scholarly journals Combining a Cloud-Resolving Model with Satellite for Cloud Process Model Simulation Validation

2014 ◽  
Vol 53 (2) ◽  
pp. 521-533 ◽  
Author(s):  
Renato G. Negri ◽  
Luiz A. T. Machado ◽  
Stephen English ◽  
Mary Forsythe
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Process Model ◽  
Model Simulation ◽  
Numerical Models ◽  
Tropical Convection ◽  
Infrared Observation ◽  
Cloud Resolving Model ◽  
The Uk ◽  
High Level

AbstractAdvances in computer power have made it possible to increase the spatial resolution of regional numerical models to a scale encompassing larger convective elements of less than 5 km in size. One goal of high resolution is to begin to resolve convective processes, and therefore it is necessary to evaluate the realism of convective clouds resolved explicitly at this resolution. This paper presents a method that is based on satellite comparisons to examine the simulation of continental tropical convection over Africa, in a high-resolution integration of the Met Office Unified Model (UK UM), developed under the Cascade project. The spatial resolution of these simulations is 1.5 km, the temporal resolution is 15 min, and the convection is resolved explicitly. The Spinning Enhanced Visible and Infrared Imager (SEVIRI) radiometer measurements were simulated by the Radiative Transfer for the Television and Infrared Observation Satellite (TIROS) Operational Vertical Sounder (RTTOV) model, and then a comparison between the simulations and real SEVIRI measurements was performed. The analysis using the presented method shows that the UK UM can represent tropical convection dynamics realistically. However, an error has been found in the high-level humidity distribution, which is characterized by strong humidity gradients. A key point of this paper is to present a method for establishing the credibility of a convection-permitting model by direct comparison with satellite data.

scholarly journals The Cloud-resolving model Radar SIMulator (CR-SIM) Version 3.3: description and applications of a virtual observatory

2020 ◽  
Vol 13 (4) ◽  
pp. 1975-1998 ◽  
Author(s):  
Mariko Oue ◽  
Aleksandra Tatarevic ◽  
Pavlos Kollias ◽  
Dié Wang ◽  
Kwangmin Yu ◽  
...  
Keyword(s):  
High Resolution ◽  
Climate Models ◽  
Model Simulation ◽  
Atmospheric Model ◽  
Cloud Microphysics ◽  
Virtual Observatory ◽  
Design Strategies ◽  
Modeling Framework ◽  
Cloud Resolving Model ◽  
Radar Simulator

Abstract. Ground-based observatories use multisensor observations to characterize cloud and precipitation properties. One of the challenges is how to design strategies to best use these observations to understand these properties and evaluate weather and climate models. This paper introduces the Cloud-resolving model Radar SIMulator (CR-SIM), which uses output from high-resolution cloud-resolving models (CRMs) to emulate multiwavelength, zenith-pointing, and scanning radar observables and multisensor (radar and lidar) products. CR-SIM allows for direct comparison between an atmospheric model simulation and remote-sensing products using a forward-modeling framework consistent with the microphysical assumptions used in the atmospheric model. CR-SIM has the flexibility to easily incorporate additional microphysical modules, such as microphysical schemes and scattering calculations, and expand the applications to simulate multisensor retrieval products. In this paper, we present several applications of CR-SIM for evaluating the representativeness of cloud microphysics and dynamics in a CRM, quantifying uncertainties in radar–lidar integrated cloud products and multi-Doppler wind retrievals, and optimizing radar sampling strategy using observing system simulation experiments. These applications demonstrate CR-SIM as a virtual observatory operator on high-resolution model output for a consistent comparison between model results and observations to aid interpretation of the differences and improve understanding of the representativeness errors due to the sampling limitations of the ground-based measurements. CR-SIM is licensed under the GNU GPL package and both the software and the user guide are publicly available to the scientific community.

scholarly journals Numerical simulation of "An American Haboob"

2013 ◽  
Vol 13 (10) ◽  
pp. 26175-26215 ◽  
Author(s):  
A. Vukovic ◽  
M. Vujadinovic ◽  
G. Pejanovic ◽  
J. Andric ◽  
M. R. Kumjian ◽  
...  
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Dust Storm ◽  
Sonoran Desert ◽  
Vegetation Index ◽  
Model Simulation ◽  
Numerical Models ◽  
Horizontal Resolution ◽  
Dust Concentration ◽  
Dust Events

Abstract. A dust storm of fearful proportions hit Phoenix in the early evening hours of 5 July 2011. This storm, an American haboob, was predicted hours in advance because numerical, land-atmosphere modeling, computing power and remote sensing of dust events have improved greatly over the past decade. High resolution numerical models are required for accurate simulation of the small-scales of the haboob process, with high velocity surface winds produced by strong convection and severe downbursts. Dust productive areas in this region consist mainly of agricultural fields, with soil surfaces disturbed by plowing and tracks of land in the high Sonoran desert laid barren by ongoing draught. Model simulation of the 5 July 2011 dust storm uses the coupled atmospheric-dust model NMME-DREAM with 3.5 km horizontal resolution. A mask of the potentially dust productive regions is obtained from the land cover and the Normalized Difference Vegetation Index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS). Model results are compared with radar and other satellite-based images and surface meteorological and PM10 observations. The atmospheric model successfully hindcasted the position of the front in space and time, with about 1 h late arrival in Phoenix. The dust model predicted the rapid uptake of dust and high values of dust concentration in the ensuing storm. South of Phoenix, over the closest source regions (~ 25 km), the model PM10 surface dust concentration reached ~ 2500 μg m−3, but underestimated the values measured by the PM10stations within the city. Model results are also validated by the MODIS aerosol optical depth (AOD), employing deep blue (DB) algorithms for aerosol loadings. Model validation included Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), equipped with the lidar instrument, to disclose the vertical structure of dust aerosols as well as aerosol subtypes. Promising results encourage further research and application of high-resolution modeling and satellite-based remote sensing to warn of approaching severe dust events and reduce risks for safety and health.

scholarly journals Numerical simulation of "an American haboob"

2014 ◽  
Vol 14 (7) ◽  
pp. 3211-3230 ◽  
Author(s):  
A. Vukovic ◽  
M. Vujadinovic ◽  
G. Pejanovic ◽  
J. Andric ◽  
M. R. Kumjian ◽  
...  
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Dust Storm ◽  
Sonoran Desert ◽  
Mesoscale Model ◽  
Model Simulation ◽  
Numerical Models ◽  
Atmospheric Model ◽  
Dust Concentration ◽  
Dust Events

Abstract. A dust storm of fearful proportions hit Phoenix in the early evening hours of 5 July 2011. This storm, an American haboob, was predicted hours in advance because numerical, land–atmosphere modeling, computing power and remote sensing of dust events have improved greatly over the past decade. High-resolution numerical models are required for accurate simulation of the small scales of the haboob process, with high velocity surface winds produced by strong convection and severe downbursts. Dust productive areas in this region consist mainly of agricultural fields, with soil surfaces disturbed by plowing and tracks of land in the high Sonoran Desert laid barren by ongoing draught. Model simulation of the 5 July 2011 dust storm uses the coupled atmospheric-dust model NMME–DREAM (Non-hydrostatic Mesoscale Model on E grid, Janjic et al., 2001; Dust REgional Atmospheric Model, Nickovic et al., 2001; Pérez et al., 2006) with 4 km horizontal resolution. A mask of the potentially dust productive regions is obtained from the land cover and the normalized difference vegetation index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS). The scope of this paper is validation of the dust model performance, and not use of the model as a tool to investigate mechanisms related to the storm. Results demonstrate the potential technical capacity and availability of the relevant data to build an operational system for dust storm forecasting as a part of a warning system. Model results are compared with radar and other satellite-based images and surface meteorological and PM10 observations. The atmospheric model successfully hindcasted the position of the front in space and time, with about 1 h late arrival in Phoenix. The dust model predicted the rapid uptake of dust and high values of dust concentration in the ensuing storm. South of Phoenix, over the closest source regions (~25 km), the model PM10 surface dust concentration reached ~2500 μg m−3, but underestimated the values measured by the PM10 stations within the city. Model results are also validated by the MODIS aerosol optical depth (AOD), employing deep blue (DB) algorithms for aerosol loadings. Model validation included Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), equipped with the lidar instrument, to disclose the vertical structure of dust aerosols as well as aerosol subtypes. Promising results encourage further research and application of high-resolution modeling and satellite-based remote sensing to warn of approaching severe dust events and reduce risks for safety and health.

scholarly journals The Cloud Resolving Model Radar Simulator (CR-SIM) Version 3.2: Description and Applications of a Virtual Observatory

2019 ◽  
Author(s):  
Mariko Oue ◽  
Aleksandra Tatarevic ◽  
Pavlos Kollias ◽  
Dié Wang ◽  
Kwangmin Yu ◽  
...  
Keyword(s):  
High Resolution ◽  
Numerical Model ◽  
Prediction Models ◽  
Model Simulation ◽  
Sampling Strategy ◽  
Virtual Observatory ◽  
Design Strategies ◽  
Modeling Framework ◽  
Cloud Resolving Model ◽  
Radar Simulator

Abstract. Ground-based observatories use multi-sensor observations to characterize cloud and precipitation properties. A challenge is how to design strategies to best use these observations to understand the atmosphere and evaluate atmospheric numerical prediction models. This paper introduces the Cloud resolving model Radar SIMulator (CR-SIM), which uses output from high-resolution atmospheric models to emulate multi-wavelength, zenith-pointing, and scanning radar observables and multi-sensor (multi-radar and radar-lidar) integrated products. CR-SIM allows comparisons of the same variables between an atmospheric model simulation and remote sensing products using a forward modeling framework consistent with the microphysical assumptions used in the numerical model simulations. In this paper, we present several applications of CR-SIM for evaluation of a numerical model, quantification of retrieval uncertainty, and optimization of radar sampling strategy using observing system simulation experiments. These applications demonstrate that the application of CR-SIM as a virtual observatory operator on high-resolution model output helps interpret the differences between model results and observations and also improve under-standing of the representativeness errors due to the sampling limitations of the ground-based observatories. CR-SIM is licensed under the GNU GPL package and both the software and the user guide are freely available to scientific community.

scholarly journals High-resolution stream network delineation using digital elevation models: assessing the spatial accuracy

2018 ◽  
Author(s):  
Giuseppe Amatulli ◽  
Sami Domisch ◽  
Jens Kiesel ◽  
Tushar Sethi ◽  
Dai Yamazaki ◽  
...  
Keyword(s):  
High Resolution ◽  
Digital Elevation Model ◽  
Spatial Resolution ◽  
Global Scale ◽  
Spatial Accuracy ◽  
Stream Network ◽  
Digital Elevation ◽  
Elevation Model ◽  
High Level ◽  
Unites States

We used the hydrologically corrected Multi-Error- Removed Improved-Terrain Digital Elevation Model at a 3 arc- second (90 m) spatial resolution to derive a seamless, standardized stream network by using GRASS-GIS hydrological modules. We compared the spatial accuracy of the derived stream network with the NHDPlusV2 dataset across the conterminous Unites States. The results demonstrate that spatial accuracy is in the order of 1 pixel displacement compared to the NHDPlusV2 locations, indicating a high level of accuracy. The implemented methodology will be extended to a global scale hydrography in an upcoming project.

scholarly journals High-resolution stream network delineation using digital elevation models: assessing the spatial accuracy

2018 ◽  
Author(s):  
Giuseppe Amatulli ◽  
Sami Domisch ◽  
Jens Kiesel ◽  
Tushar Sethi ◽  
Dai Yamazaki ◽  
...  
Keyword(s):  
High Resolution ◽  
Digital Elevation Model ◽  
Spatial Resolution ◽  
Global Scale ◽  
Spatial Accuracy ◽  
Stream Network ◽  
Digital Elevation ◽  
Elevation Model ◽  
High Level ◽  
Unites States

We used the hydrologically corrected Multi-Error- Removed Improved-Terrain Digital Elevation Model at a 3 arc- second (90 m) spatial resolution to derive a seamless, standardized stream network by using GRASS-GIS hydrological modules. We compared the spatial accuracy of the derived stream network with the NHDPlusV2 dataset across the conterminous Unites States. The results demonstrate that spatial accuracy is in the order of 1 pixel displacement compared to the NHDPlusV2 locations, indicating a high level of accuracy. The implemented methodology will be extended to a global scale hydrography in an upcoming project.

Evaluation of Tropical Cyclone Center Identification Methods in Numerical Models

2014 ◽  
Vol 142 (11) ◽  
pp. 4326-4339 ◽  
Author(s):  
Leon T. Nguyen ◽  
John Molinari ◽  
Diana Thomas
Keyword(s):  
High Resolution ◽  
Tropical Cyclone ◽  
Model Simulation ◽  
Numerical Models ◽  
Vortex Center ◽  
Identification Methods ◽  
Cyclone Center ◽  
Tangential Wind ◽  
Wind Profiles ◽  
Tropical Cyclone Center

Abstract Identifying the center of a tropical cyclone in a high-resolution model simulation has a number of operational and research applications, including constructing a track, calculating azimuthal means and perturbations, and diagnosing vortex tilt. This study evaluated several tropical cyclone center identification methods in a high-resolution Weather Research and Forecasting (WRF) Model simulation of a sheared, intensifying, asymmetric tropical cyclone. The simulated tropical cyclone (TC) contained downshear convective cells and a mesovortex embedded in a broader TC vortex, complicating the identification of the TC vortex center. It is shown that unlike other methods, the pressure centroid method consistently 1) placed the TC center within the region of weak storm-relative wind, 2) produced a smooth track, 3) yielded a vortex tilt that varied smoothly in magnitude and direction, and 4) was insensitive to changes in horizontal grid resolution. Based on these results, the authors recommend using the pressure centroid to define the TC center in high-resolution numerical models. The pressure centroid was calculated within a circular region representing the size of the TC inner core. To determine this area, the authors propose normalizing by the innermost radius at which the azimuthally averaged storm-relative tangential wind at 2-km height equals 80% of the maximum (R80) at 2-km height. Although compositing studies have often normalized by the radius of maximum wind (RMW), R80 proved less sensitive to slight changes in flat tangential wind profiles. This enables R80 to be used as a normalization technique not only with intense TCs having peaked tangential wind profiles, but also with weaker TCs having flatter tangential wind profiles.

ATTITUDE TO OPEN ACCESS IN RUSSIAN SCHOLARLY COMMUNITY: 2018. SURVEY RESULTS AND ANALYSIS

2018 ◽  
Vol 1 (1) ◽  
pp. 6-21 ◽  
Author(s):  
I. K. Razumova ◽  
N. N. Litvinova ◽  
M. E. Shvartsman ◽  
A. Yu. Kuznetsov
Keyword(s):  
Open Access ◽  
Open Access Publishing ◽  
Scholarly Community ◽  
Research Areas ◽  
Survey Results ◽  
The Difference ◽  
Policies And Programs ◽  
The Uk ◽  
High Level ◽  
Access Policies

Introduction. The paper presents survey results on the awareness towards and practice of Open Access scholarly publishing among Russian academics.Materials and Methods. We employed methods of statistical analysis of survey results. Materials comprise results of data processing of Russian survey conducted in 2018 and published results of the latest international surveys. The survey comprised 1383 respondents from 182 organizations. We performed comparative studies of the responses from academics and research institutions as well as different research areas. The study compares results obtained in Russia with the recently published results of surveys conducted in the United Kingdom and Europe.Results. Our findings show that 95% of Russian respondents support open access, 94% agree to post their publications in open repositories and 75% have experience in open access publishing. We did not find any difference in the awareness and attitude towards open access among seven reference groups. Our analysis revealed the difference in the structure of open access publications of the authors from universities and research institutes. Discussion andConclusions. Results reveal a high level of awareness and support to open access and succeful practice in the open access publications in the Russian scholarly community. The results for Russia demonstrate close similarity with the results of the UK academics. The governmental open access policies and programs would foster the practical realization of the open access in Russia.

Mapping and Monitoring of the Land Use/Cover Changes in the Wider Area of ltanos, Crete, Using Very High Resolution EO Imagery With Specific Interest in Archaeological Sites

2019 ◽  
Author(s):  
Sawyer Reid stippa ◽  
George Petropoulos ◽  
Leonidas Toulios ◽  
Prashant K. Srivastava
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Satellite Images ◽  
Archaeological Site ◽  
Digital Photography ◽  
Archaeological Sites ◽  
Large Area ◽  
High Resolution Imagery ◽  
Site Mapping ◽  
Rule Sets

Archaeological site mapping is important for both understanding the history as well as protecting them from excavation during the developmental activities. As archaeological sites generally spread over a large area, use of high spatial resolution remote sensing imagery is becoming increasingly applicable in the world. The main objective of this study was to map the land cover of the Itanos area of Crete and of its changes, with specific focus on the detection of the landscape’s archaeological features. Six satellite images were acquired from the Pleiades and WorldView-2 satellites over a period of 3 years. In addition, digital photography of two known archaeological sites was used for validation. An Object Based Image Analysis (OBIA) classification was subsequently developed using the five acquired satellite images. Two rule-sets were created, one using the standard four bands which both satellites have and another for the two WorldView-2 images their four extra bands included. Validation of the thematic maps produced from the classification scenarios confirmed a difference in accuracy amongst the five images. Comparing the results of a 4-band rule-set versus the 8-band showed a slight increase in classification accuracy using extra bands. The resultant classifications showed a good level of accuracy exceeding 70%. Yet, separating the archaeological sites from the open spaces with little or no vegetation proved challenging. This was mainly due to the high spectral similarity between rocks and the archaeological ruins. The satellite data spatial resolution allowed for the accuracy in defining larger archaeological sites, but still was a difficulty in distinguishing smaller areas of interest. The digital photography data provided a very good 3D representation for the archaeological sites, assisting as well in validating the satellite-derived classification maps. All in all, our study provided further evidence that use of high resolution imagery may allow for archaeological sites to be located, but only where they are of a suitable size archaeological features.

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