Saturday, November 5, 2011

Launching the XBT

This morning started at 6am since I volunteer for the XBT/XCTD/water watch from 6-9am with Julie Jackson and Joe Warren. The XBT stands for Expendable Bathy Thermograph and XCTD is an Expendable Conductivity-Temperature-Depth probe. Both are missile-like probes that have heavy tips and are launched with a black device that looks like a gun, so we couldn’t resist taking some cool looking pictures.

Both the XBT and XCTD are connected by a thin copper wire to a computer on board, so when we launch them they collect data on the temperature and salinity of the ocean continuously through the water column.  The probe drops until it reaches 1000m which takes about 5-10 min, then we break the copper wire and the data collection stops.

The XBT and XCTD stations are spaced so we collect data every 5-6 miles. Occasionally we have to take some water samples to measure salinity, CO2 and oxygen of the water where we launched the XBT and XCTD. All these data are collected as an ongoing collaboration with researchers from different parts of the world, who are interested in characterizing the water properties of the Drake Passage. The R/V L.M. Gould has been collecting these data every 6 weeks for the last 5-6 years.

Even though our hands get cold during these stations, the weather has been nice to us and we haven’t encountered the bad weather that is usual for the Drake Passage. We have 5-6 ft swells with wind speed of 25 knots, which makes it a little challenging to type in the laptop since occasionally you have to use one hand to hold on to the bench.

Stay tuned for more news, since tomorrow we’ll be arriving at Cape Sheriff (Livingston Island) and helping NOAA scientists on board to get settled for their 4 month long camp!

Submitted by Paola Batta-Lona – November 5, 2011

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