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Climate prediction is of great significance to the prevention of drought and flood. "Ground-synoptic" map is a method for short-term climate prediction. The main content of this method is "Geothermal Vortex"(GV). Therefore, some characteristics of 3.2 m soil temperature anomaly (hereinafter abbreviated as T′ 3.2 m) and GV are analyzed by using the data of monthly soil temperature at the depth of 3.2 m from 1980 to 2017 in China. Results show that there are regional differences in the frequency of positive anomaly. Overall, there are more positive anomalies in southern China and fewer in Western China. Soil temperature anomaly has good memory, the shortest being 5 months and the longest being nearly 2 years. Moreover, results show the nonuniform distribution of memory duration and decreases from northwest to southeast as a whole. Statistical analysis of GV shows that the average life cycle of each GV is 9.7 months, with an average horizontal scale of 604 km and a characteristic scale of 2.4 cm/s. Spatially, the GV scale is largest in Northwest, with a horizontal scale of 1087 km, and the GV appear most frequently in North China. The central location of GV is uneven, mainly in the central area with strong crustal activity and large absolute vertical deformation rate or in the high value area of soil heat flow. [ABSTRACT FROM AUTHOR]

Land surface temperature(LST) is an important indicator to study climate change and test the performance of regional climate model simulation. RegCM4.6 is the representative version of regional climate model RegCM, which is coupled with advanced third-generation land surface model NCAR CLM4.5. Currently, RegCM4.6 has become an important tool to study regional climate change in China. However, its ability to simulate land surface temperature in mainland China and the reasons for its deviation have not been systematically studied, and targeted improvement work is lacking. The present study is the first to employ LST data collected from 809 Chinese meteorological stations from the last 30 years to comprehensively assess the ability of CLM4.5 to simulate LST. Sensitivity tests of soil thermal conductivity (STC) were carried out to improve the model. Although the coupled regional climate model could accurately simulate the temporal and spatial variation of LST, a cold bias of 2~8 °C existed for all of mainland China, which was larger in seasons with more precipitation and greater soil moisture than other seasons. Deviation increased from southeast to northwest. which was caused by the incoming long-wave radiation, sensible heat, and latent heat simulated. There was a significant linear relationship between the observed and simulated LSTs, with correlation coefficients for all the stations ranged from 0.75 to 0.9 (P < 0.001). The observed LST increased at a rate of 0.58 °C/decade, but the simulated LST increased at a lower rate. Assessment of three different STC schemes showed that the Lu-Ren scheme was the most suitable for LST simulation in mainland China. Developing a new STC scheme that considers the role of water vapor can effectively improve the model when used in mainland China. [ABSTRACT FROM AUTHOR]

Using data observed at a photovoltaic (PV) power plant at the edge of the Gurbantünggüt Desert and at an undeveloped site in the Gobi desert in the summers of 2019 and 2020, we compared and analyzed the variations of radiation and surface albedo in various wavelength bands. Components of the solar radiation received by the surface of the arid regions of China were ranked infrared (IR) > visible (VIS) > ultraviolet (UV). The observed surface albedo of the PV site was significantly lower than that at the undeveloped desert site. The mean surface albedo values for shortwave broadband (SW), IR, VIS, and UV at the PV site were 0.14, 0.15, 0.13, and 0.08, respectively, and the corresponding values for the undeveloped site were 0.22, 0.23, 0.23, and 0.10, respectively. We also developed a parametric formula for the surface albedo at the PV plant given data observed on typical sunny days. We then validated the parametric formula using observations taken in the summers of 2019 and 2020. The results showed that the parametric formula could precisely simulate variations of the surface albedo and reflected radiation of the PV plant. [ABSTRACT FROM AUTHOR]

We used the data of observational site in photovoltaic power plant (PV site) and reference site in summer 2020 to compare the characteristics of surface energy flux of PV site and Gobi underlying surface. We defined the photovoltaic virtual flux and calculated the proportion of photovoltaic power generation in the net radiation by using daily power generation and generating hours. The results show that the net radiation of PV site was larger than that of reference site throughout the day. Compared with the reference site, the sensible heat flux and latent heat flux of PV site increased by 6.0% and 53.5%, respectively. Sensible heat flux, soil heat flux, latent heat flux, and photovoltaic virtual flux accounted for 43.2%, 14.5%, 8.6%, and 6.1% of the net radiation, respectively. The sensible heat accounted for the largest proportion; the energy balance closure increased from 0.60 to 0.67 in the daytime. [ABSTRACT FROM AUTHOR]