scholarly journals Some peculiarities in longitude distribution of sunspot groups over last four eleven-year solar cycles

2016 ◽  
Vol 2 (2) ◽  
pp. 28-36
Author(s):  
Алексей Рыбак ◽  
Alexey Rybak
Keyword(s):  
Data Center ◽  
Sunspot Cycle ◽  
Solar Cycles ◽  
Large Sunspot ◽  
Using Data ◽  
Average Size ◽  
National Geophysical Data Center ◽  
Northern And Southern Hemispheres ◽  
Observation Period ◽  
Sunspot Groups

This paper considers a longitude distribution of sunspot groups over 1982–2013, using data from the National Geophysical Data Center (Boulder, USA). The space-time distribution of sunspot groups is analyzed in coordinate sectors calculated from heliographic longitudes of the groups. A longitude extent of a coordinate sector is compared to the average size of one active region (30–40°). Then, in each coordinate sector, evolutionary activity of sunspot groups is summarized according to classification values after Malde throughout the observation period. The longitude distribution of large sunspot groups plotted in such a way does not reveal anticorrelation between Northern and Southern hemispheres in sunspot cycle 23.

scholarly journals Some peculiarities in longitude distribution of sunspot groups over last four eleven-year solar cycles

2016 ◽  
Vol 2 (2) ◽  
pp. 22-28
Author(s):  
Алексей Рыбак ◽  
Alexey Rybak
Keyword(s):  
Data Center ◽  
Sunspot Cycle ◽  
Solar Cycles ◽  
Using Data ◽  
Average Size ◽  
National Geophysical Data Center ◽  
Northern And Southern Hemispheres ◽  
Observation Period ◽  
Made In ◽  
Sunspot Groups

This paper considers a longitude distribution of sunspot groups over 1982–2013, using data from the National Geophysical Data Center (Boulder, USA). The space-time distribution of sunspot groups is analyzed in coordinate sectors calculated from heliographic longitudes of the groups. A longitude extent of a coordinate sector is compared to the average size of one active region (30–40°). Then, in each coordinate sector, evolutionary activity of sunspot groups is summarized according to Malde classification indices throughout the observation period. The longitude distribution of large sunspot groups made in such a way does not reveal anticorrelation between Northern and Southern hemispheres in sunspot cycle 23.

scholarly journals The 22-year cycle in the geomagnetic 27-day recurrences reflecting on the F2-layer ionization

2004 ◽  
Vol 22 (4) ◽  
pp. 1171-1176 ◽  
Author(s):  
E. M. Apostolov ◽  
D. Altadill ◽  
M. Todorova
Keyword(s):  
Solar Cycle ◽  
Geomagnetic Activity ◽  
Activity Index ◽  
Solar Rotation ◽  
Rotation Period ◽  
Sunspot Cycle ◽  
Solar Cycles ◽  
Solar Radio Flux ◽  
Critical Frequency Fof2 ◽  
Northern And Southern Hemispheres

Abstract. Solar cycle variations of the amplitudes of the 27-day solar rotation period reflected in the geomagnetic activity index Ap, solar radio flux F10.7cm and critical frequency foF2 for mid-latitude ionosonde station Moscow from the maximum of sunspot cycle 18 to the maximum of cycle 23 are examined. The analysis shows that there are distinct enhancements of the 27-day amplitudes for foF2 and Ap in the late declining phase of each solar cycle while the amplitudes for F10.7cm decrease gradually, and the foF2 and Ap amplitude peaks are much larger for even-numbered solar cycles than for the odd ones. Additionally, we found the same even-high and odd-low pattern of foF2 for other mid-latitude ionosonde stations in Northern and Southern Hemispheres. This property suggests that there exists a 22-year cycle in the F2-layer variability coupled with the 22-year cycle in the 27-day recurrence of geomagnetic activity. Key words. Ionosphere (mid-latitude ionosphere; ionosphere- magnetosphere interactions) – Magnetospheric physics (solar wind-magnetosphere interactions)

scholarly journals A statistical study on solar soft X-ray flare and the sources

2012 ◽  
Vol 8 (S294) ◽  
pp. 551-552
Author(s):  
Juan Guo
Keyword(s):  
Magnetic Structure ◽  
Data Center ◽  
Sunspot Group ◽  
Statistical Study ◽  
Geophysical Data ◽  
X Ray ◽  
National Geophysical Data ◽  
National Geophysical Data Center ◽  
Class Flare ◽  
Sunspot Groups

AbstractWe surveyed 28 year of Solar X-ray flares and sunspot group records supplied by the National Geophysical Data Center (NGDC) to study the dependence of different class Xray flares on the magnetic structure of sunspot groups statistically. It is found that 82.5% X-class flare, 51.4% M-class flare, 26.3% C-class flare, and 10.1% B-class flare occurred in the sunspot group with βγδ structure. There are 6.6% X-class flares, 17.5% M-class flare, 39.1% C-class flare, and 60.4% B-class flare occurred out of sunspot group.

The LDE-Type Flare Occurrence (1969-1993)

1994 ◽  
Vol 144 ◽  
pp. 279-282
Author(s):  
A. Antalová
Keyword(s):  
Time Series ◽  
Fourier Analysis ◽  
Sunspot Cycle ◽  
List Type ◽  
Type Number ◽  
Solar Cycles ◽  
Type Iv ◽  
Long Duration ◽  
Cycle Maximum ◽  
Flare Index

AbstractThe occurrence of LDE-type flares in the last three cycles has been investigated. The Fourier analysis spectrum was calculated for the time series of the LDE-type flare occurrence during the 20-th, the 21-st and the rising part of the 22-nd cycle. LDE-type flares (Long Duration Events in SXR) are associated with the interplanetary protons (SEP and STIP as well), energized coronal archs and radio type IV emission. Generally, in all the cycles considered, LDE-type flares mainly originated during a 6-year interval of the respective cycle (2 years before and 4 years after the sunspot cycle maximum). The following significant periodicities were found:• in the 20-th cycle: 1.4, 2.1, 2.9, 4.0, 10.7 and 54.2 of month,• in the 21-st cycle: 1.2, 1.6, 2.8, 4.9, 7.8 and 44.5 of month,• in the 22-nd cycle, till March 1992: 1.4, 1.8, 2.4, 7.2, 8.7, 11.8 and 29.1 of month,• in all interval (1969-1992):a)the longer periodicities: 232.1, 121.1 (the dominant at 10.1 of year), 80.7, 61.9 and 25.6 of month,b)the shorter periodicities: 4.7, 5.0, 6.8, 7.9, 9.1, 15.8 and 20.4 of month.Fourier analysis of the LDE-type flare index (FI) yields significant peaks at 2.3 - 2.9 months and 4.2 - 4.9 months. These short periodicities correspond remarkably in the all three last solar cycles. The larger periodicities are different in respective cycles.

The national geophysical data center bathymetric program

1992 ◽  
Vol 15 (2-3) ◽  
pp. 165-175 ◽  
Author(s):  
Maureen R. Kenny ◽  
Kurt E. Brown
Keyword(s):  
Data Center ◽  
Geophysical Data ◽  
National Geophysical Data ◽  
National Geophysical Data Center

Variation of Quiet Sun Radiation during Solar Cycles 23 and 24

2017 ◽  
Vol 13 (S335) ◽  
pp. 11-13
Author(s):  
Mahender Aroori ◽  
G. Yellaiah ◽  
K. Chenna Reddy
Keyword(s):  
Radio Emission ◽  
Brightness Temperature ◽  
Statistical Method ◽  
Solar Radio ◽  
Solar Radio Emission ◽  
Solar Cycles ◽  
Quiet Sun ◽  
Data Centre ◽  
National Geophysical Data ◽  
Using Data

AbstractRadio observations play a very important role in understanding the structure of the solar atmosphere. In this paper the quiet sun component of the solar radio emission has been investigated using data obtained from the Solar Indices Bulletin, National Geophysical Data Centre. By statistical method, the quiet sun component is estimated for 84 successive basic periods containing three solar rotations each using data obtained at different frequencies. From the quiet sun component we estimate the brightness temperature in each observing frequency.

scholarly journals Trajectories of Postload Plasma Glucose in the Development of Type 2 Diabetes in Japanese Adults

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Rie Oka ◽  
Kyoko Shibata ◽  
Masaru Sakurai ◽  
Mitsuhiro Kometani ◽  
Masakazu Yamagishi ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Plasma Glucose ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Transition Age ◽  
Japanese Workers ◽  
Japanese Adults ◽  
Using Data ◽  
Observation Period

We aimed to clarify how the trajectories of 1-hour postload plasma glucose (PG) and 2-hour PG were different in the development of type 2 diabetes. Using data of repeated health checkups in Japanese workers from April 2006 to March 2016, longitudinal changes of fasting, 1-hour, and 2-hour PG on the oral glucose tolerance test were analyzed with a linear mixed effects model. Of the 1464 nondiabetic subjects at baseline, 112 subjects progressed to type 2 diabetes during the observation period (progressors). In progressors, 1-hour PG and 2-hour PG showed gradual increases with slopes of 1.33 ± 0.2 and 0.58 ± 0.2 mg/dL/year, respectively, followed by a steep increase by which they attained diabetes. Until immediately before the diabetes transition, age- and sex-adjusted mean level of 2-hour PG was 149 ± 2.7 mg/dL, 34 ± 2.7 (30%) higher compared to nonprogressors, while that of 1-hour PG was 206 ± 4.1 mg/dL, 60 ± 4.3 mg/dL (41%) higher compared to nonprogressors. In conclusion, diabetes transition was preceded by a mild elevation of 2-hour PG for several years or more. The elevation in 1-hour PG was larger than that of 2-hour PG until immediately before the transition to diabetes.

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