Dear Ed,

I have analyzed  data of ozonesoundings  against  diagnostics I obtained from you
and  found that with one exception (ln07022611.csv), the problem is invariably associated  
with gaps in  ozone.

On the 26th of February 2007 Poland was under influence of the polar vortex 
with  extremely strong winds  in the middle startosfere.
Large gradients in total ozone field over Central Europe could be seen.
Therefore,  the values of wind speed and  Dobson correction 0.9  seem to be acceptable. 
 
A detailed analysis of  one ozonesounding performed on the 4th of  April has been performed.
A simulation  showed several layers with gaps in ozone  
between 14697m and 16383m   a.s.l. 
The simulation also showed that there were problems with telemetry 
and gaps occurred as well in PTU  data. 
I suspect that  there is  a bug in the conversion program (sndpro 1.321).
The bug is probably asociated with the value of -327.68 (please look for it into file ln07040411.csv)
( as far as I remember the value of -32768 is reserved to code  numeric overflow).
I am afraid that at the moment I can do nothing about it 
since I have neither acces to source code of the program
nor to the  documentation of the binary files ('s','z').
So, if you have possibilities, I kindly ask you to  try and find the bug, 
recompile the program and send it  back to me.
To run the program  please find  attached two binary files ('s' , 'z').
The binary  files are obtained with  DigiCORA III ,SPS220 system and radiosondes RS92SGPW/ECC6.
To make the 's' and 'z'  files we rename  special.spf (for  raw PTU and special sensor data)  
 and ozone.spf (for EDT and calculated ozone data), respectively. 
While making neccesary changes in  the conversion program I think it is worth to  interpolate  ozone
values for  standard pressure levels,  and to mark the values at the tropopause, as it was  done before. 
The inclusion of ozone values at 925hPa and 850hPa levels would be interesting to see changes in 
the low tropospheric ozone. 
 


I would also like to  inform you that  in the previous years we had even more serious problems 
with ozonesoundings. Signal from ozonesonde launched at Legionowo
was  lost at random height (most often in cold season) with  no ozone data higher up. 
In such cases usually  the PTU data were reported normally up to the balloon burst level.
In that way we have lost many valuable ozonesoundings, 
some performed on alert basis for the Match campaigns.
We have informed Vaisala about  our difficulties, but the reason is still the mistery.
Fortunately,  recent changes in Vaisala radiosounding system  has improved the situation:
in cases of  gaps in ozone data,  the rest of ozone data is now stored normally.
Ozone gaps have been   found  recently:  in November (Ln07112811.csv) 
and December (Ln07120511.csv, Ln07121911.csv).



As I mentioned last time,  I am  the Scientific Authority for ozonesoundings performed  at Legionowo since 2007. 
To reflect this  I am sending again  results of our  ozonesoundings, this time for extended period 02-12.2007.
I hope that my remarks will soon  help to solve the  problem of ozone gaps.




Best regards,
Bogdan
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Mr Bogumil Kois
Institute of Meteorology and Water Management
Centre of Aerology
Zegrzynska 38
05-119 Legionowo
Poland
e-mail: Bogdan.Kois@imgw.pl
tel:  +4822 7673118
fax: +4822 7742746
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