A Progress Report on the Development of the High-Resolution Rapid Refresh Ensemble

AbstractThe High-Resolution Rapid Refresh Ensemble (HRRRE) is a 36-member ensemble analysis system with nine forecast members that utilizes the Advanced Research Weather Research and Forecasting (ARW-WRF) dynamic core and the physics suite from the operational Rapid Refresh/High-Resolution Rapid Refresh deterministic modeling system. A goal of HRRRE development is a system with sufficient spread amongst members, comparable in magnitude to the random error in the ensemble mean, to represent the range of possible future atmospheric states. HRRRE member diversity has traditionally been obtained by perturbing the initial and lateral boundary conditions of each member, but recent development has focused on implementing stochastic approaches in HRRRE to generate additional spread. These techniques were tested in retrospective experiments and in the May 2019 Hazardous Weather Testbed Spring Experiment (HWT-SE). Results show a 6–25% increase in the ensemble spread in 2-m temperature, 2-m mixing ratio, and 10-m wind speed when stochastic parameter perturbations are used in HRRRE (HRRRE-SPP). Case studies from HWT-SE demonstrate that HRRRE-SPP performed similar to or better than the operational High-Resolution Ensemble Forecast system version 2 (HREFv2) and the non-stochastic HRRRE. However, subjective evaluations provided by HWT-SE forecasters indicated that overall, HRRRE-SPP predicted lower probabilities of severe weather (using updraft helicity as a proxy) compared to HREFv2. A statistical analysis of the performance of HRRRE-SPP and HREFv2 from the 2019 summer convective season supports this claim, but also demonstrates that the two systems have similar reliability for prediction of severe weather using updraft helicity.

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A Performance Comparison between Multiphysics and Stochastic Approaches within a North American RAP Ensemble

Monthly Weather Review ◽

10.1175/mwr-d-16-0160.1 ◽

2017 ◽

Vol 145 (4) ◽

pp. 1161-1179 ◽

Cited By ~ 25

Author(s):

Isidora Jankov ◽

Judith Berner ◽

Jeffrey Beck ◽

Hongli Jiang ◽

Joseph B. Olson ◽

...

Keyword(s):

Stochastic Perturbation ◽

Performance Comparison ◽

Added Value ◽

Stochastic Methods ◽

Weather Research And Forecasting ◽

Attractive Alternative ◽

Forecast Performance ◽

Parameterization Schemes ◽

Stochastic Parameter ◽

Parameter Perturbations

Abstract A stochastic parameter perturbation (SPP) scheme consisting of spatially and temporally varying perturbations of uncertain parameters in the Grell–Freitas convective scheme and the Mellor–Yamada–Nakanishi–Niino planetary boundary scheme was developed within the Rapid Refresh ensemble system based on the Weather Research and Forecasting Model. Alone the stochastic parameter perturbations generate insufficient spread to be an alternative to the operational configuration that utilizes combinations of multiple parameterization schemes. However, when combined with other stochastic parameterization schemes, such as the stochastic kinetic energy backscatter (SKEB) scheme or the stochastic perturbation of physics tendencies (SPPT) scheme, the stochastic ensemble system has comparable forecast performance. An additional analysis quantifies the added value of combining SPP and SPPT over an ensemble that uses SPPT only, which is generally beneficial, especially for surface variables. The ensemble combining all three stochastic methods consistently produces the best spread–skill ratio and generally outperforms the multiphysics ensemble. The results of this study indicate that using a single-physics suite ensemble together with stochastic methods is an attractive alternative to multiphysics ensembles and should be considered in the design of future high-resolution regional and global ensembles.

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Warning Information in a Preconvection Environment from the Geostationary Advanced Infrared Sounding System—A Simulation Study Using the IHOP Case

Journal of Applied Meteorology and Climatology ◽

10.1175/2010jamc2441.1 ◽

2011 ◽

Vol 50 (3) ◽

pp. 776-783 ◽

Cited By ~ 21

Author(s):

Jun Li ◽

Jinlong Li ◽

Jason Otkin ◽

Timothy J. Schmit ◽

Chian-Yi Liu

Keyword(s):

High Resolution ◽

Simulation Study ◽

Model Simulation ◽

Weather Research And Forecasting ◽

Forecasting Model ◽

High Temporal Resolution ◽

Potential Utility ◽

Convective Initiation ◽

System A ◽

Atmospheric Data

Abstract In this paper, a convective initiation event from the International H2O Project (IHOP) field experiment is used to demonstrate the potential utility of a future geostationary advanced infrared (IR) sounder for severe storm nowcasting applications. An advanced IR sounder would provide detailed stability information (e.g., lifted index and other parameters) with high temporal resolution useful for determining favorable locations for convective initiation. Atmospheric data from a high-resolution Weather Research and Forecasting model simulation was used to generate simulated Hyperspectral Environmental Suite (HES) and Advanced Baseline Imager (ABI) stability products. Comparison of these products shows that the ABI [or the current Geostationary Operational Environmental Satellite (GOES) Sounder] provides limited stability information before the storm development as a result of the limited spectral IR information for temperature and moisture profiling. The high spatial and temporal geostationary advanced IR sounder, however, can provide critical information about the destabilization much earlier than the current GOES Sounder or ABI.

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Evaluating NARCCAP model performance for frequencies of severe-storm environments

Advances in Statistical Climatology Meteorology and Oceanography ◽

10.5194/ascmo-2-137-2016 ◽

2016 ◽

Vol 2 (2) ◽

pp. 137-153 ◽

Cited By ~ 4

Author(s):

Eric Gilleland ◽

Melissa Bukovsky ◽

Christopher L. Williams ◽

Seth McGinnis ◽

Caspar M. Ammann ◽

...

Keyword(s):

Climate Change ◽

High Resolution ◽

Spatial Patterns ◽

Climate Models ◽

Severe Weather ◽

Severe Storm ◽

Distributional Properties ◽

The Impact ◽

Verification Techniques ◽

Better Than

Abstract. An important topic for climate change investigation is the behavior of severe weather under future scenarios. Given the fine-scale nature of the phenomena, such changes can only be analyzed indirectly, for example, through large-scale indicators of environments conducive to severe weather. Climate models can account for changing physics over time, but if they cannot capture the relevant distributional properties of the current climate, then their use for inferring future regimes is limited. In this study, high-resolution climate models from the North American Regional Climate Change Assessment Program (NARCCAP) are evaluated for the present climate state using cutting-edge spatial verification techniques recently popularized in the meteorology literature. While climate models are not intended to predict variables on a day-by-day basis, like weather models, they should be expected to mimic distributional properties of these processes, which is how they are increasingly used and therefore this study assesses the degree to which the models are actually suitable for this purpose. Of particular value for social applications would be to better simulate extremes, rather than inferring means of variables, which may only change by small increments thereby making it difficult to interpret in terms of the impact on society. In this study, it is found that the relatively high-resolution NARCCAP climate model runs capture areas, spatial patterns, and placement of the most common severe-storm environments reasonably well, but all of them underpredict the spatial extent of these high-frequency zones. Some of the models generally perform better than others, but some models capture spatial patterns of the highest frequency severe-storm environment areas better than they do more moderate frequency regions.

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Digital Processing of STEM Images

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100097752 ◽

1981 ◽

Vol 39 ◽

pp. 236-237

Author(s):

A. V. Crewe ◽

M. Ohtsuki

Keyword(s):

High Resolution ◽

Low Dose ◽

Assembly Language ◽

Processing System ◽

Principal Component ◽

Digital Processing ◽

Image Analysis System ◽

Black And White ◽

Analysis System ◽

Dose Imaging

We have assembled an image processing system for use with our high resolution STEM for the particular purpose of working with low dose images of biological specimens. The system is quite flexible, however, and can be used for a wide variety of images.The original images are stored on magnetic tape at the microscope using the digitized signals from the detectors. For low dose imaging, these are “first scan” exposures using an automatic montage system. One Nova minicomputer and one tape drive are dedicated to this task.The principal component of the image analysis system is a Lexidata 3400 frame store memory. This memory is arranged in a 640 x 512 x 16 bit configuration. Images are displayed simultaneously on two high resolution monitors, one color and one black and white. Interaction with the memory is obtained using a Nova 4 (32K) computer and a trackball and switch unit provided by Lexidata.The language used is BASIC and uses a variety of assembly language Calls, some provided by Lexidata, but the majority written by students (D. Kopf and N. Townes).

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High-resolution electron microscopy of Cu2O surfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143584 ◽

1986 ◽

Vol 44 ◽

pp. 396-397

Author(s):

V. Castano ◽

W. Krakow

Keyword(s):

High Resolution ◽

Natural Extension ◽

High Resolution Electron Microscopy ◽

Point Of View ◽

Initial Oxidation ◽

System A ◽

Resolution Electron ◽

Surface Reconstructions ◽

Atomic Surface ◽

Au Thin Films

In non-UHV microscope environments atomic surface structure has been observed for flat-on for various orientations of Au thin films and edge-on for columns of atoms in small particles. The problem of oxidation of surfaces has only recently been reported from the point of view of high resolution microscopy revealing surface reconstructions for the Ag2O system. A natural extension of these initial oxidation studies is to explore other materials areas which are technologically more significant such as that of Cu2O, which will now be described.

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Automated high-resolution microscopy: the approaches so far

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100125312 ◽

1987 ◽

Vol 45 ◽

pp. 58-61

Author(s):

W. O. Saxton

Keyword(s):

High Resolution ◽

Early Stage ◽

Automatic Recording ◽

Microprocessor Control ◽

Alternative Systems ◽

Electron Image ◽

Complete Automation ◽

Analysis System ◽

High Resolution Microscopy

Recent commercial microscopes with internal microprocessor control of all major functions have already demonstrated some of the benefits anticipated from such systems, such as continuous magnification, rotation-free diffraction and magnification, automatic recording of mutually registered focal series, and fewer control knobs. Complete automation of the focusing, stigmating and alignment of a high resolution microscope, allowing focal series to be recorded at preselected focus values as well, is still imminent rather than accomplished, however; some kind of image pick-up and analysis system, fed with the electron image via a TV camera, is clearly essential for this, but several alternative systems and algorithms are still being explored. This paper reviews the options critically in turn, and stresses the need to consider alignment and focusing at an early stage, and not merely as an optional extension to a basic proposal.

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Application Fuzzy Logic System for Accurate Sheet Trim Shower Position

ACMIT Proceedings ◽

10.33555/acmit.v3i1.43 ◽

2019 ◽

Vol 3 (1) ◽

pp. 186-192

Author(s):

Yudi Wibawa

Keyword(s):

Fuzzy Logic ◽

Fuzzy Logic Controller ◽

Dc Motor ◽

Automation System ◽

Paper Making ◽

System A ◽

Accurate Position ◽

And Performance ◽

Better Than ◽

Logic System

This paper aims to study for accurate sheet trim shower position for paper making process. An accurate position is required in an automation system. A mathematical model of DC motor is used to obtain a transfer function between shaft position and applied voltage. PID controller with Ziegler-Nichols and Hang-tuning rule and Fuzzy logic controller for controlling position accuracy are required. The result reference explains it that the FLC is better than other methods and performance characteristics also improve the control of DC motor.

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