The coronal electron density distribution determined from dual-frequency ranging measurements during the 1991 solar conjunction of the ULYSSES spacecraft

Details The coronal electron density distribution determined from dual-frequency ranging measurements during the 1991 solar conjunction of the ULYSSES spacecraft The coronal electron density distribution determined from dual-frequency ranging measurements during the 1991 solar conjunction of the ULYSSES spacecraft

May 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994apj...426..373b&link_type=abstract

Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 426, no. 1, p. 373-381

Astronomy and Astrophysics

Astrophysics

44

Doppler Effect, Electron Density Profiles, Radio Occultation, Radio Probing, Rangefinding, Solar Corona, Solar Wind, Solar Activity, Ulysses Mission, Voyager 2 Spacecraft

Scientific paper

Dual-frequency ranging and Doppler measurements were conducted in support of the Ulysses Solar Corona Experiment (SCE) at and around the spacecraft's first solar conjunction in 1991 August. The differential group delay time between range codes on the two downlink carrier signals at the wavelengths 13.1 and 3.6 cm, a direct measure of the total electron content between spacecraft and ground station, was used to derive the electron density distribution in the solar corona. Linear power-law representations of the coronal electron density were derived for the range of solar distances from 4 solar radii to 40 solar radii on both sides of the Sun. The corona was found to be very nearly symmetric; the radial falloff exponent being 2.54 +/- 0.05 for occultation ingress (east solar limb) and 2.42 +/- 0.05 for egress (west limb), respectively. The departure of these exponents from the inverse equare relation implies that significant solar wind acceleration is occurring within the radial range of the observations. The electron density level was found to be considerably lower than that observed during the 1988 December solar occultation of Voyager 2. Although the smoothed sunspot number Rz (a standard indicator of solar activity) was almost the same in 1988 December and 1991 August, the mean electron density at 20 solar radii was found to be 1.7 +/- 0.1 x 103/cu cm during the Ulysses conjunction, a decline by almost a factor of 4 from the value obtained during the Voyager conjunction.

Affiliated with

Also associated with

No associations

Rating

The coronal electron density distribution determined from dual-frequency ranging measurements during the 1991 solar conjunction of the ULYSSES spacecraft 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 The coronal electron density distribution determined from dual-frequency ranging measurements during the 1991 solar conjunction of the ULYSSES spacecraft, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The coronal electron density distribution determined from dual-frequency ranging measurements during the 1991 solar conjunction of the ULYSSES spacecraft will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-884939