This award supported research at the Jicamarca Radio Observatory between 2015--2017. Established through a collaborative effort between the U.S. and Peru in the 1960s at the start of the space age, Jicamarca is one of the world's largest radars and is used for studying the earth's upper atmosphere and ionosphere. Jicamarca is owned and operated by the Peruvian Geophysical Institute with support from the National Science Foundation through an award to Cornell University. Jicamarca has made a number of important discoveries over the years and continues to make significant contributions to what we know about aeronomy and space physics/ space weather at low latitudes. Extensive background information is available at https://en.wikipedia.org/wiki/Jicamarca_Radio_Observatory

Under this award, important outcomes were achieved following a number of different lines of research. The outcomes came from research performed by our users, our staff, or a combination. They are reported on in detail in peer-reviewed publications numbering 51 in 2015, 49 in 2016, and 26 in 2017. Some highlights are here:

1. Incoherent scatter profiles were measured to altitudes approaching 10,000 km over Jicamarca. The experiments were performed using very long pulses and involved long integration times. The experiments were intended to assess whether Jicamarca could be used to monitor plasmaspheric drainage and refilling during geomagnetic storms and represented a return to an experimental program begun in the early days of the observatory (it can).  The results were highlighted in an EOS Spotlight: https://eos.org/research-spotlights/after-decades-high-altitude-observations-revived-at-jicamarca

2. Jicamarca was used to create synthetic images of the Moon. While Jicamarca is much less sensitive than the planetary radar at Arecibo which is commonly used for lunar mapping, it can penetrate the surface of the moon by virtue of its longer wavelength. It may be possible to identify subsurface features, indicative of the presence of water for example, using VHF SAR. The results, published by Vierinen et al.,  appeared in Icarus (297), 2017.

3. The incoherent scatter spectrum was simulated numerically using a particle in cell (PIC) code for the first time by BU graduate student E. R. Williams and coleagues. This novel approach to the problem gave new insights into the peculiar behavior of the incoherent scatter spectrum at small magnetic aspect angles, a fundamental theoretical problem which has resisted other analyses.

4. In a paper by A. Maute and colleagues, the signatures of lunar and solar tides were teased out of ionospheric drift measurements over Jicamarca during a period of sudden stratospheric warming.

5. A new program of topside ionospheric measurements over Jicamarca was initiated. The program involves the use of a complicated set of pulses, includuing long pulses, together with a novel analysis approach rooted in statistical inverse methods. We have measured all ionospheric state parameters up through about 1500-km altitude and used the information to improve our modeling.

6. The detailed electrodynamics of meteor trails, including the large electric fields that accompany and extend well outside of them, was simulated for the first time by colleagues at Boston University. The idea that the meteor trail fields can trigger ionospheric instability is also now being considered.

7. The longstanding mystery of the enigmatic 150-km echoes was largely resolved with the publication by M Oppenheim and colleagues of a theory involving the upper-hybrid instability. The theory was tested using PIC codes and found to be able to account for the main features of the echoes. Detailed studies about how the instability produces the necklace-shaped echoes, one of the most startling phenomena in low-latitude space physics, continue.

8. The AMISR-14 radar, a small version of the PFISR and RISR radars deployed at high latitudes, was used to observe smal-scale plasma density irregularities in the electrojet and the postsunset F-region for the first time. The AMISR-14 utilizes electronic beam steering and so complements the aperture synthesis imaging methods employed presently at Jicamarca at VHF.

9. A network of HF beacons was deployed in Peru surrounding the Jicamarca radaro. The beacons employ pseudorandom noise (PRN) coding and yield pseudorange and Doppler-shift measurements, much like GPS. Unlike GPS, the ray paths connecting the receive and transmit stations bend considerably, and statistical inverse methods must be used to interpret the results. Using the beacon data, we can reconstruct the ionospheric electron density regionally.

In addition to research, Jicamarca supports education, training, and career development at the undergraduate, graduate, and post-graduate levels. Every year, we organize two internship programs: one for local students at the beginning of the year and the other for international students at the end. These programs offer excellent opportunities for students to learn about the basics of aeronomy, plasma physics, radar, and signal processing. Under these programs, the students gain hands-on experience with the operation of the Jicamarca radar and peripheral instrumentation. Students are assigned projects on topics of interest related, most often, to instrumentation or data analysis. 

Last Modified: 01/02/2020
Modified by: David L Hysell