The China National Climate Center and Centers for Environmental Prediction data were used in this work. Using the knowledge of synoptic principles analysis, rain snow weather process middle east from December 28 to 30, 2020 was analyzed. results show that: 1) This a large-scale precipitation process. Affected by cold wave, temperature drops sharply, many places dropped below extreme value, acco...

This study investigates the autumn precipitation in Sichuan Basin (SB), China combination with reanalysis data sets of aerosol and meteorological fields from 2008 to 2018. To identify impacts on precipitation, we carefully selected divided into multiple groups according vorticity, amount category, pollution level, geopotential height (GH) upper troposphere. Our show that SB are generally reduce...

A 48-hr. forecast for the entire Korthern Hemisphere of a barotropic hydrostatic atmosphere is made with the "primitive equations." Overlapping Mercator and stereographic grids are used, together with the finite-difference scheme proposed by Eliassen. Initial data corresponded to a Haurwitz-type pattern of wave number 4. The initial wind field was nondivergent and the initial geopotential field...

In this paper we try to suggest a possible novel method to determine some selected even zonal harmonics Jl of the Earth’s geopotential. Time series many years long of suitably linearly combined residuals of some Keplerian orbital elements of certain existing geodetic SLR satellites would be examined. A CHAMP/GRACE-only background reference model should be used for the part of the geopotential w...

In this paper we calculate explicitly the secular classical precessions of the node Ω and the perigee ω of an Earth artificial satellite induced by the static, even zonal harmonics of the geopotential up to degree l = 20. Subsequently, their systematic errors induced by the mismodelling in the even zonal geopotential coefficients Jl are compared to the general relativistic secular gravitomagnet...

Abstract Atmospheric blocking events, which cause abnormal weather conditions, have been studied from a viewpoint of quasi‐stationary barotropic circulation systems because their apparent lack vertical tilt. However, this work demonstrates that events often such structure anomalies in geopotential height and temperature are horizontally out‐of‐phase, allowing to produce fluxes heat against the ...

to doing this research daily interpolated temperature data from asfezari data base have been used. in order to recognition extreme cold days, the normalized temperature deviation index (ntdi) applied. then the index sorted according to extensive and severity and first 500 days selected for analysis. the geopotential height data extracted from www.esrl.noaa.gov data base. the thickness anomaly c...

using satellite altimetry derived mean sea level (msl), geopotential coefficients in terms of ellipsoidal harmonics from recent satellite gravimetry missions, gravity potential values over a grid consisting of 33,486 points at global sea areas are computed and the mean value of the gravity potential at msl is calculated as a new geoid’s potential value. in this way we have exactly followed the ...

Discrete Spherical Harmonic Transforms (SHTs) are commonly defined for equiangular grids on the sphere. However, when global array data exhibit near equidistributed patterns rather than equiangular grids, discrete SHTs require appropriate adaptations for analysis and synthesis. Computational efficiency and reliability impose structural constraints on possible equidistribution characteristics of...

In this paper we try to suggest a possible novel method to determine some selected even zonal harmonics Jl of the Earth’s geopotential. Time series many years long of suitably linearly combined residuals of some Keplerian orbital elements of certain existing geodetic SLR satellites would be examined. A CHAMP/GRACE-only background reference model should be used for the part of the geopotential w...