1. XBT and continuous ship-borne meteorological measurements
Vanessa Cardin
Davide Deponte – Paolo Mansutti
National Institute of Oceanography and Experimental Geophysics - OGS
With the contribution of ENEA-CRAM and IOF
ADRICOSM-EXTension Final Meeting
Rome November 2006

2. OUTLINE OBJECTIVE OF THE TASKS OVERVIEW TRACK: PLOCE – MALTA
Some results
Correlation with satellite data
NEW TRACK: TRIESTE – DURRES
Meteorological station
Longitudinal Track
Upgrade
CONCLUSIONS
FUTURE PLANS

3. OBJECTIVE OF THE TASKS:
Subtask Design of the automatic meteorological station for the VOS-XBT system
The meteo measurements on board of VOS will be wind, air temperature, pressure and humidity. Many instruments and systems can be selected. During the first 6 months of the project, ENEA, IOF and OGS will make an analysis of the existing sensors, explore the possibility to use Iridium/Globalstar data transmission, design and realize a compact package of sensors, data storage and transmission system to be installed on the selected ships. The real-time data transmission system, data transmission and quality control protocol will be developed
Responsible: ENEA, OGS, IOF
Participants: HEIS
Duration: 0 – 3 month
Subtask XBT and continuous ship-borne meteorological measurements along the transect Ploce-Malta
The automatic meteorological station developed in Subtask for continuous wind, temperature, atmospheric pressure and humidity measurements will be installed on the ship LIPA. Positioning and installation of sensors on the ship as well as the crew members preparation for the use of the meteorological station will be carried out in co-operation with the shipping company “Losinjplov”.
The meteorological station will be operative all the time while ship will be cruising. The XBT measurements are planned to be carried out on a monthly basis excluding two summer months (July and August) with a spatial resolution of 10 nautical miles as in the previous program which has been operative since The Deep Blue type of XBT will be used as they can go down to 900 m depth. The data will collected monthly, transmitted in real time to the ENEA center and the cruises will be co-ordinated with the VOS2 surveys on the transect Dubrovnik-Bari.
Responsible: OGS
Participants: Add participants from the entering countries.
Duration: 0 – 24 month

4. Overview - Statistics 1999 – 5 cruises 2000 – 15 cruises 20 cruises
ADRICOSM: Jan/01-Oct/03:
33 XBT x 24 campaign = 792
+ 49 XBT lost (DEEP BLUE)
6 XBT x 24 campaign =144
+ 4 XBT lost (T6)
ADRICOSM-EXT: Oct/05-May/06
Ploce-Malta: 227 XBT (7 cruises)
207 profiles + 20 XBT lost
Data were collected along the tracks Ploče-Malta, crossing longitudinally the South Adriatic Pit
Trieste- Durries: 17 XBT (1 cruise)
14 XBT + 3 XBT lost

5. Some results … and analysis
Xbt measurements
Satellite imageries

13. Satellite Imageries
The biological response to mixing and convection is clearly seen from the MODIS imageries being in agreement with XBT’s results
The spring primary production (intermittent phytoplankton blooms) coincides with calm weather intervals, which usually separate cold air outbreaks and violent vertical mixing episodes.
A chlorophyll-a patch on a basin scale appears at the beginning of the spring (end of march)

14. New Track: Ferry Venezia XBT + Meteo measurements
Characteristics: Flag: Italian Length overall: m Breadth moulded: m Gross Tonnage: 8 T Built: 1978 Agency: AGEMAR

15. New Track: XBT and Meteo measurements
Meteo domain:
Trieste - Durries
Xbt domain:
Latitude Longitude
45°10’N; °05’ E
41°25’N; °30’ E
Longitudinal measurements:
Track 1: Trieste – Durries
Track 2: Trieste – Durries – Bari – Durries - Trieste

17. Meteo-station components: (task 1.2.1)
Sensors:
wind speed and direction
Air temperature,
Air humidity
Air pressure
GLOBSTAR (Satellite) communication
Time interval: 10 seconds
Campabell logger CR1000 with accumulator and power supply
Need to be Upgraded:
GPS system for position registration

18. Satellite modem
Campebell CR1000 logger
Voltage regulator
Rechargable battery
Main switch regulator

19. Meteorological measurements along the Trieste – Durries Track

20. Some Conclusions …
Based on XBT data collected along two transects in the Southern Adriatic in the period October 2005 – May 2006 it was possible to obtain the time evolution of the thermal conditions from the pre-conditioning, through winter convection and then spreading phase;
XBT surveys have shown the vertical convection reaching 900m depth in the centre of the pit;
The biological response to mixing and convection is clearly seen from the MODIS imageries being in agreement with XBT’s results: A Chl-a patch covered the whole southern Adriatic pit in early April followed by meanders ;
In the spreading phase starting from early April, the signal of the cold water vein flowing along the Italian shelf break was clearly evident on the Italian shelf contributing to the strengthening of the South Adriatic Gyre;
XBT data combined with basin-wide surveys and satellite data can give the right “picture” of the hydrographic conditions of the basin;

21. Future plans
Continuation of XBT’s measurements along the Trieste – Durries Track for at least 6 cruises (winter ); this will provide value information of the pre-condition/mixing/spreading phase in the Southern Adriatic;
Meteorological data will be sampled along the Trieste – Duress track providing useful information;
An upgrade of the meteorological station will be done: GPS and Gyro-Compass will be installed enabling to accomplish the truth wind velocity/direction
All data (storical and recent) XBT are shown on the OGS– Adricosm-EXT web page