January 11 lecture Flashcards
What are XBT’s? what are they used for?
“eXpendable Bathy Theromgraph”
used in property sampling to measure ocean temperatures in the top 1000 - 1500 m range
What makes XBT’s Good to use?
- cheap and expendable
- Can be launched from merchant ships
What are sampling bottles and what are they used for?
also called “Nasen bottles”
- They collect samples to be brought to the surface for future examination?
What is one PRO and one CON of sampling bottles?
PRO: They can have thermometers added to them
CON: Care must be taken in order to prevent cross contamination of the bottles samples.
What are CTD’s What can it measure ( four things )
“Conductivity Temperature
Device”
- Measures temperature
- conductivity
- Salinity
- It can also measure depth as the probe descends
What is a Rosette sampler?
It is a device that includes a CDT and several sampling bottles.
The bottles can be activated at any depth as the device descends
What four things must be considered when Planning a ocean research mission?
- Cruise plan must be generated
- Must focus on the scientific objectives
- Identify stations where observations can be made
- To make measurements thru region to understand spatial structure.
When measuring Currents what are Direct measurements?
Directly determine speed and direction of ocean motion.
What are the two types of Direct current measurements?
Passive and active
When measuring currents what are indirect methods?
They infer motion from other types of measurements
What are indirect measurements of currents useful for?
They are usefu for gathering data of motion over larger areas and longer time scales
What are Indirect measuremnets of currents most commonly based off of? And what is their biggest flaw?
they are based upon ocean tracer measurements,
although there is data density issues in some regions.
What is Passive (Direct) measurements? How are they conducted?
They basically involve placing an item in the water and letting it flow and following it.
What type of instrument is used for Passive (Direct) measurements of currents?
Simplest ones are unplanned, based on objects that end up in the water.
Like plastic or wood.
What are Subsurface Floats? What are they used for?
They are devices that can be set to float at a given depth or density of water in order to follow a water mass.
They will return to the surface in order to send off their data and then return back to their position
