منابع مشابه
High-latitude Artificial Aurora Using the Eiscathigh-gain Hf Facility
The EISCAT high-frequency (HF) transmitter facility at Ramfjord, Norway, has been used to accelerate F-region electrons sufficiently to excite the oxygen atoms and nitrogen molecules, resulting in optical emissions at 630, 557.7 and 427.8 nm. During O-mode transmissions at 5.423 MHz, using 630 MW effective radiated power, in the hours after sunset on 12 November 2001 several new observations we...
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Herein we show that the historical records of mid-latitude auroras from 1700 to 1966 present oscillations with periods of about 9, 10–11, 20–21, 30 and 60 years. The same frequencies are found in proxy and instrumental global surface temperature records since 1650 and 1850, respectively, and in several planetary and solar records. We argue that the aurora records reveal a physical link between ...
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The monochromatic, aberration-corrected, dual-beam low energy electron microscope (MAD-LEEM) is a novel instrument aimed at imaging of nanostructures and surfaces at sub-nanometer resolution that includes a monochromator, aberration corrector and dual beam illumination. The monochromator reduces the energy spread of the illuminating electron beam, which significantly improves spectroscopic and ...
متن کاملSeasonal variabilities of low-latitude mesospheric winds
Observations of mesospheric winds over a period of four years with the partial re ̄ection radar at Tirunelveli (8.7°N, 77.8°E), India, are presented in this study. The emphasis is on describing seasonal variabilities in mean zonal and meridional winds in the altitude region 70±98 km. The meridional winds exhibit overall transequatorial ̄ow associated with dierential heating in the Northern and ...
متن کاملObliquity forcing of low-latitude climate
The influence of obliquity, the tilt of the Earth's rotational axis, on incoming solar radiation at low latitudes is small, yet many tropical and subtropical paleoclimate records reveal a clear obliquity signal. Several mechanisms have been proposed to explain this signal, such as the remote influence of high-latitude glacials, the remote effect of in-5 solation changes at mid-to high latitudes...
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ژورنال
عنوان ژورنال: Journal of Research of the National Bureau of Standards, Section D: Radio Propagation
سال: 1959
ISSN: 1060-1783
DOI: 10.6028/jres.063d.029