A unique, high-altitude plasma cavity formed over Arecibo during an ionospheric heating campaign conducted at the observatory in June of 2019. Simultaneously, the Arecibo Incoherent Scatter Radar (ISR) collected measurements of the narrow cavity, revealing an exceptionally deep depletion of the electron density and a strong enhancement of the electron and ion temperatures. Read More

The Arecibo Observatory invites you to submit proposals for the use of the HF facility during 2018. HF experiments at Arecibo are scheduled by demand in periods of 5-7 days around new moon. Proposals should specify the associated diagnostics required: the incoherent scatter radar (ISR), active and passive optical instruments and others.