Ground observations and possible source regions of two types of Pc 1-2 micropulsations at very high latitudes

first_imgWe have used 1-year’s data from the recently installed Magnetometer Array for Cusp and Cleft Studies (MACCS) in Arctic Canada and from two stations of the developing “conjugate” array of Automated Geophysical Observatories (AGOs) in Antarctica to study ULF waves in the Pc 1–2 (100–600 mHz) frequency band at cusp and polar cap latitudes (Λ ∼ 74° – 80°). In this paper we focus on the spectral properties and latitudinal and local time distributions of Pc 1–2 events observed during 1994 and use these along with several case studies to infer the source locations of the two major wave types we have observed. We found little variation in center-band frequency of the Pc 1–2 waves we observed, but the average event bandwidth was distinctly wider at stations near 80° MLAT than at stations near 75° MLAT. Broadband waves, with diffuse spectral character, dominated at the higher latitudes, but their occurrence was confined at most stations to within 4 hours of local magnetic noon. Waves with narrower bandwidth were much more common in our data set, and were the statistically dominant wave type at the lower-latitude MACCS stations. Their occurrence was also limited to the dayside but extended both later and more widely in local time than the more broadband waves. These multistation observations, combined with data from the DMSP, IMP 8, and Geotail satellites, suggest the possibility that these two wave types originate in quite different regions near the magnetospheric boundary; the more narrowband waves in the subsolar and postnoon equatorial region, and the more broadband waves in the high-latitude plasma mantle (and possibly at the poleward edge of the cusp). The cusp itself appears to not be a significant source of Pc 1–2 wave activity that can be detected by ground observatories.last_img read more

Ringo Starr Reportedly Working On Next Solo Album

first_imgRingo Starr is back in the studio, according to a new report from Billboard which was confirmed by the drummer’s publicist over the weekend. The unnamed project will follow Starr’s fall 2017 release of his Give More Love solo album.Related: Watch The Beatles’ Surprise Rooftop Performance, Played On This Day In 1969Starr triggered the excitement about the possibility of more new music when he shared a photo of himself in the studio alongside Toto/All Starr Band guitarist Steve Lukather to his Twitter late last week. Starr’s publicity reps have since confirmed that he is indeed already hard at work on the next batch of solo tunes.Ringo won’t have too much time to write and record this year (unless the project is already secretly complete), as he and his All Starr Band are scheduled to begin their 2019 world tour later this week with an opening performance at Harrah’s Resort Southern California in Funner, CA on Thursday, March 21st. The tour is scheduled to continue until fall, with performances in Japan throughout the spring before returning to the U.S. for notable shows at New York City’s Pier 17 Rooftop, and the Woodstock 50th Anniversary weekend festivities in upstate New York.More recently, Ringo was named a Commander of the Order of the British Empire by Queen Elizabeth II, and even appeared on a new single from Jenny Lewis for her own forthcoming album.Fans can head to Starr’s website for tickets and info to his 2019 world tour.[H/T Billboard]last_img read more