Results 91 to 100 of about 14,203 (319)

Assimilation of Dual‐Pol Radar KDP Observations With the GSI Ensemble Kalman Filter for the Analysis and Prediction of a Squall Line

Journal of Geophysical Research: Atmospheres, Volume 130, Issue 11, 16 June 2025.
Abstract The direct assimilation of dual‐polarization radar observations is realized within the gridpoint statistical interpolation data assimilation (DA) system using the ensemble Kalman filter method. This study involves three experiments designed to evaluate the impacts of assimilating the polarimetric variable specific differential phase (KDP) for ...
Feifei Shen, Aiqing Shu, Jinzhong Min, Zheng Wu, Yi Wang, Dongmei Xu, Jiajun Chen, Shen Wan   +7 more
wiley   +1 more source

Exact solutions and automorphic systems of the geopotential forecast equation [PDF]

The study of the recently constructed group foliation for the geopotential forecast equation is continued. The group foliation consists of two systems, namely the automorphic and resolving systems, the analysis of which facilitates the derivation of invariant solutions for the original equation.
arxiv   +1 more source

Triangulated spherical splines for geopotential reconstruction

Journal of Geodesy, 2008
We present an alternate mathematical technique than contemporary spherical harmonics to approximate the geopotential based on triangulated spherical spline functions, which are smooth piecewise spherical harmonic polynomials over spherical triangulations.
Lai, M., Shum, C., Baramidze, V., Wenston, P.   +3 more
openaire   +4 more sources

A Novel Thermodynamical Predictor of Tropical High‐Cloud Area Coverage: Estimated Anvil‐Outflow Stability

Geophysical Research Letters, Volume 52, Issue 11, 16 June 2025.
Abstract The stability at the lapse‐rate tropopause (LRT) was previously defined as the upper‐tropospheric stability (UTS and SUT) but might underestimate the stability control on high‐level clouds, since there is little direct connection between convective processes and the thermal stratification at the LRT.
Zhenquan Wang, Jian Yuan
wiley   +1 more source

A preliminary experiment of determining the geopotential difference using two hydrogen atomic clocks and TWSTFT technique

Geodesy and Geodynamics, 2020
General relativity theory (GRT) concludes that a precise clock ticks at different running rates if it is under the influence of different geopotentials.
Kuangchao Wu, Ziyu Shen, Wenbin Shen, Xiao Sun, Chenghui Cai, Yifan Wu   +5 more
doaj  

Reanalysis Data Sets Underestimate the 1928–29 Summer Precipitation Deficits During the Late‐1920s Megadrought in Northern China

Geophysical Research Letters, Volume 52, Issue 11, 16 June 2025.
Abstract Numerous tree‐ring and historical records indicate a megadrought in the Loess Plateau (LP) of northern China during 1928–29, yet its dynamical causes remain unclear. This study reconstructs LP summer precipitation from 1901 to 2000 using multiple paleoclimate proxies to assess precipitation and reanalysis data sets.
Congxi Fang, Yu Liu, Changfeng Sun, Huiming Song, Lijun Su, Zhiman Su, Lu Wang, Qiufang Cai, Qiang Li, Liang Yi, Jinlei Chen, Meng Ren, Linlin Cui   +12 more
wiley   +1 more source

Recovery of Rapid Water Mass Changes (RWMC) by Kalman Filtering of GRACE Observations

Remote Sensing, 2020
We demonstrate a new approach to recover water mass changes from GRACE satellite data at a daily temporal resolution. Such a product can be beneficial in monitoring extreme weather events that last a few days and are missing by conventional monthly GRACE
Guillaume Ramillien, Lucía Seoane, Maike Schumacher, Ehsan Forootan, Frédéric Frappart, José Darrozes   +5 more
doaj   +1 more source

On a possible new approach for investigating the secular variations of the low-degree geopotential coefficients [PDF]

A. Reimer (ed.), Quantum Gravity Research Trends, vol. 250, Nova, Hauppauge (N. Y.), 2006, pp. 273-296, 2004
In this paper we try to suggest a possible novel method to determine some selected even zonal harmonics J_l 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.
arxiv  

Intensified Interannual Variability of Arctic Sea Ice Modulated by Strengthened North Atlantic Oscillation Leads to an Enhanced Impact on Asian Winter Cold Extremes

Geophysical Research Letters, Volume 52, Issue 11, 16 June 2025.
Abstract Arctic sea ice concentration (SIC) exhibits significant interannual variability despite a persistent decline due to global warming. This variability is influenced by atmospheric internal variability such as the North Atlantic Oscillation (NAO) and the Pacific‐North American pattern (PNA).
Cen Wang, Hui Su, Jianqiu Zheng, Shiwei Yu, Huisi Mo, Luancheng Xu   +5 more
wiley   +1 more source

A data-driven approach to precipitation parameterizations using convolutional encoder-decoder neural networks [PDF]

arXiv, 2019
Numerical Weather Prediction (NWP) models represent sub-grid processes using parameterizations, which are often complex and a major source of uncertainty in weather forecasting. In this work, we devise a simple machine learning (ML) methodology to learn parameterizations from basic NWP fields.
arxiv