TemperatureTemperature (along with salinity) affects the density and thus the stability of the water column. This in turn profoundly affects many biological processes in the upper ocean. Warmer water is less dense and thus tends to stay on top of colder water. During winter, storm winds mix the water column, and the temperature is nearly uniform in the top several hundred meters. As spring approaches, increasing solar radiation warms the surface waters and this warmer, buoyant water stays on top. This increases the stability of the water column, preventing deeper, nutrient-rich water from being mixed into the surface from below. The stable surface layer keeps the phytoplankton near the surface where there is plenty of light, plus plenty of nutrients brought to the surface by winter mixing. This combination of conditions allows the organisms to grow rapidly, and a spring bloom occurs.CTD.
CTD stands for Conductivity, Temperature, and Depth recorder. It is an electronic instrument that continuously records the salinity (by measuring conductivity), temperature, and depth (by measuring pressure) as the instrument is lowered on a hydrowire from a ship. The temperature is instantly recorded from the surface to depth, and gives a profile of temperature and how it changes throughout the water column. (Return to top)Salinity Salinity refers to the saltiness of the water. Salinity (along with temperature) affects the density and thus stability of the water column. This in turn profoundly affects many biological processes in the upper ocean. Saltier water is more dense and thus tends to sink below fresher water. Oceanographers can identify where a water mass comes from just by noting its salt content and temperature. CTD. CTD stands for Conductivity, Temperature, and Depth recorder. It is an electronic instrument that continuously records the salinity (by measuring conductivity), temperature, and depth (by measuring pressure) as the instrument is lowered on a hydrowire from a ship. The CTD continually records salinity from the surface to depth, and gives a profile of salinity and how it changes throughout the water column. BATS technicians also analyze the salinity of water collected from the CTD once it is back onboard ship. They make this measurement on a salinometer. This machine measures the salt content of the water directly, rather than by measuring the water's conductivity. (Return to top)Many organisms are also adapted to live at different temperatures; thus the temperature of the water can determine the diversity or numbers of organisms living there. As temperature changes with season and location, the diversity and numbers of organisms can change as well.
Temperature data is collected with the
Salinity data is collected with the
