TP-PROFILE: Monitoring the Thermodynamic Structure of the Troposphere over the Third Pole

Ground-based microwave radiometers(MWRs)operating in the K-and V-bands(20–60 GHz)can help us obtain temperature and humidity profiles in the troposphere.Aside from some soundings from local meteorological observatories,the tropospheric atmosphere over the Tibetan Plateau(TP)has never been continuously observed.As part of the Chinese Second Tibetan Plateau Scientific Expedition and Research Program(STEP),the Tibetan Plateau Atmospheric Profile(TPPROFILE)project aims to construct a comprehensive MWR troposphere observation network to study the synoptic processes and environmental changes on the TP.This initiative has collected three years of data from the MWR network.This paper introduces the data information,the data quality,and data downloading.Some applications of the data obtained from these MWRs were also demonstrated.Our comparisons of MWR against the nearest radiosonde observation demonstrate that the TP-PROFILE MWR system is adequate for monitoring the thermal and moisture variability of the troposphere over the TP.The continuous temperature and moisture profiles derived from the MWR data provide a unique perspective on the evolution of the thermodynamic structure associated with the heating of the TP.The TP-PROFILE project reveals that the low-temporal resolution instruments are prone to large uncertainties in their vapor estimation in the mountain valleys on the TP.

DFT Study on the Correlation between Thermodynamical Property and Molecular Structure of Polybromo-phenoxathiin

Complete optimization was conducted for 136 polybromo-phenoxathiin congeners（PBPTs） on the B3LYP/6-31G＊ level with Gaussian 03 program.The structural parameters and thermodynamical parameters of each molecule were obtained under the standard state of 298.15 K and 1.013×10^5 Pa.Reverse linear regression was employed to establish the quantitative structure-property correlation models between heat capacity at constant volume（CVθ）,entropy（Sθ）,standard heat of formation（△fHθ） and standard free energy of formation（△fGθ） of PBPTs and the structural parameters（the most negative atomic charge（q^-） and molecular average polarizability（α））.These models presented better correlations（r^2〉0.97）.And they were validated by variance inflation factor（VIF） and t-test,which can better explain the regularity of thermodynamical property of PBPTs,and has good stability and great prediction ability.

Theoretical Studies on the Molecular Structures and Thermodynamic Properties of Polychlorinated Fluoranthenes

DFT-B3LYP/6-311G＊＊ method has been used to optimize molecular geometric structures of 527 polychlorinated fluoranthene（PCFRT） congeners and calculate their thermo-dynamic properties in the ideal gas state,such as heat capacity at constant volume（Cv）,entropy（S）,standard enthalpy of formation（ΔfH） and standard Gibbs free energy of formation（ΔfG）.The relations of Cv,S,ΔfH and ΔfG with the number and position of chlorine atoms have also been explored,from which the relative stability of PCFRT congeners was theoretically proposed according to the magnitude of the relative standard Gibbs free energy of formation（Δr,fG）.It was found that some of the PCFRT isomers are in a nonplanar configuration and there are intramolecular Cl…Cl weak interactions in some of the isomers.With increasing the number of chlorine atoms,the values of ΔfH and ΔfG of the most stable PCFRT isomers decrease initially and then increase.The values of ΔfH and ΔfG of PCFRT congeners with the same number of chlorine atoms show a strong dependence on the positions of chlorine atoms.The relative thermodynamic stability of PCFRT isomers is determined mainly by intramolecular adjacent Cl…Cl nuclear repulsive interaction between Cl atoms at two different six-membered rings.Most PCFRT congeners are easier to form thermodynamically than their parent compound.

On the Evolution and Structure of a Radiation Fog Event in Nanjing

An extremely dense radiation fog event during 10-11 December 2007 was studied to understand its macro-micro-physics in relation to dynamic and thermodynamic structures of the boundary layer, as well as its structural evolution in conjunction with the air-surface exchange of heat and water vapor. The findings are as follows. The extreme radiation fog process was divisible into formation, development, mature, and dissipation phases, depending on microstructure and visibility. This fog event was marked by rapid evolution that occurred after sunrise, when enhanced surface evaporation and cold air intrusion led to a three order of magnitude increase in liquid water content （LWC） in just 20 minutes. The maximum droplet diameter （MDD） increased four-fold during the same period. The fog structure was two-layered, with the top of both the surface-layer and upper-layer components characterized by strong temperature and humidity inversions, and low-level jets existed in the boundary layer above each fog layer. Turbulence intensity, turbulent kinetic energy, and friction velocity differed remarkably from phase to phase： these features increased gradually before the fog formation and decreased during the development phase; during the mature and dissipation phases these characteristics increased and then decreased again. In the development and mature stages, the mean kinetic energy of the lower-level winds decreased pronouncedly, both in the horizontal and vertical directions.

Studies of Structural and Thermodynamic Properties for Polychlorinated Thianthrenes by Density Functional Theory

The structural and thermodynamic （PCTAs） in the ideal gas state at 298.15 K and 1.013 properties of 75 polychlorinated thianthrenes ×10^5 Pa have been calculated at the B3LYP/6- 31G＊ level using Gaussian 98 program. Based on the output data of Gaussian, the isodesmic reactions were designed to calculate standard enthalpy of formation （△fH^θ） and standard free energy of formation （△fH^θ） of PCTAs congeners. The relations of these thermodynamic parameters with the number and position of C1 atom substitution （Npcs） were discussed, and it was found that there exists high correlation between thermodynamic parameters （total energy （TE）, zero-point vibrational energy （ZPE）, thermal correction to energy （Eth）, heat capacity at constant volume （Cv^θ）, entropy （S^θ）, enthalpy （H^θ）, free energy （G^θ）, standard enthalpies of formation （△fH^θ） and standard Gibbs energies of formation （△fG^θ）） and Npcs. On the basis of the relative magnitude of their △fG^θ, the order of relative stability of PCTA congeners was theoretically proposed. In addition, the correlations between structural parameters and Npcs were also discussed. The good correlations were found between molecular average polarizability （α）, energy of the highest occupied molecular orbital （EHOMO）, molecular volume （Vm） and Npcs, and all R^2 values are larger than 0.95. Moreover, it was supposed that the isomer groups with higher toxicity should be Tri-CTA and TCTA.

Elastic properties and electronic structures of lanthanide hexaborides

The structural, elastic, and electronic properties of a series of lanthanide hexaborides（Ln B6） have been investigated by performing ab initio calculations based on the density functional theory using the Vienna ab initio simulation package.The calculated lattice and elastic constants of Ln B6 are in good agreement with the available experimental data and other theoretical results. The polycrystalline Young＇s modulus, shear modulus, the ratio of bulk to shear modulus B/G, Poisson＇s ratios, Zener anisotropy factors, as well as the Debye temperature are calculated, and all of the properties display some regularity with increasing atomic number of lanthanide atoms, whereas anomalies are observed for Eu B6 and Yb B6. In addition, detailed electronic structure calculations are carried out to shed light on the peculiar elastic properties of Ln B6.The total density of states demonstrates the existence of a pseudogap and indicates lower structure stability of Eu B6 and Yb B6 compared with others.

The Structural,Dielectric,Lattice Dynamical and Thermodynamic Properties of Zinc-Blende CdX(X=S,Se,Te) from First-Principles Analysis

The structural, dielectric, lattice dynamical and thermodynamic properties of zinc-blende CdX （X=S, Se, Te） are studied by using a plane-wave pseudopotential method within the density-functional theory. Our calculated lattice constants and bulk modulus are compared with the pubfished experimental and theoretical data. In addition, the Born effective charges, electronic dielectric tensors, phonon frequencies, and longitudinal opticaltransverse optical splitting are calculated by the linear-response approach. Some of the characteristics of the phonon-dispersion curves for zinc-blende CdX （X= S, Se, Te） are summarized. What is more, based on the lattice dynamical properties, we investigate the thermodynamic properties of CdX （X= S, Se, Te） and analyze the temperature dependences of the Helmholtz free energy F, the internal energy E, the entropy S and the constant-volume specific heat Cv. The results show that the heat capacities for CdTe, CdSe, and CdS approach approximately to the Petit-Dulong limit 6R.

Finescale Spiral Rainbands Modeled in a High-Resolution Simulation of Typhoon Rananim (2004)

Finescale spiral rainbands associated with Typhoon Rananim （2004） with the band length ranging from 10 to nearly 100 km and band width varying from 5 to 15 km are simulated using the Fifth-Generation NCAR/Penn State Mesoscale Model （MM5）. The finescale rainbands have two types： one intersecting the eyewall and causing damaging wind streaks, and the other distributed azimuthally along the inner edge of the eyewall with a relatively short lifetime. The formation of the high-velocity wind streaks results from the interaction of the azimuthal flow with the banded vertical vorticity structure triggered by tilting of the horizontal vorticity. The vertical advection of azimuthal momentum also leads to acceleration of tangential flow at a relatively high Mtitude. The evolution and structures of the bands are also examined in this study. Further investigation suggests that the boundary inflection points are related tightly to the development of the finescale rainbands, consistent with previous findings using simple symmetric models. In particular; the presence of the level of inflow reversal in the boundary layer is a crucial factor controlling the formation of these bands. The near-surface wavy peaks of vertical vorticity always follow the inflection points in radial flow. The mesoscale vortices and associated convective updrafts in the eyewall are considered to strengthen the activity of finescale bands, and the updrafts can trigger the formation of the bands as they reside in the environment with inflow reversal in the boundary layer.

A numerical simulation of latent heating within Typhoon Molave

The weather research and forecasting（WRF） model is a new generation mesoscale numerical model with a fine grid resolution（2 km）, making it ideal to simulate the macro-and micro-physical processes and latent heating within Typhoon Molave（2009）. Simulations based on a single-moment, six-class microphysical scheme are shown to be reasonable, following verification of results for the typhoon track, wind intensity, precipitation pattern, as well as inner-core thermodynamic and dynamic structures. After calculating latent heating rate, it is concluded that the total latent heat is mainly derived from condensation below the zero degree isotherm, and from deposition above this isotherm. It is revealed that cloud microphysical processes related to graupel are the most important contributors to the total latent heat. Other important latent heat contributors in the simulated Typhoon Molave are condensation of cloud water, deposition of cloud ice, deposition of snow, initiation of cloud ice crystals, deposition of graupel, accretion of cloud water by graupel, evaporation of cloud water and rainwater,sublimation of snow, sublimation of graupel, melting of graupel, and sublimation of cloud ice. In essence, the simulated latent heat profile is similar to ones recorded by the Tropical Rainfall Measuring Mission, although specific values differ slightly.

Synthesis,Characterization and Theoretical Studies on a Thiocarbamide Derivative Containing Schiff Base Group

A thiocarbamide derivative containing Schiff base groups,1,5-bis[4-（dimethylamino）benzylidene]thiocarbonohydrazide,has been synthesized and characterized by elemental analysis,IR,^1H NMR,UV and X-ray single-crystal diffraction.Density function theory（DFT） calculations at the B3LYP/6-31G＊ and PBE0/6-31G＊ levels for optimized geometries and electronic transition spectra have been performed.Comparative studies show that both B3LYP/6-31G＊ and PBE0/6-31G＊ methods can well reproduce the molecular structure,and the latter is more reliable than the former to simulate electronic spectra.NPA calculational results at the B3LYP/6-31G＊ level indicate the title compound to be a potential multidentate ligand to the metallic ions.Based on the vibrational analysis,thermodynamic properties at different temperatures have been obtained.

Mean Structure of Tropical Cyclones Making Landfall in China's Mainland

The mean kinematic and thermodynamic structures of tropical cyclones （TCs） making landfall in main-land China are examined by using sounding data from 1998 to 2009. It is found that TC landfall is usually accompanied with a decrease in low-level wind speed, an expansion of the radius of strong wind, weakening of the upper-level warm core, and drying of the mid-tropospheric air. On average, the warm core of the TCs dissipates 24 h after landfall. The height of the maximum low-level wind and the base of the stable layer both increase with the increased distance to the TC center;however, the former is always higher than the latter. In particular, an asymmetric structure of the TC after landfall is found. The kinematic and thermodynamic structures across various areas of TC circulation diff er, especially over the left-front and right-rear quadrants （relative to the direction of TC motion）. In the left-front quadrant, strong winds locate at a smaller radius, the upper-level temperature is warmer with the warm core extending into a deep layer, while the wet air occupies a shallow layer. In the right-rear quadrant, strong wind and wet air dwell in an area that is broader and deeper, and the warmest air is situated farther away from the TC center.

Oscillation of Surface PM2.5 Concentration Resulting from an Alternation of Easterly and Southerly Winds in Beijing： Mechanisms and Implications

We used simultaneous measurements of surface PM_（2.5） concentration and vertical profiles of aerosol concentration,temperature, and humidity, together with regional air quality model simulations, to study an episode of aerosol pollution in Beijing from 15 to 19 November 2016. The potential effects of easterly and southerly winds on the surface concentrations and vertical profiles of the PM_（2.5） pollution were investigated. Favorable easterly winds produced strong upward motion and were able to transport the PM_（2.5） pollution at the surface to the upper levels of the atmosphere. The amount of surface PM_（2.5） pollution transported by the easterly winds was determined by the strength and height of the upward motion produced by the easterly winds and the initial height of the upward wind. A greater amount of PM_（2.5） pollution was transported to upper levels of the atmosphere by upward winds with a lower initial height. The pollutants were diluted by easterly winds from clean ocean air masses. The inversion layer was destroyed by the easterly winds and the surface pollutants and warm air masses were then lifted to the upper levels of the atmosphere, where they re-established a multi-layer inversion. This region of inversion was strengthened by the southerly winds, increasing the severity of pollution. A vortex was produced by southerly winds that led to the convergence of air along the Taihang Mountains. Pollutants were transported from southern–central Hebei Province to Beijing in the boundary layer. Warm advection associated with the southerly winds intensified the inversion produced by the easterly winds and a more stable boundary layer was formed. The layer with high PM_（2.5） concentration became dee-per with persistent southerly winds of a certain depth. The polluted air masses then rose over the northern Taihang Mountains to the northern mountainous regions of Hebei Province.

A Numerical Investigation of the Eyewall Evolution of a Tropical Cyclone

In this study, a high-resolution numerical simulation is conducted to investigate the eyewall evolution of Typhoon Imbudo （2003）. The eyewall contraction, breakdown, and reformation are successfully simulated by the model. The eyewall accordantly shrinks throughout the whole troposphere prior to landfall, while it exhibits different variations after landfall in the lower and upper troposphere, respectively. It is found that the dry air advected into the storm inner core through a low-θe channel, the reduced surface latent heat transfer, and the increased inflows in the coastal region are associated with the eyewM1 contraction. Accompanied with the high-to-low wavenumber change in the vortex Rossby waves, the initial polygonal eyewall transforms to an elliptical one. Such a wavenumber change is likely associated with the change of interaction between the rainbands and the eyewall. The corresponding features of the time-averaged and vertical dynamic and thermodynamic structures are also examined during the storm passage. A tangential wind budget analysis indicates that a strong acceleration due to the contributions of both the eddy and the mean circulation is located in the lower layer in the eyewall during pre-landfall, and the mean circulation contribution to the change in the tendency of the azimuthally averaged tangential wind counteracts the eddy contribution.