scholarly journals Relating observations of contrail persistence to numerical weather analysis output

2009 ◽  
Vol 9 (4) ◽  
pp. 1357-1364 ◽  
Author(s):  
D. P. Duda ◽  
R. Palikonda ◽  
P. Minnis
Keyword(s):  
High Resolution ◽  
Wind Shear ◽  
Meteorological Data ◽  
Atmospheric Stability ◽  
Satellite Observations ◽  
Prediction System ◽  
Atmospheric Conditions ◽  
Advanced Regional Prediction System ◽  
Numerical Weather ◽  
Regional Prediction

Abstract. The potential for using high-resolution meteorological data from two operational numerical weather analyses (NWA) to diagnose and predict persistent contrail formation is evaluated using two independent contrail observation databases. Contrail occurrence statistics derived from surface and satellite observations between April 2004 and June 2005 are matched to the humidity, vertical velocity, wind shear and atmospheric stability derived from analyses from the Rapid Update Cycle (RUC) and the Advanced Regional Prediction System (ARPS) models. The relationships between contrail occurrence and the NWA-derived statistics are analyzed to determine under which atmospheric conditions persistent contrail formation is favored within NWAs. Humidity is the most important factor determining whether contrails are short-lived or persistent, and persistent contrails are more likely to appear when vertical velocities are positive. The model-derived atmospheric stability and wind shear do not appear to have a significant effect on contrail occurrence.

scholarly journals Relating observations of contrail persistence to numerical weather analysis output

2008 ◽  
Vol 8 (5) ◽  
pp. 18385-18407
Author(s):  
D. P. Duda ◽  
R. Palikonda ◽  
P. Minnis
Keyword(s):  
Meteorological Data ◽  
Atmospheric Stability ◽  
Quantitative Agreement ◽  
Atmospheric Conditions ◽  
Formation Theory ◽  
Advanced Regional Prediction System ◽  
Numerical Weather ◽  
Regional Prediction ◽  
Upper Limits ◽  
Upper Tropospheric Humidity

Abstract. The potential for using high-resolution meteorological data from two operational numerical weather analyses (NWA) to diagnose and predict persistent contrail formation is evaluated using two independent contrail observation databases. Contrail occurrence statistics derived from surface and satellite observations between April 2004 and June 2005 are matched to the humidity, vertical velocity, wind shear and atmospheric stability derived from analyses from the Rapid Update Cycle (RUC) and the Advanced Regional Prediction System (ARPS) models. The relationships between contrail occurrence and the NWA-derived statistics are analyzed to determine under which atmospheric conditions persistent contrail formation is favored within NWAs. Humidity is the most important factor determining whether contrails are short-lived or persistent, and persistent contrails are more likely to appear when vertical velocities are positive, and more likely to spread when the atmosphere is less stable. Although artificial upper limits on upper tropospheric humidity within the NWAs prevent a direct quantitative agreement of model data with contrail formation theory, logistic regression or similar statistical methods may improve the prediction of contrail occurrence.

scholarly journals Basic Diagnosis and Prediction of Persistent Contrail Occurrence Using High-Resolution Numerical Weather Analyses/Forecasts and Logistic Regression. Part II: Evaluation of Sample Models

2009 ◽  
Vol 48 (9) ◽  
pp. 1790-1802 ◽  
Author(s):  
David P. Duda ◽  
Patrick Minnis
Keyword(s):  
Relative Humidity ◽  
Wind Direction ◽  
Meteorological Data ◽  
Logistic Models ◽  
Satellite Observations ◽  
Lapse Rate ◽  
Prediction System ◽  
Advanced Regional Prediction System ◽  
Regional Prediction ◽  
Surface Models

Abstract A probabilistic forecast to accurately predict contrail formation over the conterminous United States (CONUS) is created by using meteorological data based on hourly meteorological analyses from the Advanced Regional Prediction System (ARPS) and the Rapid Update Cycle (RUC) combined with surface and satellite observations of contrails. Two groups of logistic models were created. The first group of models (SURFACE models) is based on surface-based contrail observations supplemented with satellite observations of contrail occurrence. The most common predictors selected for the SURFACE models tend to be related to temperature, relative humidity, and wind direction when the models are generated using RUC or ARPS analyses. The second group of models (OUTBREAK models) is derived from a selected subgroup of satellite-based observations of widespread persistent contrails. The most common predictors for the OUTBREAK models tend to be wind direction, atmospheric lapse rate, temperature, relative humidity, and the product of temperature and humidity.

High-Resolution Large-Eddy Simulations of Flow in a Steep Alpine Valley. Part I: Methodology, Verification, and Sensitivity Experiments

2006 ◽  
Vol 45 (1) ◽  
pp. 63-86 ◽  
Author(s):  
Fotini Katopodes Chow ◽  
Andreas P. Weigel ◽  
Robert L. Street ◽  
Mathias W. Rotach ◽  
Ming Xue
Keyword(s):  
Land Use ◽  
Soil Moisture ◽  
High Resolution ◽  
Turbulence Models ◽  
Large Eddy Simulations ◽  
Swiss Alps ◽  
Advanced Regional Prediction System ◽  
Alpine Valley ◽  
Regional Prediction ◽  
Large Eddy

Abstract This paper investigates the steps necessary to achieve accurate simulations of flow over steep, mountainous terrain. Large-eddy simulations of flow in the Riviera Valley in the southern Swiss Alps are performed at horizontal resolutions as fine as 150 m using the Advanced Regional Prediction System. Comparisons are made with surface station and radiosonde measurements from the Mesoscale Alpine Programme (MAP)-Riviera project field campaign of 1999. Excellent agreement between simulations and observations is obtained, but only when high-resolution surface datasets are used and the nested grid configurations are carefully chosen. Simply increasing spatial resolution without incorporating improved surface data gives unsatisfactory results. The sensitivity of the results to initial soil moisture, land use data, grid resolution, topographic shading, and turbulence models is explored. Even with strong thermal forcing, the onset and magnitude of the upvalley winds are highly sensitive to surface processes in areas that are well outside the high-resolution domain. In particular, the soil moisture initialization on the 1-km grid is found to be crucial to the success of the finer-resolution predictions. High-resolution soil moisture and land use data on the 350-m-resolution grid also improve results. The use of topographic shading improves radiation curves during sunrise and sunset, but the effects on the overall flow are limited because of the strong lateral boundary forcing from the 1-km grid where terrain slopes are not well resolved. The influence of the turbulence closure is also limited because of strong lateral forcing and hence limited residence time of air inside the valley and because of the stable stratification, which limits turbulent stress to the lowest few hundred meters near the surface.

scholarly journals Progress toward High-Resolution, Real-Time Radiosonde Reports

2016 ◽  
Vol 97 (11) ◽  
pp. 2149-2161 ◽  
Author(s):  
Bruce Ingleby ◽  
Patricia Pauley ◽  
Alexander Kats ◽  
Jeff Ator ◽  
Dennis Keyser ◽  
...  
Keyword(s):  
High Resolution ◽  
Real Time ◽  
Numerical Weather Prediction ◽  
Meteorological Data ◽  
Weather Prediction ◽  
Vertical Resolution ◽  
Not Given ◽  
Rounding Errors ◽  
Numerical Weather

Abstract Some real-time radiosonde reports are now available with higher vertical resolution and higher precision than the alphanumeric TEMP code. There are also extra metadata; for example, the software version may indicate whether humidity corrections have been applied at the station. Numerical weather prediction (NWP) centers and other users need to start using the new Binary Universal Form for Representation of Meteorological Data (BUFR) reports because the alphanumeric codes are being withdrawn. TEMP code has various restrictions and complexities introduced when telecommunication speed and costs were overriding concerns; one consequence is minor temperature rounding errors. In some ways BUFR reports are simpler: the whole ascent should be contained in a single report. BUFR reports can also include the time and location of each level; an ascent takes about 2 h and the balloon can drift 100 km or more laterally. This modernization is the largest and most complex change to the worldwide reporting of radiosonde observations for many years; international implementation is taking longer than planned and is very uneven. The change brings both opportunities and challenges. The biggest challenge is that the number and quality of the data from radiosonde ascents may suffer if the assessment of the BUFR reports and two-way communication between data producers and data users are not given the priority they require. It is possible that some countries will only attempt to replicate the old reports in the new format, not taking advantage of the benefits, which include easier treatment of radiosonde drift and a better understanding of instrument and processing details, as well as higher resolution.

Parallel weather modeling with the advanced regional prediction system

1997 ◽  
Vol 23 (14) ◽  
pp. 2243-2256 ◽  
Author(s):  
A. Sathye ◽  
M. Xue ◽  
G. Bassett ◽  
K. Droegemeier
Keyword(s):  
Prediction System ◽  
Advanced Regional Prediction System ◽  
Regional Prediction ◽  
Weather Modeling
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