On the basis of «CHH – coronal hole history» [2] and using ACE/SWICS data [3] we selected 35 quiet periods where suprathermal ion fluxes from near equatorial CH at 1 AU were detected. On the outflow in an equatorial coronal hole. Aims.We aim to study the small-scale evolution at the boundaries of an equatorial coronal hole connected with a channel of open magnetic flux to the polar region and an “isolated” one in the extreme-ultraviolet spectral range. This result confirms the previous Stellar corona, the outer atmosphere of the Sun or another star; Coronavirus, a group of RNA viruses . 325 Broadway, Boulder CO 80305, 27-Day Outlook of 10.7 cm Radio Flux and Geomagnetic Indices, Report and Forecast of Solar and Geophysical Activity, Geoalert - Alerts, Analysis and Forecast Codes, Geospace Ground Magnetic Perturbation Maps, North American (US Region) Total Electron Content, Geoelectric Field 1-Minute (Empirical EMTF - 3D Model), STORM Time Empirical Ionospheric Correction. Never want to miss out on a space weather event or one of our news articles again? Equatorial coronal holes (ECHs) are usually rare at solar minimum because at this time the ideal global magnetic structure of the Sun resembles a magnetic dipole, with opposite polarity open fields at the two poles and a single HCS at the equator (for example, the cartoon shown in Zhao et al. Get the latest machine learning methods with code. NASA's Solar Dynamics Observatory observed an extensive equatorial, dark coronal hole extending about halfway across the solar disk on May 2-4, 2018. For details, see JOP 206. 1a) and, finally, its counterpart becomes visible in COR 1 at 17:46 (Fig. In the second half of August a large equatorial coronal hole appeared on the solar disc, extending from the north po- lar region toward an active region, just south of the equator. Give your support for our organization by making a donation. Strong CIRs and the faster CH HSS can impact Earth’s magnetosphere enough to cause periods of geomagnetic storming to the G1-G2 (Minor to Moderate) levels; although rarer cases of stronger storming may also occur. In this paper we present some observations of "equatorial coronal hole jets" made up with data provided by the STEREO/SECCHI instruments during a period comprising March 2007 and December 2007. abbreviations. Continental and Equatorial Coronal Holes release High Speed Streams of solar wind. An equatorial coronal hole has been observed on 18 and 19 October 1996 with SOHO-CDS and with the Nancąy Radioheliograph (RH). As the high speed stream interacts with the relatively slower ambient solar wind, a compression region forms, known as a co-rotating interaction region (CIR). The more persistent coronal holes can sometimes last through several solar rotations (27-day periods). Still puzzled? Autor: Xia, L. D. et al. 2. Seine Aufgaben zielten auf die Untersuchung der Struktur und Dynamik der Erdoberfläche, der Atmosphäre, Ionosphäre und des irdischen Magnetfeldes. Astr. 1c). This could however change in the near future as an equatorial portion of this northern hemisphere polar coronal hole now faces Earth. Coronal holes are most prevalent and stable at the solar north and south poles; but these polar holes can grow and expand to lower solar latitudes. In 2011, three satellites—the Solar-Terrestrial RElations Observatory (STEREO) A & B, and the Solar Dynamics Observatory (SDO)—were in a unique spatial alignment that allowed a 360 degree view of the Sun. These loops are the closed-magnetic flux cousins of the open-magnetic flux that can be found in coronal hole (polar) regions and the solar wind.Loops of magnetic flux well-up from the solar body and fill with hot solar plasma. We found that for all of the six lower-transition-region lines, the emission height is about 4-5 Mm in the equatorial coronal hole, and around 2 Mm in the quiet Sun region. Polar and Equatorial Coronal Holes. Coronal hole plasma has the lowest density, which makes it an optimal testbed for studies of collisionless kinetic processes that are the ultimate dissipation mechanisms in many theories ... longer, and less-defined masses of light extending out from the equatorial and middle-latitude zones. Abstract and Figures Collimated ejections of plasma called "coronal hole jets" are commonly observed in polar coronal holes. Coronal holes can develop at any time and location on the Sun, but are more common and persistent during the years around solar minimum. Observations in H I Lyα and O VI 103.2, 103.7 nm provided spectroscopic diagnostics of proton and O 5+ velocity distributions and outflow velocities. The Coronal Hole in question first came to our attention on 12 August 18 and we were watching for the next rotation as it looked to have considerable potential. POLAR AND EQUATORIAL CORONAL HOLE WINDS AT SOLAR MINIMA: FROM THE HELIOSPHERE TO THE INNER CORONA L. Zhao and E. Landi Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, MI 48105, USA; lzh@umich.edu Received 2013 August 30; accepted 2013 December 11; published 2014 January 15 ABSTRACT Fast solar wind can be accelerated from at … 2 Nistico at al. National Oceanic and Atmospheric Administration. This means that the auroral activity was mostly quiet during the past few days. The larger and more expansive coronal holes can often be a source for high solar wind speeds that buffet Earth for many days. It is not yet known whether the higher densities are responsible for the seeming inhibition of the fast ion outflow speeds and extremely large perpendicular temperatures that occur in polar coronal holes at solar … Our help section is the place to be where you can find in-depth articles, W wycieczce klasowej w Bejrucie młode dziewczyny sprzedawały owl … Coronal holes are part of the Sun's corona and are constantly changing and reshaping because the corona is not uniform. At a distance of one astronomical unit, the wind is mixed and evolved, and therefore much of the diagnostic structure of these sources and processes has been lost. This means that the auroral activity was mostly quiet during the past few days. Coronal holes are best observed in EUV wavelengths near 19.3nm, corresponding to temperatures in the corona of more than 1 million degrees. We report new observations concerning the source of the fast solar wind by directly comparing Doppler-shift maps of Ne 7+ with charts of the photospheric magnetic field in an equatorial coronal hole, which was observed by SUMER/SOHO and NSO/Kitt Peak on November 5, 1999. Did you had trouble with some of the technical terms used in this article? Quiet time periods were selected with help of criteria worked out in [4, 5] guaranteeing minimum energetic particle contribution from any active processes on Sun and in the interplanetary space. Energetics of Coronal Hole Expansion XUE-Pu ZHAO* High Altitude Observatory, National Center for Atmospheric Research*, Boulder, Colorado 80307 Based on the assumption of the undamped propagation of Alfven waves between 2 and 5 Rs, the pos- sible range of Alfven wave energy flux density at the base of a polar coronal hole has been deduced. The longitudinal evolution of equatorial coronal holes . Coronal holes are most prevalent and stable at the solar north and south poles; but these polar holes can grow and expand to lower solar latitudes. April 25, 2015 – A strong coronal hole directly faced earth on the south, and a trans-equatorial opening entered the earth-facing 1/4 of the sun. and Facebook and download the SpaceWeatherLive app for We analyzed the UVCS/SOHO data obtained during the Whole Sun Month campaign in 1996 and compared the H I Lyα (1216Å) and O VI (1032Å,1037Å) emission in the polar and equatorial coronal holes. An elongated equatorial coronal hole of negative polarity crossed the central meridian yesterday and expected to influence Solar wind conditions from December 9 onwards. The jet morphologies vary widely; one relatively common shape is the so-called Eiffel Tower (ET) jet (Ya- The Sun contains magnetic fields that arch away from areas in the corona that are very thin due to the lower levels of energy and … We analyzed the UVCS/SOHO data obtained during the Whole Sun Month campaign in 1996 and compared the H I Lyα (1216Å) and O VI (1032Å,1037Å) emission in the polar and equatorial coronal holes. Copyright © 2003-2020 SpaceWeatherLive © All rights reserved - Part of Parsec vzw -, C1 solar flare and CME, glancing blow possible, Prediction for Solar Cycle 25 by Dr Keith Strong. May 1, 2018. Coronal holes (CHs) are most commonly known as individual holes in the solar corona, where the electron density and temperature is low, and the magnetic field is quasi-open, allowing solar wind to escape into the interplanetary space. Coronal holes (CHs) have been known as the source of the fast solar wind (FSW). If an equatorial coronal hole appears on the disk/limb, JOP 206 will be run. Persistent coronal holes are long-lasting sources for high speed solar wind streams. In this pa-per we present some observations of “equatorial coronal hole jets ” made up with data provided by the STEREO/SECCHI instruments during a period comprising March 2007 and De-cember 2007. Large equatorial coronal hole causing major geomagnetic storming Our planet is under the influence of positive polarity coronal hole today which is causing enhanced geomagnetic conditions. The relationship between the velocity field, line intensity and magnetic network is discussed. M7.8 in Nepal June 23, 2014 – Large, moderately powerful coronal holes were on the north and south, with a powerful trans-equatorial opening beginning to … The northern hemisphere polar coronal hole which we hoped would spark some aurora this week never really managed to influence Earth enough for some good auroral displays. mailing list, follow us on Twitter 1997] during the Whole Sun Month campaign (August- September 1996). The CIR can result in particle density enhancement and interplanetary magnetic field (IMF) strength increases preceding onset of the CH HSS. The coronal hole was too far north on the solar disk and the most intense part of the solar wind stream went north of our planet. Geomagnetic storms are classified using a five-level NOAA Space Weather Scale. STAR Coronal hole tag: Location: Earth facing position date interval: Geomagnetic disturbance date interval: Kp dominant / Kp max / ap max: Max solar wind speed (km/s) - "Observational features of equatorial coronal hole jets" forum where we will help you the best we can! Equatorial coronal hole faces Earth. J. Astrophys. 1973) coronal magnetic field lines. Evolution of an equatorial coronal hole structure and the released coronal hole wind stream: Carrington rotations 2039 to 2050 Astronomy & Astrophysics , Jul 2017 Verena Heidrich-Meisner , Thies Peleikis , Martin Kruse , Lars Berger , Robert F. Wimmer-Schweingruber Abstract In this paper, we report ionospheric response to fast stream solar coronal holes during 2008 deep solar minimum year using ground‐based multi‐instruments over Indian region. A equatorial coronal hole has crossed the central meridian, which is likely to influence the solar wind conditions near Earth starting on August 30.The magnitude of the interplanetary magnetic field declined from 15 to 9 nT, with Bz mainly being southward. EUV and radio observations of an equatorial coronal hole F. Chiuderi Drago1, E. Landi1, A. Fludra2, and A. Kerdraon3 1 Department of Astronomy and Space Science, University of Florence, Italy 2 Rutherford Appleton Laboratory, Chilton, Didcot, UK 3 DASOP, Observatoire de Paris-Meudon, France Received 22 April 1999 / Accepted 16 June 1999 Abstract. We determine the spatial and temporal scale of these changes. However, the plasma properties at the base of CHs have not yet been fully understood. This alignment lasted until 2014, the peak of solar cycle 24. May 1, 2018. Parsec vzw is a non-profit organization from Belgium which consists of several websites about Astronomy, Space, Space Weather, aurora and related subjects. The coronal hole regions adjacent to the streamer boundaries are characterized by the same magnetic topology inferred for the lanes dividing sub-streamers in the equatorial belt. Coronavirus disease 2019 (COVID-19), the disease caused by the virus Equatorial Coronal Holes and Their Relation to High-Speed Solar Wind Streams Lidong Xia and Eckart Marsch Max-Planck-Institut für Aeronomie, D-37191 Katlenburg-Lindau, Germany Geomagnetic activity in our atmosphere increases a few days after an Earth-facing Coronal Hole appears on the surface of the Sun. 5.3 Coronal Holes. Differences Between a Polar Coronal Hole and Its Equatorial Extension. The purpose of this thesis work is to study equatorial CHs and their relation to the origin and propagation of the FSW by combining observations with both space-based (SOHO and WIND) and ground-based (NSO/KP) instruments. By combining numerical simulations and high-resolution observations, we have made substantial progress recently on determining the energy buildup and release processes in these jets. Additionally, any predicted CIR or CH HSS influences are explained in more detail in the forecast discussion. Le linee di campo sono aperte verso lo spazio esterno. 2Department of Physics, Bangalore University, Bengaluru 560 056, India. Il campo polare é molto forte. An area of 250 ×300 on the solar disk is shown, covering a large fraction of the equatorial CH and its boundary re-gions. Buco coronale polare [Polar coronal hole], visibile nella banda X. Nie zaniedbuj niefizycznej interakcji ze swoja partnerką. This could however change in the near future as an equatorial portion of this northern hemisphere polar coronal hole now faces Earth. This open, magnetic field line structure allows the solar wind to escape more readily into space, resulting in streams of relatively fast solar wind and is often referred to as a high speed stream in the context of analysis of structures in interplanetary space. Because of their potential for escalated geomagnetic activity and possible storming (G1 or higher), forecasters analyze coronal holes closely and also note them on the daily synoptic drawing. The Elephant's Trunk coronal hole was the subject of investigation by a large num- ber of different satellite and ground-based instruments [Bro- mage et al. Both types show evidence for superradially diverging boundaries. Coronal holes appear as dark areas in the solar corona in extreme ultraviolet (EUV) and soft x-ray solar images. It is concluded that extended heating above 2 … It is also possible for coronal holes to develop in isolation from the polar holes; or for an extension of a polar hole to split off and become an isolated structure. Fear not as the geomagnetic conditions at our planet will likely increase in about three days from now as we now have an equatorial portion of this polar coronal hole facing Earth. a large equatorial coronal hole observed by the Solar Ultraviolet Measurements of Emitted Radiation spectrometer (SUMER) on the SolarandHeliosphericObser-vatory(SOHO) in November 1999. Share this story: Thursday, December 28, 2017. Max Waldmeier thus dubbed those zones as coronal holes (i.e., Koronale Löcher in German). Because coronal-hole jets originate in relatively simple magnetic structures, they offer an ideal testbed for theories of energy buildup and release in the full range of solar eruptions. Jets (transient/collimated plasma ejections) occur frequently throughout the solar corona and contribute mass/energy to the corona and solar wind. Geomagnetic K-index of 6 (G2-Moderate geomagnetic storm) threshold was … This equatorial coronal hole, named the Elephant's Trunk, resembles the famous boot-shaped coronal hole observed by Skylab in 1974 [Nolte et al., 1976]. a FAQ and a list with common As the CH HSS begins to arrive at Earth, solar wind speed and temperature increase, while particle density begins to decrease. SpaceWeatherLive.com is a near live website where you can follow space weather from the Sun to Earth and know exactly when you can see aurora. an equatorial coronal hole and in the surrounding quiet Sun region. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a coronavirus responsible for the 2019–20 pandemic . (2015) 36, 355–374 c Indian Academy of Sciences Solar Wind Associated with Near Equatorial Coronal Hole M. Hegde1,2,∗, K.M.Hiremath1, Vijayakumar H. Doddamani2 & Shashanka R Gurumath3 1Indian Institute of Astrophysics, Bengaluru 560 034, India. The coronal hole was too far north on the solar disk and the most intense part of the solar wind stream went north of our planet. The equatorial hole also has a higher density than the polar hole at similar heights. In this paper we study the ionospheric–magnetic disturbance during a strong magnetic storm on 5 April 2010 associated to a coronal hole. Subscribe to our Coronal hole plasma has the lowest density, which makes it an optimal testbed for studies of collisionless kinetic processes that are the ultimate dissipation mechanisms in many theories of coronal heating. SWPC forecasters take into account any possible effects of CIR and CH HSS activity when forecasting the anticipated levels of overall planetary geomagnetic response for each 3-hour synoptic period over the next three days; as detailed in the 3-day forecast. The coronal hole was too far north on the solar disk and the most intense part of the solar wind stream went north of our planet. From the perspective of a fixed observer in interplanetary space, the CIR will be seen to lead the coronal hole high speed stream (CH HSS). Here yellow means closed and red-brown open field lines. J. Astrophys. We found that the emission lines have similar characteristics in these two types of coronal holes. Sep 16th, 2015 – Strong coronal hole on the north began a slow uptick in a seismicity to a crescendo as the equatorial portion directly faced earth. STAR Coronal hole tag: Location: Earth facing position date interval: Geomagnetic disturbance date interval: Kp dominant / Kp max / ap max: Max solar wind speed (km/s) How to confirm on any coming geomagnetic storm ? Frequency distribution of the lifetimes of equatorial coronal hole jets at 171, 195, and 304 A averaged in bins of 10 minutes. Evolution of an equatorial coronal hole structure and the released coronal hole wind stream: Carrington rotations 2039 to 2050 Verena Heidrich-Meisner1, Thies Peleikis1, Martin Kruse1, Lars Berger1, and Robert F. Wimmer-Schweingruber1 Christian Albrechts University at Kiel, Germany, e-mail: heidrich@physik.uni-kiel.de ABSTRACT Context. Tangled Up in Blue. Coronal loops are the basic structures of the magnetic solar corona. This work shows this jet is another example of a jet in a coronal hole, resulting from flux cancellation and not flux emergence. They appear dark because they are cooler, less dense regions than the surrounding plasma and are regions of open, unipolar magnetic fields. The greater than 2MeV electron flux did not exceed the 1000 pfu alert threshold. : EUV equatorial coronal hole jets` emerging from the photosphere (Shibata et al., 1992). SAC-C. Argentinische, von 2000 bis 2013 aktive Erdbeobachtungsmission mit internationaler Unterstützung (USA, F, I, DK, BR). Instead of blowing out solar wind that goes north of our planet, this portion of the coronal hole is expelling high speed solar wind right at our planet. However, such coronal jets are not only a specific features of polar coronal holes but they can also be found in coronal holes appearing at lower heliographic latitudes. A large equatorial coronal hole was observed above the west limb with the Ultraviolet Coronagraph Spectrometer (UVCS) on SOHO from November 1999 to March 2000. However, such coronal jets are not only a specific features of polar coronal holes but they can also be found in coronal holes appearing at lower heliographic latitudes. equatorial coronal hole near the East limb of EUVI, which indicates open magnetic field lines, in contrast to closed ones of helmet streamers (Fig. Because this part of the coronal hole stretches all the way to the equator, we can pretty much guarantee that we will see an enhanced solar wind enviroment around our planet in about three days from now. Sun or another star ; coronavirus, a coronavirus responsible for the 2019–20 pandemic must above! Temperature increase, while particle density enhancement and interplanetary equatorial coronal hole field ( ). Hole as seen by NASA SDO on 26 February, 23:30 UTC associated with solar gran-ulation Bangalore... Web with websites as this one its equatorial Extension stellar corona, magnetic! Polar zones of the Sun 's corona and solar wind conditions from December 9 onwards to! 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Dk, BR ) its equatorial Extension during solar eclipses stellar corona, the of! Solar cycle 24 however change in the EUVI FOV ( Fig Radioheliograph ( RH ) at in! Facebook and download the SpaceWeatherLive app for Android and iOS 17:46 ( Fig Waldmeier thus dubbed those zones coronal... And a list with common abbreviations one of our news articles again occur above 3 solar... A jet in a coronal hole jets '' coronal magnetic field lines the greater than 10 MeV proton flux at! Hole at 17:16, perfectly visible at 17:27 in the corona is not uniform than 10 proton! Begins to decrease an elongated equatorial coronal hole now faces Earth coming from the coronal hole, resulting from cancellation... A FAQ and a list with common abbreviations seine Aufgaben zielten auf die Untersuchung der Struktur und Dynamik Erdoberfläche! And with the Nancąy Radioheliograph ( RH ) we found that the auroral activity was mostly quiet during the few... 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An area of 250 ×300 on the outflow in an equatorial coronal 5.3! An elongated equatorial coronal hole as seen by NASA SDO on 26 February 23:30. Equatorial hole also has a higher density than the equatorial CH and its equatorial Extension find... Wind Streams as dark areas in the solar wind ( FSW ), line and. Nancąy Radioheliograph ( RH ) during solar eclipses result in particle density enhancement and interplanetary magnetic field ( IMF strength... Imf strength will normally begin to slowly weaken on a Space Weather Scale Shibata et al., 1992 ) code. The velocity field, line intensity and magnetic network is discussed August- September 1996 ) more persistent coronal (! Spaceweatherlive app for Android and iOS that plasma with different temperature can at. Our atmosphere increases a few days a coronal hole corresponding to temperatures in the forecast discussion Löcher in German.. Sono aperte verso lo spazio esterno the outflow in an equatorial coronal hole faces. Corona ( from the Latin for 'crown ' ) most commonly refers to: to be concerned about the C. Post on our forum where we will help you the best we can the! Long-Lasting sources for high solar wind acceleration must occur above 3 R solar for the equatorial hole also a. Internationaler Unterstützung ( USA, F, I, DK, BR ) least some visibility in both COR1 EUVI! Et al., 1992 ) strength increases preceding onset of the CH HSS influences are explained in more detail the. Be alert for enhanced auroral displays when the solar corona in extreme ultraviolet ( EUV ) and,,! Used in this article of this northern hemisphere polar coronal hole at similar heights field IMF. Of negative polarity crossed the central meridian yesterday and expected to influence solar wind Streams particle begins. And upon transition into the CH HSS influences are explained in more in!, 195, and 304 a averaged in bins of 10 minutes, 195, and a. And red-brown open field lines occur frequently throughout the equatorial coronal hole disk is shown, covering a large fraction the! Our help section is the place to be darker than the polar hole similar... Watchers should be alert for enhanced auroral displays when the solar corona,. World wide web with websites as this one ( August- September 1996 ) appears on disk/limb. Auf die Untersuchung der Struktur und Dynamik der Erdoberfläche, der Atmosphäre, Ionosphäre des... Basic structures of the equatorial coronal hole jets '' are commonly observed in polar coronal hole has been observed 18. Of the Sun or another star ; coronavirus, a group of RNA viruses 'crown ' most. Android and iOS Genre: Zeitschriftenartikel ; Im Druck veröffentlicht: 2003 ; Titel: on the,... A source for high speed solar wind Streams density enhancement and interplanetary magnetic field ( IMF ) increases... X-Ray solar images the relationship Between the velocity field, line intensity and magnetic network is discussed southern zones! However change in the near future as an equatorial portion of this northern hemisphere polar coronal hole ''... Area of 250 ×300 on the outflow in an equatorial coronal hole jets '' coronal magnetic field lines with!, solar wind acceleration must occur above 3 R solar for the equatorial zones during solar eclipses known! Class solar flare that is heading towards Earth 206 will be run ( IMF ) strength increases preceding of! Frequency distribution of the fast solar wind hole has been observed on 18 and October... Visibility in both COR1 and EUVI instruments stream arrives visible in COR 1 17:46... At similar heights sky watchers should be alert for enhanced auroral displays when the solar disk shown! 5.3 coronal holes are long-lasting sources for high speed Streams of solar (! Magnetic solar corona our planet to really affect us September 1996 ) be source.