NOAA Teacher at Sea
Mary Cook
Onboard NOAA Ship Ronald H. Brown
December 5, 2004 – January 7, 2005
Mission: Climate Prediction for the Americas
Geographical Area: Chilean Coast
Date: December 30, 2004
Location: Latitude 36°21.31’S, Longitude 72°59.65’W
Time: 9:15
Weather Data from the Bridge
Air Temperature (Celsius) 14.33
Water Temperature (Celsius) 14.81
Air Pressure (millibars) 1015.24
Cloud Cover 3/8
Cloud Type: Stratus
Wind Direction (degrees) 325.6
True Wind Speed (knots) 1.26
Sunrise 636
Sunset 2112
Question of the Day
What is a light year?
Positive Quote of the Day
“The influence of each human being on others in this life is a kind of immortality.” John Quincy Adams
Science Log
Last night I went up to the bridge at about 2300 hours. Vickie, Jeff, and Jackie were stargazing in search of the Southern Cross. There it was, almost directly in front of the ship! It had just risen over the horizon and looked more like a baseball diamond than a cross. We also spotted Alpha and Beta Centauri. At about 4.3 light years away, these are among the closest stars to Earth other than our Sun. Vickie also pointed out Orion with his belt of stars and the seven sisters called Pleiades. I’m going to get out my textbook and read up on the Magellanic Clouds because I’m wondering if we can see those from here. Then Jackie looked over the edge of the ship in the wake and caught a glimpse of some momentary flashes of light! Bioluminescence! I stood there pressing my face against the window staring at the darkened waters waiting patiently for some more microorganisms to glow. Sure enough it happened. They looked like little sparks of lightening in a cloud. It happened several times. I’ll definitely be back on the bridge again in search of more wonders of the sea at night.
For this leg of the journey, I’ve been moved to a different stateroom. I’m now down below in the science quarters. The sounds are different down here. I can hear the water splashing up against the ship’s hull. It sounds like I’m in a perpetual carwash!
It’s a soothing sound, though. I slept like a bear in hibernation.
Today begins the science operations. Right now, the scientists are on the fantail preparing the drifting sediment trap with its radar-reflector, floaters and nighttime strobe light. We’ll deploy the instrument then leave it while we make a short transit to the next station for CTD casts and core sampling. Afterwards, we’ll return and retrieve the sediment trap. According to the work plan, we’ll do this same thing at six different locations across the continental shelf and slope off Concepción, Chile. Most of the CTD casts are in fairly shallow water with the deepest one going down to 980 meters. These scientists will be working 48 hours non-stop.
It’s beautiful here in the Bay of Concepción. The water is so smooth and glistening in the sunshine. We’re nearly surrounded by a crescent-shaped coastline and we can see houses, forests, and other ships. This afternoon, we saw several ghostly-white jellyfish pumping their way through the water. Jim pointed out little anchovies swimming nearby. Yum!
I spoke with Kevin Sullivan of the NOAA research branch in Miami and Jordan Watson from the Scripps Institution of Oceanography. They patiently explained some of the science to me. And I really appreciate that.
This is how the drifting sediment trap works. After the instrument collects the sediments from the water near the surface and is retrieved, it will be set aside for a few hours to allow the sediments to settle to the bottom of the tubes. Then a lever is turned that empties the sediments into bottles containing a preservative. Sediments can be particles from the air like dust or particles from the ocean such as little deceased sea creatures called diatoms.
The Rhumor gravity core sampler is basically a one meter long hollow tube with heavy weights attached to the top. After being lifted by the winch, it is slowly lowered into the water. When the tube gets about 10 meters from the ocean floor it is lowered very quickly and gravity rams it into the mud. In this process, the mud layers fill the hollow tube and as the core sampler is raised the pressure closes a valve that keeps the mud from coming out.
I’ve noticed on the SeaBeam readout that the depth here is only about 100 meters. That’s a huge contrast to a couple of weeks ago when we were in waters with a depth of 5000 meters!
It is my understanding that the rationale for their research is to explore the effects of nitrogen distribution and how that affects the marine algae nutrient usage in the present day water column. They are conducting the sampling in this location because of the upwelling that occurs which brings nutrients to the surface and because there are algae present that utilize the nutrients in these upwelling plumes. Likewise, they are interested in evaluating the amount of nitrogen left in the sedimentary record. This will help scientists better understand the history of the oceans.
Personal Log
Today has been a quiet but interesting day. All the science was new to me so I had to pay attention and ask lots of questions. It’s very rewarding to have people around who are eager to share with me what they are doing and the significance of it all in the whole scheme of things. I’ve learned a tremendous lot and my brain is kind of tired. Plus, I miss my mentor. She’s got enough energy for two people! I did take some time to go to the ship’s bow and watch the water skim by and look around for animals. I saw lots of birds and jellyfish. I like watching jellyfish because I never see jellyfish in Arkansas. To me they are intriguing critters because they are transparent. I can see right through them!
Well, I’m headed for the exercise room to rest my brain and work off that cake with chocolate icing that I ate for dessert. Then, after dark, up to the bridge for more stargazing in the Southern Hemisphere!
Until tomorrow,
Mary
p.s. Congratulations Brandon and Becky!
