NOAA Teacher at Sea
Aboard NOAA Ship Ka’imimoana
August 16-30, 2002
Day 10: August 20, 2002
Our location and the weather observations at 1500 today were:
Visibility: 12 nautical miles (nm)
Wind direction: 030 (direction from which the wind is blowing)
Wind speed: 18 kts
Sea wave height: 4-5′
Swell wave height: 5-7′
Sea water temperature: 26.0°C
Sea level pressure: 1011.9 mb
Dry bulb temperature: 25.8°C
Wet bulb temperature: 24.2°C
Cloud cover: 7/8, Cumulus
“A man is ethical only when life is sacred to him…and when he devotes himself helpfully to all life that is in need of help.”
– Albert Schweitzer
WELCOME to a new time zone! We are now 9 hours off Greenwich Mean Time (GMT), the current time in Greenwich, England along the 0° meridian. We just crossed into this new time zone overnight as we cruised southeast toward 8°N latitude, 125°W longitude. At 8°N, 125°W we’ll find the first buoy that needs to be replaced, which is typical after floating in the water for one year (see the web site http://www.pmel.noaa.gov/tao for a map and description of the Tropical Atmosphere Ocean (TAO) buoy array). During our travels southward along the 125°W longitude line, a few of the moorings (buoys) will simply need to be repaired instead of replaced. The sensors that will be replaced may have been vandalized by fishermen, damaged due to severe weather, or the sensors may need to be recalibrated. In any case, we’ll either replace sensors or fix them at each buoy.
I just walked (well, swayed) out on the buoy deck and discovered that the ship’s first replacement buoy is being constructed. This buoy will replace the one currently floating at our first stop. It’s amazing how the whole project comes together with many scientists working in harmony. See today’s photo log for pictures of the newest buoy at various stages of completion.
Dr. Paul Freitag, our Chief Scientist, provided some more information about the instruments on the buoys. First, the buoys are anchored to the ocean floor, which is still hard for me to believe. All of the buoys have sensors to measure temperature/relative humidity and an anemometer to measure wind speed along with wind direction. Some of the buoys have sensors measuring precipitation and solar radiation, but not all are equipped to with this expensive instrumentation. The buoy itself (the orange and white donut part) is composed of a foam core surrounded by fiberglass. Below this there is a rigid stainless steel bridle connected to a wire rope which is used for the first 500 meters of the mooring. On these 500 meters of wire rope there are nine subsurface temperature sensors (thermistors) followed by two pressure sensors accompanying two more thermistors. The pressure readings correspond well with measurements of ocean depth. Water temperatures are measured below the surface at 1 meter (m), 20 m, 40 m, 60 m, 80 m, 100 m, 120 m, 140 m, 180 m, 300 m, and 500 m. Below 500 m, eight-strand plaited nylon line is used down to the anchor, with some sites requiring nearly 3 miles of line (see the diagram at http://www.pmel.noaa.gov/images/atlas.gif). The amazing thing is that the subsurface temperature sensors transmit and receive data from the buoy with an inductive coupling technique, which means that they’re not wired directly to the main line, yet data are transmitted along the cable. The sensors simply clamp onto the wire rope that serves as one of the inductive elements. This makes it much easier to assemble and deploy the extremely long cable. One aspect of meteorology that I find fascinating is the instrumentation, so I spend much of my time looking at the wiring and instrument manufacturers and asking the scientists many questions about what and why and how…they haven’t seemed to mind so far.
Here is some more information about the people and activities on the ship. There are 31 people on board (seven of us are women) with bunk space available for only two more. There are 5 officers, 1 cadet, 10 scientists, and the remaining crew members who focus on making the ship and science work efficiently. We all greatly appreciate their help. Everyone eats breakfast from 7:00-8:00 AM (0700-0800), lunch from 11:00-12:00 (1100-1200), and dinner from 4:30-5:30 PM (1630-1730). There is a small store selling candy and snacks, soda, shirts and hats on the ship that is open each night from 1930-2000 hours. We can email from any computer on board (I’ve counted at least 14 computers) and all of our email messages are sent and received in a bundle two times a day around 0900 and 1600. There is a laundry room with three washers/dryers on the second deck forward on the starboard side of the ship. There are two lounges with library materials including books, magazines and board games. Movies are shown every night on two channels in the lounges at both 1730 and repeated at 2000. So, you can see that it’s easy to keep busy on the ship. Two extra treats on this cruise include guitar/music playing sessions for all those who brought their musical instruments on board, and French lessons every other night. Je m’appelle Diane. J
After seeing more flying fish today, I decided to do some research to find out exactly what these fish are all about. I learned that they’re often referred to as “bluebirds of the sea” and that they spread their pectoral fins, glide for a few seconds, and then splash back into the sea. When they swim, their long fins are folded against their body. Flight speeds of up to 35 miles per hour have been monitored and flights as long as 13 seconds covering up to 450 feet have been timed. Photography has proven that they are gliders and not true flyers (all information obtained in “Fishes of the Pacific Coast” by Gar Goodson, Stanford University Press, 1988). I’ll keep my eye on these beauties and attempt to take a photo so you can share this delight!
The first person to answer my question of the day posed in my August 17th log was Tom Taddeo (my incredibly smart uncle from Mechanicsburg, PA – thanks for responding!) who gave the correct answer regarding the definition of pitch, roll, and yaw of a ship. Yes, pitch is when the ship tips in a fore-and-aft direction (from front to back), roll means the ship tips from side to side due to the sea or swell, and yaw means that the ship swings involuntarily from side to side when advancing forward. I’d love to hear from more of you so I can acknowledge more people in my logs.
The afternoon was spent testing the computer and camera equipment that will enable us to connect with all of you via upcoming live webcasts. Fortunately, everything seems to be working very well! We even managed to get a wireless microphone to work. We’ll be testing again tomorrow and hope to have a general broadcast ready to go by the end of the week. Please contact Jennifer Hammond at email@example.com if you’d like to receive the live broadcast. We’ll be interviewing scientists and talking about life at sea!
We enjoyed a wonderful dinner again tonight and I’m nearly ready for bed. It was great to hear from Dana Tomlinson (our last Teacher at Sea!), Nancy from ASU, and as always, my husband, family members, and friends. I invite more of you to email with questions that you might have about the Ka’imimoana or what it’s like to live on a ship.
Until tomorrow when I discuss CTD’s (what are they, you ask?!? – more tomorrow!)…bon soir.
Question of the day: What is the difference between sea wave height and swell wave height?
P.S. I just walked outside and rain was falling on the buoy deck under bright pink clouds – beautiful!