OceanEddiesScan (Your good friend to scan eddies in sea surface height field)

based on the Chelton SSH method(Chelton et al., 2011)

Forth Edition

2024.5.27

OES version 0.2

• The Ocean Eddy Scan now fixed most of the bugs

let's present you some examples:

Scan eddies in a SSH data:

use singleSliceScan(ssh, lat, lon) to scan the ssh field:

load(datapath);

eddies = singleSliceScan(ssh, lat, lon);

which will return a 1xN struct, each struct contains the eddies characters like:

• amplitude
• radius
• latitude and longtitude of the center
• cyclone or anticyclone eddy
• edge of the eddy

you can use map toolbox like m_map to draw the result like:

which the black lines present the eddies' edges, and the center point color represent the cyclone(blue) and anticyclone(red)

Ocean Scan

For one slice (one day) field data, you can use the function: singleSliceScan(ssh, lat, lon) to get the eddies in the ssh field.

Third Edition

2024.4.27

OES version 0.1.2

• fixed some bugs
• Add the contour info of the eddy, the edge of the eddies now will produce.

Second Edition

2024.4.22

OES version 0.1.1

• Add the Thermo Dynamic Scan, which is used to judge if the eddies is a warm or cold core.
• fixed some bugs.
• Note: while using the field which longtitude is uncontinuous, make it continuous in your certain field.

First Edition

2024.4.15

I GIVE U THE FIRST EDITION!

OceanEddiesScan(OES) version 0.1.0

within:

eddiesScan.m

the eddies scan function, with input eddiesScan(ssh, lat, lon, dates).

I scan every day's ssh, by using the singleSliceScan.m in the utils, then use eddyTrack.m to combine them.

I will explain these funcitions in utils later.

test:

some test function to test the function eddiesScan.m, contourData.m and singleSliceScan.m

I recommod eddyScanTest to check if the main function of the project eddiesScan works.

test data:

some ssh data, that I stole from the other project called OceanEddies, their one is pretty complicate, so I created my own one.

utils

all the function use in eddiesScan.m

some functions here can be able to used in other project:

calCirAver(field, lat, lon, center, r)

I haven't use it yet, it's a function return the points average field value on the circle u give by center and r

contourData(field, lat, lon)

It's a good function gives u the field contour information, and returns a struct of every contour.

the struct is more readable than the return value of contourData, but it is also the reason for a low speed in the project

dLatLon(lat1, lat2, lon1, lon2)

return the distance on spherical surface, by calculating the angle between two vectors and times Earth radius with it.

eddyTrack(oldEddy, newEddy, date)

to update the eddy set by using the s value:

$$ s = \sqrt{(\frac{\Delta a}{a_0})^2+(\frac{\Delta d}{d_0})^2+(\frac{\Delta A}{A_0})^2} $$

which a is area, d is distance, and A is ampltitude. To connact the smallest s value of oldEddy.

singleSliceScan(ssh, lat, lon)

to scan a single slice, but u can also use eddiesScan to do that

I dont wanna introduce the rest, I'm tired and I wanna sleep. Good day, sir.