Coherent and incoherent scatter radar observations during intense mid-latitude spread F

An intense mid-latitude spread-F event occurred over Puerto Rico during the night of February 17, 1998. Simultaneous observations were made with the C ornell University Portable Radar Interferometer (CUPRI) located near Isabel a, PR, the University of Illinois VHF radar located at Salinas, PR, GPS rec eivers at Isabela and St. Croix, measuring total electron content, the Arec ibo incoherent scatter radar, and the Cornell All-Sky imager located at the Arecibo Observatory. This was the first time that such a broad range of co mplementary instrumentation captured a mid-latitude spread-F space weather event. It was the first (and still only) time that a spread-F event over th e Caribbean exhibited large Doppler shifts in the VHF spectra. This event w as characterized with multiple filaments that initially produced receding D oppler velocities exceeding 300 m/s as seen by CUPRI and the Illinois radar . The Arecibo incoherent scatter radar recorded line-of-sight velocities ex ceeding 100 m/s that moved the F-layer peak to over 400-km altitude. Airglo w images of 630.0 nm emissions from F-region heights showed depleted struct ures oriented southeast to northwest. The large velocities observed with th e radars suggest that we caught this event in a stage of explosive developm ent. It is interesting that the first fully documented Caribbean event occu rred during a magnetically active period.