Resumen presentado en: URSI General Assembly, New Delhi, October 2005.

We have installed a VHF radar on board the Peruvian Vessel BIC Humboldt. Most of radar componentes are similar to those used by the JULIA system at Jicamarca (receptor, transmitor, acquisition (control system). However as expected the antenna design and installation is quite different.

We are happy to acknowledge the support of Commandante Hector Soldi (Expedition Leader) and Teniente Italo Huertas (Base Commander) in insuring the installation and ongoing support of Peru's Machu Picchu Base. Additional support from both Peru's Comision Nacional de Asuntos Antartidos (CONAAN) and Consejo Nacional de Ciencias y Technologia (CONCYTEC), the Argentinean Navy, and the Uraguayan Air Force are greatly appreciated. The untiring assistance of S. Villegas and J. Fernandez, who have been associated with this project since its inception, is also gratefully acknowledged. This research is based upon work supported by NSF's Office of Polar Programs under Grant #DPP 922446.

Correlation studies performed on data from recent mesospheric experiments conducted with the 50-MHz Jicamarca radar in May 2003 and July 2004 are reported. The study is based on signals detected from a combination of vertical and off-vertical beams. The nominal height resolution was 150 m and spectral estimates were obtained after ~1 min integration. Spectral widths and backscattered power generally show positive correlations at upper mesospheric heights in agreement with earlier findings (e.g., Fukao et al., 1980) that upper mesospheric echoes are dominated by isotropic Bragg scatter. In many instances in the upper mesosphere, a weakening of positive correlation away from layer centers (towards top and bottom boundaries) was observed with the aid of improved height resolution. This finding supports the idea that layer edges are dominated by anisotropic turbulence. The data also suggests...

Sounding rocket experiments were conducted during the NASA EQUIS II campaign on Kwajalein Atoll designed to elucidate the electrodynamics and layer structure of the postsunset equatorial F region ionosphere prior to the onset of equatorial spread F (ESF). Experiments took place on 7 and 15 August 2004, each comprised of the launch of an instrumented and two chemical release sounding rockets. The instrumented rockets measured plasma number density, vector electric fields, and other parameters to an apogee of about 450 km. The chemical release rockets deployed trails of trimethyl aluminum (TMA) which yielded wind profile measurements. The Altair radar was used to monitor coherent and incoherent scatter in UHF and VHF bands. Electron density profiles were also measured with rocket beacons and an ionosonde. Strong plasma shear flow was evident in both experiments. Bottom-type scattering laye...