This is a repository copy of Systematic variations of macrospicule properties observed by SDO/AIA over half a decade. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/153993/ Version: Published Version Article: Kiss, T.S., Gyenge, N. and Erdélyi, R. (2017) Systematic variations of macrospicule properties observed by SDO/AIA over half a decade. Astrophysical Journal, 835 (1). 47. ISSN 0004-637X https://doi.org/10.1088/1361-6528/aa5272 © 2017 The American Astronomical Society. Reproduced in accordance with the publisher's self-archiving policy. Reuse Items deposited in White Rose Research Online are protected by copyright, with all rights reserved unless indicated otherwise. They may be downloaded and/or printed for private study, or other acts as permitted by national copyright laws. The publisher or other rights holders may allow further reproduction and re-use of the full text version. This is indicated by the licence information on the White Rose Research Online record for the item. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ The Astrophysical Journal, 835:47 (10pp), 2017 January 20 doi:10.3847/1538-4357/aa5272 © 2017. The American Astronomical Society. All rights reserved. SYSTEMATIC VARIATIONS OF MACROSPICULE PROPERTIES OBSERVED BY SDO/AIA OVER HALF A DECADE T. S. Kiss1,2, N. Gyenge1,3, and R. Erdélyi1 1 Solar Physics and Space Plasmas Research Centre (SP2RC), School of Mathematics and Statistics, University of Sheffield Hicks Building, Hounsfield Road, Sheffield, S3 7RH, UK; robertus@sheffield.ac.uk 2 Department of Physics, University of Debrecen, Egyetem tér 1, Debrecen, H-4010, Hungary 3 Debrecen Heliophysical Observatory (DHO), Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences Debrecen, P.O.Box 30, H-4010, Hungary Received 2016 September 30; revised 2016 November 30; accepted 2016 December 4; published 2017 January 18 ABSTRACT Macrospicules (MSs) are localized small-scale jet-like phenomena in the solar atmosphere, which have the potential to transport a considerable amount of momentum and energy from the lower solar atmospheric regions to the transition region and the low corona. A detailed statistical analysis of their temporal behavior and spatial properties is carried out in this work. Using state-of-the-art spatial and temporal resolution observations, yielded by the Atmospheric Imaging Assembly of Solar Dynamics Observatory, we constructed a database covering a 5.5 year long period, containing 301 macrospicules that occurred between 2010 June and 2015 December, detected at 30.4 nm wavelength. Here, we report the long-term variation of the height, length, average speed, and width of MS in coronal holes and Quiet Sun areas both in the northern and southern hemisphere of the Sun. This new database helps to refine our knowledge about the physical properties of MSs. Cross-correlation of these properties shows a relatively strong correlation, but not always a dominant one. However, a more detailed analysis indicates a wave- like signature in the behavior of MS properties in time. The periods of these long-term oscillatory behaviors are just under two years. Also, in terms of solar north/south hemispheres, a strong asymmetry was found in the spatial distribution of MS properties, which may be accounted for by the solar dynamo. This latter feature may then indicate a strong and rather intrinsic link between global internal and local atmospheric phenomena in the Sun. Key words: Sun: chromosphere – Sun: corona – Sun: activity – Sun: oscillations 1. INTRODUCTION speed, could play an important role in the energy and momentum transportation from the photosphere to the chromo- Our knowledge of the different layers and structures of the sphere or low corona. Their capability of guiding MHD waves solar atmosphere has improved greatly in the past decades. is discussed by, e.g., Zaqarashvili & Erdélyi (2009). However, the structural fine-scale details of the atmosphere still There are, however, much larger spicule-like, also abundant, leave many open questions (see the review papers of e.g., dynamic jets detected to be present in the solar atmosphere: ) Judge 2006; Lipartito et al. 2014 . A challenging task is to macrospicules (MSs). The investigation of macrospicules identify and catalog the small-scale, localized observable fi fi fl reaches back at least 40 years. The rst modern observation phenomena (e.g., bushes, brils, occuli, grains, mottles, of macrospicules was carried out by Bohlin et al. (1975). With spicules, etc.) present in the chromospheric zoo in regards of the 30.4 nm spectroheliograph onboard the Skylab mission, their numbers and variety. These often rapidly appearing and Bohlin et al. (1975) identified 25 MSs with lengths of 8″–25″ fi disappearing, ne structures are popularly observed in, e.g., the (some extreme cases were even with 30″–60″). Their lifetime is α He II (»30.4 nm) emission line, H (»656.28 nm), and Ca II about 8–45 minutes without any reported correlation at that (»393.366 nm) absorption lines. time between the length and lifetime. Most MSs are formed One class of the set of highly dynamic phenomena is the inside coronal hole (CH) regions. Their name, initially, was spicules. They are abundant, spiky-like gas jets at the suggested to be “EUV macrospiclues” after the wavelength chromospheric solar limb (Secchi 1877). Their upward mass band they were detected in. fl ux is about 100 times that of the solar wind (Sterling 2000;de Labonte (1979) observed 32 macrospicules with the 25 cm Pontieu et al. 2004; Sterling et al. 2010). Spicules are aperture vacuum telescope at Big Bear Solar Observatory using ( ) detectable both on the disk often called as mottles and at Hα and D3 filters during an observation campaign of 122 hr. the limb at any given moment of time. Depending on their size The length (8″–33″) and lifetime (4–24 minute) of these MSs and lifetime, spicules can be classed into two groups. Spicules were similar to those reported in Bohlin et al. (1975). with 7000–11,000 km length, 5–15 minute lifetime, and 25 km Dere et al. (1989) investigated 10 MSs with the UV −1 s propagating speed are called “classic,” or lately debatably spectroheliograph onboard the Spacelab-2 mission. The referred to as type-I spicules (Beckers 1968; Zaqarashvili & properties of the MSs found were similar, again, to those Erdélyi 2009). The other group is claimed to contain the reported in the previous two studies, but the main innovation is − smaller and faster (5000 km average height, 50–100 km s 1 the development of temporal resolution: Spacelab-2 was able to propagation speed) so-called type-II spicules (on disk often observe macrospicules with a lifetime down to three minutes. labeled as Rapid Blueshifted Excursiors (RBEs) referring to The breakthrough came with the age of high-resolution one of their distinct observable properties) with shorter lifetime, spacecraft: Solar Heliospheric Observatory (SOHO, Fleck 10–150 s (de Pontieu et al. 2007, 2012; Sekse et al. 2012; et al. 2000) opened new avenues in solar physics with much Kuridze et al. 2015). Spicules, irrespective of their lifetime and greater temporal and spatial resolution than before. In the 1 The Astrophysical Journal, 835:47 (10pp), 2017 January 20 Kiss, Gyenge, & Erdélyi Figure 1. Series of images about a Quiet Sun macrospicule on SDO/AIA 30.4 nm images. The phenomenon occurred between 12:20 and 12:43 on 03.07.2012 on the western solar limb. The bottom panel images are overplotted by the tetragon assumption of MS. In the first column, the brightening is clearly visible, which may be the precursor of the jet itself. context relevant for our paper, we recall that Pike & Harrison fast upward propagation was measured between the mid- (1997) used SOHO/Coronal Diagnostic Spectrometer (CDS) to transition region (N VII—765 Å) and the lower corona (Ne VIII investigate the physics of MSs with the first multi-wavelength —770 Å) with »145 km s-1. On-limb observations suggest observation and described them as multi-thermal structures. that spicules can be precursors for macrospicules. The authors claimed that X-ray jets and EUV MSs are a Madjarska et al. (2011) analyzed three macrospicules with manifestation of the same underlying physical phenomena, four instruments (Hinode/SOT, EIS, XRT and SOHO/ which could be the source of the fast solar wind as well. They SUMER). These co-aligned images revealed that macrospi- also described, first, an associated “pre-existing bright point,” cules do not seem to appear in a spectral line formed over which can be a sub-flare brightening. 300,000 K. In a follow-up study, Pike & Mason (1998) employed On the theoretical side, Murawski et al. (2011) carried out SOHO/CDS to detect the rotational properties of MSs. Blue one of the first numerical simulations for MSs as a velocity- and redshifted emission was observed on either side of the axis shock in the transition region. They employed the FLASH code of MSs above the limb, which suggests the rotation of MSs. (Lee & Deane 2009) to solve the two-dimensional MHD The rotation velocities increase with height, so the macro- equations by implementing a VAL IIIC solar temperature spicules they observed were labeled "solar tornadoes.” The model (Vernazza et al. 1981). Many properties of simulated separation of blue- and redshifted regions on two sides of the MSs matched the abovementioned, observed lifetime, length, macrospicule is clearly visible. and velocity. Parenti et al. (2002) investigated the density and temperature Another new era of MS observation has began with the of MSs.