GCOS GOOS WCRP/OOPC IX/3 

page 62 

is essential if we are to move towards a system which can meet the required range of 

objectives. 

We need to avoid the perception that VOSClim with its minimum target of 200 ships 

will replace the full functionality of the VOS. Both VOS and VOSClim form part of the draft 

implementation of the Global Climate Observing System (GCOS, 2004). Monitoring the VOS 

from a climate perspective urgently needs to begin. The monitoring of VOS that is presently 

undertaken by NWP centres is designed to measure the quantity of observations and to 

identify gross errors in the data. Climate monitoring would require different information, for 

example the number and distribution of reports containing the variables required to calculate 

the four components of the heat flux to good accuracy (compared to the output of NWP 

models). In the past it has been possible to identify errors in models using VOS fluxes. We 

need to ensure that as models improve, the fluxes from VOS are of good enough quality for 

validation in regions away from dedicated surface flux reference sites. 

Action: Encourage JCOMM to begin a dialogue with the operators of VOS fleets to ensure 

that the data collected continues to meet the requirements of the global climate observing 

system for high quality data from which the ocean surface exchanges of heat, moisture and 

momentum can be calculated. It is necessary to build on current monitoring of VOS weather 

reports to include assessment against the requirements of the global climate observing system 

alongside the monitoring for numerical weather prediction. This monitoring for climate is the 

essential first step towards raising the number of VOS that make climate quality observations. 

References 

Berry,  D.  I.  and  E.  C.  Kent,  2004:  The  Effect  of  Instrument  Exposure  on  Marine  Air 

Temperatures:  An  assessment  using  VOSClim  data,  to  be  submitted  to  the  International 

Journal of Climatology.8 

Diaz, H. F., C. K. Folland, T. Manabe,, D. E. Parker, R. W. Reynolds and S. D. Woodruff, 

2002: Workshop on Advances in the Use of Historical Marine Climate Data (Boulder, Co., 

USA, 29th Jan   1st Feb 2002). WMO Bulletin. 51, 377 380. 

GCOS, 2003: Second Report on the Adequacy of the Global Observing Systems for Climate 

in Support of the United Nations Framework Convention on Climate Change, GCOS 82, 

74pp. [Available from http://www.wmo.ch/web/gcos/publications.htm ]. 

GCOS, 2004: Draft GCOS Implementation plan, presented at the 12th Session of the GCOS 

Steering Committee, Geneva, 15 18th March 2004.9 

JCOMM, 2003a: VOS Climate Project Fourth Project Meeting Final Report, London, UK, 

21 22 July 2003, JCOMM Meeting Report No. 23  

[available from http://www.wmo.ch/web/aom/marprog/Publications/publications.htm ]. 

JCOMM, 2003b: Ship Observations Team (SOT) Second Meeting Report, London, UK, 28 

July   1 August 2003, JCOMM Meeting Report in preparation  

[available from http://www.wmo.ch/web/aom/marprog/Publications/publications.htm ]. 

8

 June 2004: Now submitted 

9

 Latest draft available from http://www.wmo.ch/web/gcos/GIP_Introduction.htm