COSMO

MLSO UCoMP Science Data Now Available

kolinski — Tue, 19 Dec 2023 20:31:47 +0000

MLSO UCoMP Science Data Now Available kolinski Tue, 12/19/2023 - 13:31

Author:

kolinski

Dec 19, 2023

The Mauna Loa Solar Observatory Upgraded Coronal Multi-Channel Polarimeter (UCoMP) coronagraph science data (version 1.0.1) have now been released to the community via the Mauna Loa web page.

Sample of UCoMP data on the MLSO website.

These data cover the period from July 18, 2021 through Nov 9, 2022. UCoMP observes the solar corona from 1.04 to ~2 solar radii in 9 coronal emission lines. Data have been released for 5 coronal emission lines: FeXIII 1074.7 and 1079.8 nm; FeXI 789.4 nm; FeX 637.4 nm; and FeXV 706.2 nm. Science products are in fits format and include: Level 1 observations of Stokes I, Q, U, and V at multiple wavelengths across each emission line; Level 2 products: Intensity [center wavelength, enhanced and peak]; line-of-sight Doppler velocity; FWHM Line Width; weighted average Stokes I, Q, U, V and linear polarization; plane-of-sky magnetic field azimuth and radial azimuth; and a noise mask. Quicklook images and movies are also provided.

The UCoMP Data User Guide is provided with every fits tar download and quicklook zip download. Please see the user guide for more information.

This is the first release of the data and some problems remain. The most significant are stray light, wavelength tuning drift and image alignment. The stray light and wavelength drift impact the line width and Doppler images. We are working to solve these issues for the next release in 2024. The guide includes the link to the GitHub system where you can read details about all UCoMP issues.

Please report any problems or questions about UCoMP data to mlso_data_requests@ucar.edu

Magnetic field and plasma diagnostics for solar coronal mass ejections: A case study using the forward modeling approach

whawkins — Fri, 03 Mar 2023 22:05:34 +0000

Magnetic field and plasma diagnostics for solar coronal mass ejections: A case study using the forward modeling approach whawkins Fri, 03/03/2023 - 15:05

Author:

whawkins

Mar 3, 2023

Synthesized results of the Fe xiii 10747 line, along with several POS cross section quantities in the model during CME eruption (a)-(e): Intensity (Stokes I), linear polarization degree(L/I), line width, Doppler velocity, and azimuth derived from synthesized signals. (f)-(h): Magnetic field, temperature, and density distributions in the POS. The arc-shaped contour in each panel represents ∇ · v = −0.05. Two leading fronts (LF) can be distinguished in panel (a). Each white arrow in panel (g) represents the POS projection of the deduced shock normals. The solar disk is indicated by the yellow curve in each panel. The region below 1.05R⊙ is masked.

Solar Physics: The proposed COronal Solar Magnetism Observatory (COSMO) Large Coronagraph (LC) will provide unique observations to study coronal mass ejections (CMEs) with its ability to diagnose the magnetic field and plasma properties in the solar corona. Here we take a realistic magnetohydrodynamic CME model, and synthesize the signals of several coronal emission lines (CELs) to perform forward modeling of COSMO LC observation of a CME. We use the Stokes parameters of the Fe xiii 10747 Angstrom line to diagnose the magnetic field and plasma properties of the CME flux rope. The results show that COSMO LC can provide magnetic field measurements of CME progenitors with a high spatial resolution (2′′ pixels). By using a worse resolution (6′′ pixels), the COSMO LC observation may also be used to qualitatively study the evolution of magnetic field during the CME eruption. We then use the synthetic signals of several other CELs to diagnose the physical conditions in the CME leading front, including the shock. The COSMO LC observations of the Fe xiii 10798/10747 Angstrom and Ar xiii 8300/10143 Angstrom line pair can provide density diagnostics of the front. By observing several CELs with different formation temperatures, the COSMO LC can be used to diagnose the temperature and ionization states in the front. We suggest that the Fe xiii 10747 Angstrom line should be given the highest priority when observing CMEs, while observations of the Fe xiii 10798 Angstrom, Fe xiv 5303 Angstrom, Fe xv 7062 Angstrom, and Ar xiii 10143 Angstrom lines can also provide valuable information on CMEs.

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.

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.

COSMO

MLSO UCoMP Science Data Now Available

Recent News

Magnetic field and plasma diagnostics for solar coronal mass ejections: A case study using the forward modeling approach

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

NSF Approves Funding For COSMO

Recent News

The Marshall Field Site

Recent News