hidden treasures in the dmsp database...2016/10/04 · hidden treasures in the dmsp database...

Hidden Treasures in the DMSP Database

Raffiniert ist der Herrgott aber boshaft ist er nicht.

William J. Burke

Boston College / Institute for Scientific Research

4 October 2016

DMSP’s Hidden Treasures

Abstract

Since the early 1960s optical sensors on DMSP satellites have provided meteorological

information about regions of Earth that are strategically important but not easily accessible such

as oceans and the Asian land mass. Starting in the late 1970s DMSP’s mission grew to include

space environment monitors. Acquired space data have supported development of particle

precipitation and cross polar cap potential models as well as numerous case studies related to solar

wind-magnetosphere-ionosphere coupling. This presentation follows the evolution of the author’s

efforts to find new ways to combine data from DMSP plasma-drift, magnetometer and particle

detectors for remotely sensing characteristics of energy sources in the magnetosheath and ring

current that drive stormtime electrodynamics in the high-latitude ionosphere. Critical for

achieving this goal is the reflection coefficient of Alfvén waves that carry Poynting flux between

distant generators to ionospheric loads. Data acquired by multiple sensors on DMSP F16, F17

and F18 during the magnetic storm of 17 March 2013 are used to illustrate both the subtle

opportunities and pitfalls encountered while pursuing this goal.

Outline

• My (present) understanding of relevant high-latitude electrodynamics

• New opportunities found after MSTIDs entered my life

- Interhemispheric coupling at mid latitudes

- C/NOFS observations and Alfvén wave reflectance

• DMSP orbital mechanics and scientific payloads

• Magnetometer and ion-drift coordinate systems

• Separating δB and V components parallel and perpendicular to B0

• DMSP measurements during 17 March 2013 storm

• Opportunities and limits of Alfvén-wave reflection analyses

• Summary and Conclusions


Brief Historical Background


• Dungey, (1961): Magnetic merging hypothesis

• Vasyliunas, (1970): Ring current pressure gradients drive R-2 FACs

• Heikkila, (198?): A j E problem with the merging hypothesis

• Nopper & Carovillano, (1978), Relation between FACs and potential

distributions in the ionosphere and magnetosphere.

• Siscoe, (1983): FACs are carried by shear Alfvén waves

• Kan and Sun (1985): Relationship between Alfvén wave δB and VP

• Siscoe et al, (2002): R-1 system effects on B in magnetosphere

• Love and Gannon (2006) , Local-time distribution of Dst DB after

main-phase onset

5

1 mV/m ≈ 6.4 kV/RE

2

02

E G SW TV B Sin

IEF

SW gate Residual

Empirical Linear Relations

AE, S3-2, DMSP & DE-2

The Bastille Day 2000 storm roused us from our linear slumber

Define: eVS = PC/ 2 RE LY

The solar wind carries a weak

magnetic field that in the Earth’s

frame of reference looks like an

electric field that “imposes” a

potential across the polar cap.

61.5 14.4 / ( )Y X SWL L P nPa



Bastille Day Lesson

PC saturates when IMF BZ << 0

for long periods

Siscoe et al. (JGR, 2002) used MRC’s

Integrated Space Model

R1 currents alter magnetopause shape

and thereby limit merging rate

PC = E S / (E + S )

S = 1600 PSW 0.33

(nPa) / S

E = 0 + G V BT Sin2 (/2)

Validation using DMSP

Ober et al. (JGR, 2003) 10.7( )

2

PC

Y

dDst DstF

dt L

17 April 2002


Sudden Commencement Early Main Phase Deep main phase

Local time distribution of Dst magnetic perturbations

Love and Gannon (2010), Movie-maps of low-latitude magnetic storm

disturbances, Space Weather , 18, doi:10.1029/2009SW0005 18.


j

j

E

E j

j

E

B

VSW

Heikilla’s Dilemma Dungey’s Hypothesis

A Big Picture Consideration

In the post-cusp magnetosheath j E < 0. Plasma flow in it must provide the

mechanical energy that generates the field-aligned responsible for convection

in the polar cap.


0

200

400

600

800

1000

B

Z (

nT

)

X’

Y’

BY’

(1) Perturbation:

(2) Rotation angle:

(3) Ampère’s law:

2 2

Y X sat X of Y sat Y ofB B B B B

1cos 37 /Ysat XB B

||

0 0

1 1Y YB d Bj

X Vsat Cos dt

Infinite Current Sheet Approximation

BX

By

BZ

UT

MLat

MLT

02:59

41.0

19.6

03:02

49.9

19.4

03:05

58.70

19.0

03:08

67.0

18.3

03:11

74.0

17.1

1 June 2013


A MSTID Generated Opportuniy

6 March 1973

5 March 1973

7 March 1973

14 October 1973

21-22 June 1973

ISR experiment at Arecibo

Behnke, R. (1979) F layer

height bands in the nocturnal

ionosphere over Arecibo,

J. Geophys. Res., 84, 974-978.

Burnside et al. JGR. (1983)

Radar + Fabry-Perrot study

Of common volumes

1. Typical horizontal scales of 200 to 500 km and Dhmax 20 km.

2. Typical periods of an hour or two.

3. Extend in length can exceed 2000 km, between 20 and 55 MLat

4. Orientation: NE–SW (NW – SE in northern (southern) hemisphere,

tilted ~ 20 from magnetic meridians.

5. Southwest (northwest) phase velocities in the northern (southern)

hemisphere with speeds of ~ 200 m/s.

6. Detection rates much higher near solstices than equinoxes and

favor the winter hemisphere.

7. No obvious dependence on levels of magnetic activity.

8. Mostly occur with sporadic E layers in conjugate hemispheres.

9. As described here, MSTIDs are post-sunset phenomena.

10. Studied with ionosondes, GPS/TEC networks, All-Sky-Imagers, and

coherent/incoherent backscatter radars.

MSTID Properties

TEC measurements

over North America

Tsugawa et al. (2007)

Conjugate E-field

perturbations

from DE-2.

Saito et al. (1985)


Interhemispheric Coupling Problem

• Similar MSTID structures at conjugate locations reported in the Asian-Australian

and American sectors at stations separated by thousands of kilometers.

• Unlikely that similar driving gravity wave structures develop simultaneously.

• Some mechanism must carry energy/information between hemispheres.

• Electrostatic E-fields alone cannot generate field-aligned Poynting flux, i.e.

• Information/energy must be carried by inter-hemispheric field-aligned currents

(FACs) flowing between generator and load ionospheres.

• Siscoe (1983) showed : Shear Alfvén waves are the only MHD mode carries FACs.

0|| 0

0

ˆ 0e sE BS B


MSTID Phenomenology and Dynamics


||

ˆ ˆ ˆ ˆ( ) ( ) ˆmer zon mer zon mer zon zon mer

o o o

E E B B E B E BE BS B

|| 2ˆ0.8 [ ( / ) ( ) ( / ) ( )]zon mer mer zon

WS E mV m B nT E mV m B nT B

m

In mks units has the dimensions Watts / m2 with E in Volts/m and B in Tesla.

Converting to common E and B units yield S with dimensions in W /m2

• Poynting vector component along B:

• AFRL tasked us to investigate CNOFS’ potential for remotely identifying

MSTID activity.

• Electric and magnetic perturbation vector from CNOFS satellite are provided

as the field-aligned, meridional , azimuthal components

||S

0 0ˆ ˆ* ( ) *A A S

j B E B E

01/A AVS = Alfvén

conductance

Kan and Sun (1985) derived an equation for currents carried by Alfvén waves.

• Plasma velocity induced by Alfvén wave with magnetic perturbation

• + and – signs refer to wave propagation antiparallel and parallel to .

• Taking the curl of yields:


B V

0

0

0 0

ˆ / i p i A

E BBV B A m N V

B B

0B

*BB

No

rth

ern

Hem

isp

her

e


MSTID Phenomenology and Dynamics

Boston University All-Sky Imager Network

BU all-sky image data are available at http://sirius.bu.edu/dataview/data/

ASI schematic

Mendillo et al. (1997)

557.7

605.0

630.0

644.4

695.0

777.4

nm

• On 17 Feb 2010 C/NOFS

made three passes across

the northern portion of the

El Leoncito FoV.

• MSTID structures observed

in 630.0 nm all-sky images

at El Leoncito and Arecibo

• C/NOFS recorded ion density,

electric and magnetic field

perturbations

El Leoncito

Glat 31.8° S,

Glong 69.3° W,

Mlat 18.0° S

http://sirius.bu.edu/dataview/data/

Methodology used in data analysis:

• VEFI electric and magnetic field data first calculated in s/c coordinates.

• Transform into coordinates, assuming E B = 0

• Perform least-square polynomial regression analyses on E and B components.

• Calculate E* and B* by subtracting regression from measured values of E and B

• Calculate S = (E* B*) / 0 and V* = (E* ) / B

Example: N* calculation

ˆ ˆB

ˆ B

17 February 2010 Observations

• Subtract IGRF and Vsat B0 components

from measured B and E vectors.

• Fit data to 4th order polynomials

• Subtracted fit from initial data and

calculated E*, B* and N*

• < E*>, < B* >, <V*> and <N*> 0


17 February 2010 Observations

C/NOFS - El Leoncito Conjunction

• Limited B* measurements during 1st pass

• S|| mostly positive ; maximum ~ 8 W/m2

• Phases of B* and V* anticorrelate

• Consistent with Alfvén wave propagation

along B0 from southern hemisphere source!

80 W 60 W 70 W

20 S

30 S

40 S


Alfvén Wave Reflectance

• Often when I have spoken about Alfvénic coupling between high and low

altitudes it is easy to see the light go on. “Yeah, with measured E and δB

you can just ratio them to calculate Alfvén speeds and thus show you are right!”

• This is not the case: measured E* and δB* are superpositions of incident

( Ei and δBi ) and reflected (E*r and δB*r ) wave fields, where

and

.

• The reflection () coefficient for Alfvén waves in the ionosphere is

ΣPR and ΣAR = 1/μ0VAR are the Pedersen and Alfvénic conductances in

the refection layer. Since ΣPR > ΣAR , > 0.

• Polarities of E and S|| change by 180 on reflection, that of δB does not.

• We next demonstrate a way to determine using only measured E* and δB*

r iB B r iE E

( ) / ( )PR AR PR AR S S S S


Mallinckrodt and Carlson, 1978]

Alfven Wave Reflectance

• The measured Poynting flux (S||m) is

Since at the detection site,

some vector algebra shows that

• Define a quantity Pm that has the same dimensions as S|| m

• Then and

• This information makes it possible to infer the incident E, δB and S||

2 2m m i i

|| m 0 0 || i

0 0

E × δB E × δBˆ ˆS = B = 1- B = S 1- μ μ

0

0

0 0

ˆ / i i

i i i p i A

B E BV B A m N V

B B

22 2 2

|| m 0 || |S |= E (1 ) | | (1 )i i

A

cS

Ve


2 2

22

0 0P = E E E 1m m m i

A A

c c

V Ve e

|S|| m | / Pm = (1+ ) / (1- ) || || = (| | ) / (| | )m m m mS P S P


0

0.2

0.4

0.6

0.8

1

0

0.5

1

1.5

2

2.5

|B

*m

| |

B*

i| (n

T)

0

10

20

30

40

50

3:20 3:21 3:22

S||

m

S||

i (

W/m

2)

0

5

10

15

20

|E*

m |

|E

*i |

(m

V/m

)

0

2

4

6

8

10

0

1

2

3

4

5

|S ||

| (

W

/m 2

) P* m

( W

/m 2 )

1 2 3 4

-4

-2

0

2

4

E*

mer

E*

zon

(mV

/m)

-4

-2

0

2

4

B

*m

er

B*zon

(n

T)

Alfven Wave Reflectance

Can this technique be applied at high latitudes

using DMSP measurements?

DMSP Orbital Mechanics


Polar orbit (I = 90o)

Sun-synchronous

DMSP: h 848 km

I = 98.8

Angular momentum

vector for polar orbit

• Angular momentum vectors of polar-

orbiting s/c fixed in inertial coordinate

system but appear to precess to west

by < 1 per day with respect t0 LT.

• Sun-synchronous orbits are fixed

wrt LT, but angular momentum vectors

precesses to east by < 1 per day in

inertial coordinates.

• Torqueing effect of crossing Earth’s

equatorial bulge.

• Satellite drag decreases orbit and

diminishes equatorial torque, causing

orbital planes to precess slowly to west.


• SSJ5: Fluxes of electrons and ions

30 eV – 30 keV 19 log-spaced steps.

• SSM: B field vectors on 5-m boom

• SSIES:

Ion Drift Meter: VH & VV

Retarding Potential Analyzer:

Ni, Ti , Vin-track, ion composition Spherical Langmuir Probe: Ne, Te

DMSP Scientific Sensors and Data Presentation

• SSM data provided as measured and

at 1-s cadence, in s/c centered coordinates with

X vertically downward, Y in-track, and

Z anti-sunward directions.

• where = IGRF field

transformed into s/c coordinates.

• UTD provides V in s/c centered coordinates

with X in-track, Y sunward, and

Z vertically upward directions.

• For clarity in calculations presented below

the UTD coordinate system was adopted and

transformed accordingly.

mB

0B0- , mB B B

B

0, , mB B B


DMSP Data Analysis: Untangling Nature’s Web at high Latitudes

The going-in emphasis was to adapt DMSP data to find incident quantities

via Kan-Sun model in high-latitude environments. Three issues appear:

(1) Must unfold and components along and perpendicular to .

applied to F16, F17 and F18 data from 17 March 2013 storm

(2) Must distinguish between electrostatic from electromagnetic contributions

(3) Must also identify regions in which

mBmV 0B

0 0 0 0 0 0 ||ˆ ˆ ˆ ˆ ˆ ˆ( ) ( ) ( )B B B B B B B B B B B B

0 0 0 0 0 0 ||ˆ ˆ ˆ ˆ ˆ ˆ( ) ( ) ( )V B V B B B V B V B V V

0 0

0

1ˆ ˆ ( ) + ( )m es em

AV B B V V

t B

= / 0

mY

m

BB

X


• Examples to the left come from

calculation of (top) and

B || , V || (bottom) from magnetic

perturbation and plasma velocity

components measured during a north

high-latitude pass of F16 between

06:46 and 0716 UT on 17 March 2013.

• During this and all other high-latitude

passes of F16, F17 and F18, calculations

indicated that

B || X B || Y and V Z 0

• Only BZ and VZ had significant field-

aligned very small perpendicular

components at high latitudes.

• This result is representative of what

was seen by all DMSP satellites

throughout the day.

Perpendicular and Parallel Component Separation


Interplanetary Parameters and Sym-H Index on 17 March 2013

Sym-H

SSC: -9 to +31 nT, 05:57-06:01 UT

1st minimum: -104 nT, 10:24 UT

2nd minimum: -130 nT, 20:30 UT

Presented intervals:


F16 MLat- MLT

trajectories in

early main phase

Output shows that: • VZ and BZ very small

at high latitudes in all cases.

• In polar cap VY and BY

strongly anti-correlated,

less so in auroral oval.

• Agrees with K-S model with

VY - BY variations 180

out of phase in northern high

magnetic latitudes.

• VX noisy everywhere, and

sometime in phase with BX

during this northern hemi-

sphere pass.

12

50o

70o 18 06

00

60o 80o


Early Main Phase Northern Hemisphere


-3000

-1500

0

1500

3000

VX

perp

V

Y p

erp

V

Z p

erp

(m/s

)

-1500

-750

0

750

1500

7:40 7:45 7:50 7:55 8:00 8:05B

X p

erp

B

Y p

erp

BZ

per

p (

nT

)

7:20 7:25 7:30 7:35 7:40 7:45 7:35 7:40 7:45 7:50 7:55 8:00

Early Main Phase Southern Hemisphere


Late Main Phase Northern Hemisphere

16:40 16:45 16:50 16:55 17:00 17:05

-1600

-800

0

800

1600

15:15 15:20 15:25 15:30 15:35 15:40 15:45B

X p

erp

B

Y p

erp

BZ

per

p (

nT

)

-3000

-1500

0

1500

3000

VX

perp

V

Y p

erp

V

Z p

erp

(m/s

)

16:05 16:10 16:15 16:20 16:25 16:3014:10 14:15 14:20 14:25 14:30 14:35

-1600

-800

0

800

1600

16:05 16:10 16:15 16:20 16:25 16:30B

X p

erp

B

Y p

erp

BZ

per

p (

nT

)

-3000

-1500

0

1500

3000

VX

perp

V

Y p

erp

V

Z p

erp

(m/s

)


Late Main Phase Southern Hemisphere


We next return to the Kan-Sun equation . The – sign applies to

Alfvén waves propagating toward the northern ionosphere. Since this expresses a

vector relationship, it applies to all relevant components. First, concentrate on the

measured Y component of and .

Their ratio is

A major problem remains: The ratio yields a single equation

with two unknowns and .

Does this represent the end of the road?

With SSIES and SSM alone, mostly Yes, but DMSP offers other paths.

0 /V B

BV

( ) (1 )Ym Y es Yi Yr Y es YiV V V V V V

0

(1 ) 1 (1 )

(1 ) (1 )

Ym Y es Yi Y es

Ym Ym Yi Ym

V V V V

B B B B

(1 )Ym Yi Yr YiB B B B

/Y m Y mV B Y esV


0

0

1/ 1

/ 1 1

AR PRPR AR

PR AR AR PR

V

V

S S S

S S S

Two approaches suggest themselves:

• The first was to simply ignore Ves so that .

• This approach appears to be most valid in the polar cap. During the northern

polar cap transit of F16 (16:46- 1716 UT) this approximation yielded 0.8

• At auroral latitudes evidence for electrostatic effects were too large to ignore.

• The second was to return to the Mallinckrodt and Carlson (1978) formula

then rely on SSJ5 and empirically based models to estimate ΣPR and ΣAR..

0

1 (1 )

(1 )

Ym

Ym

V

B

Resolving the Dilemma

10.70.77P FS

02

40

16

e

P

EQ

E

S

5.7p

P oQS

2 2( ) ( )e p e p

P P P

S S S


Auroral Oval: Precipitating electrons [Robinson et al. , 1987]

Precipitating protons [Galand and Richmond, 2000]

Electrons and protons

Q0 = energy flux in mW/m2 => eV/cm2-s-sr => 10-11 mW/m2 assuming isotropy

over downcoming hemisphere

<E> in keV => 0.5 – 20 keV for precipitating electrons and > 5 keV for protons

==========================================================================

Polar cap: Ober et al. [2003] used ACE and DMSP data acquired over a large portion

of a solar cycle to show that the stormtime saturation potential depended on F10.7.

With F10.7 = 124 on 17 March 2013 ΣP = 8.64 mho in polar cap.

In the dipole approximation B 6 104 nT. IRI puts average NHMF2 5.2 105 cm-3 .

Thus, 0 VAR 0.57 mho-1 and 0.65.

Toward Resolving the Dilemma


Summary and Conclusions

• This presentation sought to demonstrate that in principle the Kan-Sun equation

can be applied to DMSP measurements to gain information about impedance

mismatches between electrodynamic generators in the magnetosphere and

magnetosheath with circuit loads in the high-latitude ionosphere.

• Unfortunately, the equation relating measured V and δB contains two variables

Ves and . While it is possible to identify some regions in which Ves effects

exist their values are not always clear.

• Empirically based models, along with SSJ measurements can be employed

to estimate , but to date, have not been implements extensively.

• My failure to take Casey Stengel’s warning* into consideration when I

promised to give this presentation was clearly a mistake.

* “It’s hard to make predictions, especially about the future.”


References Galand, M., and A. D. Richmond (2001), Ionospheric electrical conductances produced by auroral proton

precipitation, J. Geophys. Res., 106, 117 - 125.

Kan, J. R., and W. Sun (1985), Simulation of the westward traveling surge and Pi2 pulsations during substorms,

J. Geophys. Res., 90, 10,911-10,920.

Love, J. J., and J. L. Gannon (2010), Movie-maps of low-latitude magnetic storm disturbances, Space Weather, 8,

S06001, doi:10,1029/2009SW000518.

Mallinckrodt, A. J., and C. W. Carlson (1978), Relations between transverse electric fields and field-aligned

currents, J. Geophys. Res., 83, 1426-1432.

Nopper, R. W., and R. L. Carovillano (1978), Polar-equatorial coupling during magnetically active periods.

Geophys. Res. Lett., 5, 699-702.

Ober, D. M., N. C. Maynard, and W. J. Burke (2003), Testing the Hill model of transpolar potential saturation, J.

Geophys. Res., 108, (A12), 1467, doi:10.1029/2003JA010154.

Robinson, R. M., R. R. Vondrak, K. Miller, T. Dabbs, and D. A. Hardy (1987), On calculating

ionospheric conductances from the flux and energy of precipitating electrons, J. Geophys. Res., 92,

2565 - 2569.

Siscoe, G. L., N. U. Crooker, and K. D. Siebert, Transpolar potential saturation: Roles of region 1

current system and solar wind ram pressure, J. Geophys. Res., 107(A10), 1321, doii:10.1029/2001JA009176, 2002.

hidden treasures in the dmsp database...2016/10/04 · hidden treasures in the dmsp database...

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