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HomeSolarSolar ConditionsSolar Wind Speed Saturday, Mar 07 2015 00:03 UT
Solar Conditions

Solar Wind Speed

Updates: every 10 minutes

(last updated 06 Mar 2015 23:55 UT)

Solar Wind Parameters Used: Date: 06 03 2015 2352 UT Velocity: 503 km/sec Bz: 1.0 nT Density = 4.0 p/cc Calculated Information from Solar wind parameters: Magnetopause Stand Off Distance = 11.7Re Solar Wind Dynamic Pressure Dp = 0.85nPa

Solar Wind Speed diagram

The above diagram indicates solar wind speed and strength of the interplanetary magnetic field (IMF) in a north/south direction. Higher solar wind speeds and strong south pointing (negative) IMF are associated with geomagnetic storms on earth. The red area on the image indicates an approximate region in which disturbed conditions might be expected.

The plots on this page were produced from data supplied by the NOAA Space Weather Prediction Center (SWPC). This Real Time Solar Wind (RTSW) data set originates from NASA's Advanced Composition Explorer (ACE) satellite. The above image shows with a black square the value of the solar wind speed (horizontal) axis and the strength of the interplanetary magnetic field in a north/south direction (Bz - vertical axis). Higher solar wind speeds and strong south pointing (negative) interplanetary magnetic field are associated with geomagnetic disturbances on earth. The red area on the image indicates an approximate region in which disturbed conditions might be expected. The coloured dot within the black square, is an indicator of solar wind density, and is yellow when density exceeds 5 particles per cubic cm, red when density exceeds 10 particles per cubic cm, otherwise green.

The ACE spacecraft is positioned at the L1 point between the Earth and the sun and gives approximately one hour advance notice of conditions on Earth.

The solar wind magnetic field, can be measured in three compoenents, Bz, Bx, and By. Bx lies along the Sun-Earth line, with Bz and By defining a vertical plane (the clock "face"). The solar wind clock angle is the angle produced from the vector sum of By and Bz.

The image below shows recent trends in solar wind speed and interplanetary magnetic field north/south direction.

Solar Wind Trend diagram

Solar Wind Model Driven by ACE data

IPS is running an ACE data driven model of the solar wind each day in the Australian Space Forecast Centre. The model output displays a complete solar rotation of several solar wind parameters, over the last 27 days.

Using 27 day persistance, which is the average solar roatation period, IPS forecasters can use this information to anticipate the arrival of the coronal hole high speed stream, and warn its customers of the expected disturbance.

Reference

Florens, "M. S. L., Cairns, S. A. Knock, and P. A. Robinson (2007), Data-driven solar wind model and prediction of type II bursts, Geophys. Res. Lett., 34, L04104, doi:10.1029/2006GL028522".

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