skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: QUANTIFYING SPICULES

Abstract

Understanding the dynamic solar chromosphere is fundamental in solar physics. Spicules are an important feature of the chromosphere, connecting the photosphere to the corona, potentially mediating the transfer of energy and mass. The aim of this work is to study the properties of spicules over different regions of the Sun. Our goal is to investigate if there is more than one type of spicule, and how spicules behave in the quiet Sun, coronal holes, and active regions. We make use of high cadence and high spatial resolution Ca II H observations taken by Hinode/Solar Optical Telescope. Making use of a semi-automated detection algorithm, we self-consistently track and measure the properties of 519 spicules over different regions. We find clear evidence of two types of spicules. Type I spicules show a rise and fall and have typical lifetimes of 150-400 s and maximum ascending velocities of 15-40 km s{sup -1}, while type II spicules have shorter lifetimes of 50-150 s, faster velocities of 30-110 km s{sup -1}, and are not seen to fall down, but rather fade at around their maximum length. Type II spicules are the most common, seen in the quiet Sun and coronal holes. Type I spicules aremore » seen mostly in active regions. There are regional differences between quiet-Sun and coronal hole spicules, likely attributable to the different field configurations. The properties of type II spicules are consistent with published results of rapid blueshifted events (RBEs), supporting the hypothesis that RBEs are their disk counterparts. For type I spicules we find the relations between their properties to be consistent with a magnetoacoustic shock wave driver, and with dynamic fibrils as their disk counterpart. The driver of type II spicules remains unclear from limb observations.« less

Authors:
 [1];  [2];  [3]
  1. NASA Ames Research Center, Moffett Field, CA 94035 (United States)
  2. Lockheed Martin Solar and Astrophysics Laboratory, Org. A021S, Building 252, 3251 Hanover Street, Palo Alto, CA 94304 (United States)
  3. Institute of Theoretical Astrophysics, P.O. Box 1029, Blindern, NO-0315 Oslo (Norway)
Publication Date:
OSTI Identifier:
22086486
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 759; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALGORITHMS; ASTRONOMY; ASTROPHYSICS; CALCIUM IONS; CHROMOSPHERE; LIFETIME; PHOTOSPHERE; SHOCK WAVES; SOLAR PROMINENCES; SPATIAL RESOLUTION; SUN; TELESCOPES

Citation Formats

Pereira, Tiago M. D., De Pontieu, Bart, and Carlsson, Mats, E-mail: tiago.pereira@nasa.gov. QUANTIFYING SPICULES. United States: N. p., 2012. Web. doi:10.1088/0004-637X/759/1/18.
Pereira, Tiago M. D., De Pontieu, Bart, & Carlsson, Mats, E-mail: tiago.pereira@nasa.gov. QUANTIFYING SPICULES. United States. doi:10.1088/0004-637X/759/1/18.
Pereira, Tiago M. D., De Pontieu, Bart, and Carlsson, Mats, E-mail: tiago.pereira@nasa.gov. Thu . "QUANTIFYING SPICULES". United States. doi:10.1088/0004-637X/759/1/18.
@article{osti_22086486,
title = {QUANTIFYING SPICULES},
author = {Pereira, Tiago M. D. and De Pontieu, Bart and Carlsson, Mats, E-mail: tiago.pereira@nasa.gov},
abstractNote = {Understanding the dynamic solar chromosphere is fundamental in solar physics. Spicules are an important feature of the chromosphere, connecting the photosphere to the corona, potentially mediating the transfer of energy and mass. The aim of this work is to study the properties of spicules over different regions of the Sun. Our goal is to investigate if there is more than one type of spicule, and how spicules behave in the quiet Sun, coronal holes, and active regions. We make use of high cadence and high spatial resolution Ca II H observations taken by Hinode/Solar Optical Telescope. Making use of a semi-automated detection algorithm, we self-consistently track and measure the properties of 519 spicules over different regions. We find clear evidence of two types of spicules. Type I spicules show a rise and fall and have typical lifetimes of 150-400 s and maximum ascending velocities of 15-40 km s{sup -1}, while type II spicules have shorter lifetimes of 50-150 s, faster velocities of 30-110 km s{sup -1}, and are not seen to fall down, but rather fade at around their maximum length. Type II spicules are the most common, seen in the quiet Sun and coronal holes. Type I spicules are seen mostly in active regions. There are regional differences between quiet-Sun and coronal hole spicules, likely attributable to the different field configurations. The properties of type II spicules are consistent with published results of rapid blueshifted events (RBEs), supporting the hypothesis that RBEs are their disk counterparts. For type I spicules we find the relations between their properties to be consistent with a magnetoacoustic shock wave driver, and with dynamic fibrils as their disk counterpart. The driver of type II spicules remains unclear from limb observations.},
doi = {10.1088/0004-637X/759/1/18},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 759,
place = {United States},
year = {2012},
month = {11}
}