The wind profiler at Piura, Peru (81°West, 6° South) has been in almost continuous operation since January 1989. The profiler is operated jointly by the University of Colorado (CIRES), NOAA's Aeronomy Lab, and the University of Piura (Peru). It is the eastern-most profiler in a chain of profilers extending across the tropical Pacific.

Recent observations using the Peruvian\U.S. Profiler at Machu Picchu Base in Antarctica show that PMSE are vastly weaker in the southern hemisphere relative to the north. The difference in average echo strength in the two hemispheres is of the order 23-33 dB. Since the PMSE occurrence is closely associated with the extremely low temperatures that are a well-know feature of the high-latitude summer mesopause region, the most obvious explanation for this discrepancy is that the mesopause temperatures are wanner in the southem hemisphere than they are in the north.

En: World Data Center A. Upper Atmosphere Geophysics, Report UAG-17

We compare two types of VHF vertical velocity measurement techniques using a special configuration of the Jicamarca 50-MHz radar antenna. Zenith (vertically directed single-beam) techniques and spaced antenna (SA) techniques are compared using a 54-hour concurrent data set. We compare two different zenith techniques using different antenna beam widths (0.85° and 3.5°). In addition, we compare vertical velocities measured by a “quasi” Doppler beam swinging (QDBS) technique and a SA approach that incorporate either “inferred” or “corrected” vertical velocities. All of the results are compared in terms of statistical basis. Results are presented for both quiet (low wind, low variability) and active (high wind, high variability) conditions. We use the results of the narrow-beam zenith technique as a reference profile and discuss its validity as a reference. Our comparisons show...

On the basis of scattering theory, we present four different contributions to angle-of-arrival (AOA) measurements using spaced antenna (SA) radar systems. We show that the measurement of the scattering parameters is needed to estimate most AOA contributions (e.g., tilt angle of layers). We analyze a general SA system (i.e., receiving antennas not necessarily symmetrically placed about the transmitter) and show, theoretically, that such systems can be used for vertical velocity corrections without explicitly knowing the scattering parameters (e.g., correlation lengths). The theoretical AOA expressions are compared with lower atmospheric data (3–21 km) obtained with the Jicamarca VHF radar system in Perú. We compare the AOAs obtained by a time and a frequency domain method, giving both methods essentially the same information. While the results are comparable, frequency domain AOAs tend...

We have used the Jicamarca radar system to measure horizontal winds by a variety of time domain and frequency domain spaced antenna techniques. Horizontal wind comparisons for two orthogonal components are carried out in a statistical sense, i.e., using correlation coefficients, mean differences, standard deviation of differences, and percentage of failures. We find that a simple technique that assumes horizontally isotropic scattering compares very closely with the more complicated full correlation analysis techniques. Techniques that attempt to correct for turbulence appear to be very sensitive to the way we estimate the width of the cross‐correlation/spectra functions. This is particularly true above 15 km, where discrepancies in the wind speed are apparent. In general, all techniques give essentially the same wind direction.

"Presentado en Conferencia Latinoamericana sobre Ciencias Espaciais e Atmosféricas na Antártida, Sao Paulo, 20-25 Noviembre de 1994"

The purpose of these historical notes is to present the early history of the Jicamarca Radio Observatory (JRO), a research facility that has been conducting observations and studies of the equatorial ionosphere for more than 50 years. We have limited the scope of these notes to the period of the construction of the observatory and roughly the first decade of its operation. Specifically, this period corresponds to the directorships under Kenneth Bowles, Donald Farley, and Tor Hagfors and the first period of Ronald Woodman, i.e., the years between 1960 and 1974. Within this time frame, we will emphasize observational and instrumental developments which led to define the capabilities of the Jicamarca incoherent scatter (IS) radar to measure the different physical parameters of the ionosphere. At the same time, we partially cover the early history of the IS technique which has been used by m...

Se presenta un informe de avance sobre un proyecto dendrocronológico en búsqueda de registros de la ocurrencia del fenómeno El Niño en el pasado. El proyecto se desarrolla en la zona norte de la costa del Perú, una región muy sensible a la ocurrencia del fenómeno El Niño y de la Oscilación del Sur (ENSO). Varias especies locales han sido seleccionados para este estudio. éste incluye observaciones fenológicas del crecimiento radial y de las características del anillado de crecimiento en sus ranas y troncos. Las especies más estudiadas y con los registros de observación más largos son el Palo Santo, el Haltaco y el Sapote. Se presentan los registros de crecimiento de estas tres especies, incluyendo años secos y años El Niño. El Sapote no presenta anillos completos de crecimiento. Su crecimiento parece estar controlado principalmente por la presencia de agua en el subsuelo...

Resumen.

Ciências espaciais e da atmosfera na Antártica (CLACEAA), organizada por pesquisadores; do Instituto Nacional de Pesquisas Espaciais (INPE) e a colaboração de pesquisadores latino-americanos, foi realizada na cidade de Serra Negra, SP, de 20 a 25 de novembro de 1994. Editores René A. Medrano-B, Enio B. Pereira.

The SOUSY (SOUnding SYstem) radar was relocated to the Jicamarca Radio Observatory (JRO), near Lima, Peru in 2000, where the radar controller and acquisition system were upgraded to state-of-the-art parts to take full advantage of its potential for high-resolution atmospheric sounding. Due to its broad bandwidth (4 MHz), it is able to characterize clear-air backscattering with high spatial resolution (37.5 m). A campaign conducted at JRO during July 2014 aimed to characterize the lower troposphere with a high temporal resolution (8.1 Hz) using the DataHawk (DH) small unmanned aircraft system, which provides in-situ atmospheric measurements at scales as small as 1 m in the lower troposphere, and can be GPS-guided to sample within the beam of the radar. This was a unique opportunity to make coincident observations by both systems, and to directly compare their in-situ and remotely sensed p...

Resumen.