Ionospheric Response to Sudden Stratospheric Warming Events across Longitudes during Solar Cycle 24

2021 ◽  
Author(s):  
Sumedha Gupta ◽  
A.K. Upadhayaya ◽  
Devendraa Siingh
Keyword(s):  
Solar Cycle ◽  
Stratospheric Warming ◽  
Sudden Stratospheric Warming ◽  
Ionospheric Response ◽  
Solar Cycle 24 ◽  
Cycle 24

Ionospheric Variability: Response to Sudden Stratospheric Warming events during Solar Cycle 24

2021 ◽  
Author(s):  
Sumedha Gupta ◽  
Arun Kumar Upadhayaya ◽  
Devendraa Siingh
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Electron Content ◽  
Vertical Total Electron Content ◽  
Stratospheric Warming ◽  
Sudden Stratospheric Warming ◽  
Total Electron ◽  
Ionospheric Response ◽  
Solar Cycle 24 ◽  
Cycle 24

<p>With low solar activity and unusual progression, Solar Cycle 24 lasted from December 2008 to December 2019 and is considered to be the weakest cycle in the last 100 years. During such quiet solar background conditions, the wave forcing from lower atmosphere will have a perceivable effect on the ionosphere. This study examines the ionospheric response to meteorological phenomenon of Sudden Stratospheric Warming (SSW) events during Solar Cycle 24 (Arctic winter 2008/09 to 2018/19). Ionospheric response to each of these identified warming periods is quantified by studying ground – based Global Positioning System (GPS) derived vertical Total Electron Content (VTEC) and its deviation from monthly median (ΔVTEC) for four longitudinal chains, selected from worldwide International GNSS service (IGS) stations. Each chain comprises of eight stations, chosen in such a way as to cover varied latitudes both in Northern and Southern Hemispheres. A strong latitude – dependent response of VTEC perturbations is observed after the peak stratospheric temperature anomaly (ΔT<sub>max</sub>). The semidiurnal behaviour of VTEC, with morning increase and afternoon decrease, is mostly observed at near-equatorial stations. This vertical coupling between lower and upper atmosphere during SSW is influenced by prominent 13-14 days periodicities in VTEC observations, along with other periodicities of 7, 5, and 3 days. It is seen that the ionospheric response increases with increase in solar activity. Further, under similar ionizing conditions, quite similar ionospheric response is observed, irrespective of ΔT<sub>max</sub> and type of SSW event being major or minor. However, under similar SSW strength (ΔT<sub>max</sub>), no prominent pattern in ionospheric response is observed. The causative mechanism for the coupling processes in the atmosphere during these SSW events is discussed in detail.</p>

Low-latitude ionospheric response from GPS, IRI and TIE-GCM TEC to Solar Cycle 24

2019 ◽  
Vol 364 (12) ◽  
Author(s):  
S. S. Rao ◽  
Monti Chakraborty ◽  
Sanjay Kumar ◽  
A. K. Singh
Keyword(s):  
Solar Cycle ◽  
Low Latitude ◽  
Ionospheric Response ◽  
Solar Cycle 24 ◽  
Cycle 24

Assessing ionospheric response during some strong storms in solar cycle 24 using various data sources

2017 ◽  
Vol 122 (1) ◽  
pp. 1064-1082 ◽  
Author(s):  
John Bosco Habarulema ◽  
Zama Thobeka Katamzi ◽  
Patrick Sibanda ◽  
Tshimangadzo Merline Matamba
Keyword(s):  
Solar Cycle ◽  
Data Sources ◽  
Ionospheric Response ◽  
Solar Cycle 24 ◽  
Cycle 24

scholarly journals Ionospheric response to X-class solar flares in the ascending half of the subdued solar cycle 24

2016 ◽  
Vol 125 (6) ◽  
pp. 1235-1244 ◽  
Author(s):  
Rumajyoti Hazarika ◽  
Bitap Raj Kalita ◽  
Pradip Kumar Bhuyan
Keyword(s):  
Solar Cycle ◽  
Solar Flares ◽  
Ionospheric Response ◽  
Solar Cycle 24 ◽  
Cycle 24

Perturbations of Global Wave Dynamics During Stratospheric Warming Events of the Solar Cycle 24

2020 ◽  
Author(s):  
Valery Yudin ◽  
Larisa Goncharenko ◽  
Svetlana Karol ◽  
Lynn Harvey
Keyword(s):  
Solar Cycle ◽  
Solar Maximum ◽  
Electron Content ◽  
Semidiurnal Tide ◽  
Stratospheric Warming ◽  
Total Electron ◽  
Wave Dynamics ◽  
Diurnal Cycles ◽  
Solar Cycle 24 ◽  
Cycle 24

<p>The paper presents analysis and interpretation of observed perturbations of global wave dynamics in the Ionosphere-Thermosphere-Mesosphere (ITM) during the recent mid-winter Arctic Sudden Stratospheric Warming (SSW) events under solar minimum (2009, 2010, 2018, and 2019), transition to solar maximum (2012) and solar maximum (2013) conditions of the Solar Cycle 24. Employing the 116-level configuration of the thermosphere extension of Whole Atmosphere Community Climate Model (WACCMX-116L), constrained by the meteorological troposphere-stratosphere analyses of Goddard Earth Observing System, version 5 (GEOS-5) of Global Modeling and Data Assimilation Office, we study and characterize the striking amplifications of the solar thermal semidiurnal tide, as one of the main drivers of the ITM variability, after onsets of major and minor SSW events. The dominance and growth of the semidiurnal tide over the diurnal and terdiurnal modes in the lower thermosphere above ~100 km are typical features of the tidal dynamics during major SSW events of the Solar Cycle 24 as suggested by model predictions. The growth of the semidiurnal tidal mode during SSW events is also supported by observational analysis of diurnal cycles from temperature space-borne observations (SABER/TIMED). In the vertical domain of the meteor radar observations at the Southern extra-tropics and low latitudes the model and data revealed the systematic presence of the strong quasi two-day wave wind oscillations that prevail over the tidal winds between 80 and 100 km during mid-January SSW events. In the high and middle latitudes of the Northern Hemisphere model simulations are capable to reproduce the day-to-day variability of tidal and PW oscillations deduced from satellite temperature data. The self-consistent whole atmosphere predictions of global-scale components of neutral dynamics (prevailing winds, planetary waves and tides) become important factor to reproduce and forecast the perturbed state of the ITM as observed from the ground and the space during SSW events of the Solar Cycle 24. The SSW-driven global perturbations of tides can significantly change diurnal cycles of the plasma in the low-latitude and extra-tropical E-region of the ionosphere as will be briefly illustrated by day-day variations of observed and simulated total electron content and plasma drifts.</p>

Regression Analysis of Sunspot Numbers for the Solar Cycle 24 in Comparison to Previous Three Cycles

2014 ◽  
Vol 4 (2) ◽  
pp. 477-483
Author(s):  
Debojyoti Halder
Keyword(s):  
Regression Analysis ◽  
Solar Cycle ◽  
Sunspot Number ◽  
The Sun ◽  
Sunspot Numbers ◽  
Solar Cycle 24 ◽  
Current Cycle ◽  
Cycle 24

Sunspots are temporary phenomena on the photosphere of the Sun which appear visibly as dark spots compared to surrounding regions. Sunspot populations usually rise fast but fall more slowly when observed for any particular solar cycle. The sunspot numbers for the current cycle 24 and the previous three cycles have been plotted for duration of first four years for each of them. It appears that the value of peak sunspot number for solar cycle 24 is smaller than the three preceding cycles. When regression analysis is made it exhibits a trend of slow rising phase of the cycle 24 compared to previous three cycles. Our analysis further shows that cycle 24 is approaching to a longer-period but with smaller occurrences of sunspot number.

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