How is ultra-low frequency (ULF) hydromagnetic power typically characterized in the deep polar cap?

AGO5 Noon (87*S CGMLat)

AGO6 Noon (85*S CGMLat)

SPA Noon (75*S CGMLat)

MCM Noon (80*S CGMLat)

Pc6

Pc5

Pc4

N E V Median Power

…as a function of… (i) frequency band (row),

(ii) magnetic field direction (column),

(iii) location (color), and � (iv) local time (x axis)

Kevin Urban: Sample Visualizations from Rethinking the Polar Cap (JGR, 2016)

Median-Relative Spectra = (Dynamic Spectra) / (Time-Independent

Median Spectrum)

AGO5 @ 87*S CGMLat

100  10  1  0.1  0.01  0.001  1e-­‐4  1e-­‐5  1e-­‐6  1e-­‐7  1-­‐e-­‐8  

nT2  

Pc7  Pc6  Pc5  Pc4  Pc3  

Pc7  Pc6  Pc5  Pc4  Pc3  

50  25  10  5.0  2.0  1.0  0.50  0.20  0.10  0.04  0.01  

Pc7  Pc6  Pc5  Pc4  Pc3  

Pc7  Pc6  Pc5  Pc4  Pc3  

Pmed{f}  

Kevin Urban: Sample Visualizations from Rethinking the Polar Cap (JGR, 2016)

AGO5 @ 87*S CGMLat AGO6 @ 85*S CGMLat MCM @ 80*S CGMLat

CGM

EDA

EDD

AGO5

VOS

DMC

AGO6

MIRAGO1

AGO4

MCMCSY

DRV

TNB

SBA

SUDSPA

DVS

2001

50  

25  

10  

5.0  

2.0  

1.0  

0.50  

0.20  

0.10  

0.04  

0.01  

Pmed{f}  

Pc7  Pc6  Pc5  Pc4  Pc3  

Pc7  Pc6  Pc5  Pc4  Pc3  

Pc7  Pc6  Pc5  Pc4  Pc3  

How is ultra-low frequency (ULF) hydromagnetic power typically characterized in the deep polar cap?

Kevin Urban: Sample Visualizations from Rethinking the Polar Cap (JGR, 2016)