Joint USAF/NOAA Report of Solar and Geophysical Activity 22 Jul 2002

:Product: Report of Solar-Geophysical Activity

:Issued: 2002 Jul 22 2210 UTC

# Prepared jointly by the U.S. Dept. of Commerce, NOAA,

#Space Environment Center and the U.S. Air Force.

#

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 203 Issued at 2200Z on 22 Jul 2002

IA.  Analysis of Solar Active Regions and Activity from  21/2100Z

to 22/2100Z:  Solar activity was low. Only infrequent small subflares

occurred. New Region 39 (S12E68), the likely site of the X3 event

late on 20 July, rotated fully into view as a moderate-sized group

with penumbra on both the leader and trailer spots. Limb proximity

hinders magnetic analysis. Other new regions emerging on the disk

today are; 40 (S22E01), 41 (N16E22), and 42 (S18E38). Region 30

(N20W86) is beginning its west limb passage, and Region 36 (S07W15)

remains the most prominent region visible.

IB.  Solar Activity Forecast:  Solar activity is expected to be

moderate. Regions 30, 36, and 39 are all possible sites for an

isolated event.

IIA.  Geophysical Activity Summary 21/2100Z to 22/2100Z:

The geomagnetic field was at quiet to minor storm levels during the

period. Nearly steady southward Bz (5 nT) coupled with enhanced

radial speed (500+ km/s), brought intervals of disturbed conditions.

A small greater than 10 MeV proton event, likely related to the X3

on 20 July, began at 22/0655 UTC. The tentative maximum is 26 pfu at

22/1635 UTC. Fluxes remain in excess of 20 pfu now. The energetic

electron flux at geosynchronous orbit attained high levels again

today.

IIB.  Geophysical Activity Forecast:  The geomagnetic field is

expected to be unsettled for the next three days.

III.  Event Probabilities 23 Jul-25 Jul

Class M    70/70/70

Class X    20/20/20

Proton     60/30/20

PCAF       yellow

IV.  Penticton 10.7 cm Flux

Observed           22 Jul 190

Predicted   23 Jul-25 Jul  190/190/195

90 Day Mean        22 Jul 161

V.  Geomagnetic A Indices

Observed Afr/Ap 21 Jul  017/019

Estimated Afr/Ap 22 Jul  015/017

Predicted Afr/Ap 23 Jul-25 Jul  015/012-010/010-010/010

VI.  Geomagnetic Activity Probabilities 23 Jul-25 Jul

A.  Middle Latitudes

Active                40/30/30

Minor storm           20/15/15

Major-severe storm    05/05/05

B.  High Latitudes

Active                50/40/40

Minor storm           25/15/15

Major-severe storm    05/05/05