Abstract Finescale simulations (with 500-m grid spacing) using the Weather Research and Forecasting Model (WRF) were used to investigate impacts of urban processes urbanization on a localized, summer, heavy rainfall in Beijing. Evaluation radar gauge data shows that this configuration WRF with three-dimensional variational assimilation local weather GPS precipitable water can simulate event generally well. Additional conducted test sensitivity simulation storm different land-use scenarios....

Abstract An indirect radar reflectivity assimilation scheme has been developed within the Weather Research and Forecasting model three-dimensional data system (WRF 3D-Var). This scheme, instead of assimilating directly, assimilates retrieved rainwater estimated in-cloud water vapor. analysis is provided to show that avoids linearization error Z – q r (reflectivity–rainwater) equation. A new observation operator introduced assimilate The performance demonstrated by observations into Rapid...

Abstract Weather forecasting skill has been improved over recent years owing to advances in the representation of physical processes by numerical weather prediction (NWP) models, observational systems, data assimilation and postprocessing, new computational capability, effective communications training. There is an area that received less attention so far but can bring significant improvement forecasting—the calibration NWP a process which model parameters are tuned using certain...

Abstract Background error modeling plays a key role in variational data assimilation system. The National Meteorological Center (NMC) method has been widely used systems to generate forecast ensemble from which the climatological background covariance can be modeled. In this paper, characteristics of via NMC are investigated for system Weather Research and Forecasting (WRF-Var) Model. statistics extracted short-term 3-km-resolution forecasts June, July, August 2012 over limited-area domain....

Abstract The evolution of planetary boundary layer (PBL) was investigated using observations from a laser ceilometer, an eddy covariance system, and automatic meteorological station in the north Nanjing city during air pollution episode 2016–2017 winter. Based on 7‐day observation under clean to polluted day, we recorded temporal variations backscatter signals observed by then intercompared height (PBLH) retrieved individual methods. results show that signal gradient, standard deviation,...

The USGS (United States Geological Survey) land-use data used in the Weather Research and Forecasting (WRF) model have become obsolete as they are unable to accurately represent actual underlying surface features. Therefore, this study developed a new multi-satellite remote-sensing dataset based on latest GLC2015 (Global Land Cover, 2015) data, which had 300 m spatial resolution. were update default dataset. Based observational from national meteorological observing stations Xinjiang,...

Due to the availability of observations and effectiveness bias correction, it is still a challenge assimilate data from polar orbit satellites into limited-area frequently updated model. This study assessed initial application satellite radiance multiple platforms in Rapid-refresh Multi-scale Analysis Prediction System (RMAPS). Satellite advanced microwave sounding unit-A (AMSU-A) humidity (MHS) were used. Two 12-day retrospective runs conducted evaluate impact assimilating on 0–24 h...

Abstract. To facilitate the future inclusion of aerosol–radiation interactions in regional operational numerical weather prediction (NWP) system RMAPS-ST (adapted from Weather Research and Forecasting, WRF) at Institute Urban Meteorology (IUM), China Meteorological Administration (CMA), impacts on forecast surface radiation meteorological parameters during a heavy pollution event (6–10 December 2015) over northern were investigated. The aerosol information was simulated by RMAPS-Chem WRF...

In August 2018, the Institute of Urban Meteorology (IUM) in Beijing co-organized with Sinovation Ventures a Weather Forecasting Contest (WFC)—one AI (artificial intelligence) Challenger Global Contests. The WFC aims to take advantage techniques improve quality weather forecast. Across world, more than 1000 teams enrolled and about 250 completed real-time forecasts, among which top 5 were awarded final contest. contest results show that AI-based ensemble models exhibited improved skill for...

Ground-based microwave radiometers (MWRPS) can provide continuous atmospheric temperature and relative humidity profiles for a weather prediction model. We investigated the impact of assimilation ground-based based on rapid-refresh multiscale analysis system-short term (RMAPS-ST). In this study, five MWRP-retrieved were assimilated precipitation enhancement that occurred in Beijing 21 May 2020. To evaluate influence their assimilation, two experiments with without MWRPS set. Compared to...

Herein, a case study on the impact of assimilating satellite radiance observation data into rapid-refresh multi-scale analysis and prediction system (RMAPS) is presented. This targeted 48 h period from 19–20 July 2016, which was characterized by passage low pressure that produced heavy rainfall over North China. Two experiments were performed 24 forecasts every 3 h. The results indicated forecast prior to assimilation could not accurately predict events Beijing surrounding area. advanced...

In this study, the temperature and relative humidity profiles retrieved from five ground-based microwave radiometers in Beijing were assimilated into rapid-refresh multi-scale analysis prediction system-short term (RMAPS-ST). The precipitation bifurcation that occurred on 4 May 2019 was selected as a case to evaluate impact of their assimilation. For purpose, two experiments set. Control experiment only conventional observations radar data, while profilers (MWRPS) observations, radiometer...

The regional ensemble prediction system (REPS) of North China is currently under development at the Institute Urban Meteorology, Meteorological Administration, with initial condition perturbations provided by global dynamical downscaling. To improve performance REPS, a comparison two perturbation methods conducted in this paper: (i) Breeding, which was specifically designed for and (ii) Dynamical Consecutive tests were implemented to evaluate performances both operational REPS environment....

Due to the difficulty in accurately interpreting surface emissivity spectra, problems remain application of passive microwave satellite observations over land surfaces. This study develops a parameterized soil model quantify and rapidly for Gaussian-correlated rough We first analyze sensitivity parameters using advanced integral equation (AIEM) simulated data. On basis analysis previous empirical models, two function factors that consider polarization dependence reflectivity are developed...

Ground-based microwave radiometers (MWR) are used to provide temperature and relative humidity (RH) profiles mainly at boundary layer with temporal resolution of 1–2 minutes. However, accuracy MWR away from radiosondes locations is not satisfactory. In this study, we proposed RH retrieval models based on fifth-generation reanalysis (ERA5) data that allow the replacement original model adjacent radiosondes. The study focuses how resolve unrepresentativeness ERA5 data. A quality control scheme...

The Advanced Technology Microwave Sounder (ATMS) mounted on the Suomi National Polar-Orbiting Partnership (NPP) satellite can provide both temperature and humidity information for a weather prediction model. Based rapid-refresh multi-scale analysis system—short-term (RMAPS-ST), we investigated impact of ATMS radiance data assimilation strong rainfall forecasts. Two groups experiments were conducted to forecast heavy precipitation over North China between 18 July 20 2016. initial conditions...

The Ensemble Transformation (ET) method and its variation ET-based Sensitivity (ETS) have been used in adaptive observation studies. However, the solution of ensemble transformation matrix ET ETS methods is not unique. A general mathematical formulation for derived then a generalized equation derived. It proved that previous special implementation newly formulation. Another practicable avoids calculating inverse some matrices proposed. This showed physically reasonable statistical...