Semi-Idealized Modeling of Lightning Initiation Related to Vertical Air Motion and Cloud Microphysics

A three-dimensional charge^lischarge numerical model is used, in a semi-idealized mode, to simulate a thunder- storm cell. Characteristics of the granpel microphysics and vertical air motion associated with the lightning initiation are revealed, which could be useful in retrieving charge strength during lightning when no charge^diseharge model is available, The results show that the vertical air motion at the lightning initiation sites （Wini） has a cubic polynomial correlation with the maximum updraft of the storm cell （WceH_m^x）, with the adjusted regression coefficient R2 of ap- proximately 0.97. Meanwhile, the graupel mixing ratio at the lightning initiation sites （qg-ini） has a linear correlation with the maximum graupel mixing ratio of the storm cell （qg-cell-max） and the initiation height （Zini）, with the coeffi- cients being 0.86 and 0.85, respectively. These linear correlations are more significant during the middle and late stages of lightning activity. A zero-charge zone, namely, the area with very low net charge density between the main positive and negative charge layers, appears above the area of qg-oewm and below the upper edge of the granpel re- gion, and is found to be an important area for lightning initiation. Inside the zero-charge zone, large electric intensity forms, and the ratio of qice （ice crystal mixing ratio） to qg （graupel mixing ratio） illustrates an exponential relation- ship to qg-ini. These relationships provide valuable clues to more accurately locating the high-risk area of lightning initiation in thunderstorms when only dual-polarization radar data or outputs from numerical models without char- ging/discharging schemes are available. The results can also help understand the environmental conditions at light- ning initiation sites.

Hypersphere World-Universe Model: Basic Ideas

Hypersphere World-Universe Model (WUM) envisions Matter carried from the Universe into the World from the fourth spatial dimension by Dark Matter Particles (DMPs). Luminous Matter is a byproduct of Dark Matter (DM) self-annihilation. WUM introduces Dark Epoch (spanning from the Beginning of the World for 0.45 billion years) and Luminous Epoch (ever since for 13.77 billion years). Big Bang discussed in Standard Cosmology (SC) is, in our view, transition from Dark Epoch to Luminous Epoch due to Rotational Fission of Overspinning DM Supercluster’s Cores and self-annihilation of DMPs. WUM solves a number of physical problems in SC and Astrophysics through DMPs and their interactions: Angular Momentum problem in birth and subsequent evolution of Galaxies and Extrasolar systems;Fermi Bubbles—two large structures in gamma-rays and X-rays above and below Galactic center;Coronal Heating problem in solar physics—temperature of Sun’s corona exceeding that of photosphere by millions of degrees;Cores of Sun and Earth rotating faster than their surfaces;Diversity of Gravitationally-Rounded objects in Solar system and their Internal Heating. Model makes predictions pertaining to Rest Energies of DMPs, proposes New Type of their Interactions. WUM reveals Inter-Connectivity of Primary Cosmological Parameters and calculates their values, which are in good agreement with the latest results of their measurements.

A parameterization scheme for upward lightning in the cloud model and a discussion of the initial favorable environmental characteristics in the cloud

The upward lightning(UL) initiated from the top of tall buildings(at least above 100 m) is a type of atmospheric discharge. Currently, we understand the nature of the UL from ground observations, but the corresponding theoretical research is lacking. Based on an existing bidirectional leader stochastic model, a stochastic parameterization scheme for the UL has been built and embedded in an existing two-dimensional thundercloud charge/discharge model. The ULs simulated from the experiments with two-dimensional high resolution agree generally with the observation results. By analyzing the charge structure of thunderstorm clouds, we determined the in-cloud environmental characteristics that favor the initiation of conventional cloud-to-ground(CG) flashes and analyzed the differences and similarities of some characteristics of the positive and the negative UL. Simulation results indicate that the positive ULs are typically other-lightning-triggered ULs(OLTUL) and are usually a discharge phenomenon between the ground and the lower positive charge region appearing below the main middle negative charge region. The effect of the previous in-cloud lightning(IC) process of space electrical field provides favorable conditions for the initiation of a positive UL. Its entire discharge process is limited, and the branches of the leader are fewer in number as its discharge is not sufficient. A negative UL is generally a discharge phenomenon of the dipole charge structure between the ground and the main negative charge region. The lower temperature stratification and the sinking of the hydrometeors typically initiate a negative UL. Negative ULs develop strongly and have more branches. The OLTUL is initiated mainly during the development stage of a thunderstorm, while the self-triggered UL(STUL) is initiated mainly during the dissipation stage of a thunderstorm.