Recurrent high-speed solar wind co-rotating interaction region imprint on the ionosphere and atmosphere: GPS TEC variations and atmospheric gravity waves

2020 ◽  
Author(s):  
James M. Weygand ◽  
Paul Prikryl ◽  
Reza Ghoddousi-Fard ◽  
Lidia Nikitina ◽  
Bharat S. R. Kunduri
Keyword(s):  
Solar Wind ◽  
Gravity Waves ◽  
High Latitude ◽  
High Speed ◽  
Geomagnetic Storms ◽  
Coronal Holes ◽  
Lower Thermosphere ◽  
Ionospheric Currents ◽  
Atmospheric Gravity Waves ◽  
Atmospheric Gravity

<p>High-speed streams (HSS) from coronal holes dominate solar wind structure in the absence of coronal mass ejections during solar minimum and the descending branch of solar cycle. Prominent and long-lasting coronal holes produce intense co-rotating interaction regions (CIR) on the leading edge of high-speed plasma streams that cause recurrent ionospheric disturbances and geomagnetic storms. Through solar wind coupling to the magnetosphere-ionosphere-atmosphere (MIA) system they affect the ionosphere and neutral atmosphere at high latitudes, and, at mid to low latitudes, by the transmission of the electric fields [1] and propagation of atmospheric gravity waves from the high-latitude lower thermosphere [2].</p><p>The high-latitude ionospheric structure, caused by precipitation of energetic particles, strong ionospheric currents and convection, results in changes of the GPS total electron content (TEC) and rapid variations of GPS signal amplitude and phase, called scintillation [3]. The GPS phase scintillation is observed in the ionospheric cusp, polar cap and auroral zone, and is particularly intense during geomagnetic storms, substorms and auroral breakups. Phase scintillation index is computed for a sampling rate of 50 Hz by specialized GPS scintillation receivers from the Canadian High Arctic Ionospheric Network (CHAIN). A proxy index of phase variation is obtained from dual frequency measurements of geodetic-quality GPS receivers sampling at 1 Hz, which include globally distributed receivers of the RT-IGS network that are monitored by the Canadian Geodetic Survey in near-real-time [4]. Temporal and spatial changes of TEC and phase variations following the arrivals of HSS/CIRs [5] are investigated in the context of ionospheric convection and equivalent ionospheric currents derived from  a ground magnetometer network using the spherical elementary current system method [6,7].</p><p>The Joule heating and Lorentz forcing in the high-latitude lower thermosphere have long been recognized as sources of internal atmospheric gravity waves (AGWs) [2] that propagate both upward and downward, thus providing vertical coupling between atmospheric layers. In the ionosphere, they are observed as traveling ionospheric disturbances (TIDs) using various techniques, e.g., de-trended GPS TEC maps [8].</p><p>In this paper we examine the influence on the Earth’s ionosphere and atmosphere of a long-lasting HSS/CIRs from recurrent coronal holes at the end of solar cycles 23 and 24. The solar wind MIA coupling, as represented by the coupling function [9], was strongly increased during the arrivals of these HSS/CIRs.</p><p> </p><p>[1] Kikuchi, T. and K. K. Hashimoto, Geosci. Lett. , 3:4, 2016.</p><p>[2] Hocke, K. and K. Schlegel, Ann. Geophys., 14, 917–940, 1996.</p><p>[3] Prikryl, P., et al., J. Geophys. Res. Space Physics, 121, 10448–10465, 2016.</p><p>[4] Ghoddousi-Fard et al., Advances in Space Research, 52(8), 1397-1405, 2013.</p><p>[5] Prikryl et al. Earth, Planets and Space, 66:62, 2014.</p><p>[6] Amm O., and A. Viljanen, Earth Planets Space, 51, 431–440, 1999.</p><p>[7] Weygand J.M., et al., J. Geophys. Res., 116, A03305, 2011.</p><p>[8] Tsugawa T., et al., Geophys. Res. Lett., 34, L22101, 2007.</p><p>[9] Newell P. T., et al., J. Geophys. Res., 112, A01206, 2007.</p>

Rapid intensification of tropical cyclones: Vortex waves seeded by aurorally-generated atmospheric gravity waves?

2020 ◽  
Author(s):  
Lidia Nikitina ◽  
Paul Prikryl ◽  
Shun-Rong Zhang
Keyword(s):  
Solar Wind ◽  
Tropical Cyclones ◽  
Gravity Waves ◽  
Lower Thermosphere ◽  
Lower Atmosphere ◽  
Rapid Intensification ◽  
Mean Flow ◽  
Atmospheric Gravity Waves ◽  
Convective Bursts ◽  
Atmospheric Gravity

<p>Convective bursts have been linked to intensification of tropical cyclones [1]. We consider a possibility of convective bursts being triggered by aurorally-generated atmospheric gravity waves (AGWs) that may play a role in the intensification process of tropical cyclones [2]. A two-dimensional barotropic approximation is used to obtain asymptotic solutions representing propagation of vortex waves [3] launched in tropical cyclones by quasi-periodic convective bursts. The absorption of vortex waves by the mean flow and formation of the secondary eyewall lead to a process of an eyewall replacement cycle that is known to cause changes in tropical cyclone intensity [4]. Rapid intensification of hurricanes and typhoons from 1995-2018 is examined in the context of solar wind coupling to the magnetosphere-ionosphere-atmosphere (MIA) system. In support of recently published results [2] it is shown that rapid intensification of TCs tend to follow arrival of high-speed solar wind when the MIA coupling is strongest. The coupling generates internal gravity waves in the atmosphere that propagate from the high-latitude lower thermosphere both upward and downward. In the lower atmosphere, they can be ducted [5] and reach tropical troposphere. Despite their significantly reduced amplitude, but subject to amplification upon over-reflection in the upper troposphere, these AGWs can trigger/release moist instabilities leading to convection and latent heat release. A possibility of initiation of convective bursts by aurorally generated AGWs is investigated. Cases of rapid intensification of recent tropical cyclones provide further evidence to support the published results [2].</p><p>References</p><p>[1] Steranka et al., Mon. Weather Rev., 114, 1539-1546, 1986.</p><p>[2] Prikryl et al., J. Atmos. Sol.-Terr. Phys., 2019.</p><p>[3] Nikitina L.V., Campbell L.J., Stud. Appl. Math., 135, 377–446, 2015.</p><p>[4] Willoughby H.E., et al., J. Atmos. Sci., 39, 395–411, 1982.</p><p>[5] Mayr H.G., et al., J. Geophys. Res., 89, 10929–10959, 1984.</p>

White-light solar corona structure observed by naked eye and processed images

2020 ◽  
Vol 495 (2) ◽  
pp. 2170-2178 ◽  
Author(s):  
Vojtech Rušin ◽  
Paul Prikryl ◽  
Emil A Prikryl
Keyword(s):  
Solar Wind ◽  
White Light ◽  
High Speed ◽  
Geomagnetic Storms ◽  
Interplanetary Space ◽  
Coronal Holes ◽  
Human Vision ◽  
Naked Eye ◽  
Wide Range ◽  
White Light Corona

ABSTRACT Light and dark adaptation and luminance contrast enhancement are well-known characteristics of human vision that allow us to observe a wide range of light intensity not fully captured in standard camera images. The naked-eye observations of total eclipses, some recorded with spectacular detail in artists’ paintings, reveal structure that is consistent with images obtained by telescopes equipped with recording media. The actual shape of the corona during a total eclipse depends not only on the phase of the solar cycle but, as can be simply demonstrated, also on the day-to-day variability and spatial distribution of coronal intensity that is determined by solar surface magnetic fields, including the locations of coronal holes that are the sources of high-speed solar wind causing geomagnetic storms. The latter were very similar for the eclipses in 1932, 1994, and 2017, which is the main reason why the naked-eye observations, as well as the processed images (1994 and 2017), of the white-light corona displayed very similar shapes. White-light corona image processing is a useful technique to enhance the contrast to observe fine-scale structure that is consistent with the physics of the solar atmosphere shaped by the magnetic field drawn out into the interplanetary space by solar wind.

scholarly journals The influence of solar wind on extratropical cyclones – Part 2: A link mediated by auroral atmospheric gravity waves?

2009 ◽  
Vol 27 (1) ◽  
pp. 31-57 ◽  
Author(s):  
P. Prikryl ◽  
D. B. Muldrew ◽  
G. J. Sofko
Keyword(s):  
Solar Wind ◽  
Gravity Waves ◽  
Significant Response ◽  
Extratropical Cyclones ◽  
High Latitudes ◽  
Atmospheric Gravity Waves ◽  
Low Latitudes ◽  
Slantwise Convection ◽  
High Level ◽  
Atmospheric Gravity

Abstract. Cases of mesoscale cloud bands in extratropical cyclones are observed a few hours after atmospheric gravity waves (AGWs) are launched from the auroral ionosphere. It is suggested that the solar-wind-generated auroral AGWs contribute to processes that release instabilities and initiate slantwise convection thus leading to cloud bands and growth of extratropical cyclones. Also, if the AGWs are ducted to low latitudes, they could influence the development of tropical cyclones. The gravity-wave-induced vertical lift may modulate the slantwise convection by releasing the moist symmetric instability at near-threshold conditions in the warm frontal zone of extratropical cyclones. Latent heat release associated with the mesoscale slantwise convection has been linked to explosive cyclogenesis and severe weather. The circumstantial and statistical evidence of the solar wind influence on extratropical cyclones is further supported by a statistical analysis of high-level clouds (<440 mb) extracted from the International Satellite Cloud Climatology Project (ISCCP) D1 dataset. A statistically significant response of the high-level cloud area index (HCAI) to fast solar wind from coronal holes is found in mid-to-high latitudes during autumn-winter and in low latitudes during spring-summer. In the extratropics, this response of the HCAI to solar wind forcing is consistent with the effect on tropospheric vorticity found by Wilcox et al. (1974) and verified by Prikryl et al. (2009). In the tropics, the observed HCAI response, namely a decrease in HCAI at the arrival of solar wind stream followed by an increase a few days later, is similar to that in the northern and southern mid-to-high latitudes. The amplitude of the response nearly doubles for stream interfaces associated with the interplanetary magnetic field BZ component shifting southward. When the IMF BZ after the stream interface shifts northward, the autumn-winter effect weakens or shifts to lower (mid) latitudes and no statistically significant response is found at low latitudes in spring-summer. The observed effect persists through years of low and high volcanic aerosol loading. The similarity of the response in mid-to-high and low latitudes, the lack of dependence upon aerosol loading, and the enhanced amplitude of the effect when IMF BZ component shifts southward, favor the proposed AGW link over the atmospheric electric circuit (AEC) mechanism (Tinsley et al., 1994). The latter requires the presence of stratospheric aerosols for a significant effect and should produce negative and positive cloud anomalies in mid-to-high and low latitudes, respectively. However, if the requirement of aerosols for the AEC mechanism can be relaxed, the AGW and AEC mechanisms should work in synergy at least in mid-to-high latitudes.

Severe weather in the context of solar wind coupling to the magnetosphere-ionosphere-atmosphere system

2020 ◽  
Author(s):  
Paul Prikryl ◽  
Vojto Rušin ◽  
Pavel Šťastný ◽  
Maroš Turňa ◽  
Martina Zeleňáková
Keyword(s):  
Solar Wind ◽  
High Speed ◽  
Coronal Holes ◽  
Lower Thermosphere ◽  
Severe Weather ◽  
Lower Atmosphere ◽  
Extratropical Cyclones ◽  
Rapid Intensification ◽  
Rainfall Events ◽  
Slantwise Convection

&lt;p&gt;Tropical and extratropical cyclones can intensify into the most destructive weather systems that have significant societal and economic impacts. Rapid intensification of such weather systems has been examined in the context of solar wind coupling to the magnetosphere-ionosphere-atmosphere (MIA) system. It has been shown [1,2] that explosive extratropical cyclones and rapid intensification of tropical cyclones tend to follow arrivals of high-speed solar wind when the MIA coupling is strongest. The coupling generates atmospheric gravity waves (AGWs) that propagate from the high-latitude lower thermosphere both upward and downward [3,4]. In the upper atmosphere, AGWs are observed as traveling ionospheric disturbances. In the lower atmosphere, they can reach the troposphere and be ducted [4] to low latitudes. Despite significantly reduced wave amplitude, but subject to amplification upon over-reflection in the upper troposphere, these AGWs can trigger/release moist instabilities leading to convection and latent heat release, which is the energy driving the storms. The release of conditional symmetric instability is known to initiate slantwise convection producing rain/snow bands in extratropical cyclones. Severe weather, including severe winter storms, heavy snowfall and rainfall events, have been examined in the context of MIA coupling [5]. The results indicate a tendency of significant weather events, particularly if caused by low pressure systems in winter, to follow arrivals of solar wind high-speed streams from coronal holes. In the present paper we review the published results and provide further evidence to support them. This includes the occurrence of heavy rainfall events and flash floods, as well as the rapid intensification of recent hurricanes and typhoons, with the goal to identify sources of AGWs at high latitudes that may play a role in triggering convective bursts potentially leading to such events.&lt;/p&gt;&lt;p&gt;[1] Prikryl P., et al., J. Atmos. Sol.-Terr. Phys., 149, 219&amp;#8211;231, 2016.&lt;/p&gt;&lt;p&gt;[2] Prikryl P., et al., J. Atmos. Sol.-Terr. Phys., 183, 36&amp;#8211;60, 2019.&lt;/p&gt;&lt;p&gt;[3] Prikryl P., et al., Ann. Geophys., 23, 401&amp;#8211;417, 2005.&lt;/p&gt;&lt;p&gt;[4] Mayr H.G., et al., J. Geophys. Res., 89, 10929&amp;#8211;10959, 1984.&lt;/p&gt;&lt;p&gt;[5] Prikryl P., et al., J. Atmos. Sol.-Terr. Phys., 171, 94&amp;#8211;110, 2018.&lt;/p&gt;

Goose Bay radar observations of Earth-reflected, atmospheric gravity waves in the high-latitude ionosphere

1990 ◽  
Vol 95 (A6) ◽  
pp. 7693 ◽  
Author(s):  
J. C. Samson ◽  
R. A. Greenwald ◽  
J. M. Ruohoniemi ◽  
A. Frey ◽  
K. B. Baker
Keyword(s):  
Gravity Waves ◽  
High Latitude ◽  
Atmospheric Gravity Waves ◽  
Radar Observations ◽  
High Latitude Ionosphere ◽  
Atmospheric Gravity

A century of geomagnetic storms, CMEs and HSS/SIRs

2021 ◽  
Author(s):  
Kalevi Mursula ◽  
Timo Qvick ◽  
Lauri Holappa
Keyword(s):  
Solar Wind ◽  
High Speed ◽  
Geomagnetic Storms ◽  
Coronal Holes ◽  
Active Regions ◽  
Time Interval ◽  
Dst Index ◽  
Intensity Category ◽  
Interaction Regions ◽  
Storm Index

&lt;p&gt;Geomagnetic storms are mainly driven by the two main solar wind transients: coronal mass ejections (CME) and high-speed solar wind streams with related (corotating) stream interaction regions (HSS/SIR). CMEs are produced by new magnetic flux emerging on solar surface as active regions, and their occurrence follows the occurrence of sunspots quite closely. HSSs are produced by coronal holes, whose occurrence at the ecliptic is maximized in the declining phase of the solar cycle.&lt;/p&gt;&lt;p&gt;Geomagnetic storms are defined and quantified by the Dst index that measures the intensity of the ring current and is available since 1957. We have corrected some early errors in the Dst index and extended its time interval from 1932 onwards using the same stations as the Dst index (CTO preceding HER). This extended storm index is called the Dxt index. We have also constructed Dxt3 and Dxt2 indices from three/two of the longest-operating Dst stations to extend the storm index back to 1903, covering more than a century of storms.&lt;/p&gt;&lt;p&gt;We divide the storms into four intensity categories (weak, moderate, intense and major), and use the classification of solar wind by Richardson et al. into CME, HSS/SIR and slow wind -related flows in order to study the drivers of storms of each intensity category since 1964. We also correct and use the list of sudden storm commencements (SSC) collected by Father P. Mayaud, and divide the storms of each category into SSC-related storms and non-SSC storms.&lt;/p&gt;&lt;p&gt;Studying geomagnetic storms of different intensity category and SSC relation allows us to study the occurrence of CMEs and HSS/SIR over the last century. We also use these results to derive new information on the centennial evolution of the structure of solar magnetic fields.&lt;/p&gt;

scholarly journals Polar cap patches, GPS TEC variations, and atmospheric gravity waves

2021 ◽  
Author(s):  
Paul Prikryl ◽  
Robert G. Gillies ◽  
David R. Themens ◽  
Bharat S. R. Kunduri ◽  
Roger Varney ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Joule Heating ◽  
Sudden Change ◽  
Lower Atmosphere ◽  
Small Scale ◽  
Neutral Atmosphere ◽  
Ionospheric Currents ◽  
Atmospheric Gravity Waves ◽  
Gps Tec ◽  
Atmospheric Gravity

&lt;p&gt;The southward pointing field of view of the Canadian component of the Resolute Bay Incoherent Scatter Radar (RISR-C) is well suited for observing the ionospheric signatures of flux transfer events and subsequent polar patch formation in the cusp. &amp;#160;The fast azimuthally oriented flows and associated density depletions often show an enhanced ion temperature from Joule heating caused by the sudden change in plasma flow direction. The newly formed polar patches are then observed as they propagate through the field-of-views of both RISR-C and RISR-N. In the ionosphere, the electron density gradients imposed in the cusp, and small-scale irregularities resulting from gradient-drift instability, particularly in the trailing edges of patches, cause GPS TEC and phase variations, and sometimes amplitude scintillation. The neutral atmosphere is affected by ionospheric currents resulting in Joule heating. The pulses of ionospheric currents in the cusp launch atmospheric gravity waves (AGWs) causing traveling ionospheric disturbances, as they propagate equatorward and upward. On the other hand, the downward propagating AGW packets can impact the lower atmosphere, including the troposphere. Despite significantly reduced wave amplitudes, but subject to amplification upon over-reflection in the upper troposphere, these AGWs can trigger/release existing moist instabilities, initiating convection and latent heat release, the energy leading to intensification of storms.&lt;/p&gt;

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