[email address] 
Mr M Jones 
 
Direct tel:  +44(0)1392 884036 
Request-18029-
 
Direct fax:  +44(0)1392 885681 
[email address] 
   
 
 
 
 
 
 
 
   
 
 
 
 
Our ref:   15-09-2009-170539-001                                     22 September 2009                                                
 
 
 
 
Dear Mr Jones 
  
Re: Freedom of Information  
 
Your email dated 14 September 2009 has been considered to be a request for information in 
accordance with the Freedom of Information Act 2000.  
 
Your questions:   
I am looking into the effects of jet aircraft upon our weather and would like to  
                     see your weather satellite images of Britain which were produced on 11/09/2009 which show 
the contrails produced by aircraft. 
 
I would also like to know whether the Met Office takes aircraft contrails into consideration 
when forecasting the weather, since sometimes it seems that the sky is just covered in the 
exhaust vapour trails from aircraft. 
 
The Met Office holds this information. 
 
I attach 8 pictures, 4 from the 11th and 4 from 12th, 2 visible and 2 infra red. 
  
These pictures do show some vapour trails, especially over Ireland on the morning of the 
12th, but by midday the visible picture does not show anything as the vapour trails are too 
thin. On the 11th there is a lot of naturally formed cirrus cloud which is mixing with the vapour 
trails and making it very difficult on these pictures to sort them out. 
  
We do not take vapour trail cirrus into account in forecasts in general, as they are quite 
difficult to forecast if they are permanent or not, which makes all the difference to the state of 
the sky. However, we would mention it in forecasts if we actually saw them persisting and 
starting to cover the sky, something that does not happen too regularly. 
  
                     I hope this answers your enquiry. 
 
The information supplied to you continues to be protected by the Copyright, Designs and 
Patents Act 1988 (the Act).  Unless specifically permitted by the Act, any reproduction of the 
information, in whole or in part, requires the permission of the copyright holder. Most  
 

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documents supplied by the Ministry of Defence will have been produced by government 
officials and will be Crown Copyright. You can find details on the arrangements for re-using 
Crown Copyright from the Office of Public Sector Information at: http://www.opsi.gov.uk/click-
use/index.htm
 
Information you receive may also include third party owned information. Such information 
must not be reproduced, in whole or in part, without first obtaining the permission of any such 
third party rights holder. 
 
If you are not satisfied with this response or you wish to complain about any aspect of the 
handling of your request, then you should contact me in the first instance. If informal 
resolution is not possible and you are still dissatisfied then you may apply for an independent 
internal review by contacting the Head of Corporate Information, 6th Floor, MOD Main 
Building, Whitehall, SW1A 2HB (e-mail [email address]). Please note that any request for 
an internal review must be made within 40 working days of the date on which the attempt to 
reach informal resolution has come to an end. 
 
If you remain dissatisfied following an internal review, you may take your complaint to the 
Information Commissioner under the provisions of Section 50 of the Freedom of Information 
Act. Please note that the Information Commissioner will not investigate your case until the 
MOD internal review process has been completed. Further details of the role and powers of  
the Information Commissioner can be found on the Commissioner's website, 
http://www.ico.gov.uk. 
 
Yours sincerely,  
 
 
FOI Manager               
 
 
 
 
 
 
 
 

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