concentration pathway (RCP) scenarios, with the rise under RCP8.5 reaching 5.1 °C/100 years. Long-wave radiation increases under the different emission scenarios, while downward short-wave radiation increases under the low- and medium-emission concentration pathways, but decreases under RCP8.5. Upward short-wave radiation reduces under the various emission scenarios, and the marginal growth decreases as the emission concentration increases. [ABSTRACT FROM AUTHOR]