NOAA Teacher at Sea
Scott Sperber
Onboard Research Vessel Kilo Moana
July 9-17, 2009
Mission:Woods Hole Oceanographic Institution Hawaii Ocean Time series Station; Albert J. Plueddemann, Chief Scientist
Geographical area of cruise: Central Pacific, north of O’ahu
Date: July 13, 2009
Weather Data from the Bridge
Temperature: 24.13 C
Humidity: 72%
Science and Technology Log
The ship moved to the location of the old buoy last night. Visually, what a difference between the two. This one is certainly not the bright yellow color of the new one launched just 3 days ago. Yesterday I mentioned that the two thermometers on the new buoy were not reading identical temperatures and that they were about 0.4 degrees difference. After asking a few questions I came to be informed that the importance of this particular series of expeditions, WHOTS, is that it is the accuracy of this longevity study that gives it its validity. NOAA’s value of this study is that the study is an ongoing study not one that collects data brings it back to a lab and analyzes it and that is the end of it.
Science is not a one shot deal. This is something I have tried to stress with my students over the years. Good science, good data, is done with multiple sampling, either longevity study or many samples over a shorter period of time. Any data can happen once but for it to be valid it needs to be substantiated. For a number of years now the WHOTS study has not only brought back this type of data but has been able to note the small changes in this particular environment. It has shown how these micro changes, shown over time, have an overall affect on a macro scale. This is the credence of this study is. The fact that small changes do over a long period of time do show an effect. The simple fact that the ship stayed on station for 3 days to calibrate the measurements with the new buoy, and then moved to the location of the old buoy shows the effort to make sure that even the most infinitesimal piece of data is made constant and notable.
Today, at this second location, there is being made shallow casts (samplings) with the SEABIRD at depths up to 200m every 4 hours. These depths are the same depths as those of the instruments on the buoys. Sometimes during the course of a years study the sensors will have a tendency to drift (change) or jump in their data. These casts, engineering calibration casts, close to the buoys standardize the CTDs again reading temperature, conductivity, dissolved oxygen and then calculating density. These calibrations of any drifts serve as a comparison over the course of the year and are used to recalibrate the data. With the recovery of the old buoy, one year worth of data will be downloaded and the similarities of all data with past weather conditions will be analyzed. Again the sensors that are on the buoy are; MICROCATS, acoustic Doppler current meters and vector measuring current meters.
Personal Log
Kuhio gave a shot at fishing this morning. Because the old buoy has been in the water for a year it has become a floating reef. So far Kuhio has hooked into and rough aboard 4 Mahi mahi. YUM, fresh fish tonight. I have been told that all over the old buoy and its sensors will be organisms of all types. Jeff has asked be if I would help scrap off the old sensors. OH BOY. Dirty smelly job I am sure.