This paper documents a study to examine the sensitivity to cloud droplet effective radius and liquid water path and the alleviation the energy imbalance at the top of the atmosphere and at the surface in the latest ve...This paper documents a study to examine the sensitivity to cloud droplet effective radius and liquid water path and the alleviation the energy imbalance at the top of the atmosphere and at the surface in the latest version of the Grid-point Atmospheric Model of the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics （LASG）, Institute of Atmospheric Physics （IAP） （GAMIL1.1.0）. Considerable negative biases in all flux components, and thus an energy imbalance, are found in GAMIL1.1.0. In order to alleviate the energy imbalance, two modifications, namely an increase in cloud droplet effective radius and a decrease in cloud liquid water path, have been made to the cloud properties used in GAMIL. With the increased cloud droplet effective radius, the single scattering albedo of clouds is reduced, and thus the reflection of solar radiation into space by clouds is reduced and the net solar radiation flux at the top of the atmosphere is increased. With the reduced cloud optical depth, the net surface shortwave radiation flux is increased, causing a net warming over the land surface. This results in an increase in both sensible and latent heat fluxes over the land regions, which is largely balanced by the increased terrestrial radiation fluxes. Consequently, the energy balance at the top of atmosphere and at the surface is achieved with energy flux components consistent with available satellite observations.展开更多
The analysis of the coupling mechanism of thermal-hydraulic-mechanical(THM)fields,and solid-liquidgas(SLG)phases during gas extraction process is of profound significance to explore its numerical application in the ga...The analysis of the coupling mechanism of thermal-hydraulic-mechanical(THM)fields,and solid-liquidgas(SLG)phases during gas extraction process is of profound significance to explore its numerical application in the gas occurrence regularity and its effective extraction radius.In this study,the Hudi coal mine in Qinshui basin is taken as the research area,the influencing factors of gas occurrence were analyzed,the differences in overburden load for gas pressure distribution and the factors influencing the effective extraction radius were further discussed by using the COMSOL software.The results show that the derivation of mathematical model in gas extraction shows that the process is a process the THM fields restrict each other,and the SLG phases influence each other.The longer the extraction time,the larger the influencing range of borehole,and the better the extraction effect.The larger the diameter of borehole,the larger the effective extraction radius,and the influence on gas extraction effect is smaller in the early stage and larger in the late stage.The borehole arrangement should be flexibly arranged according to the actual extraction situation.The higher the porosity,the higher the permeability,the better the gas extraction effect.The larger the overburden load of reservoir,the stronger the effective stress,which will result in the more severe the strain,and the closure of pore and fracture,which in turn will lead to the decrease of permeability and slow down the gas extraction.The relationship among extraction time,borehole diameter,negative pressure of gas extraction,permeability with effective extraction radius is exponential.This study has important theoretical and practical significance for clarifying and summarizing the gas occurrence regularity and its engineering practice.展开更多
Effect of the injected plasma on the effective radius of the magnetic bubble in plasma sail is discussed. Results from solving both the two-dimensional magneto-hydrodynamic（MHD） equations and the magnetic flux conse...Effect of the injected plasma on the effective radius of the magnetic bubble in plasma sail is discussed. Results from solving both the two-dimensional magneto-hydrodynamic（MHD） equations and the magnetic flux conservation equation indicate that the effective radius of the magnetic bubble formed by the pure dipole field is very small, and the rate of the falloff of the magnetic field can be effectively reduced by the inflation of the high-density plasma. The falloff rate of the magnetic field can be r^-1.4. The effective radius of the magnetic bubble can hence be 8.2 km. The effective radius of the magnetic bubble increases about thirty-six times, comparing to the case of the pure dipole field.展开更多
Airborne dust is an important constituent in the Martian atmosphere because of its radiative interaction with the atmospheric circulation.Dust size is one crucial factor in determining this effect.In reality dust size...Airborne dust is an important constituent in the Martian atmosphere because of its radiative interaction with the atmospheric circulation.Dust size is one crucial factor in determining this effect.In reality dust sizes are varied;however,in numerical modeling of dust processes,dust size has usually been described by choice of a particular size distribution function,or by use of fixed values of effective radius(ER)and effective variance(EV).In this work,we present analytical expressions that have been derived to specify ER and EV for Nbin dust schemes,based on a model-calculated dust mixing ratio.Numerical simulations based on this approach thus would consider the effects of variable ER on the atmospheric radiation and their interaction.Results have revealed some interesting features of the dust distribution parameters,such as seasonal and spatial variation of ER and EV,which are generally consistent with some previous observational and modeling studies.Compared with the usual approach of using a fixed ER,simulation results from the present approach suggest that the variability of ER can have significant effects on the simulated thermal field of the Martian atmosphere.展开更多
For the basins with debris flow development,its channel terrain exhibits a tortuous shape,which significantly restricts the movement of debris flows and leads to severe erosion effects on the concave bank.Therefore,th...For the basins with debris flow development,its channel terrain exhibits a tortuous shape,which significantly restricts the movement of debris flows and leads to severe erosion effects on the concave bank.Therefore,this study aims to analyze the shear force of debris flows within the bend channel.We established the relationship between the shear force and bend curvature through laboratory experiments.Under the long-term erosion by debris flows,the curvature radius of bends gradually increases,however,when this increasing trend reaches an equilibrium state with the intensity of debris flow discharge,there will be no significant change in curvature radius.In general,the activity pattern and discharges of debris flows would remain relatively stable.Hence,we can infer the magnitude of debris flow discharges from the terrain parameters of the bend channel.展开更多
基金This work was jointly supported by the 973 Project(Grant No.2005CB321703)the National Natural Science Foundation of China(Grant No.40221503)the Chinese Academy of Sciences International Partnership Creative Group entitled"The Climate System Model Development and Application Studies".
文摘This paper documents a study to examine the sensitivity to cloud droplet effective radius and liquid water path and the alleviation the energy imbalance at the top of the atmosphere and at the surface in the latest version of the Grid-point Atmospheric Model of the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics （LASG）, Institute of Atmospheric Physics （IAP） （GAMIL1.1.0）. Considerable negative biases in all flux components, and thus an energy imbalance, are found in GAMIL1.1.0. In order to alleviate the energy imbalance, two modifications, namely an increase in cloud droplet effective radius and a decrease in cloud liquid water path, have been made to the cloud properties used in GAMIL. With the increased cloud droplet effective radius, the single scattering albedo of clouds is reduced, and thus the reflection of solar radiation into space by clouds is reduced and the net solar radiation flux at the top of the atmosphere is increased. With the reduced cloud optical depth, the net surface shortwave radiation flux is increased, causing a net warming over the land surface. This results in an increase in both sensible and latent heat fluxes over the land regions, which is largely balanced by the increased terrestrial radiation fluxes. Consequently, the energy balance at the top of atmosphere and at the surface is achieved with energy flux components consistent with available satellite observations.
基金financially supported by the University Synergy Innovation Program of Anhui Province(No.GXXT-2021-018)the National Natural Science Foundation of China(No.42102217)+3 种基金the Natural Science Research Project of Anhui University(Nos.KJ2020A0315,KJ2020A0317)the Institute of Energy,Hefei Comprehensive National Science Center(No.21KZS218)the Natural Science Foundation of Anhui Province(No.2108085MD134)the Foundation of State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing(No.PRP/open-2005)
文摘The analysis of the coupling mechanism of thermal-hydraulic-mechanical(THM)fields,and solid-liquidgas(SLG)phases during gas extraction process is of profound significance to explore its numerical application in the gas occurrence regularity and its effective extraction radius.In this study,the Hudi coal mine in Qinshui basin is taken as the research area,the influencing factors of gas occurrence were analyzed,the differences in overburden load for gas pressure distribution and the factors influencing the effective extraction radius were further discussed by using the COMSOL software.The results show that the derivation of mathematical model in gas extraction shows that the process is a process the THM fields restrict each other,and the SLG phases influence each other.The longer the extraction time,the larger the influencing range of borehole,and the better the extraction effect.The larger the diameter of borehole,the larger the effective extraction radius,and the influence on gas extraction effect is smaller in the early stage and larger in the late stage.The borehole arrangement should be flexibly arranged according to the actual extraction situation.The higher the porosity,the higher the permeability,the better the gas extraction effect.The larger the overburden load of reservoir,the stronger the effective stress,which will result in the more severe the strain,and the closure of pore and fracture,which in turn will lead to the decrease of permeability and slow down the gas extraction.The relationship among extraction time,borehole diameter,negative pressure of gas extraction,permeability with effective extraction radius is exponential.This study has important theoretical and practical significance for clarifying and summarizing the gas occurrence regularity and its engineering practice.
基金supported by National Natural Science Foundation of China (No. 10975136)
文摘Effect of the injected plasma on the effective radius of the magnetic bubble in plasma sail is discussed. Results from solving both the two-dimensional magneto-hydrodynamic（MHD） equations and the magnetic flux conservation equation indicate that the effective radius of the magnetic bubble formed by the pure dipole field is very small, and the rate of the falloff of the magnetic field can be effectively reduced by the inflation of the high-density plasma. The falloff rate of the magnetic field can be r^-1.4. The effective radius of the magnetic bubble can hence be 8.2 km. The effective radius of the magnetic bubble increases about thirty-six times, comparing to the case of the pure dipole field.
基金the FDCT of Macao(Grant nos.080/2015/A3 and 0088/2018/A3).
文摘Airborne dust is an important constituent in the Martian atmosphere because of its radiative interaction with the atmospheric circulation.Dust size is one crucial factor in determining this effect.In reality dust sizes are varied;however,in numerical modeling of dust processes,dust size has usually been described by choice of a particular size distribution function,or by use of fixed values of effective radius(ER)and effective variance(EV).In this work,we present analytical expressions that have been derived to specify ER and EV for Nbin dust schemes,based on a model-calculated dust mixing ratio.Numerical simulations based on this approach thus would consider the effects of variable ER on the atmospheric radiation and their interaction.Results have revealed some interesting features of the dust distribution parameters,such as seasonal and spatial variation of ER and EV,which are generally consistent with some previous observational and modeling studies.Compared with the usual approach of using a fixed ER,simulation results from the present approach suggest that the variability of ER can have significant effects on the simulated thermal field of the Martian atmosphere.
基金funded by the National Natural Science Foundation of China(Grant No.42201095)the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(Grant No.2019QZKK0902)the Postdoctoral Special Funding Project of Sichuan Province(Funding No.TB2023028).
文摘For the basins with debris flow development,its channel terrain exhibits a tortuous shape,which significantly restricts the movement of debris flows and leads to severe erosion effects on the concave bank.Therefore,this study aims to analyze the shear force of debris flows within the bend channel.We established the relationship between the shear force and bend curvature through laboratory experiments.Under the long-term erosion by debris flows,the curvature radius of bends gradually increases,however,when this increasing trend reaches an equilibrium state with the intensity of debris flow discharge,there will be no significant change in curvature radius.In general,the activity pattern and discharges of debris flows would remain relatively stable.Hence,we can infer the magnitude of debris flow discharges from the terrain parameters of the bend channel.
