scholarly journals Evidence for Reality of Rapid Solar Radio Fluctuation

1993 ◽  
Vol 141 ◽  
pp. 355-358
Author(s):  
Fu Qijun ◽  
Hu Chumin ◽  
Zhao Bing ◽  
Jin Shenzhen ◽  
Yu. Yurovsky ◽  
...  
Keyword(s):  
Conclusive Evidence ◽  
High Time Resolution ◽  
Frequency Range ◽  
Applied Physics ◽  
Solar Microwave ◽  
Fine Structures ◽  
University Of Bern ◽  
Puzzling Problem ◽  
First Time ◽  
Microwave Bursts

Since fast fine structures (FFS) superimposed on microwave bursts were found with high time resolution observations, they have been observed in extensive frequency range (Slottje 1978; Fu, et al. 1986; Stähli and Magun 1986; and Stepanov and Yurovsky 1991), and these results make understanding of the emission deepening. But, at the same time, the puzzling problem, these phenomena originate from sun or are only artificial, is often concerned and disputed (Benz and Fürst 1987). As it was pointed out by Benz and Fürst (1987), “the only really reliable way to study solar microwave fluctuation is to use two or more widely separated radio telescopes”.In this paper, some of FFS events superimposed on microwave bursts simultaneously obtained at Beijing Astronomical Observatory (BAO), Crimea Astrophysical Observatory (CAO) and Institute of Applied Physics, University of Bern (IAP), are presented at first time. It is a conclusive evidence of rapid radio fluctuation originating from sun and associated with flare appearance.

scholarly journals Sources of type III solar microwave bursts

2016 ◽  
Vol 2 (2) ◽  
pp. 15-27 ◽  
Author(s):  
Дмитрий Жданов ◽  
Dmitriy Zhdanov ◽  
Сергей Лесовой ◽  
Sergey Lesovoi ◽  
Сусанна Тохчукова ◽  
...  
Keyword(s):  
Energy Release ◽  
Complex Analysis ◽  
Primary Energy ◽  
Original Method ◽  
Burst Source ◽  
Energy Release Region ◽  
Siberian Solar Radio Telescope ◽  
Solar Microwave ◽  
Fine Structures ◽  
Microwave Bursts

Microwave fine structures allow us to study plasma evolution in an energy release region. The Siberian Solar Radio Telescope (SSRT) is a unique instrument designed to examine fine structures at 5.7 GHz. A complex analysis of data from RATAN-600, 4–8 GHz spectropolarimeter, and SSRT, simultaneously with EUV data, made it possible to localize sources of III type microwave bursts in August 10, 2011 event within the entire frequency band of burst occurrence, as well as to determine the most probable region of primary energy release. To localize sources of III type bursts from RATAN-600 data, an original method for data processing has been worked out. At 5.7 GHz, the source of bursts was determined along two coordinates, whereas at 4.5, 4.7, 4.9, 5.1, 5.3, 5.5, and 6.0 GHz, their locations were identified along one coordinate. The size of the burst source at 5.1 GHz was found to be maximum as compared to those at other frequencies.

A New Catalogue of Fine Structures Superimposed on Solar Microwave Bursts

2004 ◽  
Vol 4 (2) ◽  
pp. 176-188 ◽  
Author(s):  
Qi-Jun Fu ◽  
Yi-Hua Yan ◽  
Yu-Ying Liu ◽  
Min Wang ◽  
Shu-Juan Wang
Keyword(s):  
Solar Microwave ◽  
Fine Structures ◽  
Microwave Bursts

scholarly journals Far Infrared and Submillimeter Continuum Observations of Solar Flares: Justifications and Prospects for Ground-Based Experiments

1994 ◽  
Vol 154 ◽  
pp. 93-101
Author(s):  
P. Kaufmann ◽  
E. Correia ◽  
J. E. R. Costa ◽  
A. M. Zodi
Keyword(s):  
Solar Flare ◽  
Spectral Component ◽  
Far Infrared ◽  
Primary Energy ◽  
Continuum Emission ◽  
High Time Resolution ◽  
Applied Physics ◽  
High Definition ◽  
Spectral Bands ◽  
University Of Bern

Solar flare observations in the sub-mm spectral bands are essentially non-existent. There is evidence that some solar bursts exhibit a spectral component rising in intensity towards wavelengths shorter than 3 mm, displaying fast sub-second pulses at different repetition rates. On the other hand, the spectral features of white light flares are also unknown in the infra-red range of frequencies. In both wavelength ranges the physics of the emission processes may involve particles accelerated to high energies. The diagnostics of solar flare continuum emission in the IR and sub-mm spectral regions will provide crucial tests on various flare models and bring some clues on the initial primary energy release mechanisms. We propose the construction and operation of a ground-based telescope, operating at two sub-millimeter wavelengths (at about 210 GHz and 405 GHz), with high time resolution (one millisecond), capable of determining the spatial position of burst emission centroids with high definition (a few arcseconds) using the multiple beam technique. Final installation and operation at a high-altitude site in the Argentinian Andes mountains are planned in a joint cooperation with Argentina's Instituto de Astronomia y Fisica del Espacio, IAFE (M. Rovira and associates) and Complejo Astronomico El Leoncito, CASLEO, San Juan (H. Levato and associates); and Switzerland's University of Bern, Institute of Applied Physics, IAP, Bern (A. Magun and associates).

scholarly journals Sources of type III solar microwave bursts

2016 ◽  
Vol 2 (2) ◽  
pp. 12-21
Author(s):  
Дмитрий Жданов ◽  
Dmitriy Zhdanov ◽  
Сергей Лесовой ◽  
Sergey Lesovoi ◽  
Сусанна Тохчукова ◽  
...  
Keyword(s):  
Energy Release ◽  
Complex Analysis ◽  
Primary Energy ◽  
Original Method ◽  
Burst Source ◽  
Siberian Solar Radio Telescope ◽  
Solar Microwave ◽  
Extreme Uv ◽  
Fine Structures ◽  
Microwave Bursts

Microwave fine structures allow us to study plasma evolution in an energy release region. The Siberian Solar Radio Telescope (SSRT) is a unique instrument designed to examine fine structures at 5.7 GHz. A complex analysis of data from RATAN-600, 4–8 GHz spectropolarimeter, and SSRT, simultaneously with extreme UV data, made it possible to localize sources of III type microwave drift bursts in August 10, 2011 event within the entire frequency band of burst occurrences, as well as to determine the most probable region of primary energy release. To localize sources of III type bursts from RATAN-600 data, an original method for data processing has been worked out. At 5.7 GHz, the source of bursts was determined along two coordinates whereas at 4.5, 4.7, 4.9, 5.1, 5.3, 5.5 and 6.0 GHz, their locations were identified along one coordinate. The size of the burst source at 5.1 GHz was found to be maximum as compared to source sizes at other frequencies.

scholarly journals Effects of RFI on Solar Microwave Bursts Observed with Hightime Resolution

1991 ◽  
Vol 112 ◽  
pp. 222-227
Author(s):  
Xianhan Luo
Keyword(s):  
Solar Activity ◽  
Time Scale ◽  
Activity Cycle ◽  
Solar Activity Cycle ◽  
High Time Resolution ◽  
Radio Frequency Interference ◽  
Solar Microwave ◽  
Solar Microwave Burst ◽  
Time Structures ◽  
Microwave Bursts

ABSTRACTSolar microwave burst observations with high time resolution (~ 1 ms) are important but difficult to make. It is shown by the experiments of radiometer at wavelength 21 cm on 1 ms time scale that some ultrafast time structures in microwaves, which includes spike impulses, switch-on and switch-off structures, etc., may not be from solar emission but from RFI (radio-frequency interference) or from radiometer itself. Because of the uncertainty at 21 cm and other several wavelengths, we suggest that joint observations of the solar microwave bursts on 1 ms time scale should be carried out on the peak years of the 22nd solar activity cycle.

scholarly journals ARIS-Campaign: intercomparison of three ground based 22 GHz radiometers for middle atmospheric water vapor at the Zugspitze in winter 2009

2011 ◽  
Vol 4 (9) ◽  
pp. 1979-1994 ◽  
Author(s):  
C. Straub ◽  
A. Murk ◽  
N. Kämpfer ◽  
S. H. W. Golchert ◽  
G. Hochschild ◽  
...  
Keyword(s):  
Water Vapor ◽  
Noise Temperature ◽  
Rotational Transition ◽  
Atmospheric Water Vapor ◽  
Transition Line ◽  
Applied Physics ◽  
Atmospheric Water ◽  
Max Planck ◽  
Institute Of Technology ◽  
University Of Bern

Abstract. This paper presents the Alpine Radiometer Intercomparison at the Schneefernerhaus (ARIS), which took place in winter 2009 at the high altitude station at the Zugspitze, Germany (47.42° N, 10.98° E, 2650 m). This campaign was the first direct intercomparison between three new ground based 22 GHz water vapor radiometers for middle atmospheric profiling with the following instruments participating: MIRA 5 (Karlsruhe Institute of Technology), cWASPAM3 (Max Planck Institute for Solar System Research, Katlenburg-Lindau) and MIAWARA-C (Institute of Applied Physics, University of Bern). Even though the three radiometers all measure middle atmospheric water vapor using the same rotational transition line and similar fundamental set-ups, there are major differences between the front ends, the back ends, the calibration concepts and the profile retrieval. The spectrum comparison shows that all three radiometers measure spectra without severe baseline artifacts and that the measurements are in good general agreement. The measurement noise shows good agreement to the values theoretically expected from the radiometer noise formula. At the same time the comparison of the noise levels shows that there is room for instrumental and calibration improvement, emphasizing the importance of low elevation angles for the observation, a low receiver noise temperature and an efficient calibration scheme. The comparisons of the retrieved profiles show that the agreement between the profiles of MIAWARA-C and cWASPAM3 with the ones of MLS is better than 0.3 ppmv (6%) at all altitudes. MIRA 5 has a dry bias of approximately 0.5 ppm (8%) below 0.1 hPa with respect to all other instruments. The profiles of cWASPAM3 and MIAWARA-C could not be directly compared because the vertical region of overlap was too small. The comparison of the time series at different altitude levels show a similar evolution of the H2O volume mixing ratio (VMR) for the ground based instruments as well as the space borne sensor MLS.

scholarly journals Nonlinear analysis of decimetric solar bursts

2009 ◽  
Vol 5 (S264) ◽  
pp. 279-281
Author(s):  
Reinaldo R. Rosa ◽  
Mauricio J. A. Bolzan ◽  
Francisco C. R. Fernandes ◽  
H. S. Sawant ◽  
Marian Karlický
Keyword(s):  
Solar Radio ◽  
Inhomogeneous Plasma ◽  
Active Regions ◽  
Singularity Spectrum ◽  
Frequency Range ◽  
Radio Emissions ◽  
Magnetic Structures ◽  
Fine Structures ◽  
Solar Bursts ◽  
Solar Radio Emissions

AbstractThe solar radio emissions in the decimetric frequency range (above 1 GHz) are very rich in temporal and spectral fine structures due to nonlinear processes occurring in the magnetic structures on the corresponding active regions. In this paper we characterize the singularity spectrum, f(α), for solar bursts observed at 1.6, 2.0 and 3 GHz. We interpret our findings as evidence of inhomogeneous plasma turbulence driving the underlying plasma emission process and discuss the nonlinear multifractal approach into the context of geoeffective solar active regions.

THE ANGLO-NORMAN ABBEY CHURCH OF ST ALBANS AND THE AISLELESS NAVE OF ITS CRUCIFORM PREDECESSOR: THE MATERIAL EVIDENCE

2020 ◽  
pp. 1-15
Author(s):  
Jill A Franklin
Keyword(s):  
Conclusive Evidence ◽  
Diagnostic Feature ◽  
Anglo Saxon ◽  
Existing Building ◽  
Cruciform Structure ◽  
Anglo Norman ◽  
First Time ◽  
New Evidence ◽  
Material Evidence ◽  
Solid Walls

Within the Romanesque abbey church at St Albans (Hertfordshire), the vestiges of an earlier structure have been identified for the first time. A hitherto unrecorded feature in the transept, noted by the author in 2017, indicates that, at some stage, the nave lacked its existing arcade piers and instead had solid walls. The implications of this are considerable, calling for a thorough reassessment of the building’s history. For now, it is important to record the primary evidence, so as to make it available for further research. This article aims to provide a concise account of the evidence and a summary of what it might mean. According to the thirteenth-century chronicler, Matthew Paris, the existing church was begun in 1077 and completed in 1088. New evidence indicates, however, that the Romanesque building, with its aisled nave and presbytery, was preceded by a cruciform structure without aisles. The inference is that the existing building contains the fabric of this unaisled predecessor. The obvious conclusion – that it therefore represents the lost Anglo-Saxon abbey church – does not follow without question; as yet, excavation has yielded no conclusive evidence of an earlier church on the site. The critical diagnostic feature presented here for the first time adds substance to the view that the remodelling of unaisled buildings was not uncommon in the post-Conquest period, including large as well as minor churches, as identified long ago at York Minster and, more recently, at Worksop Priory.

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