Science goals and objectives: the solar wind plays a central role in shaping the physical characteristics of interplanetary space and IT is vitally important to the loss of mass and momentum from…

This is a $528,136.00 grant awarded by NASA to the Smithsonian Astrophysical Observatory (SAO), a division of the Smithsonian Institution, to investigate the physical and dynamical properties of low-latitude coronal holes and adjacent quiet-sun regions on the Sun. The research aims to better understand the role of the solar wind in shaping interplanetary space and the mechanisms that drive the heating and acceleration of solar plasmas. The study will leverage data from current NASA missions such as SDO and IRIS, as well as ground-based observatories, to systematically analyze the morphology, magnetic structure, and intensity fluctuations in these solar features. This work supports NASA's Heliophysics research objectives to explore and characterize the physical processes in the space environment. The award is a grant for research and does not have a set-aside designation.

Science goals and objectives: the solar wind plays a central role in shaping the physical characteristics of interplanetary space and IT is vitally important to the loss of mass and momentum from the sun itself. We know that fast, and sometimes slow, wind originates from coronal holes, but the exact locations within them, and the mechanisms that cause the heating and outward acceleration of solar plasmas, are not understood. Coronal holes (CH) have weaker coronal emission than surrounding quiet-sun (QS) regions but this difference is not so apparent in chromospheric/transition-region emission. Analyses indicate that CHS and adjacent QS regions have comparable numbers of small loops leading to similar emission at lower heights. In contrast, long loops reaching coronal heights, which are common in the QS, are rare in CHS where open magnetic field lines allow the outward flow of the plasma. We will investigate the spatiotemporal distribution of the physical and dynamical parameters of low-latitude CHS and compare to adjacent QS regions. In particular we seek to answer the following questions: 1) what is the contribution of small-scale structure to the global properties of CHS and adjacent QS regions? 2) what are the physical, dynamical, and topological properties of CHS, and how do these compare to QS regions? And 3) do the same physical processes operate in CHS and QS regions? Do they depend on coronal location? Where within the coronal regions do the processes dominate? Is there a correlation to the small-scale coronal structure? Mission data: we will use data from current missions of the heliophysics system observatory: SDO and iris and from ground-based observatories. These missions provide high temporal and spatial resolution of measurements in the photosphere, chromosphere, and corona. All data are publicly available in the space physics data facility's (spdf) heliophysics data portal (HDP) and the solar data analysis center's (sdac) virtual solar observatory (VSO). Methodology: we propose to investigate this problem primarily using observations. The objectives are to: 1) systematically study the morphology and location of low-latitude CHS 2) analyze the distribution of physical parameters within CHS and QS regions. UV and white-light imaging and UV spectra will provide the necessary plasma diagnostics 3) probe the magnetic structure of CHS using photospheric magnetograms by comparing these observations to the distribution of small-scale coronal structure, to modeled magnetic-field lines and flux from potential field extrapolations and 4) investigate the dynamical properties of the UV emission at different locations in the solar atmosphere by uncovering the scaling properties of the intensity fluctuations, relating these properties to the magnetic field topology, and determining how the underlying emission processes compare between low-latitude CHS and adjacent QS regions. Relevance to NASA: the proposed investigation will extend the frontier of knowledge of CHS and QS regions by 1) connecting magnetic topology with plasma parameters and 2) exploring spatiotemporal variation of processes due to different magnetic topologies and global differences in solar activity level. This strongly supports the heliophysics research objective to "explore and characterize the physical processes in the space environment from the sun to the heliopause and throughout the universe."(goal #1). The research objectives are ideally suited to address the heliophysics decadal survey goals, #1. "determine the origins of the sun's activity and predict the variations in the space environment" and #4. "discover and characterize fundamental processes that occur both within the heliosphere and throughout the universe."