Steven Tomczyk

International UCoMP Users Workshop

whawkins — Thu, 07 Sep 2023 19:23:33 +0000

International UCoMP Users Workshop whawkins Thu, 09/07/2023 - 13:23

Author:

whawkins

Sep 7, 2023

Steve displaying slides at UCoMP users workshop.

HAO director Holly Gilbert comments: "There was great energy around the UCoMP Users Workshop last week, with many visitors coming from around the world to participate. Thanks to those who made it a success, including many early career folks!"

The first-ever UCoMP Data User’s Workshop was held the week of August 29 and was a great success. The purpose was to introduce UCoMP to the community and to organize working groups to collaborate on UCoMP first results to be published in a topical issue of Solar Physics. The workshop combined tutorial-type presentations from the UCoMP team, discussions between the UCoMP team and users, user presentations, and hands-on activities for attendees. There were 41 attendees: 23 in-person and 18 remote. Recordings of the presentations can be found on the UCoMP Youtube channel.

Coronal spectral diagnostics: The Coronal Solar Magnetic Observatory (COSMO)

whawkins — Thu, 15 Dec 2022 17:59:57 +0000

Coronal spectral diagnostics: The Coronal Solar Magnetic Observatory (COSMO) whawkins Thu, 12/15/2022 - 10:59

Author:

whawkins

Dec 15, 2022

Example of UCOMP daily temperature map obtained with the superposition of daily average images of Fe XV 706 nm (red), Fe XIII 1074 nm (green) and 789 nm (blue) of the solar corona; on the disk, an SDO/AIA multi-channel image has been inserted.

Frontiers in Astronomy and Space Sciences: Enrico Landi, Sarah E. Gibson, Steven Tomczyk, Joan Burkepile, Giuliana de Toma, Jie Zhang, Tom Schad, Therese A. Kucera, Katharine K. Reeves, Hebe Cremades in Frontiers in Astronomy and Space Science emphasize THE NEED: Understanding and predicting the major phenomena taking place in the solar corona, such as flares and Coronal Mass Ejections (CMEs), the heating and evolution of the solar atmosphere, and the acceleration of the solar wind, are fundamental challenges to predict our own star. These challenges are related to the solar magnetism and to the physical properties of solar plasmas: meeting them requires two types of measurements: (A) Spectrally resolved, simultaneous observations of the entire corona in multiple spectral lines emitted by chromospheric to hot coronal plasmas at high spatial resolution and cadence for long periods of time; and (B) Coronal magnetic field measurements. THE PROBLEM: The current fleet of space instruments suffers from three main limitations: (A) EUV narrow-band imagers provide simultaneous 2D images of the corona, but lack adequate plasma diagnostic capabilities; (B) High-resolution EUV spectrometers have the required diagnostic potential, but their narrow field of view prevents a continuous and simultaneous coverage of the entire corona. (C) No current instrument can measure the global coronal magnetic field. THE SOLUTION: Visible to near-IR coronagraphs coupled to tunable filters combine the strengths of both EUV high resolution spectrometers and EUV imagers in one single instrument by (1) providing 2D images of the whole field of view at a single wavelength; (2) spectrally resolving individual lines near-simultaneously across the entire field of view, and (3) measuring the magnetic field through polarimetry. The proposed Coronal Solar Magnetism Observatory (COSMO) visible to near-IR coronagraph would allow the measurement of: (A) simultaneous plasma thermal structure of the whole solar corona and CMEs; (B) plasma velocity vector; and (C) coronal magnetic field. The technology behind visible/near-IR coronagraphs coupled to tunable filters is mature; ground-based implementation of such instruments would provide long-term, easily-upgradable data sets.

Astro2020 calls out global coronal magnetic measurements as requiring investment

kolinski — Thu, 14 Apr 2022 19:43:54 +0000

Astro2020 calls out global coronal magnetic measurements as requiring investment kolinski Thu, 04/14/2022 - 13:43

Author:

kolinski

Apr 14, 2022

The recent Decadal Survey in Astronomy and Astrophysics, Pathways to Discovery in Astronomy and Astrophysics for the 2020s, stated the following:

"To fully address the survey’s science goals for solar and stellar astrophysics, very high-resolution observations in the restricted field-of-view of DKIST would need to be supplemented by global synoptic measurements. Two critical measurement gaps exist that require investment in the coming decade: Measurements of the magnetic field in the global corona and greatly improved synoptic observations of the solar photosphere. Such observations of the Sun are also critical to the national priority to better understand and predict space weather and its effects at Earth and elsewhere."

Cover of "Pathways to Discovery in Astronomy and Astrophysics for the 2020s"

NSF Approves Funding for COSMO Next Stage

kolinski — Mon, 07 Mar 2022 17:30:25 +0000

NSF Approves Funding for COSMO Next Stage kolinski Mon, 03/07/2022 - 10:30

COSMO Site and Design Advancement Updates

kolinski — Mon, 07 Mar 2022 16:47:44 +0000

COSMO Site and Design Advancement Updates kolinski Mon, 03/07/2022 - 09:47

Author:

kolinski

Mar 7, 2022

Recent NSF Funding for COSMO Site and Design Advancement (COSADA)

Final Design of COSMO Large Coronagraph (LC)
Site Survey

Final Design of COSMO Large Coronagraph (LC)

The National Science Foundation (NSF) has provided funding for the final design of the COSMO Large Coronagraph (LC). At 1.5 meter aperture, the LC will be the world’s largest refractive telescope, and will enable observations of the global coronal magnetic fields. The LC will have a 1° field of view (FOV), observing out to 2 solar radii, i.e., 1 solar radius above the solar surface, at all heliolatitudes, using a Stokes polarimeter and a narrow-band electro-optically tuned birefringent filter. The very broad wavelength range of the LC extends from the optical to the near infrared, allowing it to observe structures over a wide range of coronal temperatures. The polarimetric measurements diagnose the strength and direction of the coronal magnetic field. The LC’s large aperture will finally allow circular polarization measurements over the entire corona--these measurements are sensitive to the coronal magnetic field strength in the direction of the Sun-Earth line through the Zeeman effect. The linear polarization from resonant scattering of photospheric radiation is then used to measure the direction of the magnetic field in the plane of sky, orthogonal to the Sun-Earth line, along with coronal wave measurements which diagnose the plane-of-sky magnetic field strength.

Unlike a spectrograph, the LC’s tunable filter allows simultaneous observations over the entire FOV, combining the strengths of simultaneous 2-D imaging and high-resolution spectroscopy into a single instrument. The 1° FOV allows the study of typical large-scale coronal structures and enables the LC to track the build up of magnetic energy in the corona leading to solar eruptions known as Coronal Mass Ejections (CMEs). The broad wavelength provides information on coronal plasma thermal structure, density and dynamical status using standard diagnostic techniques.

The LC final design is a 3-year proposal that will produce a final design of the telescope and mount and will include all reviews and construction cost estimates for all specified LC elements. In March of 2021, UCAR contracts released a Request for Proposal for companies to propose to design the COSMO LC. Five excellent proposals were received as a result of the RFP. After an extensive evaluation process, the project selected European Industrial Engineering to award the LC design contract in June of 2021. A contract was executed and work on the design commenced in September of 2021. Steady progress on the design has ensued, and the first major milestone, the Systems Requirements Review, is scheduled for the week of March 7-11, 2022.

COSMO Site Survey

Identifying a final site for the COSMO observatory is necessary for significant risk reduction and for determining construction costs. Sites in Hawaii are known to have good coronal skies but other sites have not been fully tested. The site survey includes data-mining to determine candidate sites, data analysis, and construction and deployment of site testing equipment to six sites.

Figure 1. Damon Burke and Steve Tomczyk of HAO, shown with the COSMO Phase I site survey equipment currently at the NCAR Marshall Field site just south of Boulder Colorado.

The site survey equipment will be deployed in two phases. The first phase of instruments will be deployed to six sites and include:

Sky Radiometers to measure Sun and sky radiance from 315 to 2200 nm, to determine aerosol and other atmospheric properties. These operate robotically and require no dome.
Weather Stations to record solar radiation, wind speed and direction, air temperature, humidity, precipitation, etc.

Phase I instrumentation is shown in Figure 1.

The second phase will deploy an array of solar scintillometers to the sites that meet COSMO requirements. The solar scintillometers measure variation of atmospheric turbulence with height. These measurements provide the height dependence of seeing that determine the height of the telescope above the ground, which is an important cost driver.

HAO purchased, and deployed all phase one equipment to the NCAR Marshall site just south of Boulder, as shown in Figure 1. The equipment is fully automated, operating nominally and will continue to acquire observations at Marshall until they are deployed to the six COSMO sites.

UCoMP Instrument Nearing Science Mission Phase

kolinski — Fri, 04 Mar 2022 16:39:13 +0000

UCoMP Instrument Nearing Science Mission Phase kolinski Fri, 03/04/2022 - 09:39

Author:

kolinski

Mar 4, 2022

The Upgraded Coronal Multi-Channel Polarimeter (UCoMP) coronagraph was deployed to Mauna Loa Solar Observatory in 2021. UCoMP observes the solar corona from 1.03 to 2 solar radii over a wide range of wavelengths, allowing scientists to explore the magnetic structure of the Sun’s corona over a wide range of plasma temperatures. UCoMP observations are needed to help understand the physical processes behind the formation of solar eruptions known as Coronal Mass Ejections (CMEs). UCoMP is nearing the end of its commissioning phase and will begin to provide science observations to the community in the spring of 2022. For more information, please see the UCoMP instrument page:

www2.hao.ucar.edu/mlso/instruments/upgraded-coronal-multi-channel-polarimeter

UCoMP Level 1 and Level 2 data products from the FeXIII emission line at 1074.7 nm.

Global Maps of the Magnetic Field in the Solar Corona

kolinski — Tue, 23 Nov 2021 16:05:28 +0000

Global Maps of the Magnetic Field in the Solar Corona kolinski Tue, 11/23/2021 - 09:05

Author:

kolinski

Nov 23, 2021

An international team led by solar physicists from Peking University, China and National Center for Atmospheric Research (NCAR), USA, has recently measured the global magnetic field of the solar corona for the first time. The team used observations from the Coronal Multi-channel Polarimeter, an instrument operated by NCAR’s High Altitude Observatory. Their results have been published in the Science magazine on August 7, 2020.

Magnetic field of the Sun calculated from the potential field source surface model (Yang, Tian, Tomczyk et al. 2020, Sci China Tech Sci).

The Sun is a magnetized star, and its magnetic field plays a critical role in shaping the solar atmosphere. The 11-year solar cycle, the spectacular solar eruptions and the million-degree solar corona are all driven or governed by the evolution of the solar magnetic field. Due to the magnetic coupling of different atmospheric layers, information on the magnetic field of the whole atmosphere is required to study the interplay between the solar plasma and magnetic field. However, routine measurements of the solar magnetic field have only been achieved at the photospheric level (solar surface). More than one century has passed since the first measurement of the solar magnetic field, we still do not have a precise knowledge of the magnetic field in the upper solar atmosphere, especially the corona, which impedes our complete understanding of the solar magnetism and its interaction with the solar plasma.

More than 20 years ago, a technique called coronal seismology or magnetoseismology has been introduced for coronal magnetic field diagnostics. This method makes use of magnetohydrodynamic (MHD) oscillations or waves that are observed in coronal loops or other coronal structures. From the MHD theory, the observed wave parameters can be used to infer the average magnitudes of the magnetic field in the oscillating structures. However, these oscillations/waves are just occasionally observed in small regions of the corona, and thus their potential for magnetic field diagnostics is limited.

A coronal image (left) and the corresponding magnetic field map (right) (Yang, Bethge, Tian, Tomczyk, et al. 2020, Science).

CoMP is a coronagraph with a 20-cm aperture. Using the Fe XIII 1074.7 nm and 1079.8 nm infrared spectral lines, it can observe the solar corona in the range of about 1.05 to 1.35 solar radii from the solar center through imaging spectroscopy and spectropolarimetry. The Doppler image sequence obtained from CoMP observations often reveal the prevalence of propagating periodic disturbances, indicating the ubiquitous presence of transverse MHD waves in the corona. The team has successfully applied the magnetoseismology method to these pervasive waves. They have extended the previously developed wave-tracking technique to the whole field of view, and obtained the global distribution of the wave phase speed. The intensity ratio of the two Fe XIII lines is sensitive to the electron density, thus has been used to derive the global map of coronal electron density. Combing the wave-tracking and density diagnostic results, they have successfully mapped the magnetic field in the global corona.

This is the first time that a global map of the coronal magnetic field has been obtained through actual coronal observations, thus marking a leap towards solving the problem of coronal magnetic field measurements. In principle, with this technique, global coronal magnetic field maps could now be routinely obtained, filling in the missing part of the measurements of the Sun’s global magnetism. Together with simultaneously measured photospheric magnetograms, these synoptic coronal magnetograms will provide critical information to advance our understanding of the magnetic coupling between different atmospheric layers as well as the physical mechanisms responsible for solar eruptions and solar cycle.

See write-ups in Science, New Scientist, Science News

Global maps of the magnetic field in the solar corona

NSF Approves Funding For COSMO

kolinski — Mon, 22 Nov 2021 18:35:43 +0000

NSF Approves Funding For COSMO kolinski Mon, 11/22/2021 - 11:35

Author:

kolinski

Nov 22, 2021

The COronal Solar Magnetism Observatory (COSMO) is a unique ground-based facility designed to address current shortfalls in our capability to measure magnetic fields in the solar corona. COSMO comprises three elements. The first two focus on chromospheric and prominence magnetometry (ChroMag), and observing the electron scattered K-corona (K-Cor). The third and central instrument is the 1.5-m aperture Large Coronagraph (LC) that will continuously observe the radiation emitted by the corona in a number of visible and near-IR emission lines.

The National Center for Atmospheric Research (NCAR) has received funding approval to survey prospective locations for the Coronal Solar Magnetism Observatory (COSMO). This new observatory offers the potential to transform our fundamental understanding of magnetic fields in the Sun’s atmosphere and how they drive the formation of solar eruptions and other space weather that can affect technologies on Earth.

NCAR news release

The Marshall Field Site

kolinski — Mon, 22 Nov 2021 17:48:18 +0000

The Marshall Field Site kolinski Mon, 11/22/2021 - 10:48

Author:

kolinski

Nov 22, 2021

Damon Burke and Steve Tomczyk standing in front of optical equipment at Marshall Fields.

HAO engineer Damon Burke and Senior Scientist Steve Tomczyk are shown in front of a suite of remote observing instrumentation at the Marshall Field site. These instruments will support the COSMO Observatory site survey project (COSADA), a 3 year project to determine scientifically optimal locations for the construction of HAO's proposed COSMO Solar Observatory. This suite of instrumentation will be deployed and operated for approximately 2 years in order to measure atmospheric conditions critical to the operation of a pair of coronagraph telescopes, such as aerosol content, sky brightness, cloud cover, and atmospheric stability. For further information, please contact COSADA Principal Investigator, Dr. Steve Tomczyk.

Mapping the magnetic field in the solar corona through magnetoseismology

kolinski — Tue, 16 Nov 2021 22:42:12 +0000

Mapping the magnetic field in the solar corona through magnetoseismology kolinski Tue, 11/16/2021 - 15:42

Publication Name: Science China Technological Sciences; Authors: Zihao Yang, Hui Tian, Steven Tomczyk, Richard Mortan, XianYong Bai, Tanmoy Samanta, and YaJie Chen

Author:

kolinski

Nov 16, 2021

Magnetoseismology, a technique of magnetic field diagnostics based on observations of magnetohydrodynamic (MHD) waves, has been widely used to estimate the field strengths of oscillating structures in the solar corona. However, previously magnetoseismology was mostly applied to occasionally occurring oscillation events, providing an estimate of only the average field strength or one-dimensional distribution of field strength along an oscillating structure. This restriction could be eliminated if we apply magnetoseismology to the pervasive propagating transverse MHD waves discovered with the Coronal Multi-channel Polarimeter (CoMP).

Analysis results for the observation on November 3, 2016 (dataset D2). The dotted and dashed curves mark the solar limb and the inner boundary of the CoMP FOV, respectively. (A) The AIA 19.3 nm image taken at 20:00:07 UT. (B)(C): The intensity maps of Fe xiii 1074.7 nm and 1079.8 nm. (D)-(E): The maps of electron number density and its uncertainty. (F): The filtered Doppler velocity map at 20:34:54 UT. (G)-(H): The maps of phase speed and its uncertainty. (I)-(J): The maps of derived BPOS and its associated uncertainty.

Using several CoMP observations of the Fe xiii 1074.7 nm and 1079.8 nm spectral lines, we obtained maps of the plasma density and wave phase speed in the corona, which allow us to map both the strength and direction of the coronal magnetic field in the plane of sky. We also examined distributions of the electron density and magnetic field strength, and compared their variations with height in the quiet Sun and active regions. Such measurements could provide critical information to advance our understanding of the Sun’s magnetism and the magnetic coupling of the whole solar atmosphere.

Steven Tomczyk

International UCoMP Users Workshop

Recent News

Coronal spectral diagnostics: The Coronal Solar Magnetic Observatory (COSMO)

Recent News

Astro2020 calls out global coronal magnetic measurements as requiring investment

Recent News

NSF Approves Funding for COSMO Next Stage

Recent News

COSMO Site and Design Advancement Updates

Recent NSF Funding for COSMO Site and Design Advancement (COSADA)

Final Design of COSMO Large Coronagraph (LC)

COSMO Site Survey

Recent News

UCoMP Instrument Nearing Science Mission Phase

Recent News

Global Maps of the Magnetic Field in the Solar Corona

Recent News

NSF Approves Funding For COSMO

Recent News

The Marshall Field Site

Recent News

Mapping the magnetic field in the solar corona through magnetoseismology

Recent News