Contrail forecasting è un software che permette di prevedere la formazione e persistenza di scie di condensazione rilasciate dai motori degli aerei ,sia a pistoni, sia a reazione, sulla base dei dati meteo forniti dai radiosondaggi (pressione,umidità relativa,temperatura) e dalla tipologia di motori utilizzati.
Questo programma nasce dal lavoro svolto da Mark Schrader nel 1997 (1) che adattando ai motori di ultima generazione il metodo classico sviluppato da Appleman nel 1953 (2) ha reso più attendibile il forecasting delle contrails.
Novità di quest'ultima release è la correzione del valore di umidità relativa rilevato dalle radiosonde RS92 subject to misstatement due to the heating produced by the sun on the sensor, the difference between measured value and actual value is called the "dry bias" and find extensive documentation on the net (3.4).
The correction algorithm SOLAR RADIATION ERROR (SRE) was developed in 2009 by LMMiloshevich (5) taking into account the atmospheric pressure, relative humidity and measured the angle of solar elevation on the date / time / place of sondaggio.Come indicated by the same author this method should not be applied when the timetable of this survey is a cloud cover as this alters the ill-defined correction value.
The implementation of the correction in the program is a collaborative effort between myself and that Markogts sincerely thank you!
How to use the software
In startup you can select the method of forecasting stardand (already present in earlier versions) or the adjusted value of rh only valid for the Vaisala RS92 radiosonde.
The input data such as pressure, relative humidity and temperature can be obtained from the following link by selecting location, date and time of the survey:
The contrail factor must be selected from the following types of engines:
Appleman ORIGINAL (CF = 0.0336)
NOT BYPASS (CF = 0.0300) propeller engines
LOW BYPASS (CF = 0.0340) jet engines of the first and second generation characteristic of the aircraft built in the 70s (eg MD80)
HIGH BYPASS (CF = 0.039) next-generation jet engines present on all modern commercial aircraft and military transport
If
you select the method with correction for rs92 is also required for the elevation angle of the sun always the date, time and place of surveys that can be derived here
Some details of the radiosonde
The Italian station carrying out soundings through the launch of at least two balloons a day (at 00 and 12Z) are:
Cuneo-Levaldigi RS92 RS92
Milan-Linate
Campoformido Udine-RS90 / RS92
St Peter Capofiume RS92 RS92
Pratica di Mare
Brindisi RS90 / RS92
Trapani RS90 RS92
Cagliari-Elmas
Milan-Linate
Campoformido Udine-RS90 / RS92
St Peter Capofiume RS92 RS92
Pratica di Mare
Brindisi RS90 / RS92
Trapani RS90 RS92
Cagliari-Elmas
The station data / radiosonde model is updated to May 2009.
HERE you can find more details on Soundings STATIONS HERE IN ITALY while describes how to derive the model of a specific radiosonde radiosonde you want to use.
GOOD USE!
Referenze:
(1) - Schrader, M.L., 1997: Calculations of Aircraft Contrail Formation Critical Temperatures . J. Appl. Meteor. , 36 , 1725–1729.
(2) - Appleman, H., 1953: The formation of exhaust condensation trails by jet aircraft . Bull. Amer. Meteor. Soc., 34, 14–20.
(3) - Vömel, H., H. Selkirk, L. Miloshevich, J. Valverde-Canossa, J. Valdés, E. Kyrö, R. Kivi, W. Stolz, G. Peng, and J.A. Diaz, 2007: Radiation Dry Bias of the Vaisala RS92 Humidity Sensor . J. Atmos. Oceanic Technol. , 24 , 953–963.
(4) - K. Yoneyama, M.fujita, N.Sato, M.Fujiwara, Y.Inai, and F.Hasebe, 2008: Correction for Radiation Dry Bias Found in RS92 Radiosonde Data during the MISMO Field Experiment . SOLA, Vol.4, 13-16.
(5) - ( 2009 ), Accuracy assessment and correction of Vaisala RS92 radiosonde Measurements water vapor, J. Geophys. Res , 114, D11305, doi: 10.1029/2008JD011565.
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