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A dynamic southern branch trough （SBT） and a dynamic northern branch ridge （NBR）， two flows around the Tibetan Plateau （FQXP） generated by the mid-latitude westerlies in the winter half-year （October-April）， have an important influence on the weather and climate of their vicinity and downstream.In this paper， differences between the mean vorticity and the multi-year mean vorticity of two key regions-where the SBT and the NBR are located in 600 hPa are used to represent the intensity of the SBT and the NBR separately.Then the difference between the strength of SBT and NBR is defined visually as the intensity index of FQXP.The relationship between the precipitation and temperature in China and the evolution of FQXP's average in winter half-year and that in autumn， winter and spring is discussed， using correlation analysis and composite analysis.The results show that the FQXP is constant in the winter half-year （October-April）， with significant interannual variations， and the strongest in winter.In the context of global warming， variations in the intensity of FQXP at each period is closely related to the precipitation and temperature in Northwest， Southwest and South China， especially in winter.FQXP has a significant relationship with the temperature changes in northwest， southwest and northeast China， and its best precipitation correlations are found in southwest and south China.Analysis of anomalous large-scale atmospheric circulation and physical quantity fields， such as water vapor flux dispersion and vertical velocity， at each layer in each time period leads to the conclusion that the bottom-up positive pressure characteristic is significant in most of Asia， which well explains the relationship between FQXP anomalies and precipitation and temperature in China at each time period.FQXP anomalies may also be one cause for high-impact weather in China during winter half-year.

In order to improve the simulation performance of NCAR CLM4.5 （The Community Land Model Version 4.5） for land surface temperature （LST） in northern China， the ability of three commonly used soil thermal conductivity （STC） models were tested in this paper.The results show that these schemes can simulate the temporal and spatial characteristics of land surface temperature in northern China well.The LST in northern China has risen in recent 30 years， especially since 2003.The trend can be simulated by all these three schemes and shows a significant correlation with the observed LST， but the simulated warming amplitude is small than that of observation.The overall evaluation based on the taylor diagram and precipitation simulation shows that LR scheme has the best simulation effect.Therefore， a new scheme of STC that more suitable for climate simulation in northern China is added to CLM4.5， which promotes the development of the land surface model.

As an important part of surface hydrological cycle and energy distribution， lake evaporation is of great practical significance.The lake photovoltaic power plant is a new form of power generation， which changes the energy distribution in the process of converting solar energy into electric energy， thus changing the evaporation of the lake.Based on the observation data inside and outside the fish-lighting complementary photovoltaic power plant from October 2020 to January 2021 in Yingfang Village， Yangzhong City， Jiangsu Province， this paper analyzed the characteristics of the changes in evaporation， and evaluated the main evaporation models.The results show that： the evaporation inside the station was less than that outside the station which affected by the shielding effect of the photovoltaic power plant， and the evaporation was reduced by 44.9%.The evaporation in autumn was obviously larger than that in winter， and the evaporation in daytime was much larger than that at night.Three evaporation models were evaluated in this paper， among which the mass transfer model had the best simulation effect.Correlation analysis showed that the daily evaporation of lake photovoltaic power plants was significantly correlated with water vapor pressure difference， temperature difference between lake and air， and net radiation flux.The hourly evaporation could be approximated as a linear regression value of net radiation， 10m wind speed， relative humidity and temperature difference between lake and air.The linear model was expressed as： y=0.08+0.0003Rn+0.0754u10-0.0035RH+0.0165Ts.

The construction and operation of photovoltaic （PV） power stations have changed the surface characteristics of the natural underlying surface， which may cause changes in land surface process factors such as surface albedo and surface roughness， affecting the characteristics of material exchange and energy distribution.In order to explore the influence of the construction of Gobi photovoltaic power station on the underlying land surface parameters and improve the land surface process model， this paper studied the characteristics of the underlying land surface parameters of the photovoltaic power station based on the observation data of the photovoltaic power station and reference stations in Wujiaqu.The results showed that the average aerodynamic roughness inside the PV plant is 0.12 m， which is much larger than the roughness of the natural Gobi underlying surface.During the daytime， the friction velocity and momentum flux inside the PV plant are larger than those at the reference site， with the maximum values in the daily variation increased by 18.8% and 38.5%， respectively.The vertical turbulent mixing in the PV plant increased by 22.2% compared to the reference site， while the latitudinal and longitudinal turbulence intensity decreased by 11.8% and 2.9%， respectively.The average soil thermal conductivity of 5~20 cm depth in photovoltaic power station is 0.33 W·（m·K）-1.

With the large-scale construction of photovoltaic power plants， the physical characteristics of the near-surface layer change accordingly.The turbulence activity as the way of interaction between the earth and the atmosphere is also affected by it.As a new form of solar power generation， lake photovoltaic power plant plays a vital role in energy application.In order to understand the characteristics of local turbulence in lake photovoltaic power plants， the observed data of the photovoltaic power plant from July to November 2021 in Yingfang Village， Fengyu Town， Yangzhong City， Jiangsu Province， were used in this study to investigate the turbulence characteristics and the variation rules of stability.The results indicate that： the installation of photovoltaic power plant enhanced the turbulence intensity， and showed as Iv>Iu>Iw， which had a certain influence on the local airflow.At the same time， the photovoltaic power plant promoted the enhancement of turbulent kinetic energy and friction velocity， and significantly increased the local momentum and heat transport.The momentum transport coefficient CD=13.36×10-3，and the sensible heat transport coefficient CH=6.01×10-3.The instability of near-ground atmosphere on photovoltaic power plant was enhanced in the daytime， and conversely， it was enhanced stability at night.After the classification of stability， the near-ground atmosphere on photovoltaic power plant was mainly concentrated in neutral and near neutral， accounting for 75.11%.

Due to the global environmental crisis， energy crisis and the urgent need to deal with climate change， governments around the world have increased the use of renewable energy.The progress of photovoltaic technology and the support of government policies have promoted the unprecedented the development of photovoltaic industry.The large-scale construction of photovoltaic plants has significantly changed the land use and land cover， caused changes in the characteristics of the land surface， led to changes in the energy budget and distribution between land and atmosphere， and then produced feedback to the local climate system.Hence， many scholars have carried out relevant research on the environmental and climate impact of photovoltaic plants.Based on the domestic and international research progress in this field， this paper systematically summarizes the research methods， conclusions and possible impact mechanisms of photovoltaic climate effects.Existing research is mainly based on large-scale photovoltaic plants in desert areas and BIPV （Building Integrated Photovoltaic） in urban areas： photovoltaic plants cause local temperature rise， resulting in "photovoltaic heat island" effect in desert areas due to the high albedo； In urban areas， photovoltaic panels can not only reduce building energy consumption， but also effectively slow down the "urban heat island" effect.

In the situation of low-carbon energy development， photovoltaic power industry develops rapidly， and photovoltaic power stations in China are mostly built in the Northwest Gobi region.In order to study the influence of Gobi photovoltaic power station on local climate and environment， this paper compared and analyzed the characteristics and differences of meteorological elements between the Gobi photovoltaic power station and the reference station in December 2019 and April， July and October 2020.The results show that the temperature of PV power station at 2 m height is lower than the reference point in all seasons at night， and the cooling effect weakens with the increase of height.The temperature of PV power station is higher than that of the reference site at 2 m height in the daytime of spring， summer and autumn， but lower than that of the reference site in the daytime of winter.With the increase of height， the warming effect weakens in spring and summer in daytime， and strengthens in autumn and winter.Because the specific heat capacity of photovoltaic panel is lower than that of soil， the temperature of photovoltaic panel is higher than the surface temperature of reference station in daytime， and the difference increases with the enhancement of solar radiation.Compared with the reference station， the wind direction in the photovoltaic power station is single and the wind speed is lower due to the shielding effect of the photovoltaic array on the wind.With the increase of height， the influence of pv array on wind field decreases.