Coronal Mass Ejection CME and Space Weather Data Activity

1
Coronal Mass Ejection (CME) and Space Weather
Data Activity

• Ruth Skoug John Steinberg
• LASSO Teacher Workshop
• July, 2008

2
(No Transcript)
3
(No Transcript)
4
Solar wind observations Dec 1999 - Jan 2000

• Proton density Np typically lt 10 particles per
  cubic centimeter
• Flow speed Vp varies
• 300-800 km/s
• Increases rapidly, then decreases more slowly
• Proton temperature Tp also varies, 105 K
• Alpha/proton density ratio Na/Np typically lt 5
• Magnetic field B typically lt 10 nT, except at the
  interface between high speed and low speed solar
  wind
• North-south component of the magnetic field Bz is
  quite variable mean is around 0
• Vp and Tp are correlated

5
Speed/Temperature Correlation

• Solar wind speed Vp and temperature Tp are
  correlated
• This is apparent in the 5-day plots
• We can quantify this by plotting temperature vs
  speed

6
YEAR DAY/TIME V T 1999 364.021
370 3.9e04 1999 364.062 370
4.5e04 1999 364.104 380 7.0e04 1999
364.146 380 8.9e04 1999 364.187 370
8.5e04 1999 364.229 380 1.1e05 1999
364.271 380 1.2e05 1999 364.312 400
1.3e05 1999 364.354 390 1.1e05 1999
364.396 390 1.1e05 1999 364.437 390
9.3e04 1999 364.479 380 7.4e04 1999
364.521 390 6.5e04 1999 364.562 400
5.3e04 1999 364.604 390 4.9e04 1999
364.646 390 5.4e04 1999 364.687 420
7.8e04 1999 364.729 450 9.9e04 1999
364.771 550 2.3e05 1999 364.812 600
3.2e05 1999 364.854 610 3.0e05 1999
364.896 650 3.7e05 1999 364.937 640
4.1e05 1999 364.979 630 4.2e05 NOTE
DAY/TIME given as Day of year fraction of day
Solar wind speed V in km/s Solar wind
temperature T in K
7
YEAR DAY/TIME V T 1999 365.021
660 4.7e05 1999 365.062 640
3.8e05 1999 365.104 650 3.3e05 1999
365.146 660 4.0e05 1999 365.187 700
4.0e05 1999 365.229 660 3.1e05 1999
365.271 660 2.9e05 1999 365.312 680
3.2e05 1999 365.354 660 3.1e05 1999
365.396 670 3.2e05 1999 365.437 630
2.2e05 1999 365.479 620 2.2e05 1999
365.521 620 2.2e05 1999 365.562 640
2.3e05 1999 365.604 650 2.7e05 1999
365.646 650 2.7e05 1999 365.687 630
2.2e05 1999 365.729 640 2.4e05 1999
365.771 640 1.9e05 1999 365.812 650
2.0e05 1999 365.854 670 2.8e05 1999
365.896 690 3.6e05 1999 365.937 670
2.9e05 1999 365.979 670 3.0e05 NOTE
DAY/TIME given as Day of year fraction of day
Solar wind speed V in km/s Solar wind
temperature T in K
8
YEAR DAY/TIME V T 2000 1.021 670
2.5e05 2000 1.062 700 2.8e05 2000
1.104 710 3.1e05 2000 1.146 720
3.5e05 2000 1.187 710 3.6e05 2000
1.229 720 3.4e05 2000 1.271 750
3.4e05 2000 1.312 760 3.4e05 2000
1.354 750 2.8e05 2000 1.396 770
2.6e05 2000 1.437 730 2.4e05 2000
1.479 730 2.3e05 2000 1.521 740
2.2e05 2000 1.563 730 2.0e05 2000
1.604 720 2.0e05 2000 1.646 720
1.8e05 2000 1.688 710 1.9e05 2000
1.729 710 1.8e05 2000 1.771 740
2.2e05 2000 1.813 720 2.1e05 2000
1.854 710 1.8e05 2000 1.896 720
1.7e05 2000 1.938 700 1.9e05 2000
1.979 700 1.9e05 NOTE DAY/TIME given as
Day of year fraction of day Solar wind
speed V in km/s Solar wind temperature T in
K
9
YEAR DAY/TIME V T 2000 2.021
700 1.9e05 2000 2.063 700
1.9e05 2000 2.104 690 1.8e05 2000
2.146 680 1.7e05 2000 2.188 690
1.7e05 2000 2.229 690 1.9e05 2000
2.271 670 1.9e05 2000 2.313 670
1.9e05 2000 2.354 660 1.9e05 2000
2.396 660 1.8e05 2000 2.438 670
2.1e05 2000 2.479 680 2.4e05 2000
2.521 710 2.4e05 2000 2.563 660
2.0e05 2000 2.604 660 2.1e05 2000
2.646 690 1.9e05 2000 2.688 680
2.1e05 2000 2.729 680 1.6e05 2000
2.771 670 1.4e05 2000 2.813 680
2.0e05 2000 2.854 670 1.9e05 2000
2.896 670 1.8e05 2000 2.938 660
1.3e05 2000 2.979 670 1.1e05 NOTE
DAY/TIME given as Day of year fraction of day
Solar wind speed V in km/s Solar wind
temperature T in K
10
YEAR DAY/TIME V T 2000 3.021
650 1.2e05 2000 3.063 620
1.0e05 2000 3.104 630 1.1e05 2000
3.146 620 1.1e05 2000 3.188 620
1.4e05 2000 3.229 610 1.3e05 2000
3.271 600 1.3e05 2000 3.313 590
1.4e05 2000 3.354 590 1.7e05 2000
3.396 590 1.5e05 2000 3.438 600
1.5e05 2000 3.479 590 1.4e05 2000
3.521 580 1.1e05 2000 3.563 560
1.3e05 2000 3.604 540 1.3e05 2000
3.646 550 9.5e04 2000 3.688 540
1.0e05 2000 3.729 550 1.2e05 2000
3.771 540 1.5e05 2000 3.813 580
1.7e05 2000 3.854 570 1.9e05 2000
3.896 570 1.7e05 2000 3.938 590
1.5e05 2000 3.979 590 1.6e05 NOTE
DAY/TIME given as Day of year fraction of day
Solar wind speed V in km/s Solar wind
temperature T in K
11
YEAR DAY/TIME V T 2000 4.021
590 1.5e05 2000 4.062 590
1.6e05 2000 4.104 590 1.5e05 2000
4.146 590 1.4e05 2000 4.187 600
1.4e05 2000 4.229 600 1.6e05 2000
4.271 590 1.6e05 2000 4.312 600
1.5e05 2000 4.354 630 2.5e05 2000
4.396 630 2.4e05 2000 4.437 600
1.5e05 2000 4.479 600 1.3e05 2000
4.521 590 1.6e05 2000 4.562 580
1.8e05 2000 4.604 560 1.8e05 2000
4.646 570 1.2e05 2000 4.687 570
1.0e05 2000 4.729 530 1.0e05 2000
4.771 550 9.5e04 2000 4.812 560
8.6e04 2000 4.854 540 9.9e04 2000
4.896 510 1.1e05 2000 4.937 520
9.8e04 2000 4.979 520 1.2e05 NOTE
DAY/TIME given as Day of year fraction of day
Solar wind speed V in km/s Solar wind
temperature T in K
12
YEAR DAY/TIME V T 2000 5.021
530 8.3e04 2000 5.062 520
7.2e04 2000 5.104 540 7.8e04 2000
5.146 510 9.8e04 2000 5.187 510
9.5e04 2000 5.229 520 9.3e04 2000
5.271 510 1.3e05 2000 5.312 520
1.4e05 2000 5.354 540 1.1e05 2000
5.396 520 1.1e05 2000 5.437 510
1.3e05 2000 5.479 510 1.5e05 2000
5.521 520 1.4e05 2000 5.562 520
1.6e05 2000 5.604 530 1.5e05 2000
5.646 520 1.6e05 2000 5.687 510
1.6e05 2000 5.729 520 1.6e05 2000
5.771 530 1.4e05 2000 5.812 540
1.1e05 2000 5.854 520 1.7e05 2000
5.896 520 1.5e05 2000 5.937 510
1.5e05 2000 5.979 520 1.3e05 NOTE
DAY/TIME given as Day of year fraction of day
Solar wind speed V in km/s Solar wind
temperature T in K
13
106
4x105
3x105
2x105
105
4x104
3x104
2x104
104
14
(No Transcript)
15
(No Transcript)
16
(No Transcript)
17
Speed/Temperature Correlation

• Solar wind speed Vp and temperature Tp are
  correlated
• This was apparent in the 5-day plots
• We quantified this by plotting temperature vs
  speed
• Lab scientists examined this correlation using 3
  years of ACE data to determine an expected
  temperature as a function of solar wind speed
• From Dec 30, 1999 to Jan 5, 2000, the expected
  temperature and the measured temperature are in
  good agreement

18
(No Transcript)
19
(No Transcript)
20
(No Transcript)
21
(No Transcript)
22
(No Transcript)
23
(No Transcript)
24
Speed/Temperature Correlation

• The solar wind speed Vp and temperature Tp are
  usually correlated, and Tp follows an expected
  temperature curve
• However, at some times, the measured temperature
  differs from the expected temperature
• At times, Tp is much lower than expected (for a
  given solar wind speed Vp)
• These times also often show other characteristics
• High alpha/proton density ratio Na/Np
• Southward pointed magnetic field Bz
• Decreasing speed Vp
• Smooth and large magnetic field B

25
Solar wind / Magnetosphere Interaction

• The solar wind is a major input to and driver of
  the Earths magnetospheric system
• Coronal mass ejections (CMEs) are a major source
  of large geomagnetic storms at the Earth

26
Effects on the Earth

• Assuming that CMEs can cause geomagnetic storms,
  predict times when you might expect a geomagnetic
  storm
• May be a time delay between solar wind
  observation and response of the magnetosphere
• A geomagnetic storm may be caused by a specific
  feature in the solar wind, that may or may not
  exactly correspond to the entire period when a
  CME was observed

27
Geomagnetic Storms

• We will identify geomagnetic storms based on the
  Dst index
• Dst measures variations in the Earths magnetic
  field
• Units nanoTesla (nT 10-9 T)
• Average based on several equatorial magnetometer
  stations
• Responds to currents in the magnetosphere
• Storm leads to more ions, flowing closer to the
  Earth, leading to a larger current
• A flowing current makes a magnetic field. An
  magnetometer on the Earth measures all magnetic
  fields, including the intrinsic magnetic field of
  the Earth and all magnetic fields caused by
  moving ions

28
The Dst index measures the variation of the
Earths magnetic field caused by geomagnetic
storms, in units of nT (nano-Tesla). A Dst of 50
nT defines a moderate storm a Dst of 100
defines a major storm.
29
The Dst index measures the variation of the
Earths magnetic field caused by geomagnetic
storms, in units of nT (nano-Tesla). A Dst of 50
nT defines a moderate storm a Dst of 100
defines a major storm.
30
(No Transcript)
31
Speed/Temperature Correlation

• The solar wind speed Vp and temperature Tp are
  usually correlated, and Tp follows an expected
  temperature curve
• However, at some times, the measured temperature
  differs from the expected temperature
• At times, Tp is much lower than expected (for a
  given solar wind speed Vp)
• These times also often show other characteristics
• High alpha/proton density ratio Na/Np
• Southward pointed magnetic field Bz
• Decreasing speed Vp
• Smooth and large magnetic field B
• These characteristics identify a Coronal Mass
  Ejection (CME)

32
CME Identification

• Try to identify coronal mass ejections (CMEs) in
  solar wind plasma and magnetic field observations
• Hardcopy pictures, 5 days per plot
• Identify times with lower than average solar wind
  proton temperatures Tp
• Low proton temperature is a common CME signature
• If time allows, can also look for other
  signatures
• High Na/Np density ratio
• z component of magnetic field Bz south (negative)
• High values of magnetic field B
• Smoothly varying B
• Decreasing speed Vp

33
Month Year
34
Month Year
35
Space Weather Forecasting

• Perhaps not surprisingly, results are mixed
• Low plasma temperature (Tp) in the solar wind is
  often a good indictor that we will see a
  geomagnetic storm at Earth
• Sometimes combining low Tp with other signatures
  provides a better indicator
• Sometimes it is not obvious what solar wind
  inputs caused a geomagnetic storm at the Earth
• Terrestrial weather forecasting provides a good
  analogy
• Hard to do on Earth, even with many weather
  stations
• In space, we have only one weather station (or
  maybe 2-3), which may or may not be located in an
  optimal location

36
(No Transcript)
37

• Note preferred order of following plots, if not
  enough groups to do all
• A) July - Aug, 1999 (very quiet, min Dst of
  -50)
• B) Sept - Oct, 2000 (several storms, Dst twice
  reaches -200)
• C) Aug - Sept, 1998 (several storms)
• D) Apr - May, 2001 (several storms)
• E) Sept - Oct, 2001 (many storms)
• F) Nov - Dec, 1998 (several storms)
• G) May - Jun, 2000 (several storms)
• H) Mar - Apr, 1999 (very quiet)

38
(No Transcript)
39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
(No Transcript)
43
(No Transcript)
44
(No Transcript)
45
(No Transcript)