Kinetic Energy Budgets during the Rapid Intensification of Typhoon Rammasun (2014)

In this study,Typhoon Rammasun(2014)was simulated using the Weather Research and Forecasting model to examine the kinetic energy during rapid intensification(RI).Budget analyses revealed that in the inner area of the typhoon,the conversion from symmetric divergent kinetic energy associated with the collocation of strong cyclonic circulation and inward flow led to an increase in the symmetric rotational kinetic energy in the lower troposphere.The increase in the symmetric rotational kinetic energy in the mid and upper troposphere resulted from the upward transport of symmetric rotational kinetic energy from the lower troposphere.In the outer area,both typhoon and Earth’s rotation played equally important roles in the conversion from symmetric divergent kinetic energy to symmetric rotational kinetic energy in the lower troposphere.The decrease in the symmetric rotational kinetic energy in the upper troposphere was caused by the conversion to asymmetric rotational kinetic energy through the collocation of symmetric tangential rotational winds and the radial advection of asymmetric tangential rotational winds by radial environmental winds.

A Case Study of the Impacts of Dust Aerosols on Surface Atmospheric Variables and Energy Budgets in a Semi-Arid Region of China

The authors present a case study investigating the impacts of dust aerosols on surface atmospheric variables and energy budgets in a semi-arid region of China. Enhanced observational meteorological data, radiative fluxes, near-surface heat fluxes, and concentrations of dust aerosols were collected from Tongyu station, one of the reference sites of the International Coordinated Energy and Water Cycle Observations Project (CEOP), during a typical dust storm event in June 2006. A comprehensive analysis of these data show that in this semi-arid area, higher wind velocities and a continuously reduced air pressure were identified during the dust storm period. Dust storm events are usually associated with low relative humidity weather conditions, which result in low latent heat flux values. Dust aerosols suspended in the air decrease the net radiation, mainly by reducing the direct solar radiation reaching the land surface. This reduction in net radiation results in a decrease in soil temperatures at a depth of 2 cm. The combination of increased air temperature and decreased soil temperature strengthens the energy exchange of the atmosphere-earth system, increasing the surface sensible heat flux. After the dust storm event, the atmosphere was dominated by higher pressures and was relatively wet and cold. Net radiation and latent heat flux show an evident increase, while the surface sensible heat flux shows a clear decrease.

THE ENERGY BUDGETS UNDER DIFFERENT SYNOPTIC CONDITIONS OVER HUAIHE RIVER BASIN DURING HUBEX FIELD OBSERVATION PERIODS IN 1999

In different synoptic conditions and at different time scales,the analysis of the energy budgets by Bowen Ratio Method and Bulk Schemes over Huaihe River Basin during the field observation periods of HUBEX in 1999 shows that,(1)the averaged latent heat flux is an order of magnitude more than the averaged sensible heat flux during the observation period:(2)the variation of total cloud amount is out of phase with the terms of energy budgets except for the downward longwave radiation which maybe is related to the cloud's height and class:(3)the values of sensible and latent heat fluxes are small during rain episodes,but thereafter,the values become high and then up to maximum.It is similar to the other terms of the energy budgets except for the downward longwave radiation.The diurnal variation of energy budgets indicates that the daytime precipitation exerts great influence to the energy budgets,but the nighttime precipitation makes little influence; (4)the variation of the latent heat flux is in phase with the evaporation,which indicates that the latent heat flux calculated by bulk schemes is reliable:(5)the means of the sensible and latent heat flux and momentum flux by bulk schemes for the time period from May to August are, respectively,30.71W/m^2.116.81W/m^2.2.86×10^(-2)N/m^2 in 1998 and 30.28W/m^2,107.35 W/m^2,2.74×10^(-2)N/m^2 in 1999.The values of these two years are similar.During summer in 1999 the magnitude and activity of sensible heat flux are strongest in June and those of the latent heat flux are in August.

Energy budgets of the Chinese green lacewing （Neuroptera： Chrysopidae） and its potential for biological control of the cotton aphid （Homoptera： Aphididae）

Energy budgets of larval stages of the Chinese green lacewing, Chrysopa sinica （Tjeder） （Neuroptera： Chrysopidae） were determined under laboratory conditions at photoperiod of 14：10 L：D, 27 ± 1℃ and 75% ± 2% RH. The energy used as ingestion, assimilation, respiration, productivity and feces was constructed for each developmental stage. In addition, under these experimental conditions, the potential of C. sinica as a biological control agent was evaluated according to the ingestion by this predator and the energy content of cotton aphid, Aphis gossypii （Glover） （Homoptera： Aphididae）. The larval stage of C. sinica was able to consume 1281.4 1-day-old aphids, 1018.7 2-day-old aphids, 626.9 3-day-old aphids, 393.5 4-day-old aphids, 312.1 5-day-old aphids or 203.5 9-day-old aphids, respectively. No significant difference was detected between the estimated number of aphids consumed by the lacewings using energetic methods and the actual number of aphids consumed by the lacewings in this experiment. Our results showed that C. sinica is an important natural enemy of the cotton aphid, and energetic methods are very useful to quantify biological control efficacy of natural enemies.

Interannual variability of eddy kinetic energy in the South China Sea related to two types of winter circulation events

Interannual variations of the eddy kinetic energy(EKE)related to two types of winter circulation events(“O”and“U”)were investigated based on the outputs of the Ocean General Circulation Model(OGCM)for the Earth Simulator(OFES)and the corresponding energetic analyses.Results show that the EKE is strong and extends eastward to offshore the Vietnam coast about 2°,associated with the weaker South China Sea western boundary current(SCSwbc)in“O”type years,while the EKE is weak and high value that can be attained is narrowed along the coast,associated with the stronger SCSwbc in“U”type years.The energy budget shows that the wind stress and barotropic/baroclinic instability are important factors to regulate the EKE in“U”and“O”years.For“U”years,under a strong winter monsoon forcing,the SCSwbc strengthen,the directly wind work and barotropic conversion from the mean kinetic energy(MKE)to EKE are weak,thus the EKE decrease corresponding to the baroclinic conversion from the kinetic energy to potential energy.However,the situation is reversed in“O”years.Under the influence of El Niño events,wind stress forces can weaken SCSwbc and enhance EKE in pattern“O”,whereas La Niña events have relatively weaker influences.The barotropic conversion rate in“O”type is nearly eight times of the“U”type.The pressure work and advection term are the main sources to greatly suppress EKE in the SCSwbc region.

Estimation of ground heat flux and its impact on the surface energy budget for a semi-arid grassland

Three approaches, i.e., the harmonic analysis （HA） technique, the thermal diffusion equation and correction （TDEC） method, and the calorimetric method used to estimate ground heat flux, are evaluated by using observations from the Semi-Arid Climate and Environment Observatory of Lanzhou University （SACOL） in July, 2008. The calorimetric method, which involves soil heat flux measurement with an HFP01SC self-calibrating heat flux plate buried at a depth of 5 cm and heat storage in the soil between the plate and the surface, is here called the ITHP approach. The results show good linear relationships between the soil heat fluxes measured with the HFP01SC heat flux plate and those calculated with the HA technique and the TDEC method, respectively, at a depth of 5 cm. The soil heat fluxes calculated with the latter two methods well follow the phase measured with the HFP01SC heat flux plate. The magnitudes of the soil heat flux calculated with the HA technique and the TDEC method are close to each other, and they are about 2 percent and 6 percent larger than the measured soil heat flux, respectively, which mainly occur during the nighttime. Moreover, the ground heat fluxes calculated with the TDEC method and the HA technique are highly correlated with each other （R2= 0.97）, and their difference is only about 1 percent. The TDEC-calculated ground heat flux also has a good linear relationship with the ITttP-calculated ground heat flux （R2 = 0.99）, but their difference is larger （about 9 percent）. Furthermore, compared to the HFP01SC direct measurements at a depth of 5 cm, the ground heat flux calculated with the HA technique, the TDEC method, and the ITHP approach can improve the surface energy budget closure by about 6 percent, 7 percent, and 6 percent at SACOL site, respectively. Therefore, the contribution of ground heat flux to the surface energy budget is very important for the semi-arid grassland over the Loess Plateau in China. Using turbulent heat fluxes with common corrections, soil heat storage between the surface and the heat flux plate can improve the surface energy budget closure by about 6 to 7 percent, resulting in a closure of 82 to 83 percent at the SACOL site.

Short photoperiod increases energy intake, metabolic thermogenesis and organ mass in silky starlings Sturnus sericeus

Environmental cues play important roles in the regulation of an animal＇s physiology and behavior. One such cue, photoperiod, plays an important role in the seasonal acclimatization of birds. It has been demonstrated that an animal＇s body mass, basal metabolic rate （BMR）, and energy intake, are all affected by photoperiod. The present study was designed to examine photoperiod induced changes in the body mass, metabolism and metabolic organs of the silky starling, Stumus sericeus. Captive silky starlings increased their body mass and BMR during four weeks of acclimation to a short photoperiod. Birds acclimated to a short photopedod also increased the mass of certain organs （liver, gizzard and small intestine）, and both gross energy intake （GEl） and digestible energy intake （DEI）, relative to those acclimated to a long photoperiod. Furthermore, BMR was positively correlated with body mass, liver mass, GEl and DEI. These results suggest that silky starlings increase metabolic thermogenesis when exposed to a short photoperiod by increasing their body and metabolic organ mass, and their GEl and DEI. These findings support the hypothesis that bird species from temperate climates typically display high phenotypic flexibility in thermogenic capacity.

Satellite Monitoring of the Surface Water and Energy Budget in the Central Tibetan Plateau

The water and energy cycle in the Tibetan Plateau is an important component of Monsoon Asia and the global energy and water cycle. Using data at a CEOP （Coordinated Enhanced Observing Period）-Tibet site, this study presents a first-order evaluation on the skill of weather forecasting from GCMs and satellites in producing precipitation and radiation estimates. The satellite data, together with the satellite leaf area index, are then integrated into a land data assimilation system （LDAS-UT） to estimate the soil moisture and surface energy budget on the Plateau. The system directly assimilates the satellite microwave brightness temperature, which is strongly affected by soil moisture but not by cloud layers, into a simple biosphere model. A major feature of this system is a dual-pass assimilation technique, which can auto-calibrate model parameters in one pass and estimate the soil moisture and energy budget in the other pass. The system outputs, including soil moisture, surface temperature, surface energy partition, and the Bowen ratio, are compared with observations, land surface models, the Global Land Data Assimilation System, and four general circulation models. The results show that this satellite data-based system has a high potential for a reliable estimation of the regional surface energy budget on the Plateau.

The Surface Energy Budget and Its Impact on the Freeze-thaw Processes of Active Layer in Permafrost Regions of the Qinghai-Tibetan Plateau

The surface energy budget is closely related to freeze-thaw processes and is also a key issue for land surface process research in permafrost regions.In this study,in situ data collected from 2005 to 2015 at the Tanggula site were used to analyze surface energy regimes,the interaction between surface energy budget and freeze-thaw processes.The results confirmed that surface energy flux in the permafrost region of the Qinghai-Tibetan Plateau exhibited obvious seasonal variations.Annual average net radiation(R_(n))for 2010 was 86.5 W m^(-2),with the largest being in July and smallest in November.Surface soil heat flux(G_(0))was positive during warm seasons but negative in cold seasons with annual average value of 2.7 W m^(-2).Variations in R_(n) and G_(0) were closely related to freeze-thaw processes.Sensible heat flux(H)was the main energy budget component during cold seasons,whereas latent heat flux(LE)dominated surface energy distribution in warm seasons.Freeze-thaw processes,snow cover,precipitation,and surface conditions were important influence factors for surface energy flux.Albedo was strongly dependent on soil moisture content and ground surface state,increasing significantly when land surface was covered with deep snow,and exhibited negative correlation with surface soil moisture content.Energy variation was significantly related to active layer thaw depth.Soil heat balance coefficient K was>1 during the investigation time period,indicating the permafrost in the Tanggula area tended to degrade.

A Case Study on MJO Energy Transport Path in a Local Multi-scale Interaction Framework

A new local kinetic energy(KE)budget for the Madden−Julian Oscillation(MJO)is constructed in a multi-scale framework.This energy budget framework allows us to analyze the local energy conversion processes of the MJO with the high-frequency disturbances and the low-frequency background state.The KE budget analysis is applied to a pronounced MJO event during the DYNAMO field campaign to investigate the KE transport path of the MJO.The work done by the pressure gradient force and the conversion of available potential energy at the MJO scale are the two dominant processes that affect the MJO KE tendency.The MJO winds transport MJO KE into the MJO convection region in the lower troposphere while it is transported away from the MJO convection region in the upper troposphere.The energy cascade process is relatively weak,but the interaction between high-frequency disturbances and the MJO plays an important role in maintaining the high-frequency disturbances within the MJO convection.The MJO KE mainly converts to interaction KE between MJO and high-frequency disturbances over the area where the MJO zonal wind is strong.This interaction KE over the MJO convection region is enhanced through its flux convergence and further transport KE to the high-frequency disturbances.This process is conducive to maintaining the MJO convection.This study highlights the importance of KE interaction between the MJO and the high-frequency disturbances in maintaining the MJO convection.

Effects of rising temperature on growth and energy budget of juvenile Eogammarus possjeticus(Amphipoda:Anisogammaridae)

Growth and energy budget of marine amphipod juvenile Eogammarus possjeticus at different temperatures(20℃,24℃,26℃,28℃,30℃,32℃ and 34℃)were investigated in this study.The results showed that the cumulative mortality rate increased significantly with rising temperature(p<0.01),and exceeded 50%after 24 h when temperature was above 30℃.With the temperature increasing from 20℃ to 26℃,the ingestion rate and absorption rate increased,but decreased significantly above 28℃(p<0.01),indicating a decline in feeding ability at high temperatures.The specific growth rate increased with rising temperature,but decreased significantly(p<0.01)after reaching the maximum value at 24℃.Similarly,the oxygen consumption and ammonia emission rates also showed a trend of first increase and then decrease.However,the O:N ratio decreased first and then increased with rising temperature,indicating that the energy demand of E.possjeticus juvenile transferred from metabolism of carbohydrate and lipid to protein.In the energy distribution of amphipods,the proportion of each energy is different.With rising temperature,the ratio of the energy deposited for growth accounted for ingested gross energy showing a trend of decrease,while the energy lost to respiration,ammonia excretion,and feces accounted for ingested gross energy being showed a trend of increase.It seemed that rising temperature increased the metabolism and energy consumption of the amphipods and,meanwhile,decreased the energy used for growth,which may be an important reason for the slow growth and small body size of the amphipods during the summer high-temperature period.

Simulation of arctic surface radiation and energy budget during the summertime using the single-column model

The surface heat budget of the Arctic Ocean （SHEBA） project has shown that the study of the surface heat budget characteristics is crucial to understanding the interface process and environmental change in the polar region. An arctic single - column model （ARCSCM） of Colorado University is used to simulate the arctic surface radiation and energy budget during the summertime. The simulation results are analyzed and compared with the SHEBA measurements. Sensitivity analyses are performed to test microphysical and radiative parameterizations in this model. The results show that the ARCSCM model is able to simulate the surface radiation and energy budget in the arctic during the summertime, and the different parameterizations have a significant influence on the results. The combination of cloud microphysics and RRTM parameterizations can fairly derive the surface solar shortwave radiation and downwelling longwave radiation flux. But this cloud microphysics parameterization scheme deviates notably from the simulation of surface sensible and latent heat flux. Further improvement for the parameterization scheme applied to the Arctic Regions is necessary.

The influence of main ecological and environmental factors on the energy budget of Schlegel＇ s black rockfish Sebastes schlegeli

In the Maidao Ecological Laboratory of the Huanghai Sea Fisheries Research Institute in 1998 ~ 2000, the continuous flow-through method was adopted to determine the energy budget components and models of Schlegel＇ s black rockfish under different ecological and environmental factors, such as temperature, food species, body mass and feeding level, etc. The body mass of test fish ranged from 21.2 to 224.5 g. The specific growth rate tended to invert ＂U＂ change with temperature increase. The ecological conversion efficiency showed the same trend as temperature and feeding level rise. Only the specific growth rate tended to decelerate the increment with the rise of feeding level. From the above quantitative relationships, the maximum and optimal growth temper- atures could be obtained as 17.5 and 16.2 ℃, and the maintenance feeding rate and optimum feeding rate as 0.8% and 4. 1% of the body mass. The specific growth rate and ecological conversion coefficient showed a decelerating decrease trend with body mass increment. The small-sized fish food was more advantageous to the feeding level increase in comparison with the small-sized shrimp food, which led to the increase of growth, metabolism and excretion, but had no significant influence on the ecological conversion coefficient. All of temperature, feeding level, body mass and food species can obviously change the energy budget models. The assigning rate of growth energy tended to change along the invert ＂U＂ curve with the increase of temperature and feeding level, and decrease with the body mass increase, but the assigning rates of metabolism energy and excretion energy were quite reverse. These relationships could be quantitatively described as quadratic or power function curve. If the above relationships proved true to other marine fish, the establishment of energy budget model of the same fish under different conditions can be largely simplified.

Yield Production and Energy Budget of Traditional Agricultural Crops in Garhwal Himalaya

The yield production and energy budget of agroecosystem was carried out at three different climatic regions, i.e., tropical, sub-tropical, and temperate in Garhwal Himalaya, India. The total human population was the highest （1 140） in tropical region, followed by 464 in temperate region, and 374 in sub-tropical region. Livestock population had also a similar trend with human population in each climatic region, which was 870, 290, and 188 in the tropical, temperate, and sub-tropical regions, respectively, in winter season, the crop production was the highest （2 332 kg hat yr-l） for Triticum aestivum in tropical region followed by 1 716 kg ha^-1 yr^-1 in sub-tropical region, and 1 473 kg ha^-1 yr^-1 in temperate region. The associated crops were Itordeurn vulgate, Brassica caml ＇stris, and Pisum sativa. However, in summer season, the most contributing crop was Oryza sativa, which had also the highest production in tropical region followed by sub-tropical region, and temperate region, i.e., 1 160, 1096, and 1 076 kg ha^-1 yr^-1, respectively. Other growing crops were Elusine coracana, Vigna mugo, Glycine soja, and Echnochlolafrumentaceae. Brassiea rugosa was the only crop grown in tropical region between the period of winter and summer season. The total root production of crops in each climatic region was the highest in tropical region （1 846.2 kg ha^-1 yr^-1）, followed by temperate region （1 841.5 kg ha^-1 yr^-1） and sub-tropical region （1442.5 kg ha^-1 yr^-1）. However, shoot components of crops were 20 241.5, 17 847.0, and 1 188.3 kg ha^-1 yr^-1, which recorded parallel to root in each climatic region. The root and shoot components of weed decreased with increasing altitudes, which were 105.39 and 1150.5 kg ha^-1 yr^-1 in tropical region, 94.55 and 1147.5 kg ha^-1 yr^-1 in sub-tropical region, and 73.33 and 871.5 kg ha^-1 yr^-1 in temperate region for root and shoot, respectively. In the energy inputs, the most contribution was of compost in each climatic region. Among the region, the highest input of compost was in temperate region followed by sub-tropical, and the lowest in temperate region. The fertilizer input was only recorded from tropical region because of its close connection with market and easy accessibility to the farmer compared to subropical and temperate regions. The energy input ranged from 0.39×10^5 to 0.44× 10^5 MJ ha^-1 （human labour）, 0.84× 10^5 to 1.09× 10^5 MJ ha^-1 （bullock labour）, 0.36×10^5 to 0.45×10^5 MJ ha^-1 （seed）, 16.65 × 10^5 to 32.65 ×10^5 MJ ha^-1 （compost）, while output ranged from 8.44 × 10^5 to 11.01 × 10^5 MJ ha^-1 （agronomic yield）, and 14.22× 10^5 to 19.35 ×10^5 MJ ha^-1 （crop-residue）. The total input was the highest in temperate region, followed by subtropical and tropical region, and the highest output was in tropical region and the lowest in sub-tropical region.

Seasonal variations in the energy budget of Elliot’s pheasant (Syrmaticus ellioti) in cage

This study aimed to discuss the energy budget of Elliot’s pheasant Syrmaticus ellioti in different seasons,with life and health,good growth and normal digestion of Elliot’s pheasant as the tested objects,The energy budget of Elliot’s pheasant was measured by daily collection of the trial pheasants’excrement in the biological garden of Guangxi Normal University from March 2011 to February 2012.The results showed that the gross energy consumption,metabolic energy and excrement energy varied by season,increasing as temperature decreased.There was significant difference in gross energy consumption,metabolic energy,excrement energy between adults and nonages.There was also a trend that food digestibility of pheasants increases as temperature increases.In the same season,the food digestibility of adults was better than that of nonages.Throughout spring,summer,autumn and winter,the metabolic energy of 4-year adults were 305.77±13.40 kJ/d,263.67±11.89 kJ/d,357.23±25.49 kJ/d and 403.12±24.91 kJ/d,respectively,and the nonages were 284.86±17.22 kJ/d,284.66±15.16 kJ/d,402.26±31.46 kJ/d and 420.30±31.98 kJ/d,respectively.The minimum metabolic energies were 247.65±21.81 g,265.86±26.53 g,respectively for each group,detected between 4-year adults and 1-year nonages.Further study is needed to determine whether 29.6 C is the optimal temperature for the Elliot’s pheasant.

The Kinetic Energy Budget and Circulation Characteristics of the Tropical Storm Irma during AMEX Phase Ⅱ

By using the data from observation on the Chinese research vessel Xiang Yang Hong No.5 and other sources during AMEX phase II, the kinetic energy budget and circulation characteristics of the tropical storm Irma were analyzed.Irma formed on the ITCZ of the Southern Hemisphere. During the formative stage of the storm, the SE trades and monsoon westerlies on both sides of the ITCZ strengthened, and more importantly, there was a strong divergent flow in upper troposphere. These contributed to the intensification of Irma. At the time when Irma formed, the Richardson number (Ri) in middle and lower troposphere was much smaller than that prior to and post the formation.When Irma intensified rapidly, the area-averaged kinetic energy in the general flow increased in the whole troposphere . The largest contribution came from kinetic energy generation term, -[v.(?)(?)] .indicates that there existed a strong ageostrophic accetration. As to the generation term , the conversion of available potential energy to kinetic energy, - |ωα|, made the largest contribution. This illustrates the importance of internal sources and of the ensemble effect of cumulus convection to the kinetic energy.To the increase of area-averaged eddy kinetic energy during the rapid intensification of Irma, the most impor tant source in the whole troposphere was the dissipation term - [E'], that should be interpreted as the. feeding of eddy kinetic energy from smaller to larger scale disturbances. Another important source was generation term, - [v' (?)(?)'], in the lower troposphere. Rather small contribution came from the energy conversion from the kinetic energy of area-mean flow to eddy kinetic energy. Therefore, the eddy kinetic energy of the developing tropical disturbance extracted both from smaller an, .arger scale motions. The former was much more important than the latter In addition, the disturbance acting as a generator and exporter, generated and exported eddy kinetic energy to the environmental atmosphere.

New physics of supersonic ruptures

Until recently,it is believed that the rupture speed above the pressure wave is impossible since spontaneously propagating ruptures are driven by the energy released due to the rupture motion,which is transferred through the medium to the rupture tip region at the maximum speed equal to the pressure wave speed.However,the apparent violation of classic theories has been revealed by new experimental results demonstrating supersonic shear ruptures.This paper presents a detailed analysis of the recently discovered shear rupture mechanism(fan hinged),which suggests a new physics of energy supply to the tip of supersonic ruptures.The key element of this mechanism is the fan‐shaped structure of the head of extreme ruptures,which is formed as a result of an intense tensile cracking process with the creation of intercrack slabs that act as hinges between the shearing rupture faces.The fan structure is featured with the following extraordinary properties:extremely low friction approaching zero;amplification of shear stresses above the material strength at low applied shear stresses;creation of a self‐disbalancing stress state causing a spontaneous rupture growth;abnormally high energy release;generation of driving energy directly at the rupture tip which excludes the need to transfer energy through the medium.The fan mechanism operates in intact rocks at stress conditions corresponding to seismogenic depths and in pre‐existing extremely smooth interfaces due to identical tensile cracking processes at these conditions.This is Paper 1(of two companion papers)which discusses the fan theory and extreme ruptures in experiments on extremely smooth interfaces.Paper 2 entitled“Fan‐hinged shear instead of frictional stick‐slip as the main and most dangerous mechanism of natural,induced and volcanic earthquakes in the earth's crust”considers extreme ruptures in intact rocks.Further study of this subject is a major challenge for deep underground science,earthquake and fracture mechanics,physics,and tribology.

Fan‐hinged shear instead of frictional stick–slip as the main and most dangerous mechanism of natural,induced,and volcanic earthquakes in the earth's crust

Frictional stick–slip instability along pre‐existing faults has been accepted as the main mechanism of earthquakes for about 60 years,since it is believed that fracture of intact rocks cannot reflect such features inherent in earthquakes as low shear stresses activating instability,low stress drop,repetitive dynamic instability,and connection with pre‐existing faults.This paper demonstrates that all these features can be induced by a recently discovered shear rupture mechanism(fan‐hinged),which creates dynamic ruptures in intact rocks under stress conditions corresponding to seismogenic depths.The key element of this mechanism is the fan‐shaped structure of the head of extreme ruptures,which is formed as a result of an intense tensile cracking process,with the creation of inter‐crack slabs that act as hinges between the shearing rupture faces.The preference of the fan mechanism over the stick–slip mechanism is clear due to the extraordinary properties of the fan structure,which include the ability to generate new faults in intact dry rocks even at shear stresses that are an order of magnitude lower than the frictional strength;to provide shear resistance close to zero and abnormally large energy release;to cause a low stress drop;to use a new physics of energy supply to the rupture tip,providing supersonic rupture velocity;and to provide a previously unknown interrelation between earthquakes and volcanoes.All these properties make the fan mechanism the most dangerous rupture mechanism at the seismogenic depths of the earth's crust,generating the vast majority of earthquakes.The detailed analysis of the fan mechanism is presented in the companion paper“New physics of supersonic ruptures”published in DUSE.Further study of this subject is a major challenge for deep underground science,earthquake and fracture mechanics,volcanoes,physics,and tribology.

Energy budget of cold and hot gas-solid fluidized beds through CFD-DEM simulations

Direct energy budget is carried out for both cold and hot flow in gas–solid fluidization systems.First,the energy paths are proposed from thermodynamic viewpoints.Energy consumption means total power input to the specific system,and it can be decomposed into energy retention and energy dissipation.Energy retention is the variation of accumulated mechanical energy in the system,and energy dissipation is the energy converted to heat by irreversible processes.Then based on the Computational Fluid Dynamics-Discrete Element Method(CFD-DEM)framework,different energy terms are quantified from the specific flow elements of fluid cells and particles as well as their interactions with the wall.In order to clarify the energy budget,it is important to identify which system is studied:the particle-fluid system or the particle sub-system.For the cold flow,the total energy consumption of the particle sub-system can well indicate the onset of bubbling and turbulent,while the variation of local energy consumption terms can reflect the evolution of heterogeneous structures.For the hot flow,different heat transfer mechanisms are analyzed and the solver is modified to reproduce the experimental results.The impact of the heat transfer mechanisms and heat production on energy consumption is also investigated.The proposed budget method has proven to be energy-conservative and easy to conduct,and it is hopeful to be applied to other multiphase flow systems.

Understanding the Surface Temperature Cold Bias in CMIP5 AGCMs over the Tibetan Plateau

The temperature biases of 28 CMIP5 AGCMs are evaluated over the Tibetan Plateau(TP) for the period 1979–2005. The results demonstrate that the majority of CMIP5 models underestimate annual and seasonal mean surface 2-m air temperatures(Tas) over the TP. In addition, the ensemble of the 28 AGCMs and half of the individual models underestimate annual mean skin temperatures(Ts) over the TP. The cold biases are larger in Tasthan in Ts, and are larger over the western TP. By decomposing the Tsbias using the surface energy budget equation, we investigate the contributions to the cold surface temperature bias on the TP from various factors, including the surface albedo-induced bias, surface cloud radiative forcing, clear-sky shortwave radiation, clear-sky downward longwave radiation, surface sensible heat flux, latent heat flux,and heat storage. The results show a suite of physically interlinked processes contributing to the cold surface temperature bias.Strong negative surface albedo-induced bias associated with excessive snow cover and the surface heat fluxes are highly anticorrelated, and the cancelling out of these two terms leads to a relatively weak contribution to the cold bias. Smaller surface turbulent fluxes lead to colder lower-tropospheric temperature and lower water vapor content, which in turn cause negative clear-sky downward longwave radiation and cold bias. The results suggest that improvements in the parameterization of the area of snow cover, as well as the boundary layer, and hence surface turbulent fluxes, may help to reduce the cold bias over the TP in the models.