ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Other Sources  (1,244)
  • Air Transportation and Safety  (811)
  • Solar Physics  (433)
  • 2015-2019  (1,244)
  • 1
    Publication Date: 2020-01-23
    Description: The dynamical effects of solar magnetoconvection span a wide range spatial and temporal scales that extend from the interior to the corona and from fast turbulent motions to global magnetic activity. To study the solar activity on short temporal scales (from minutes to hours), we use 3D radiative MHD simulations that allow us to investigate complex turbulent interactions that drive various phenomena, such as plasma eruptions, spontaneous formation of magnetic structures, funnel-like structures and magnetic loops in the corona, and others. In particular, we focus on multi-scale processes of energy exchange across layers of the solar interior and atmosphere, which contribute to coronal heating and eruptive dynamics. For modeling global-scale activity, we use a data assimilation approach that has demonstrated great potential for building reliable long-term forecasts of solar activity. In particular, it has been shown that the Ensemble Kalman Filter (EnKF) method applied to the Parker-Kleeorin-Ruzmakin dynamo model is capable of predicting solar activity up to one sunspot cycle ahead in time, as well as estimating the properties of the next cycle a few years before it begins. In this presentation, using the available magnetogram data, we discuss development of the methodology and forecast quality criteria (including forecast uncertainties and sources of errors). We demonstrate the influence of observational limitations on prediction accuracy, and we present the EnKF predictions of the upcoming Solar Cycle (25) based on both the sunspot number series and observed magnetic fields and discuss the uncertainties and potential of the data assimilation approach for modeling and forecasting solar activity.
    Keywords: Solar Physics
    Type: ARC-E-DAA-TN76509 , AGU Fall Meeting; Dec 09, 2019 - Dec 13, 2019; San Francisco, CA; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2020-01-23
    Description: Evolution of large-scale magnetic field structures in the solar photosphere and corona is controlled by motions beneath the visible surface of the Sun. Subsurface plasma flows play a critical role in formation and evolution of active regions and their activity. We analyze subsurface flow maps provided by the local helioseismology pipeline from the Helioseismic and Magnetic Imager (HMI) data on board the Solar Dynamics Observatory, and investigate links between flow characteristics and magnetic activity. The primary goal is to determine flow descriptors, which can improve solar activity forecasts. In particular, by employing machine learning classifiers, we test how the flow helicity and velocity shear descriptors can improve the prediction of initiation of flares and CME eruptions.
    Keywords: Solar Physics
    Type: ARC-E-DAA-TN76508 , AGU Fall Meeting; Dec 09, 2019 - Dec 13, 2019; San Francisco, CA; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2020-01-22
    Description: This presentation reviews voluntary safety reports received by NASA's Aviation Safety Reporting System pertaining to Hazardous Materials.
    Keywords: Air Transportation and Safety
    Type: ARC-E-DAA-TN74687 , Aviation Safety InfoShare; Oct 30, 2019; Bellevue, WA; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2020-01-22
    Description: Most of the commonly discussed solar coronal jets are of the type consisting of a single spire extending approximately vertically from near the solar surface into the corona. Recent research of a substantial number of events shows that eruption of a miniature filament (minifilament) drives at least many such single-spire jets, and concurrently generates a miniflare at the eruption site. A different type of coronal jet, identified in X-ray images during the Yohkoh era, are two-sided-loop jets, which extend from a central excitation location in opposite directions, along two opposite low-lying coronal loops that are more-or-less horizontal to the surface. We observe such a two-sided-loop jet from the edge of active region (AR) 12473, using data from Hinode XRT and EIS, and SDO AIA and HMI. Similar to single-spire jets, this two-sided-loop jet results from eruption of a minifilament, which accelerates to over 140 km/s before abruptly stopping upon striking overlying nearlyhorizontal magnetic field at 30,000 km altitude and producing the two-sided-loop jet via interchange reconnection. Analysis of EIS raster scans show that a hot brightening, consistent with a small flare, develops in the aftermath of the eruption, and that Doppler motions (40 km/s) occur near the jet-formation region. As with many single-spire jets, the trigger of the eruption here is apparently magnetic flux cancelation, which occurs at a rate of 410^18 Mx/hr, comparable to the rate observed in some single-spire AR jets. This example of a two-sided jet, along with numerous examples of single-spire jets, supports that essentially all coronal jets result from eruptions of minifiaments, and frequently the eruption of the minifilment is triggered by magnetic flux cancelation. (Details are in Sterling et al. 2019, ApJ, 871, 220.)
    Keywords: Solar Physics
    Type: MSFC-E-DAA-TN75820 , Meeting of the American Astronomical Society (AAS 2019); Jun 09, 2019 - Jun 13, 2019; St. Louis, MO; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2020-01-18
    Description: This presentation presents an overview of NASA's Aviation Safety Reporting System including report processing metrics and outreach activities.
    Keywords: Air Transportation and Safety
    Type: ARC-E-DAA-TN75565 , International Confidential Aviation Safety Systems (ICASS); Nov 18, 2019 - Nov 19, 2019; Seol; Korea, Republic of
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2020-01-18
    Description: We present 2.5D hybrid simulations of the spectral and thermodynamic evolution of an initial state of magnetic field and plasma variables that in many ways represents solar wind fluctuations. In accordance with Helios near-Sun high-speed stream observations, we start with Alfvnic fluctuations along a mean magnetic field in which the fluctuations in the magnitude of the magnetic field are minimized. Since fluctuations in the radial flow speed are the dominant free energy in the observed fluctuations, we include a field-aligned v(k) with an k(exp 1) spectrum of velocity fluctuations to drive the turbulent evolution. The flow rapidly distorts the Alfvnic fluctuations, yielding spectra (determined by spacecraft-like cuts) transverse to the field that become comparable to the k fluctuations, as in spacecraft observations. The initial near constancy of the magnetic field is lost during the evolution; we show this also takes place observationally. We find some evolution in the anisotropy of the thermal fluctuations, consistent with expectations based on Helios data. We present 2D spectra of the fluctuations, showing the evolution of the power spectrum and cross-helicity. Despite simplifying assumptions, many aspects of simulations and observations agree. The greatly faster evolution in the simulations is at least in part due to the small scales being simulated, but also to the non-equilibrium initial conditions and the relatively low overall Alfvnicity of the initial fluctuations.
    Keywords: Solar Physics
    Type: GSFC-E-DAA-TN76377 , Solar Physics (ISSN 0038-0938) (e-ISSN 1573-093X); 294; 153
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2020-01-16
    Description: The Technology Capability Level-3 (TCL3) flight tests were conducted at six different test sites located across the USA from March to May of 2018. The campaign resulted in over 830 data collection flights using 28 different aircraft and involving 20 flight crews. Flights not only varied in duration, but also in the environments and terrains over which they flew. The TCL3 tests highlighted four different types of tests: three tests focused on Communication, Navigation and Surveillance (CNS); six tests focused on Sense and Avoid (SAA) technologies; six tests focused on USS Data and Information Exchange (DAT); and five tests focused on exploring fundamental Concepts of the project (CON). This document presents data collected during the TCL3 tests that informed the operators experiencesthe quality of the unmanned aerial system (UAS) Service Supplier (USS) information that the operator was provided with, the usefulness of this information, and the usability of the automation, both while airborne and on the ground. It is intended to complement the reports written by the test sites and the quantitative reports and presentations of the UAS Traffic Management (UTM) project. With the goal of instructing what the minimum information requirements and/or best practices might be in TCL3 operations, the driving enquiry was: How do you get the information you need, when you need it, to successfully fly a UAS in UTM airspace? This enquiry touches on two requirements for displays, which are to provide adequate situation awareness (SA) and to share information through a USS. The six test sites participating in the TCL3 tests flew a subset of the 20 tests (outlined above), with most sites working on a subset of each of the four types: Communications, Navigation and Surveillance (CNS); DAT; CON; and Sense and Avoid (SAA). The, mainly qualitative, data addressed in this report was collected by the AOL (Airspace Operations Laboratory) both on-site and remotely for each test. The data consists of the contents of end-of-day debriefs, end-of-day surveys, observer notes, and flight test information, all submitted as part of the Data Management Plan (DMP).
    Keywords: Air Transportation and Safety
    Type: NASA/TM-2019-220347 , ARC-E-DAA-TN65414
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2020-01-16
    Description: The Traffic Aware Strategic Aircrew Request (TASAR) concept applies onboard automation for the purpose of advising the pilot of route modifications that would be beneficial to the flight. Leveraging onboard computing platforms with connectivity to avionics and diverse data sources on and off the aircraft, TASAR introduces a new, powerful capability for in-flight trajectory management to the cockpit and its flight crew that is anticipated to induce a significant culture change in airspace operations. Flight crews empowered by TASAR and its derivative technologies could transform from todays flight plan followers to proactive trajectory managers, taking an initial critical step towards increasing autonomy in the airspace system. TASAR was developed as a catalyst for operational autonomy, a future vision where the responsibilities and authorities of trajectory management reside with the aircraft operator and are distributed among participating aircraft, thus fulfilling a vision dating back decades and enabling a fully scalable airspace system. This NASA Technical Paper maps TASAR to its foundational vision and traces its research and development from initial concept generation to an operational evaluation by a U.S. airline in revenue service, the final stage before technology transfer and commercialization.
    Keywords: Air Transportation and Safety
    Type: NASA/TP–2019-220432 , NF1676L-34474
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2020-01-16
    Description: When a coronal mass ejection departs, it leaves behind a temporary void. That void is known as coronal dimming, and it contains information about the mass ejection that caused it. Other physical processes can cause parts of the corona to have transient dimmings, but mass ejections are particularly interesting because of their influence in space weather. Prior work has established that dimmings are detectable even in disk-integrated irradiance observations, i.e., Sun-as-a-star measurements. The present work evaluates four years of continuous Solar Dynamics Observatory Extreme Ultraviolet Experiment (EVE) observations to greatly expand the number of dimmings we may detect and characterize, and collects that information into Jamess EVE Dimming Index catalog. This paper details the algorithms used to produce the catalog, provides statistics on it, and compares it with prior work. The catalog contains 5051 potential events (rows), which correspond to all robustly detected solar eruptive events in this time period as defined by 〉C1 flares. Each row has a corresponding 27,349 elements of metadata and parameterizations (columns). In total, this catalog is the result of analyzing 7.6 million solar ultraviolet light curves.
    Keywords: Solar Physics
    Type: GSFC-E-DAA-TN75933 , Astrophysical Journal Supplement (ISSN 0067-0049) (e-ISSN 1538-4365); 244; 1; 13
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2020-01-10
    Description: This paper presents the development of ICAROUS-2 (Independent Configurable Architecture for Reliable Operation of Unmanned Systems with Distributed Onboard Services), the second generation of a software architecture that integrates several algorithms as distributed onboard services to enable robust autonomous UAS applications. In particular, the ICAROUS architecture defines a framework to perform detect and avoid, geofencing, path monitoring, path planning, and autonomous decision making to ensure safety and mission progress. Most of the core algorithms implemented in ICAROUS are formally verified using an interactive theorem prover. These algorithms are composed together using a plan execution engine, whose operational semantics is formally specified. A description of the integrated architecture, services currently available, and flight test results highlighting the capability of ICAROUS are presented.
    Keywords: Air Transportation and Safety
    Type: NF1676L-31344
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...