NOAA Teacher at Sea
Onboard NOAA Ship KA‘IMIMOANA
January 4 – 22, 2010
Mission: Oceanographic Survey
Geographical Area: Hawaiian Islands
Date: January 7, 2010
Today was a day of transit. We did a lot of work on the buoys, preparing them for deployment and Rick, with the help of Tonya our Chief Survey Technician, got about half of the cups that his students decorated for ‘shrinking’ into the mesh bags to attach to the deep CTD when we do one . The CTD is a rosette of bottles that are sent to depth, in this case 3000 meters (how many feet is that and how many atmospheres of pressure?) where water samples and a record of the Conductivity (salinity), Temperature, and Depth are taken. These CTD’s will help provide a double check for the electronic data that our buoys collect and add to the data used to model El Nino/La Nina. One of the side activities of the CTD is to send down the cups to be squeezed by the pressure. We also have a cup of similar size that will be used as a control so that students will be able to see the changes that the cups undergo. Rick also has brought along a Styrofoam wig head from his daughter Teri to see the effect on a larger scale.
In addition to our work on the buoys we had our first at sea drills including an abandon ship drill.But since we had a similar drill in port we only were required to muster to our stations with our exposure suits, long sleeve shirt, head cover, and long pants and wear our personal flotation device.
A wee bit rocky today.We have a swell that seems to be coming from the starboard (right) aft quarter, which gives the ship a strange movement that has made some of the folks a little queasy.Ships tend to roll (movement around an imaginary line running bow to stern) pitch (movement up and down around an imaginary line running 90 degrees to the direction of roll) and yaw (movement left or right of the imaginary line running bow to stern).Today the KA is doing all three at the same time which is why we are encouraged to take Meclizine HCL (Dramamine) for a few days prior to the trip and for the first few days at sea. Taking this makes it easier for the crew to function in an environment that has un-natural motion without getting ‘seasick’. Even with the weird motion of the ship, we still have work to do and for us “newbies” things to learn before we are allowed to do them, like learn how to set the ‘painter line’ for the RHIB so that we will stay attached to the ship in the advent that the engine of the RIHB doesn’t start or other various bad things that can happen to a little boat in a big ocean. We didn’t actually ride in the RHIB today, we simply learned how to enter the boat, where to sit , where the emergency items are located, and how to start and steer the boat.
One of the tasks that needs to be done prior to the deployment of our first Buoy at 8N:155W is to determine (as close as possible) the ideal position for the buoy’s anchor. To do this it is essential to know the true depth of the ocean and the topography (collectively called bathymetry) of the area within a few miles of the target latitude and longitude for the buoy.Brian, our Chief Scientist, will determine the depth and location for the anchor by using both satellite sea surface heights and actual sonar depth data from ships that have been in the area. In reality, there really isn’t much hard data, physical sonar tracks, for much of the ocean and much of the depth is determined by the actually height of the sea surface as measured by satellite. These measurements take into account variables, such as orbit of the satellite, atmospheric effects on radar, and tides and compare the computer result to a mathematical ellipsoid model of the Earth’s shape. Sounds pretty complicated, and it is, but we can use this calculated sea surface to help determine the depth of the ocean since the surface mirrors the actual topography of the ocean floor. For Academy students, you will have the opportunity to do two activities from the American Meteorological Society (AMS) that will help you understand what it is that we are attempting to do.