 |
|
|
|
Research | Polar research | Antarctic research - Photo gallery
Photo gallery
Marambio Base of the Argentinean Air Force (June 2003).
View to south-east and the Weddell Sea. Pathways with handrails are necessary due to strong winds (June 2003).
Strong winds pack snow on the north-east sides of the buildings (June 2003).
The principal mean of transportation to Marambio is by Hercules C-130 cargo planes (June 2003).
The meteorological observation field of Marambio (June 2003).
The Pinguin Point (Punta Pingüino) (September 1999).
View to the Bahía López de Bertodano and the Ross Island south-west of Marambio (September 1999).
In the polar winter and spring atmospheres, polar stratospheric clouds (PSCs) serve as surfaces for capturing free nitrogen oxides from the atmosphere and lead to release of chlorine from reservoirs. Free chlorine is the main catalyst of the chemical ozone depletion. In the photograph there are PSCs over Marambio on 4.10.1999.
Ozone sensor is an iodine-iodide redox electrochemical concentration cell made of two bright platinum electrodes immersed in potassium iodide solutions of different concentrations contained in separate cathode and anode chambers. Air is pumped into the cathode solution and current equivalent to the number of ozone molecules is generated. The current is measured and processed by a Vaisala OIF11 interface. The data is sent to a ground unit using the telemetry of a Vaisala RS80 series GPS radiosonde.
An ozone sensor is prepared in three stages. The first stage takes place 1-3 weeks before the sounding. Between the preparatory stages, the sensor is stored in a styrofoam box, which is used also in the actual sounding.
In the preparatory stages the chemical reaction of the ozone sensor and the current produced are tested using a special testing device, TSC-1 ozonizer/test unit.
The temperature, humidity and atmospheric pressure is measured during the preparations. A weigh is needed when the solutions for the ozone sensor electrochemical cells are prepared. All preparatory phases and values measured are marked down to a check list.
Vaisala RS80-GE radiosonde is used for monitoring humidity, temperature and atmospheric pressure during the sounding. Here the radiosonde is installed to a ground-check bench. Radiosonde and ozone sensor are powered by water activated batteries. There is a different water container for both batteries.
Vaisala MW11 (DigiCORA II) unit is used during the ground-check, the final preparatory stage of the ozone sensor and during the sounding to receive and process the data.
After all the preparations are made, ozone sensor is packed inside a styrofoam box, to which a radiosonde is also attached.
The styrofoam box is attached to a helium filled observation balloon and released.
In favourable conditions an ozonesonde can reach an altitude of 35-40 km.
At Marambio, the regular ozone soundings are made at 12 UT (9 AM local time). During measurement campaign a launch can take place also at another, predetermined time. A successful launch is always worth of celebration!
It has been shown that the ozone hole has a tendency to locate itself close to the South Cone of South America, and subsequently also over mainland Chile and Argentina. The Argentinean town Ushuaia in Tierra del Fuego is the most southern town in the world and frequently affected by the ozone hole. Ushuaia is one of the three locations of the Finnish-Spanish UV-monitoring network. Other locations are Marambio and Belgrano at Antarctica. In Ushuaia, the NILU-UV instrument is situated at the CADIC, Southern Centre of Scientific Research of Argentina. Photograph was taken in October, 1999.
All photos: Juha A. Karhu
Back to top Home page
|
|
|
|