Page 1 of 11

### Dynamic Planet (Oceanography)

Posted: September 3rd, 2019, 11:08 am
Alright we're back for the 2020 season!
We'll be asking questions, remembering how to use the hide function in answers, and doing good.
(which, if you forgot is)

Code: Select all

``[hide]title| content[/hide]``
or

Code: Select all

``[answer]content[/answer]``
Let's begin!
1.) What is the mixing time of the ocean, and what does it mean of a chemical's residency period is less than that? (in respect to that chemical)
2.) Name 3 differences between Western boundary currents and Eastern boundary currents. (explain why)
3.) Why are tides not identical across the globe?

### Re: Dynamic Planet (Oceanography)

Posted: September 3rd, 2019, 6:42 pm
Well here goes nothing... And hiding doesn't seem to work, but I think if u Quote u can see my answers
```
1. Mixing time is about 1000 years...if a chemical's residence time<mixing time, I'm p sure that means it's not mixed well in the oceans(i.e. non-uniform distribution)
2. a)Western Currents travel from the equator up, while eastern travel to the equator. This is because Coriolis Effect
b) Western are warmer, eastern are cold - B/c Western come from the equator, eastern from the poles
c) Western are stronger & narrower & faster & deeper than Eastern Currents cuz surface wind, gravity, Coriolis force. Basically, cuz ekman trans (which is coriolis force dragging 90 degrees to the right ), the water converges in a bulge near the center of the gyre. But since the earth is rotating....to the right(counterclockwise) the bulge shifts toward the "left" (west). Gravity acts downward, so ofc eastern currents have more "space" to "stretch out" while western currents are "cramped" and thus get the 4 properties.

Okay I'm not totally sure that's what u wanted for this question...

3) Tides vary around the world because they are caused by the gravity interplay between the moon and the sun. The moon pulls the water&earth, causing two tidal bulges on either side of the earth, and the earth rotates through these bulges causing *in most places* two high and two low tides.'Cept the earth is tilted so some places only get one high&low tide
```

### Re: Dynamic Planet (Oceanography)

Posted: September 4th, 2019, 5:52 am
Good except mixing time is 1600 years and if a substance has a residence time less than that it is a nonconservative constituent and the reason tides are different is cause of the dynamic theory of tides meaning that due to the fact that land exists and obstructs tides, tides rotate around amphidromic points which determine if they are diurnal, semidiurnal, etc. based in whenever they are Your turn!

### Re: Dynamic Planet (Oceanography)

Posted: September 5th, 2019, 4:12 am
Welp, messed that one up

El Nino!

1.What cell does El Nino "operate in"/"happen in"?(Sorry if this is vague....)
2. What are the beginning steps of El Nino? (How is it caused?) (Include change in Pressure systems, winds, and ocean currents)
3. The opposite of El Nino? And why it's good for fisheries?

### Re: Dynamic Planet (Oceanography)

Posted: September 5th, 2019, 6:40 am
AlfWeg wrote:
September 5th, 2019, 4:12 am
1.What cell does El Nino "operate in"/"happen in"?(Sorry if this is vague....)
2. What are the beginning steps of El Nino? (How is it caused?) (Include change in Pressure systems, winds, and ocean currents)
3. The opposite of El Nino? And why it's good for fisheries?

Ooh I had this stuff on my note sheet back in 2016, let’s see how we do lol

1. I guess like a Hadley cell?
2. The eastern pacific is warmed by an ocean current moving south, and therefore pressure decreases. Also, wind normally blowing east to west either weakens or reverses direction (I think? I may have forgotten some stuff oops)
3. La Nina, which is good for fish bc it leads to upwelling of cooler water which attracts fish

### Re: Dynamic Planet (Oceanography)

Posted: September 5th, 2019, 8:19 am
Giantpants wrote:
September 5th, 2019, 6:40 am
AlfWeg wrote:
September 5th, 2019, 4:12 am
1.What cell does El Nino "operate in"/"happen in"?(Sorry if this is vague....)
2. What are the beginning steps of El Nino? (How is it caused?) (Include change in Pressure systems, winds, and ocean currents)
3. The opposite of El Nino? And why it's good for fisheries?

Ooh I had this stuff on my note sheet back in 2016, let’s see how we do lol

1. I guess like a Hadley cell?
2. The eastern pacific is warmed by an ocean current moving south, and therefore pressure decreases. Also, wind normally blowing east to west either weakens or reverses direction (I think? I may have forgotten some stuff oops)
3. La Nina, which is good for fish bc it leads to upwelling of cooler water which attracts fish
Pretty much except The cell is called “Walker” or Walker Circulation, Wikipedia covers this nicely. For 2) the trade winds weaken/reverse, which cause the current that the winds push to weaken. This stops upwelling, and, not related, causes the pressure systems above Peru and Australia to swap. 3) is right, except upwelling brings up food from the ocean floor which fish are attracted to Your turn!

### Re: Dynamic Planet (Oceanography)

Posted: September 5th, 2019, 10:50 pm
Ohh okay. Thanks!
Alright...

1. From top to bottom, what are the layers in a water column of the pelagic zone?
2. What are Secchi disks used for?
3. Describe what happens to a waves properties (wavelength, amplitude, period) as it approaches the shore.

### Re: Dynamic Planet (Oceanography)

Posted: September 6th, 2019, 4:30 am
Giantpants wrote:
September 5th, 2019, 10:50 pm
Ohh okay. Thanks!
Alright...

1. From top to bottom, what are the layers in a water column of the pelagic zone?
2. What are Secchi disks used for?
3. Describe what happens to a waves properties (wavelength, amplitude, period) as it approaches the shore.
1. Epipelagic, Mesopelagic, Bathypelagic, Abysopelagic, Hadal zone
2. They measure turbidity or the amount of particles in water
3. When waves approach the shore they turn into shallow water waves once their depth is 1/20 of their wavelength, their wavelength shortens due to friction against the bottom and their amplitude heightens. Period shortens and the wave turns into a breaker.

### Re: Dynamic Planet (Oceanography)

Posted: September 6th, 2019, 6:33 am
JoeyC wrote:
September 6th, 2019, 4:30 am
1. Epipelagic, Mesopelagic, Bathypelagic, Abysopelagic, Hadal zone
2. They measure turbidity or the amount of particles in water
3. When waves approach the shore they turn into shallow water waves once their depth is 1/20 of their wavelength, their wavelength shortens due to friction against the bottom and their amplitude heightens. Period shortens and the wave turns into a breaker.

This looks good to me, except I’m pretty sure they become shallow water waves when they reach 1/2 of the wavelength. Also I forgot to ask about the wave speed, but that decreases also. So glad people know what Secchi disks are, one time they were on a test and my brother and I were so happy lmao. Anyway your turn!

### Re: Dynamic Planet (Oceanography)

Posted: September 6th, 2019, 6:49 am
They count as deep water waves at depths of 1/2 their wavelength because they do not touch bottom in a meaningful way that friction applies in a notable way 1,) Which way does warm and cold air flow in each cell? (The 3 main ones and for both hemispheres)
2.) Why do cyclones seem to defy the Coriolis effect?
3.) How does India modify weather patterns (mainly in respect to equatorial cells)