Transcript: > Measuring Ocean Temperature
The ocean plays a vital role in the climate and weather patterns. But due to climate change, it is getting warmer. This leads to more extreme weather, like hurricanes and cyclones.
Different species in the ocean are adapted to specific conditions and are negatively affected by even small increases in temperature.
To understand how the environment is changing over time at different locations, we need to measure ocean temperature. When we measure our body temperature to check for fever, or the room temperature to keep comfortable, we use a thermometer – but how can we measure the temperature of the ocean?
> CTD and Temperature Sensors
Temperature sensors do the job for us. With temperature sensors onboard, a primary instrument called CTD is widely used for temperature measurement over the water depth in the ocean. CTD stands for conductivity (for salinity measurement), temperature, and depth. In addition to those measurements, multiple other sensors are normally assembled onto CTD to measure other physical or chemical properties of the seawater, for example oxygen sensors that measure the dissolved oxygen content of the seawater. Moreover, there are Niskin bottles attached to the carousel to collect water samples from the desired depth.
CTDs are lowered to the water from ships and send back readings to the scientists, who can see the temperature variations along the water depth. Temperature sensors can also be fitted to buoys or underwater gliders which send information to the scientists onshore.
Using these instruments, scientists measure water temperatures from the equator to the poles, from the surface to the deepest ocean.
But how long will it take us to measure the ocean temperature around the globe? How about taking a picture of the ocean from space and see it all at once?
> Satellite Technology for Ocean Temperature Measurement
We can measure the sea surface temperature using an instrument that detects heat; this instrument is called a ‘radiometer’. European Space Agency’s Sentinel-3 satellite carries the Sea and Land Surface Temperature Radiometer (SLSTR), which automatically takes temperature pictures of the skin of the ocean. Although only the surface ocean temperature can be measured this way, it helps greatly to monitor how climate change is affecting different areas of the ocean.