Long-term variation in distribution of solar wind density fluctuations for 1997-2009

Details Long-term variation in distribution of solar wind density fluctuations for 1997-2009 Long-term variation in distribution of solar wind density fluctuations for 1997-2009

Dec 2011

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011agufmsh31c2023t&link_type=abstract

American Geophysical Union, Fall Meeting 2011, abstract #SH31C-2023

Physics

[2162] Interplanetary Physics / Solar Cycle Variations, [2164] Interplanetary Physics / Solar Wind Plasma, [6969] Radio Science / Remote Sensing, [6982] Radio Science / Tomography And Imaging

Scientific paper

Interplanetary scintillation (IPS) observations made with the 327-MHz multi-station system of the Solar-Terrestrial Environment Laboratory (STEL) are analyzed to investigate distribution of solar wind density fluctuations (Delta Ne) and its evolution during 1997-2009. The computer assisted tomography (CAT) method is used in the present study to deconvolve line-of-sight integration of solar wind speed and g-value data obtained from IPS observations (Asai et al., 1998). The results show that the high-(low-) latitude region is dominated by small (large) Delta Ne plasma, which corresponds to the fast (slow) solar wind. The solar wind speed data show a clear change associated with the solar cycle, and this is in good agreement with our earlier study (Tokumaru et al., 2010). In contrast, the Delta Ne data don't show such a solar cycle change, and they shows a gradual increase in fractional area of small Delta Ne region throughout the period. This trend is observed for all latitudes, and is distinct after 2005 for low latitudes. It is found that all IPS data obtained here except for those in 2000 are generally consistent with the empirical relation; Delta Ne ~ V-0.5, (where V is the solar wind speed) reported by Asai et al.(1998). The important point to note is that a marked reduction in Delta Ne occurs in 2009 for the low speed wind, V <350 km/s. Since number of IPS data for this speed range may be insufficient to conclude, we need to confirm this reduction in Delta Ne from further observations.

Affiliated with

Also associated with

No associations

Rating

Long-term variation in distribution of solar wind density fluctuations for 1997-2009 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Long-term variation in distribution of solar wind density fluctuations for 1997-2009, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Long-term variation in distribution of solar wind density fluctuations for 1997-2009 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-878678