Ultima revisione dell'autore: 11 aprile 2010.
Il mese di febbraio 2010, dopo un gennaio da dimenticare, ha offerto delle buone giornate per l'osservazione di scie di condensazione a Milano. Nel post odierno riporto alcune foto significative and a brief analysis of weather data of 13, 20, 21 and 27 February. She is especially dealt with the subject of the discrepancy between data elements and type of wake observed by testing the new software, not yet released for the correction of the data relative humidity signed Marcov & MarkoGTS.
Saturday, February 13. The day was marked by the passage of aircraft wake of a non-persistent with lasting a few seconds.
Gazpromavia Boeing 737-700 RA-73004
Aerlines Transaero Boeing B767-200
Red Wings Tu-204 RA 64050
Air France Airbus A321 F- GTAV
* The analysis of data weather of the day ( Appleman Chart, Chart relative humidity / temperature ) indicates that on February 13 were the conditions for the formation of trails of non-persistent, confirming what has been observed. Interestingly, already at 7941 m, and below 8000 m of the prophetic, were the conditions for the formation of contrails **.
Saturday, February 20. The day was characterized by the almost total absence of contrails. I only saw two planes with photographing a wake. Interesting but the iridescence in the clouds which could achieve particular photos.
Iridescenze
Brussels Airlines BAE Systems Avro 146-RJ85. Nella foto anche un A321 di passaggio.
L'analisi dei dati atmosferici della giornata ( Diagramma di Appleman , Grafico umidità relativa/temperatura ) indica che erano presenti le condizioni per la formazione di scie dagli 8500 ai 8900 metri circa. L'umidità relativa era alta, a livello della saturazione su ghiaccio considerando un errore del 10%.
Domenica 21 febbraio 2010. La giornata è stata finalmente caratterizzata dalla presenza di scie di tipo persistente. Ho osservato passages of aircraft wake passing over the city and even planes at low altitude in the direction of Malpensa. To this day I leave the reader with the fun task of identifying the planes that appear in the photos: P
aircraft at low altitude (direction Malpensa)
aircraft wake up in transit Milan
Scie persistent observed in the day.
analysis atmospheric data of the day ( Diagram of Appleman, Chart relative humidity / temperature ), characterized by very low temperatures with peaks of -63 ° C, shows that on February 21 were fully satisfies the conditions for the formation of contrails. Contrails observed were of a continuous nature, meaning, as we all know by now, the presence of high altitude air supersaturated with respect to ice. However, if we look at the relative humidity data recorded by the probe we see that saturation is achieved, even with an error of 10%.
This inconsistency has already been observed in the past on which I had promised myself to return. E 'are known to suffer from an error sensor and the literature on the accuracy of the probes is vasta. MarcoVi e MarkoGTS (ai quali vanno i miei complimenti per l'ottimo lavoro svolto) hanno da poco sviluppato un utilissimo programma che permette di correggere i valori di umidità relativa della sonda Vaisala RS92 (usata a Milano) in base al lavoro di Larry M. Miloshevich e coll. (1) conoscendo l'elevazione del sole all'ora del radiosondaggio. Ho pensato quindi di testare tale software.
Saturday, February 13. The day was marked by the passage of aircraft wake of a non-persistent with lasting a few seconds.
Gazpromavia Boeing 737-700 RA-73004
Aerlines Transaero Boeing B767-200
Red Wings Tu-204 RA 64050
Air France Airbus A321 F- GTAV
* The analysis of data weather of the day ( Appleman Chart, Chart relative humidity / temperature ) indicates that on February 13 were the conditions for the formation of trails of non-persistent, confirming what has been observed. Interestingly, already at 7941 m, and below 8000 m of the prophetic, were the conditions for the formation of contrails **.
Saturday, February 20. The day was characterized by the almost total absence of contrails. I only saw two planes with photographing a wake. Interesting but the iridescence in the clouds which could achieve particular photos.
Iridescenze
Brussels Airlines BAE Systems Avro 146-RJ85. Nella foto anche un A321 di passaggio.
L'analisi dei dati atmosferici della giornata ( Diagramma di Appleman , Grafico umidità relativa/temperatura ) indica che erano presenti le condizioni per la formazione di scie dagli 8500 ai 8900 metri circa. L'umidità relativa era alta, a livello della saturazione su ghiaccio considerando un errore del 10%.
Domenica 21 febbraio 2010. La giornata è stata finalmente caratterizzata dalla presenza di scie di tipo persistente. Ho osservato passages of aircraft wake passing over the city and even planes at low altitude in the direction of Malpensa. To this day I leave the reader with the fun task of identifying the planes that appear in the photos: P
aircraft at low altitude (direction Malpensa)
aircraft wake up in transit Milan
Scie persistent observed in the day.
analysis atmospheric data of the day ( Diagram of Appleman, Chart relative humidity / temperature ), characterized by very low temperatures with peaks of -63 ° C, shows that on February 21 were fully satisfies the conditions for the formation of contrails. Contrails observed were of a continuous nature, meaning, as we all know by now, the presence of high altitude air supersaturated with respect to ice. However, if we look at the relative humidity data recorded by the probe we see that saturation is achieved, even with an error of 10%.
This inconsistency has already been observed in the past on which I had promised myself to return. E 'are known to suffer from an error sensor and the literature on the accuracy of the probes is vasta. MarcoVi e MarkoGTS (ai quali vanno i miei complimenti per l'ottimo lavoro svolto) hanno da poco sviluppato un utilissimo programma che permette di correggere i valori di umidità relativa della sonda Vaisala RS92 (usata a Milano) in base al lavoro di Larry M. Miloshevich e coll. (1) conoscendo l'elevazione del sole all'ora del radiosondaggio. Ho pensato quindi di testare tale software.
Sottolineo che i risultati qui presentati sono semplicemente un test del software e un primo tentativo di risolvere il problema dell'incongruenza tra dato osservato/dato previsto. Ricordo anche che sarebbe auspicabile che il programma e il metodo di calcolo venisse verificato da un esperto del campo, magari dallo stesso Miloshevich. Remember that the correction Miloshevich should not apply for soundings made on cloudy days (1). We therefore in this regard during the next analysis and then we take all the results with caution.
Using the software I checked out what changes to the values \u200b\u200bof relative humidity of 21 if we apply the correction .
Chart relative humidity and temperature corrected.
From the graph we see that the correct values \u200b\u200bof relative humidity in some places exceed the saturation on ice. Based on the corrected data can then predict the formation of persistent contrails and could therefore overcome the inconsistency.
It 's interesting Note that even if we apply the correction of the data Miloshevich on Saturday 20, we obtain values \u200b\u200bof supersaturation. Surprising in this case the aircraft had not observed persistent contrails in the day (apart from a cloud similar to a secluded trail). That we would be faced with another possible inconsistency: no (or limited presence) of persistent contrails above saturation with moisture! Tentatively, a first possible explanation for this discrepancy could be that the persistence of that day was confined to quote "low" is not very busy, but the question is obviously a different story.
Saturday, February 27. The day was marked by early morning by the presence of diffuse cirrus clouds. A mid-morning appeared continuous nature trails and in the afternoon the sky was covered by a cirrostratus. Were visible phenomena of iridescence. CSA Czech Airlines A320
Scie persistent. Are clearly visible in the wake primary (characterized by rings and vortices) and the secondary trail, index of air supersaturated
phenomena of iridescence: Sundog and halo (see in the picture with the lingering scent alone with shadow ).
Analysis of data weather of the day ( Appleman Chart, Chart relative humidity / temperature ) shows that on Saturday there were 27 conditions for the formation of contrails, but again, the humidity was not recorded above saturation. Using the correction
of Miloshevich, we note again the presence of supersaturated air.
Chart relative humidity / temperature correct.
In conclusion, the month of February has offered interesting insights on the trails of aircraft. The program Marcov MarkoGTS and, in particular, could be extremely useful to provide answers to the inconsistencies that are sometimes observed between data recorded and observed data.
Notes * To deal with the analysis of atmospheric data are necessary considerations.
The subject is very complex and its comprehensive discussion is beyond the scope of this blog. What I propose to do is show a simple methodology, to anyone who is interested to test the ground, albeit with major limitations, the scientific theory of the formation of contrails.
Regarding the radiosonde is necessary to recall that: i) the probes can measure the parameters at points distant from the launch point ii) the probes measured values \u200b\u200bin a dozen points in space in the typical cruising altitude they say nothing throughout the rest of the space, iii) data della sonda andrebbero confrontati con le scie osservate nel momento in cui la sonda è in quota (la sonda raggiunge i 10mila metri intorno alle 12:30) poichè le condizioni atmosferiche possono variare rapidamente.
E' quindi necessario prendere l'analisi dei dati atmosferici con la giusta cautela. E' ovvio che il modo giusto per verificare la teoria scientifica sarebbe quello del flying test (misurare cioè i parametri atmosferici dove l'aereo sta volando) ma al momento non lo possiamo fare.
**Dato verificato con il programma Contrail Forecasting di MarcoVi (differenza tra T critica e T ambientale di 1,45°C). Il programma, basato sul lavoro di Schrader aggiornato ai motori ad alto bypass, permette di calcolare con precisione la temperatura critica di formazione delle contrails).
Referenza
(1) Miloshevich, L. M., H. Vömel, D. N. Whiteman, and T. Leblanc (2009), Accuracy assessment and correction of Vaisala RS92 radiosonde water vapor measurements, J. Geophys. Res., 114, D11305, doi:10.1029/2008JD011565.
Nota sul copyright.
Copyright © 2010 - All rights reserved. Tutti i diritti sono riservati. Per richiedere la riproduzione dell'articolo o delle fotografie scrivere all'indirizzo e-mail sciemilano@yahoo.it
Chart relative humidity and temperature corrected.
From the graph we see that the correct values \u200b\u200bof relative humidity in some places exceed the saturation on ice. Based on the corrected data can then predict the formation of persistent contrails and could therefore overcome the inconsistency.
It 's interesting Note that even if we apply the correction of the data Miloshevich on Saturday 20, we obtain values \u200b\u200bof supersaturation. Surprising in this case the aircraft had not observed persistent contrails in the day (apart from a cloud similar to a secluded trail). That we would be faced with another possible inconsistency: no (or limited presence) of persistent contrails above saturation with moisture! Tentatively, a first possible explanation for this discrepancy could be that the persistence of that day was confined to quote "low" is not very busy, but the question is obviously a different story.
Saturday, February 27. The day was marked by early morning by the presence of diffuse cirrus clouds. A mid-morning appeared continuous nature trails and in the afternoon the sky was covered by a cirrostratus. Were visible phenomena of iridescence. CSA Czech Airlines A320
Scie persistent. Are clearly visible in the wake primary (characterized by rings and vortices) and the secondary trail, index of air supersaturated
phenomena of iridescence: Sundog and halo (see in the picture with the lingering scent alone with shadow ).
Analysis of data weather of the day ( Appleman Chart, Chart relative humidity / temperature ) shows that on Saturday there were 27 conditions for the formation of contrails, but again, the humidity was not recorded above saturation. Using the correction
of Miloshevich, we note again the presence of supersaturated air.
Chart relative humidity / temperature correct.
In conclusion, the month of February has offered interesting insights on the trails of aircraft. The program Marcov MarkoGTS and, in particular, could be extremely useful to provide answers to the inconsistencies that are sometimes observed between data recorded and observed data.
Notes * To deal with the analysis of atmospheric data are necessary considerations.
The subject is very complex and its comprehensive discussion is beyond the scope of this blog. What I propose to do is show a simple methodology, to anyone who is interested to test the ground, albeit with major limitations, the scientific theory of the formation of contrails.
Regarding the radiosonde is necessary to recall that: i) the probes can measure the parameters at points distant from the launch point ii) the probes measured values \u200b\u200bin a dozen points in space in the typical cruising altitude they say nothing throughout the rest of the space, iii) data della sonda andrebbero confrontati con le scie osservate nel momento in cui la sonda è in quota (la sonda raggiunge i 10mila metri intorno alle 12:30) poichè le condizioni atmosferiche possono variare rapidamente.
E' quindi necessario prendere l'analisi dei dati atmosferici con la giusta cautela. E' ovvio che il modo giusto per verificare la teoria scientifica sarebbe quello del flying test (misurare cioè i parametri atmosferici dove l'aereo sta volando) ma al momento non lo possiamo fare.
**Dato verificato con il programma Contrail Forecasting di MarcoVi (differenza tra T critica e T ambientale di 1,45°C). Il programma, basato sul lavoro di Schrader aggiornato ai motori ad alto bypass, permette di calcolare con precisione la temperatura critica di formazione delle contrails).
Referenza
(1) Miloshevich, L. M., H. Vömel, D. N. Whiteman, and T. Leblanc (2009), Accuracy assessment and correction of Vaisala RS92 radiosonde water vapor measurements, J. Geophys. Res., 114, D11305, doi:10.1029/2008JD011565.
Nota sul copyright.
Copyright © 2010 - All rights reserved. Tutti i diritti sono riservati. Per richiedere la riproduzione dell'articolo o delle fotografie scrivere all'indirizzo e-mail sciemilano@yahoo.it
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