15 research outputs found
Management and display of four-dimensional environmental data sets using McIDAS
Over the past four years, great strides have been made in the areas of data management and display of 4-D meteorological data sets. A survey was conducted of available and planned 4-D meteorological data sources. The data types were evaluated for their impact on the data management and display system. The requirements were analyzed for data base management generated by the 4-D data display system. The suitability of the existing data base management procedures and file structure were evaluated in light of the new requirements. Where needed, new data base management tools and file procedures were designed and implemented. The quality of the basic 4-D data sets was assured. The interpolation and extrapolation techniques of the 4-D data were investigated. The 4-D data from various sources were combined to make a uniform and consistent data set for display purposes. Data display software was designed to create abstract line graphic 3-D displays. Realistic shaded 3-D displays were created. Animation routines for these displays were developed in order to produce a dynamic 4-D presentation. A prototype dynamic color stereo workstation was implemented. A computer functional design specification was produced based on interactive studies and user feedback
A Model for Calculating Desert Aerosol Turbidity Over the Oceans from Geostationary Satellite Data
A technique has been developed to infer the optical thickness of Saharan dust from Synchronous Meteorological Satellite (SMS) brightness measurements at visible wavelengths. The scattering model consists of an air layer, a dust layer and a lower boundary of variable albedo. Single-scatter properties of the dust computed from Mie theory were the basis for calculations by plane-parallel theory of radiative transfer in the dust layer. Radiative interactions between air and dust layers and the lower boundary were calculated with an adding version of the doubling scheme. Optical thickness was determined from satellite brightness measurements through a lookup table produced by the adding program. SMS visible sensors were calibrated from the prelaunch calibration measurements and measurements of sun and space. Error analysis and tests indicate a potential accuracy of âŒ0.1 unit of optical thickness. The main limits on accuracy are digitizing resolution of the SMS visible signals, and mistaking clouds for dust in the satellite imagery. This technique of inferring Saharan dust turbidity has been verified and fine-tuned using surface turbidity measurements during GATE and corresponding SMS imagery
2014 AMV intercomparison study report (comparison of NWC SAF/HRW AMVswith AMVs from other producers)
Previous Atmospheric Motion Vector (AMV) intercomparison studies, conducted from 2007 to 2009, compared the operational AMV algorithms of various satellite-derived wind producers using a common set of MSG/SEVIRI images and ancillary data. The studies assessed how the cloudy AMVs from the unique wind producers compared in terms of coverage, speed, direction, and cloud height
(Genkova et al. 2008; Genkova et al. 2010).
The goal of this new study is to:
· Include the NWC SAF/HRW algorithm in the intercomparison study in order to quantify its performance relative to the other AMV algorithms.
· Update the results of the previous AMV intercomparison studies because many of the operational AMV algorithms have changed since the last study.
· Perform follow up studies as identified in the previous intercomparison work, such as considering specific characteristics of the input data and AM
System for Analysis of Wind Collocations (SAWC): A Novel Archive and Collocation Software Application for the Intercomparison of Winds from Multiple Observing Platforms
Accurate atmospheric 3D wind observations are a high priority in the science
community. To address this requirement and to support researchers' needs to
acquire and analyze wind data from multiple sources, the System for Analysis of
Wind Collocations (SAWC) was jointly developed by NOAA/NESDIS/STAR,
UMD/ESSIC/CISESS, and UW-Madison/CIMSS. SAWC encompasses a multi-year archive
of global 3D winds observed by Aeolus, sondes, aircraft, stratospheric
superpressure balloons, and satellite-derived atmospheric motion vectors,
archived and uniformly formatted in netCDF for public consumption; identified
pairings between select datasets collocated in space and time; and a
downloadable software application developed for users to interactively
collocate and statistically compare wind observations based on their research
needs. The utility of SAWC is demonstrated by conducting a one-year (September
2019-August 2020) evaluation of Aeolus level-2B (L2B) winds (Baseline 11 L2B
processor version). Observations from four archived conventional wind datasets
are collocated with Aeolus. Recommended quality controls are applied. Wind
comparisons are assessed using the SAWC collocation application. Comparison
statistics are stratified by season, geographic region, and Aeolus observing
mode. The results highlight the value of SAWC's capabilities, from product
validation through intercomparison studies to the evaluation of data usage in
applications and advances in the global Earth observing architectureComment: 20 pages, 13 figures, 6 table
Third AMV Intercomparison Study
Ponencias presentadas en: 14th International Winds Workshop celebradas en Jeju City, Corea de Sur, del 23 al 27 de abril de 2018.This study is a continuation and update of the previous â2014 AMV Intercomparison studyâ, presented in the 12th International Winds Workshop in Copenhagen in 2014.
In this continuation, Atmospheric Motion Vectors (AMVs) calculated with Japan Meteorological Agencyâs Himawari-8 satellite data are compared, considering two different input datasets with two different image triplets for 21 July 2016. Image data are equivalent to those used by the âInternational Cloud Working Group (ICWG) Cloud Intercomparison studyâ, to improve synergies between both studies. The different centers use a prescribed configuration and their own configuration for the AMV production with these datasets.
Six different institutions participated in the study (CPTEC/INPE, EUMETSAT, JMA, KMA, NOAA and NWCSAF). This paper is a summary of the full âAMV Intercomparison Technical Reportâ, which can be found at: http://www.nwcsaf.org/aemetRest/downloadAttachment/5284. The study has been updated in November 2018 with two new datasets from EUMETSAT and KMA, which correct two issues related with the âCommon Quality Index (QIC)â and the âHeight assignmentâ respectively.The International Winds Working Group (IWWG) wants to thank EUMETSAT, the Satellite Application Facility on support to Nowcasting (NWCSAF) and Agencia Estatal de MeteorologĂa (AEMET) for the funding and support of this project
A new atmospheric motion vector intercomparison study
Ponencias presentadas en: 12th International Winds Workshop, Copenhagen, Denmark (15-20 June 2014)This study furthers a line of previously completed research regarding the similarities and differences between the operational Atmospheric Motion Vector (AMV) algorithms of various satellite-derived wind producers. By using a common set of MSG/SEVIRI images and ancillary data, past intercomparison studies assessed how the cloudy AMVs from each unique wind producer compared in terms of coverage, speed, direction, and cloud height (Genkova et al. 2008; Genkova et al. 2010). The current study focuses on including the CMA and NWC SAF AMV algorithms in the intercomparison in order to quantify its performance relative to other AMV algorithms, on updating the results of the previous AMV intercomparison studies due to the changes that have occurred since 2009, and lastly, on performing follow up studies, identified in the previous intercomparison work, to analyze particular issues in pursuance of a more complete understanding of how the different AMV algorithms compare
2018 Atmospheric Motion Vector (AMV): intercomparison study
Atmospheric Motion Vectors (AMVs) calculated by six different institutions (Brazil Center for Weather Prediction and Climate Studies/CPTEC/INPE, European Organization for the Exploitation of Meteorological Satellites/EUMETSAT, Japan Meteorological Agency/JMA, Korea Meteorological Administration/KMA, Unites States National Oceanic and Atmospheric Administration/NOAA, and the Satellite Application Facility on Support to Nowcasting and Very short range forecasting/NWCSAF) with JMAâs Himawari-8 satellite data and other common input data are here compared. The comparison is based on two different AMV input datasets, calculated with two different image triplets for 21 July 2016, and the use of a prescribed and a specific configuration. The main results of the study are summarized as follows: (1) the differences in the AMV datasets depend very much on the âAMV height assignmentâ used and much less on the use of a prescribed or specific configuration; (2) the use of the âCommon Quality Indicator (CQI)â has a quantified skill in filtering collocated AMVs for an improved statistical agreement between centers; (3) Among the six AMV operational algorithms verified by this AMV Intercomparison, JMA AMV algorithm has the best overall performance considering all validation metrics, mainly due to its new height assignment method: âOptimal estimation method considering the observed infrared radiances, the vertical profile of the Numerical Weather Prediction wind, and the estimated brightness temperature using a radiative transfer modelâ.The âSpace Science and Engineering Centerâ (SSEC) of the âUniversity ofWisconsin-Madisonâ (UW) was funded to do this research by the âEuropean Organization for the Exploitation of Meteorological Satellites (EUMETSAT)â, through the âSatellite Application Facility on Support to Nowcasting and Very short range forecasting (NWCSAF)â âVisiting Scientist Activity (VSA)â program
Demonstration and Evaluation of 3D Winds Generated by Tracking Features in Moisture and Ozone Fields Derived from AIRS Sounding Retrievals
For more than 15 years, polar winds from the Moderate Resolution Imaging Spectroradiometer (MODIS) imagery have been generated by the National Oceanic and Atmospheric Administration (NOAA) and the Cooperative Institute for Meteorological Satellite Studies (CIMSS). These datasets are a NOAA National Environmental Satellite, Data, and Information Service (NESDIS) operational satellite product that is used at more than 10 major numerical weather prediction (NWP) centers worldwide. The MODIS polar winds product is composed of both infrared window (IR-W) and water vapor (WV) tracked features. The WV atmospheric motion vectors (AMV) yield a better spatial distribution than the IR-W since both cloud and clear-sky features can be tracked in the WV images. As the new generation polar satellite-era begins with the Suomi National Polar-orbiting Partnership (S-NPP), there is currently no WV channel on the Visible/Infrared Imager/Radiometer Suite (VIIRS), resulting in a data gap with only IR-W derived AMVs possible. This scenario presents itself as an opportunity to evaluate hyperspectral infrared moisture retrievals from consecutive overlapping satellite polar passes to extract atmospheric motion from clear-sky regions on constant (and known) pressure surfaces, i.e., estimating winds in retrieval space rather than radiance space. Perhaps most significantly, this method has the potential to provide vertical wind profiles, as opposed to the current MODIS-derived single-level AMVs. In this study, the winds technique is applied to Atmospheric Infrared Sounder (AIRS) moisture retrievals from NASA’s Aqua satellite. The resulting winds are assimilated into the Goddard Earth Observing System Model, Version 5 (GEOS-5). The results are encouraging, as the AIRS retrieval polar AMVs have a similar quality as the MODIS AMVs and exhibit a positive impact in the hemispheric Day 4.5 to 6.5 forecasts for a one-month experiment in July 2012