NOAA Teacher at Sea
Onboard NOAA Ship Ronald H. Brown
December 5, 2004 – January 7, 2005
Mission: Climate Prediction for the Americas
Geographical Area: Chilean Coast
Date: December 6, 2004
Location: Latitude 19° 50.49` S, Longitude 73° 22.51`W
Time: 8:30 am
Weather Data from the Bridge
Wind Direction (degrees) 144.45
Relative Humidity (percent) 68.72
Temperature (Celsius) 18.65
Barometric Pressure (Millibars) 1012.77
Wind Speed (knots) 11.36
Wind Speed (meters/sec) 5.51
Question of Day
Based on the name, what do you think a thermosalinograph measures?
Good morning, everyone! Wow! What a great way to get a good night’s sleep, in a gently rocking ship. It’s like sleeping on a waterbed. The morning shower was a challenge, though. Being wet and soapy even on a gently rocking ship could be very dangerous. After breakfast, we met with Dan Wolfe and Chris Fairall for radiosonde deployment training. A radiosonde is a really cool giant helium filled balloon with instruments attached to a cord dangling beneath it. The radiosonde must be assembled and calibrated before launching. As the instruments detect the relative humidity, wind speed, wind direction, and temperature readings they transmit these data back to the computer onboard the ship. A radiosonde lasts for about one and a half hours and goes about 20 kilometers (12.4 miles) high. Dan actually deployed a radiosonde and we watched it go up, up and away! Then we went back into the lab and observed the data coming into the computer. I can’t wait until it is mine turn to deploy a radiosonde!
Our next training session was led by Jeff Lord and he showed us how to deploy the drifter buoys and the Argo floats. These are fairly simple to get into the water. Just record their identification numbers, fill in the log sheet for time, date, GMT, latitude and longitude, then toss them overboard. The drifting buoys are small and they measure surface temperature and pressure. The drifters have a long caterpillar-shaped drogue extending far down into the water that ensures the buoy will drift with the ocean currents and not the wind. In a few days we will deploy the first of fifteen drifter buoys and my students at Southside School will adopt this one and keep track of it online. I am amazed at the designs of all these instruments. It’s almost unbelievable what ingenuity has gone into these designs. Some are high-tech and some are low-tech but they all work together to obtain the necessary data for the scientists.
The Argo floats sink down to 2000 meters then float to the surface. On their way up they measure temperature and salinity. When the float reaches the surface, it then sends the information to a satellite. The float has a bladder that deflates and it sinks again to repeat the process. The Argo floats can keep on going for two to four years depending on their battery life.
After our training sessions, Diane and I sat down with Bruce Cowden, the ship’s boatswain, who’s also an artist, to brainstorm for a children’s book about the science work of this cruise.
At 1415, we had our “surprise” safety drills: a fire drill and an abandon ship drill. The fire drill was pretty simple. Upon hearing the alarm, we reported to our muster stations. Then the chief scientist called the bridge and said that all persons were present.
The abandon ship drill was quite another story. When we heard the alarm, we had to go to our staterooms to get our life vests and emergency bag containing the big red “gumby suit”. Then we went to our lifeboat station and put on the suit. Its purpose is to keep you dry and afloat in the event you were forced to abandon the ship.
Diane and I are taking water surface temperature readings every thirty minutes. This is really kind of fun. There’s a thermometer in a tube-shaped “bucket”. The bucket is attached to a long cord. We then swing it over the edge of the ship into the water until the bucket fills up. We raise the bucket and read the temperature immediately. This is compared to the temperature reading on an instrument mounted underneath the ship called a thermosalinograph.
Later this afternoon, we finally arrived at the deployment site for the Chilean Armada tsunami buoy. We are about 200 miles off the coast of Chile. The ship hovered over the location while the buoy was hoisted by a crane then swung over the edge and lowered into the water. At this time the men are unrolling over 5000 meters of cable to attach to the anchors which happen to old railroad wheels. It will take about one hour for the anchors to sink to the bottom of the ocean. The bottom pressure recorder will then be lowered. It detects the slightest changes in pressure as small as two centimeters and sends messages back to the surface buoy which then relays that to a satellite which has direct ground communications. The ship will stay in this position for a few hours to make sure the tsunami buoy and ground pressure recorder are communicating with each other. A RHIB ride is in the near future!
And I hope I’m on it. RHIB stands for rigid hull inflatable boat and they go really fast! Some of the workers will be riding out to the tsumani buoy to check everything out before we leave it.
I’ve just found out that I will have morning watch each day from 0800 until 1200. Everyone on board is assigned a daily four hour watch duty. My duty will be in the main lab and I will stay in contact with the bridge and help out when needed.
So tune tomorrow for more on our exciting adventure!