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Operational Forecasting Capability Today and Tomorrow Radiation Storms. Ron Zwickl with material from Joseph Kunches, Christopher Balch, and William Murtagh NOAA Space Environment Center Boulder, Colorado and Janet Luhmann et. al. CISM Model Oct. 17, 2005.

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operational forecasting capability today and tomorrow radiation storms

Operational Forecasting CapabilityToday and TomorrowRadiation Storms

Ron Zwickl

with material from

Joseph Kunches, Christopher Balch, and William Murtagh

NOAA Space Environment Center Boulder, Colorado

and

Janet Luhmann et. al. CISM Model

Oct. 17, 2005

today noaa sec s operational prediction model
Today:NOAA SEC’s Operational Prediction Model
  • Model based on empirical & statistical relationships
  • Practical aspects of this kind of model:
    • Must be based on specific observations of a solar event
    • The observations must be routinely available in real-time
    • Assessment must be done in real-time – prior to arrival of the first particles (particles may arrive before solar event is over)
    • RT analysis sometimes requires estimates of the input parameters
  • Forecasters may consider other factors in making a decision to issue a warning or a forecast.
slide4

Solar Cycle 23 produced 31 >100 MeV radiation storms.

The Large Events (in pfu’s)

14 Jul 2000 410 28 Oct 2003 186

8 Nov 2000 347 29 Oct 2003 110

15 Apr 2001 146 20 Jan 2005 652

4 Nov 2001 253

180

160

140

120

100

80

60

40

20

0

2003

2000

1976

1988

1997

1979

1982

1985

1991

1994

Cycle 23 Radiation Storms

80

-

The Sep 2005 radiation storm was the 91st >10 MeV radiation storm of Solar Cycle 23.

Totals = S3 (10) S4 (6) S5 (0)

70

-

60

-

50

-

40

-

30

-

20

-

10

-

Radiation Storms

per Cycle

sep event occurrence varies with the solar cycle in antiphase with galactic cosmic ray fluxes
SEP event occurrence varies with the solar cycle in antiphase with galactic cosmic ray fluxes

R. Mewaldt

solar flare activity 1976 2004
Solar Flare Activity 1976-2004

Courtesy R. Fisher, NASA

noaa sec nowcasts forecasts products
NOAA SEC nowcasts, forecasts, products
  • GOES real-time particle flux data
    • Range of energies 0.6 – 500 MeV
    • Event defined as flux of 10 p cm-2 s-1 ster-1 (PFU) at > 10 MeV
  • Daily forecast
    • Three day probabilities for SEP events
  • Short term warnings
    • Based primarily on flare observations
    • Thresholds: 10 PFU  10 MeV and 1 PFU  100 MeV
    • Prediction for onset time, maximum flux, time of maximum flux, and expected event duration
  • Alerts
    • Real-time reports of an observed event
    • Issued shortly after threshold has been attained
      • Additional notices at 100, 1000, and 10000 PFU.
  • Event Summaries
    • Important for users to have an ‘all-clear’ indicator
input parameters
Input parameters
  • GOES XRS data:
    • X-ray event peak flux
    • Time of maximum
    • Integrated x-ray flux (over time)
  • Ground-based H-alpha patrol or GOES-12 SXI
    • Location of the solar activity on the disk
  • Radio Telescope patrol (USAF SEON)
    • Reports of type II radio sweep
    • Reports of type IV radio sweep
probability calculation
Probability Calculation
  • Based on integrated x-ray flux, peak x-ray flux, and occurrence of type II and type IV radio sweeps
  • Current model was developed in 1998 and uses historical statistics
  • Example:

Integrated flux [0.085-0.257]

X-ray class  [M3-M8]

Radio sweep type II and type IV:

16 such events historically, 6 of which were associated with proton events => 37.5 % probability (±12%)

peak flux calculation
Peak Flux Calculation
  • Based on a best fit line of historical data between the log of integrated x-ray flux and the log of peak proton flux
  • Result below based on 1998 analysis
reliability diagram using 1996 2003 data
Uses the same form for input parameter space

Update the probability prediction based on statistics of 1996-2003 data

Any bins with less than 10 events are not used

In this case, events are combined and fewer parameters are used

Reliability diagram using 1996-2003 data
rise time calculation
Rise Time Calculation
  • Based on a best fit of historical data: time from flare maximum to proton event maximum as a function of source longitude:
  • tmin = 9.4
  • longitude = 78.0
  •  = 18.1
additional parameters under study
Additional parameters under study
  • Derived temperature from GOES XRS (Garcia 1994)
  • Low temperature flares have a higher degree of association with SEPs than high temperature flares
summary
Summary
  • Today’s space weather warnings for SEP’s are based on an empirical-statistical model
  • The main outputs:
    • Probability for an SEP event
    • Peak flux at 10 MeV
    • Rise time (between flare max and SEP max)
slide16

Gradual SEP Event with an ESP (energetic storm particle) Event: some SEP events have two peaks- a prompt one arriving 10s of minutes after the solar activity, and a second, arriving with the ICME shock

slide17
Multipoint measurements show that SEP event energy spectra depend on both time and location. A good global model should reproduce this.
marie and goes data april 2002
MARIE and GOES DataApril 2002

50

Dose Rate (mrads/day)

S14E150

30

10

104

GOES 8

103

X1 Flare

W limb CME

S14W84

102

April 30, 2002

(128 degrees)

Particles/cm2 sec sr

101

Earth

1.0

Sun

10-1

Mars

1

6

11

16

21

26

31

Courtesy F. Cucinotta, NASA

marie and goes data october 2002
MARIE and GOES DataOctober 2002

October 1, 2002

(153 degrees)

104

Sun

Earth

Mars

103

Dose Rate (mrads/day)

102

October 15, 2002

(146 degrees)

101

Sun

Earth

Mars

102

GOES 8

101

October 31, 2002

(137 degrees)

Particles/cm2 sec sr

1.0

Sun

10-1

Mars

Earth

1

6

11

16

21

26

31

Courtesy F. Cucinotta, NASA

slide20

Conditions for both the SEP Shock Source and Transport can be derived from the CISM models

Shock Front Surface

Magnetic Field Lines

theta = 60 deg

theta = 70 deg

theta = 80 deg

theta = 90 deg

  • Magnetic field lines, as observed at given locations can be:
  • part of the magnetic flux rope;
  • connected to the solar surface; or
  • disconnected from the solar surface.

(Images: D. Odstrcil)

slide21

CISM MAS/ENLIL models have all the details of both the coronal field structure

And the CME/ICME transient

Detail of an ad-hoc simulated CME in the model solar wind

Ambient Solar Wind

ICME Shock and Sheath

ICME Flux Rope Field Lines

Image courtesy of Dusan Odstrcil, CIRES

slide22

The cone model produced a detailed picture of the evolution of the disturbance in the solar wind out to 1 AU, including all of the information needed for the SEP calculations

slide23

Future Studies will use MHD simulation results including the CME/ICME ejecta

Based on adhoc 3D coronal eruption generated from a sheared field arcade with photospheric flux cancellation

From J. Linker

Resulting in a 3D Magnetic Flux Rope - Expanding into coupled solar wind model. From D. Odstrcil