NOAA Teacher at Sea
Rachel Dane
Onboard NOAA Ship Ka’imimoana
April 29 – May 10, 2005
Mission: Oceanographic Survey
Geographical Area: Puerto Ayora, Isla Santa Cruz, Galapagos
Date: May 2, 2005
Science and Technology Log
Today is the big day—my first day at sea! I am excited and nervous at the same time; with no experience sailing my main hope is that sea legs will develop quickly for me! As Academy Bay receded behind us I was a bit wistful at having to leave the Galapagos with so much left unexplored, but I am phenomenally happy to have had the experience to travel here and truly hope to return someday.
Much of my afternoon was spent picking the brain of Patrick Rafter, our Ph.D. student from the Scripps Institution of Oceanography. Patrick boarded the KA in San Diego at the start of this cruise, and is amazingly knowledgeable about marine chemistry. He is also super patient with all of my questions, and very fun to chat with! You rock, Patrick! I basically asked him for a crash course in oceanic interactions, and this is what he taught me—too cool!
Essentially, the ocean can be viewed as the shallow, warm “mixed layer” at the surface and the deep, cold ocean. The dividing line between these two is called the thermocline, and it is the level at which a rapid change in water temperature occurs. Think about it as a multi-layered cake, with each water layer maintaining a fairly unique and consistent salinity, density and water temperature. Generally, the mixed layer at the surface is the warmest. In the equatorial pacific this surface layer has a depth of about 100m, and it is this first layer of oceanic cake that NOAA is most interested in studying. Normally, the thermocline that divides the high warm layer from the lower cold layer maintains a gradually increasing easterly slope. Under normal conditions, there is also less convection occurring and less wind is present. However, under El Nino conditions the dividing line between the two layers becomes more level, creating a deeper, warmer top layer. This increase in depth of the top layer affects marine interactions in several ways. First, a much larger percentage of surface water is warmer. Second, more convection is occurring due to the warmer water temperature, and third, more wind is present. One of the major uncertainties that TAO project data is attempting to explain is the cause of this thermocline change.
Personal Log
After a long Monday and a fabulous shrimp dinner, I feel quite tired and ready to call it a day. Tomorrow, Joe will set up my ship email account; I am really looking forward to being in touch with friends and loved ones at home, and also communicating with my students! It pleases me to report that, surprisingly, my stomach feels more settled at sea then it did when we were anchored in the Bay! I’m not feeling 100% yet, but definitely well enough to give the treadmill a try tomorrow—and maybe I can even skip the Dramamine… Until tomorrow!
