[Ips-dsgr] IPS Daily Report - 22 May 07

rwc rwc at ips.gov.au
Wed May 23 09:51:51 EST 2007


SUBJ: IPS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 22/2330Z MAY 2007 BY IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 22 MAY AND FORECAST FOR 23 MAY - 25 MAY
STATUS INDICATORS SOL:GREEN   MAG:** YELLOW **     ION: GREEN
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1A. SOLAR SUMMARY
Activity 22 May:  Very low

Flares: none.

Observed 10.7 cm flux/Equivalent Sunspot Number for 22 May:  72/8


1B. SOLAR FORECAST
             23 May             24 May             25 May
Activity     Very low           Very low           Very low
Fadeouts     None expected      None expected      None expected
10.7cm/SSN    75/13              75/13              75/13

COMMENT: Solar activity was very low over the past 24 hours with 
just three B-class flares from spot region 956 (N03W47) the most 
significant of which was a long-duration B3.9 at 22/1447UT. This 
flare was associated with a Type-II radio sweep and a weak CME 
evident in SOHO LASCO imagery with an estimated velocity of 585km/s. 
The solar wind speed has returned to its pre-coronal hole level 
of around 440km/s. A solar sector boundary crossing occurred 
at 21/2220UT indicated by a change in polarity of the Interplanetary 
Magnetic Field (IMF) 'phi' angle. IMF Bz was steady and strongly 
Northward until ~0900UT when it turned southwards. It has been 
southward for the last 7 hours producing enhanced merging at 
high latitudes. A recurrent equatorial coronal hole has passed 
solar central meridian and should move into geoeffective position 
on 24 May. 

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2A. MAGNETIC SUMMARY

Geomagnetic field for Australian Region 22 May: Quiet to Unsettled,
Minor Storm at high latitudes. 

Estimated Indices 22 May :  A   K           
   Australian Region       8   12222233
      Darwin               8   22222232
      Townsville          10   22223233
      Learmonth           14   22333343
      Camden               8   11222233
      Canberra             9   11232233
      Hobart              10   12233133
      Casey(Ant)           7   12222232
    
Observed Regional daily pc3 Indices 22 May : 
      Darwin               0   (Quiet)
      Townsville           0   (Quiet)
      Learmonth            0   (Quiet)
      Camden               0   (Quiet)
      Canberra             0   (Quiet)
      Hobart              18   (Quiet)
Pc3 pulsations are high frequency (10-45 second period) variations 
of the Earths magnetic field. Daily pc3-indices are the daily sum 
of 20 minute pc3-indices for that station and have been shown to be
well correlated with rejection of high resolution aeromagnetic
survey flight-line data. 

NOTE: Indices may have been generated from data obtained in 
cooperation with the following organisations: Geoscience Australia, 
University of Newcastle Space Physics Group, Australian Government 
Antarctic Division and Space Environment Research Center, Japan.


Estimated AFr/Ap Indices 22 May : A 
           Fredericksburg         5
           Planetary              8                         

Observed AFr/Ap Indices 21 May :  A   K
           Fredericksburg         6
           Planetary              6   3100 1123     


2B. MAGNETIC FORECAST 
Date      Ap    Conditions
23 May    10    Quiet to unsettled 
24 May    16    Unsettled to active 
25 May    22    Active 

COMMENT: The geomagnetic field was generally Quiet to Unsettled 
over the UT day. Minor Storm conditions were observed at high 
latitudes after 22/1800UT in response to a steady southwards 
Interplanetary Magnetic Field (IMF) 16-23UT producing enhanced 
and steady reconnection. The Unsettled conditions were due to 
the predominantly southwards IMF in the second half of the UT 
day. A solar sector boundary crossing at 21/2220UT produced an 
isolated period of Unsettled conditions late on May 21. The weak 
CMEs of 19 May produced no obvious shocks in the solar wind 22 
May. Expect continuing Quiet- Unsettled geomagnetic conditions 
23 May. A recurrent coronal hole is expected to move into geoeffective
position 24 May. This coronal hole produced Active to Minor Storm 
conditions on its last two rotations and is expected to result 
in Unsettled to Active conditions 24-25 May with isolated periods 
of Minor Storm conditions possible at high latitudes. 

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3A. GLOBAL HF PROPAGATION SUMMARY
	            Latitude Band
Date        Low            Middle         High 
22 May      Fair           Normal         Normal         
PCA Event : No event.

3B. GLOBAL HF PROPAGATION FORECAST
	            Latitude Band
Date        Low            Middle         High 
23 May      Fair           Normal         Normal        
24 May      Normal         Normal         Normal-fair   
25 May      Normal         Normal         Normal-fair   

COMMENT: Frequencies were generally near predicted monthly values 
in the Australian region 22 May and enhanced in the Antarctic. 
20-30% MUF depressions were observed in the Equatorial PNG/Niue 
region. Spread-F was observed at some S.Aus/NZ stations overnight 
and widespread sporadic-E was observed at most Aus stations after 
dusk. Expect frequencies to be mostly near predicted monthly 
values 23 May with the exception of the PNG/Niue region which 
may experience further MUF depressions. Further spread-F likely 
at S.Aus/NZ stations overnight. Maximum Useable Frequencies are 
expected to be enhanced 24-25 May as the winter ionosphere responds 
to enhanced geomagnetic activity. 

-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY


Date   T index
22 May    10

Observed Australian Regional MUFs
   Equatorial PNG/Niue Region:
      Depressed by 20% during local day,
      Depressed by 25% during local night.
   Northern Australian Region:
      Mostly near predicted monthly values,
   Southern Australian and New Zealand Region:
      Near predicted monthly values during local day,
      Enhanced by 20% during local night.
   Antarctic Region (Casey/Scott Base/Davis/Mawson):
      Enhanced by 45% over the UT day.

Predicted Monthly T index for May:   9

4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date   T index  MUFs
23 May    12    near predicted monthly values 
24 May    26    10 to 20% above predicted monthly values 
25 May    30    10 to 20% above predicted monthly values 

COMMENT: HF conditions were mostly normal 22 May at mid latitudes. 
Equatorial stations suffered 25-30% MUF depressions over the 
UT day. Mid-high latitude stations were enhanced overnight. Periods 
of Spread-F were again observed overnight at mid- high latitude 
stations. Widespread occurrence of Sporadic-E was observed at 
Low and Mid-latitudes for a 2-3 hour period after dusk. HF conditions 
are expected to be mostly normal 23 May at mid-high latitudes. 
Low latitudes may experience further depressions. MUF enhancements 
are expected 24-25 May as the winter ionosphere responds to enhanced 
geomagnetic activity. 

-----------------------------------------------------------
5. SPACE ENVIRONMENT SUMMARY

GOES satellite data for 21 May
       Daily Proton Fluence >1 MeV:   1.4E+06
       Daily Proton Fluence >10 MeV:  1.6E+04
       Daily Electron Fluence >2 MeV: 3.70E+07   (normal fluence)   
Electron Fluence Daily Deep Dielectric Discharge Probability: 5%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
       X-ray background: A2.2

ACE Satellite Solar Wind Day Averaged Data for 21 May
Speed: 503 km/sec  Density:    1.2 p/cc  Temp:    45200 K  Bz:   2 nT

(Courtesy Space Environment Center, Boulder USA)
ACE data can be incorrect during strong proton events.
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