NOAA Teacher at Sea
Onboard NOAA Ship Ronald H. Brown
July 11 – August 10, 2009
Mission: PIRATA (Prediction and Research Moored Array in the Atlantic)
Geographical area of cruise: Tropical Atlantic
Date: July 25, 2009
Weather Data from the Bridge
Outside Temperature 26.94oC
Relative Humidity 81.85%
Sea Temperature 27.84oC
Barometric Pressure 1013.74 inches
Latitude 13o 07.114N Longitude 23o 00.000W
Science and Technology Log
I have continued to help out on the 11:30 am to 11:30 pm watch with CTDs and XBTs. Why do so many CTDs and XBTs? The scientists on board are developing a subsurface profile of the water temperature, salinity and density. Based on these data, models can be constructed and refined that can help us better understand what is happening in the Tropical Atlantic.
The Brown arrived at the second buoy that needed to be serviced on July 24th. I was lucky enough to get on the small boat sent out to take some equipment off the buoy before it was pulled up on the boat. Once at the buoy, the radiometer and the anemometer were removed. An acoustic message is then sent from the Brown to release the anchor on the buoy. The buoy is then attached to a rope from the Brown and pulled up onto the fantail. All the instrumentation and sensors below the buoy are pulled up on the Brown and exchanged. I attached a picture of the buoy to the right so you get an idea of all the instrumentation that is attached to these buoys. I could not believe all the fish that were around the buoy. Apparently, the buoy creates a small ecosystem, where all kinds of marine organism congregate. Algae and small crustaceans attach to the buoy and some of the cables that are underneath. Small fish eat the algae and crustaceans, larger fish eat the smaller fish and before you know it you have a food web. Some of the fish are huge. Yellow fin tuna, triggerfish and mahi mahi. This actually causes a big problem. Fishermen come out to these buoys and damage the buoy instrumentation when they are fishing and we end up losing valuable data.
Once the buoy is pulled up onto the ship, the fish that were around it looked for a place to go. Sometimes they come under the ship. We threw a few fishing lines in after the buoy was pulled up on the fantail and the tuna were biting like crazy. We caught a few that afternoon and had them for lunch the next day!!