Module 4

Question 1

Covariance matrices are always…

Answer 1

Square (where m=n) and symmetric

Question 2

Principal Component Analysis (PCA)

Answer 2

Way of organizing complex data into simplistic structures that order variance

Question 3

Scatter plots reveal…

Answer 3

Correlation and covariance

Question 4

Covariance

Answer 4

Measure in how variance and mean values between two or more locations are related to each other

Question 5

Row vector

Answer 5

A matrix of a single row where m = 1

Question 6

Column vector

Answer 6

A matrix of a single column where n = 1

Question 7

What is a useful working definition of climate?

Answer 7

The average of weather over time

Question 8

Climate is what you expect while weather…

Answer 8

Is what you get

Question 9

Eigenvectors (e)

Answer 9

Special column vectors which remain unchanged when multiplied by a matrix, except that they are multiplied by a scalar, the eigenvalue

Question 10

How to arrange eigenvectors

Answer 10

In order of decreasing eigenvalue

Question 11

Total variance is the sum of the…

Answer 11

Eigenvalues

Question 12

Eigenvectors of a covariance matrix are called…

Answer 12

Principal components

Question 13

Principal components are useful…

Answer 13

For identifying climate signals

Question 14

What kind of information do principal components provide?

Answer 14

How data co-varies at different locations

Question 15

Empirical Orthogonal Fuctions (EOFs)

Answer 15

Analysis to study patterns of variability and how they change with time

Question 16

Pacific Decadal Oscillation (PDO)

Answer 16

The leading EOF of sea surface temperature anomalies over the North Pacific Ocean

Question 17

North Pacific Gyre Oscillation (NPGO)

Answer 17

Relates to changes in North Pacific Gyre Circulation, considering pressure gradients, geostrophic currents, and sea surface height

Question 18

Victoria Mode

Answer 18

Second EOF of sea surface temperature anomalies which measure north-to-south change rather than east-to-west

Question 19

Positive phase of NPGO

Answer 19

Stronger gyre circulations

Question 20

Negative phase of NPGO

Answer 20

Weaker gyre circulations