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Same night observations of spread‐ F by the Jicamarca Radio Observatory in Peru and CUPRI in Alcântara, Brazil
Author(s) -
Swartz Wesley E.,
Woodman Ronald F.
Publication year - 1998
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/97gl03484
Subject(s) - altitude (triangle) , observatory , radar , nocturnal , range (aeronautics) , geology , daytime , effects of high altitude on humans , geography , meteorology , atmospheric sciences , physics , telecommunications , astronomy , geometry , mathematics , materials science , computer science , composite material
50‐MHz echoes from equatorial spread‐ F were observed on several nights by both the Jicamarca Radio Observatory (JRO) in Peru and the Cornell University Portable Radar Interferometer (CUPRI) in Alcântara, Brazil. Although little detailed correlation is expected between sites separated by such large distances, the night of October 17, 1994 shows some remarkable similarities between Peru and Brazil. On this night spread‐ F commenced at both Jicamarca and Alcântara as thin bottomside layers situated near 320 km altitude at nearly the same local times. Later, major plumes erupted that reached to over 1000 km altitude at both sites. Since plumes normally drift west to east, these are obviously not the same structures but the similarities indicate that conditions for spawning them must have been coincidentally very similar on this night. The next two nights which produced plumes over Brazil, but only bottomside layers over Peru, emphasize that local conditions on the same night can be very different at the two locations. The importance of having a sufficiently wide beam for exploring spread‐ F over a large altitude range at the Alcântara site is also explored.