What is Space Weather

Aardvark Roost AOC
Space Weather in Southern Africa
Hannes Coetzee
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What is Space Weather ?
THE ACTIVE SUN
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The Violant Sun
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What is Space Weather?
Solar eruptive events (solar flares, coronal Mass
Space weather describes the conditions in space
ejections (CMEs)) are the main drivers of space
that affect Earth and its technological systems.
weather
generation
propagation
interaction
Space weather
is a consequence
of the behaviour
sun
interplanetary space magnetosphere/earth
of the sun,
sun the nature of Earth's magnetic field and
waves
atmosphere, and our shock
location
in the solar system.
solar eruptive
events
after
ft Scherer
S h
et.
t all 2004
expelled
plasma &
ti
magnetic
fields
accelerated
particles
p
potentially
geoeffective
agents
radio emission
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The Earth‘s Space Environment
This schematic diagram shows the sun, solar wind, and Earth’s
magnetosphere the environment in which space weather is
magnetosphere,
generated.
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Sun-Earth Space Environment
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Space Weather Effects
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Communication and Navigation
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Solar Event
From SUN to Hermanus Magnetic Observatory 22
Nov 2001 – 24 Nov 2001
¾22 Nov 2001 : SOHO observation of CME on Sun
¾24 Nov 2001 : Major Magnetic Storm on Earth
¾Observations by Hermanus Magnetic Observatory
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Coronal Mass Ejection (CME)
0600 – 0800 UT :
∆F = 143 nT
∆H = -270 nT
∆D = -70 min.
∆Z = -231 nT
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CME effect on HF Radio Comms
16
14
foF2, [M
MHz]
12
10
8
6
4
8 April 2000
2
96
97
98
99
100
101
Day Number
GRAHAMSTOWN
foF2
[MHz]
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Geomagnetically Induced Currents
• GIC occur at the end of the
space weather chain.
z
GICs are driven by electric
fields produced by
variations
i ti
in
i the
th Earth's
E th'
magnetic field that occur
during
g geomagnetic
g
g
storms.
z
GICs flowing in power
transformers produce extra
magnetic flux which cause
transformer failures.
z
Intense GIC levels can
cause collapse of power
systems.
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Characterizing the Ionosphere
South African Ionosonde Network
2000 – 2009
(22.4ºS,
30.9ºE )
Madimbo
2000 – 2009
Louisvale
(28 5ºS 21 2ºE)
(28.5ºS,21.2ºE)
1973 – 2009
Installed June 2008
( )p
profiles from 1996
N(h)
Grahamstown
Hermanus
(33.3ºS, 26.5ºE)
(34.4ºS, 19.2ºE)
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Real Time Ionospheric Information
Grahamstown
33.3 S,, 26.5 E
Madimbo
22.4 S, 30.9 E
Hermanus
34.4 S,
S 19.2
1
E
Louisvale
28.5 S, 21.2 E
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Frequency Predictions
Cape Town – Pretoria
25 – 31 March 2009
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Modelling the Ionosphere
IRI – International Reference Ionosphere
global model
-- g
-- updated annually
-- covers all upper atmosphere parameters
National SA Model
-- South African Ionospheric model
-- Bottomside ionosphere
-- neural network based
Global foF2, hmF2 and M3000F2 Models
-- neural network based
-- initially trained with data from 50 worldwide stations
-- developed as PhD project in South Africa
-- current version includes 135 global stations
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Real-Time Ionospheric Map
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Total Electron Content (GPS)
integral of electron density N along cylindrical column centred on ray
path s, between receiver R and satellite S through the ionosphere. TEC
corresponds to total number of free electrons- included in cylindrical
column with sectional area 1m2.
1 TEC Unit = 1016 electrons per square meter
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Total electron Content (TEC)
Hourly GNSS-derived Ionospheric Total electron Content maps over Southern Africa for 3 March 2009
00:00
01:00
02:00
03:00
04:00
05:00
06:00
07:00
08:00
09:00
10:00
11:00
12:00
13:00
14:00
15:00
16:00
17:00
18:00
19:00
20:00
21:00
22:00
23:00
Hermanus Magnetic Observatory
South Africa
http://spaceweather.hmo.ac.za
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TEC Units (x10
0
5
10
15
20
-
-2
e .m )
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Space Weather Instruments at SANEA-IV
•HF radar
ada
•Aurora cameras
•Riometers
•Magnetometers
•Neutron Monitors
•VLF receiver
•VLF-receiver
•GPS receiver for geodecy
•Seismometer
gy
•Meteorology
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Summary
•Technology and Communications are growing at a rapid rate
•Space Weather is going to have a serious impact, especially
during high solar activity
•Northern hemisphere models and predictions not always
valid for southern hemisphere
•There is a very definite need to continue researching
Southern African Space
p
Weather
•www.spaceweather.co.za
•http://spaceweather.hmo.ac.za
h
//
h h
•http://ionosond.ru.ac.za
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Summary
Thank You
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