Synergistic Effect of the Planetary-scale Disturbance, Typhoon and Meso-β-scale Convective Vortex on the Extremely Intense Rainstorm on 20 July 2021 in Zhengzhou

On 20 July 2021,northern Henan Province in China experienced catastrophic flooding as a result of an extremely intense rainstorm,with a record-breaking hourly rainfall of 201.9 mm during 0800–0900 UTC and daily accumulated rainfall in Zhengzhou City exceeding 600 mm(“Zhengzhou 7.20 rainstorm”for short).The multi-scale dynamical and thermodynamical mechanisms for this rainstorm are investigated based on station-observed and ERA-5 reanalysis datasets.The backward trajectory tracking shows that the warm,moist air from the northwestern Pacific was mainly transported toward Henan Province by confluent southeasterlies on the northern side of a strong typhoon In-Fa(2021),with the convergent southerlies associated with a weaker typhoon Cempaka(2021)concurrently transporting moisture northward from South China Sea,supporting the rainstorm.In the upper troposphere,two equatorward-intruding potential vorticity(PV)streamers within the planetary-scale wave train were located over northern Henan Province,forming significant divergent flow aloft to induce stronger ascending motion locally.Moreover,the converged moist air was also blocked by the mountains in western Henan Province and forced to rise so that a deep meso-β-scale convective vortex(MβCV)was induced over the west of Zhengzhou City.The PV budget analyses demonstrate that the MβCV development was attributed to the positive feedback between the rainfall-related diabatic heating and high-PV under the strong upward PV advection during the Zhengzhou 7.20 rainstorm.Importantly,the MβCV was forced by upper-level larger-scale westerlies becoming eastward-sloping,which allowed the mixtures of abundant raindrops and hydrometeors to ascend slantwise and accumulate just over Zhengzhou City,resulting in the record-breaking hourly rainfall locally.

The Seismic Induced Soft Sediment Deformation Structures in the Middle Jurassic of Western Qaidamu Basin

Intervals of soft-sediment deformation structures are well-exposed in Jurassic lacustrine deposits in the western Qaidamu basin. Through field observation, many soft-sediment deformation structures can be identified, such as convoluted bedding, liquefied sand veins, load and flame structures, slump structures and sliding-overlapping structures. Based on their genesis, soft-sediment deformation structures can be classified as three types： seismic induced structures, vertical loading structures, and horizontal shear structures. Based on their geometry and genesis analysis, they are seismic-induced structures. According to the characteristics of convoluted bedding structures and liquefied sand veins, it can be inferred that there were earthquakes greater than magnitude 6 in the study area during the middle Jurassic. Furthermore, the study of the slump structures and sliding- overlapping structures indicates that there was a southeastern slope during the middle Jurassic. Since the distance from the study area to the Altyn Mountain and the Altyn fault is no more than 10km, it can be also inferred that the Altyn Mountain existed then and that the AItyn strike-slip fault was active during the middle Jurassic.

APPLICATION OF SEPARABILITY ORITERION IN DESIGN OF DEFORMATION MONITORING NETWORKS

A monitoring scheme must be so designed that several possible mod-els can be efficiently separated in the stage of analysis of deformation measure-ments.Based on the concept of separability developed by Chen and Chrzanowski,a methodology for the design of monitoring schemes has been developed by the au-thors.In the method a computer simulation technique is employed,into whichsome rules have been elaborated allowing minimal human intervention.In this pa-per the criterion is first presented and the design technique using the step one up-dating procedure is discussed.Finally,design of a simulated monitoring networkis made as a demonstrating example.

OUTLIER DETECTION AND RELIABILITY OF ADJUSTMENT MODELS WITH SINGULAR COVARIANCE MATRICES

Up to now,outlier detection and reliability theory are generallybased on the regular Gauss-Markov models,in which the covariance matrix of ob-servations is positively definite.For the adjustment models with singular covari-ance matrix,the statistics for outlier detection are derived by the authors.Thecorresponding reliability theory is developed.And the application of the theory isdemonstrated with a practical example.

A MORE GENERAL FORM OF ERROR DISTRIBUTION

This paper deduced a more general error distribution,the p-th pow-er norm distribution,based on the foundational properties of random errors.

THE ESTIMATION OF VARIANCE AND COVARIANCE COMPONENTS FOR GPS BASELINE NETWORK BY MINQUE METHOD

This paper studies the estimation of variance and covariance compo-nents for GPS baseline network by MINQUE method.The fundamental rule forselecting variance-covariance model has been presented,and the alternative algo-rithm which simultaneouly estimates fixed variance components and scalled vari-ance components of the distance,azimuth and geodetic height difference for a GPSbaseline vector has been developed.

APPLICATION OF THE HARTLEY TRANSFORM IN THE COMPUTATION OF THE GEOID IN CHINA

This paper presents a method for the computation of the Stokes for-mula using the Fast Hartley Transform（FHT）techniques.The algorithm is mostsuitable for the computation of real sequence transform,while the Fast FourierTransform（FFT）techniques are more suitable for the computaton of complex se-quence transform.A method of spherical coordinate transformation is presented inthis paper.By this method the errors,which are due to the approximate term inthe convolution of Stokes formula,can be effectively eliminated.Some numericaltests are given.By a comparison with both FFT techniques and numerical integra-tion method,the results show that the resulting values of geoidal undulations byFHT techniques are almost the same as by FFT techniques,and the computation-al speed of FHT techniques is about two times faster than that of FFT techniques.

Using repeated precise gps campaigns for research of present-day crustal movement and strain in the Qinghai-Tibetan Plateau

The problem of crustal movement in the Qing-hai-Tibetan Plateau is a hotstopic of the present-day international geodetic world. GPS observations in 1993, 1995 and 1997 are used to survey the three-dimensional displacement of GPS monitoring station in the Qinghai-Tibetan Plateau, and to calculate and analyze the present-day crustal movement and strain in the Qinghai-Tibetan Plateau. The result of repeated campaign shows that the crustal movement in the Qinghai-Tibetan Plateau is still compressing in the north and south directions, extending in the west and east directions, and uplifting in the vertical direction. The relative convergence velocity of the Himalayan block is approximately (19.5±1.7)mm/a, the strain velocity is about (5.5±6.0) mm/a, and the uplifting velocity is some (7.6±5.2) mm/a. The compression velocity of the Tibet block relative to Golmud in the north and south directions is (9.3±4.6) mm/a, the strain velocity of the middle part in the west and east directions is (15.6±6.3) mm/a,