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: January 3, 2005
Location: Latitude 45°49.53’S, Longitude 75°03.22’W
Time: 0930
Weather Data from the Bridge
Air Temperature (Celsius) 11.90
Water Temperature (Celsius) 13.55
Wind Direction (degrees) 343.52
Wind Speed (knots) 5.85
Relative Humidity (percent) 66.50
Air Pressure (millibars) 1016.06
Cloud Cover 6/8 Altocumulus
Sunrise 0615
Sunset 2152
Question of the Day
What is phytoplankton?
Quote of the Day
“Dream no small dreams for they have no power to move men.” Johann Wolfgang von Goethe
Science Log
This afternoon I interviewed Co-chief Scientist, Julio Sepúlveda, an oceanography graduate student from the University of Concepción. Julio did his Master’s thesis work for eight months at Woods Hole Oceanographic Institution in Massachusetts. In April, he’s leaving for Germany to spend three years continuing his education toward a PhD. in marine organic geochemistry. Julio has been kind enough to further explain the work they’ve been doing onboard the RONALD H. BROWN. The Chilean group of scientists include Pamela Rossel, Sergio Contreras, Rodrigo Castro, Alejandro Avila, and Luis Bravo. He says that their work has two parts: the water column process and the sedimentary record. The water samples and the sediment traps give a “picture of the moment”. They conducted the transect of samples starting at the shallow coastal waters and moving into the deeper offshore waters. These samples will provide a gradient of the nutrient concentrations at the Bay of Concepción which is part of an active upwelling location. To put it simply, they are looking at how the phytoplankton (plant-like microscopic organisms) uses the nutrients in the water. In particular they are looking at the nitrogen stable isotopes (nitrogen atoms with different masses) and their concentrations. They are trying to see how this is related to El Niño which greatly affects Chile and many places around the world. Julio explained that normally the upwelling brings cooler water containing nutrient-rich materials up to the surface. During El Niño events, the upwelling brings warmer, less nutrient-rich waters to the surface. This changes many things including the weather. The causes of El Niño are multi-varied air-sea fluxes that are not fully understood. In the last ten years the scientific community has been especially interested in knowing the possible influence of global warming in the El Niño variability. It seems that its frequency is changing and several articles indicate that El Niño is occurring more often. So their research provides a few “pixels” for capturing the entire “picture” of El Niño.
The second part of their research involves the core samples. The purpose of the core sampling is to collect the layers of sediments on the ocean floor. Julio described the layers to be like pages in a history book. Each layer tells the “story” of what was going on in the water at that location during that time. They are also looking at the degradation of the organic matter in the core samples. So, Julio says the water samples tell us about the present and the core samples tell us about the past. Using these methods of research, it is their intention to better understand the history of El Niño and better predict future El Niño events.
Personal Log
This morning we entered the fjords! Several of us were up and outside on the deck at 0630, “ooohing” and “aaahing”, taking pictures even though it’s very cold and windy out there. It is an irresistible attraction. We’re passing by the peninsula Tres Montes and we’re headed for the Bay of Tarn. All morning we’ve been sailing by emerald forest-covered mountains and black craggy rocks that have been eroded into peculiar shapes by the waves relentlessly smashing against them. The clouds are ominous and hanging low. The albatross are soaring with wings spread wide. An occasional whale sends a plume of spray into the air. I want these scenes to be indelibly saturated into my mind’s eye. I never want to forget this. No dwellings. No other ships. It’s just us. Just us and the birds and the whales. It’s good. It’s all good.
Until tomorrow,
Mary
