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216
Jun 17, 2010
06/10
by
Anderson, D. S.; Ross, W. J
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No Abstract Available
Topics: DOPPLER EFFECT, SEASONS, SOLAR CYCLES
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196
Jul 12, 2010
07/10
by
Harvey, J. W
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Daily measurements of the equivalent width of the 10830 A He I line integrated over the visible disk show: (1) an increase from about 32 to about 74 mA in the monthly mean values from the minimum to the maximum of the current solar cycle; (2) the monthly mean values are more smoothly varying than most other indices of solar activity; (3) rotation modulates the daily values in a highly variable manner with amplitudes as large as plus or minus 20%; (4) the apparent synodic rotation period is 29...
Topics: SECULAR VARIATIONS, SOLAR DIAMETER, VARIABILITY, RADII, SOLAR CYCLES, SUN
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260
Jul 12, 2010
07/10
by
NON
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No Abstract Available
Topics: SOLAR CONSTANT, SOLAR CYCLES, SOLAR MAXIMUM MISSION, VARIABILITY, CLIMATOLOGY, RADIOMETERS, SUNSPOTS
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284
Jun 1, 2011
06/11
by
Vu, Bruce; Kandula, Ma
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This paper summarizes the acoustic testing and analysis activities at the Launch System Testbed (LST) of Kennedy Space Center (KSC). A major goal is to develop passive methods of mitigation of sound from rocket exhaust jets with ducted systems devoid of traditional water injection. Current testing efforts are concerned with the launch-induced vibroacoustic behavior of scaled exhaust jets. Numerical simulations are also developed to study the sound propagation from supersonic jets in free air...
Topics: SOLAR ACTIVITY EFFECTS, GALACTIC COSMIC RAYS, SOLAR WIND, SOLAR CYCLES, MODULATION, IONS
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248
Jun 13, 2011
06/11
by
Svard, Magnus; Gong, Jing; Nordstrom, Ja
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Our objective is to derive stable first-, second- and fourth-order artificial dissipation operators for node based finite volume schemes. Of particular interest are general unstructured grids where the strength of the finite volume method is fully utilized. A commonly used finite volume approximation of the Laplacian will be the basis in the construction of the artificial dissipation. Both a homogeneous dissipation acting in all directions with equal strength and a modification that allows...
Topics: REGENERATIVE FUEL CELLS, HYDROGEN, OXYGEN, ENERGY STORAGE, SOLAR CYCLES, SAMPLING, HEALTH,...
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161
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Supplementing the measured results previously reported, this investigation of three-component measurements on a wing model of the missile ''ZR 2.0'' was conducted in the subsonic wind tunnel (open-jet 215-millimeter diameter) and in the supersonic wind tunnel (open jet 110 by 130 millimeters) at the request of the Henschel Aircraft Works, Berlin.
Topics: SOLAR COSMIC RAYS, SOLAR CYCLES, NEUTRON COUNTERS, COSMIC RAYS, CATALOGS (PUBLICATIONS),...
Through the use of observations, mathematics, mathematical tools (such as graphs), inference, testing, and prediction we have gathered evidence that there are sunspots, a solar cycle, and have begun to understand more about our star, the Sun. We are making progress in understanding the cause of the solar cycle. We expect solar cycle 24 to peak soon. Cycle 24 will be the smallest cycle in 100 years.
Topics: NASA Technical Reports Server (NTRS), SOLAR CYCLES, SUNSPOTS, SUN, PROGRESS, INFERENCE, Adams, Mitzi
On the basis of a comparison of Wolf s reconstructed record of yearly averages of sunspot number against Schwabe's observations of yearly counts of 'clusters of spots' (i.e., the yearly number of newly appearing sunspot groups) during the interval of 1826-1868, one infers that Wolf probably misplaced and underestimated the maximum amplitude for cycle 7. In particular, Schwabe's data suggest that the maximum amplitude for cycle 7 occurred in 1828 rather than in 1830 and that it measured about...
Topics: NASA Technical Reports Server (NTRS), SUNSPOTS, SOLAR CYCLES, MODEMS, COUNTING, MAXIMA, Wilson,...
An improved model of the Earth's trapped proton environment has been developed. This model, designated Trapped Proton Model version 1 (TPM-1), determines the omnidirectional flux of protons with energy between 1 and 100 MeV throughout near-Earth space. The model also incorporates a true solar cycle dependence. The model consists of several data files and computer software to read them. There are three versions of the mo'del: a FORTRAN-Callable library, a stand-alone model, and a Web-based model.
Topics: NASA Technical Reports Server (NTRS), PROTONS, SOLAR CYCLES, COMPUTER PROGRAMS, FORTRAN, LIBRARIES,...
150
150
Mar 4, 2009
03/09
by
NASA LaRC Office of Education
movies
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NASA Connect segment involving students in an activity that investigates the cycles of solar flares. The video incorporates problem solving strategies while students compute percentages of M-class flares and graph data.
Topics: NASA Connect, Sun, Solar Flares, M-class Flares, Graph, Problem Solving, Solar Cycles, Student...
Source: http://nasa.ibiblio.org/details.php?videoid=6289&start=40&subject=Science
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329
Jun 2, 2011
06/11
by
Lary, David Joh
texts
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When performing chemical data assimilation the observational, representativeness, and theoretical uncertainties have very different characteristics. In this study we have accurately characterized the representativeness uncertainty by studying the probability distribution function (PDF) of the observations. The average deviation has been used as a measure of the width of the PDF and of the variability (representativeness uncertainty) for the grid cell. It turns out that for long-lived tracers...
Topics: LOW EARTH ORBITS, SPACECRAFT CHARGING, SOLAR CYCLES, SOLAR ARRAYS, GROUND TESTS, ELECTRIC CURRENT,...
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176
Jun 2, 2011
06/11
by
Abarzhi, S. I
texts
eye 176
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Here we report multiple harmonic theoretical solutions for a complete system of conservation laws, which describe the large-scale coherent dynamics in RTI and RMI for fluids with a finite density ratio in the general three-dimensional case. The analysis yields new properties of the bubble front dynamics. In either RTI or RMI, the obtained dependencies of the bubble velocity and curvature on the density ratio differ qualitatively and quantitatively from those suggested by the models of Sharp...
Topics: SOLAR FLUX DENSITY, IRRADIANCE, ATMOSPHERIC OPTICS, AEROSOLS, PHOTOMETERS, SOLAR ROTATION,...
299
299
May 6, 2010
05/10
by
Kegelman, Jerome T.; Danehy, Paul M.; Schwartz, Richard J
texts
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Wind tunnel testing methods and test technologies for the 21st century using advanced capabilities are presented. These capabilities are necessary to capture more accurate and high quality test results by eliminating the uncertainties in testing and to facilitate verification of computational tools for design. This paper discusses near term developments underway in ground testing capabilities, which will enhance the quality of information of both the test article and airstream flow details....
Topics: ASTROPHYSICS, COSMIC RAYS, GALACTIC COSMIC RAYS, ACCELERATION (PHYSICS), EXPOSURE, MODULATION,...
A magnetic dipole rotating around an axis perpendicular to the rotation axis of the sun can account for the characteristics of the surface large-scale solar magnetic fields through the solar cycle. The polarity patterns of the interplanetary magnetic field, predictable from this model, agree with the observed interplanetary magnetic sector structure.
Topics: NASA Technical Reports Server (NTRS), INTERPLANETARY MAGNETIC FIELDS, MAGNETIC DIPOLES,...
The event-integrated fluences of energetic solar protons up to 2004 at the Earth have been determined and compared to previous data. The current solar cycle has been very active, and very large fluxes of solar protons have been observed that have had serious effects in the solar system and will have produced many radionuclides in the surfaces of meteorites. Such huge events are not expected again until about 2008 or 2009.
Topics: NASA Technical Reports Server (NTRS), RADIOACTIVE ISOTOPES, SOLAR PROTONS, SOLAR CYCLES,...
163
163
Jun 2, 2011
06/11
by
Gupta, Mohan; Douglass, Anne; Kawa, S. Randy; Pawson, Steve
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eye 163
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We have investigated the importance of intercontinental transport using source-receptor relationship. A global radon-like and seven regional tracers were used in three-dimensional model simulations to quantify their contributions to column burdens and vertical profiles at world-wide receptors. Sensitivity of these contributions to meteorological input was examined using different years of meteorology in two atmospheric simulations. Results show that Asian emission influences tracer...
Topics: CORONAL MASS EJECTION, GALACTIC COSMIC RAYS, SOLAR ACTIVITY EFFECTS, SOLAR WIND, SOLAR CYCLES,...
442
442
Jul 12, 2010
07/10
by
Griffiths, W. R.; Smirlock, M.; Aplin, J.; Fish, R. B.; Fish, D
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A design, fabrication, and implementation of a horizon control of a longwall shearer was performed. This equipment was tested and demonstrated aboveground. This hardware was also installed on a longwall face. The feasibility of providing horizon control for a shearer was demonstrated aboveground. The feasibility of retrofitting the necessary sensors in a survivable manner was demonstrated underground. Subsequent field tests of a specific component, the natural background sensor, at a western...
Topics: LUMINOSITY, SUNSPOT CYCLE, THEORETICAL PHYSICS, SOLAR CONSTANT, SOLAR CYCLES, SOLAR DIAMETER,...
139
139
Jun 11, 2011
06/11
by
Huang, Frank T.; Mayr, Hans G.; Reber, Carl A
texts
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Based on an empirical analysis of measurements with the High Resolution Doppler Imager (HRDI) on the UARS spacecraft in the upper mesosphere (95 km), persistent and regular intra-seasonal oscillations (ISO) with periods of about 2 to 4 months have recently been reported in the zonal-mean meridional winds. Similar oscillations have also been discussed independently in a modeling study, and they were attributed to wave-mean-flow interactions. The observed and modeled meridional wind ISOs were...
Topics: SOLAR CYCLES, SOLAR CORPUSCULAR RADIATION, ENERGETIC PARTICLES, PERIODIC VARIATIONS, CORONAL MASS...
When and where to look is an important issue to observers planning to observe major solar flares. Prediction of major flares is also important because they influence the Earth's environment. Techniques for utilizing recently discovered solar hot spots and a solar activity periodicity of about 154 days in determining when and where to look to catch major flares are discussed.
Topics: NASA Technical Reports Server (NTRS), OBSERVATION, SOLAR CYCLES, SOLAR FLARES, PERIODIC VARIATIONS,...
380
380
May 31, 2011
05/11
by
Feinberg, Arthur; Tauss, Jame
texts
eye 380
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Weather is a contributing factor in approximately 25-30 percent of general aviation accidents. The lack of timely, accurate and usable weather information to the general aviation pilot in the cockpit to enhance pilot situational awareness and improve pilot judgment remains a major impediment to improving aviation safety. NASA Glenn Research Center commissioned this 120 day weather datalink market survey to assess the technologies, infrastructure, products, and services of commercial avionics...
Topics: GEOMAGNETISM, SOLAR ACTIVITY EFFECTS, SOLAR CYCLES, SOLAR WIND, INTERPLANETARY MAGNETIC FIELDS,...
261
261
May 23, 2011
05/11
by
Kuhn, Richard E
texts
eye 261
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When a jet STOVL aircraft is hovering, or in a crossflow, while close to the ground wall jets flowing radially outward from the impingement points of the jets are generated. An upflow, or fountain, is generated where the wall jets from adjacent jets meet on the ground surface. The induced lift and suckdown generated by the impingement of the fountain on the lower surface of the configuration has been the subject of previous studies. This study analyzes the limited available pressure and force...
Topics: DYNAMO THEORY, QUENCHING, MATHEMATICAL MODELS, NONLINEARITY, TRAVELING WAVES, PRANDTL NUMBER, SOLAR...
412
412
Jun 1, 2011
06/11
by
Rummel, John D.; Race, Margaret S.; DeVinenzi, Donald L.; Schad, P. Jackson; Stabekis, Pericles D.; Viso, Michel; Acevedo, Sara E
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This document presents the first complete draft of a protocol for detecting possible biohazards in Mars samples returned to Earth; it is the final product of the Mars Sample Handling Protocol Workshop Series, convened in 2000-2001 by NASA's Planetary Protection Officer. The goal of the five-workshop Series vas to develop a comprehensive protocol by which returned martian sample materials could be assessed for the presence of any biological hazard(s) while safeguarding the purity of the samples...
Topics: SUNSPOTS, SPECTRORADIOMETERS, FACULAE, SOLAR CYCLES, LIGHT (VISIBLE RADIATION), PERIODIC...
High resolution power spectra of 77 years of Zurich daily sunspot numbers were computed using various lags and data point intervals. Major harmonic peaks of the approximately 124-month period showed up strongly as well as the 27-day solar rotational period.
Topics: NASA Technical Reports Server (NTRS), POWER SPECTRA, SOLAR ACTIVITY, SUNSPOTS, FOURIER...
Several indices are used to characterize the solar activity cycle. Key among these are: the International Sunspot Number, the Group Sunspot Number, Sunspot Area, and 10.7 cm Radio Flux. A valuable aspect of these indices is the length of the record -- many decades and many (different) 11-year cycles. However, this valuable length-of-record attribute has an inherent problem in that it requires many different observers and observing systems. This can lead to non-uniformity in the datasets and...
Topics: NASA Technical Reports Server (NTRS), SOLAR CYCLES, STATISTICAL TESTS, SUNSPOTS, STATISTICAL...
Modified geomagnetic precursor techniques for predicting the size of the following sunspot cycle are developed, where these techniques use the 12-month moving averages of the number of disturbed days (when Ap greater than or equals 25), the Ap index, the aa index, and the aaI index at about 4 yr during the declining portion of the preceding sunspot cycle. For cycle 24, these techniques suggest that its RM will measure about 130 +/- 14, a value outside the consensus prediction interval of the...
Topics: NASA Technical Reports Server (NTRS), GEOMAGNETISM, SOLAR CYCLES, SUNSPOT CYCLE, PREDICTIONS,...
Unlike the negative polarity solar magnetic field large-scale regular features that correlate with enhanced solar activity regions, the positive polarity regular formations formed in the weak and old background magnetic fields seem to correlate well with geomagnetically enhanced periods of time (shifted for 4 days), which means that they seem to be the source of the quiet solar wind. This behavior of the large intervals of heliographic longitude with prevailing positive polarity fields may be...
Topics: NASA Technical Reports Server (NTRS), MAGNETIC DISTURBANCES, MAGNETIC PROPERTIES, POLARITY, SOLAR...
479
479
Jul 11, 2010
07/10
by
NON
texts
eye 479
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The engineering analyses and evaluation studies conducted for the Software Requirements Analysis are discussed. Included are the development of the study data base, synthesis of implementation approaches for software required by both mandatory onboard computer services and command/control functions, and identification and implementation of software for ground processing activities.
Topics: COMETS, SOLAR CYCLES, LATITUDE, SOLAR WIND VELOCITY, STATISTICAL ANALYSIS, VARIATIONS, POLAR...
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280
Jul 12, 2010
07/10
by
Whitaker, A. F.; Little, S. A
texts
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Twenty high performance BSR 2 ohm-cm silicon solar cells manufactured by ASEC were evaluated at 1 AU conditions and at low temperature and low intensities representative of deep space. These cells showed evidence of series resistance of 1 AU conditions and approximately 50% had reduced power outputs under deep space conditions. Average efficiency of these cells was 12.4% of 1 AU conditions of 1 SC/25 C.
Topics: CARBON DIOXIDE, THEORETICAL PHYSICS, CLIMATE, PREDICTION ANALYSIS TECHNIQUES, SOLAR CYCLES, SOLAR...
A prominent feature of previous long-term temperature studies has been the appearance of warming since the 1880s, this often being taken as evidence for anthropogenic-induced global warming. In this investigation, the long-term, annual, mean temperature record (1844-1992) of the Armagh Observatory (Armagh, North Ireland), a set of temperature data based on maximum and minimum thermometers that predates the 1880s and correlates well with northern hemispheric and global standards, is examined for...
Topics: NASA Technical Reports Server (NTRS), SOLAR CYCLES, SECULAR VARIATIONS, GLOBAL WARMING,...
On the basis of the maximum amplitude-early rise correlation, cycle 23 could have been predicted to be about the size of the mean cycle as early as 12 mo following cycle minimum. Indeed, estimates for the size of cycle 23 throughout its rise consistently suggested a maximum amplitude that would not differ appreciably from the mean cycle, contrary to predictions based on precursor information. Because cycle 23 s average slope during the rising portion of the solar cycle measured 2.4, computed as...
Topics: NASA Technical Reports Server (NTRS), SUNSPOT CYCLE, SOLAR CYCLES, ESTIMATES, SLOPES, ASCENT,...
Often, the relation between monthly or yearly averages of total sunspot area, A, and sunspot number, R, has been described using the formula A = 16.7 R. Such a simple relation, however, is erroneous. The yearly ratio of A/R has varied between 5.3 in 1964 to 19.7 in 1926, having a mean of 13.1 with a standard deviation of 3.5. For 1875-1976 (corresponding to the Royal Greenwich Observatory timeframe), the yearly ratio of A/R has a mean of 14.1 with a standard deviation of 3.2, and it is found to...
Topics: NASA Technical Reports Server (NTRS), SUNSPOTS, SOLAR CYCLES, STANDARD DEVIATION, PREDICTIONS,...
Nonerupting prominences are not dull, static objects. Rather, they are composed of fine-scale blobs and threads that are highly dynamic, often appearing to travel in opposite directions on adjacent tracks (denoted counterstreaming). Because the plasma is largely constrained to travel along the magnetic field, these cool, dense features can serve as tracers of the prominence magnetic structure, a valuable resource in view of the long-standing difficulty of observing the coronal field....
Topics: NASA Technical Reports Server (NTRS), MAGNETIC FIELD CONFIGURATIONS, SOLAR PROMINENCES, SOLAR...
The results are presented of the application of Avco Data Analysis and Prediction Techniques (ADAPT) to derivation of new algorithms for the prediction of future sunspot activity. The ADAPT derived algorithms show a factor of 2 to 3 reduction in the expected 2-sigma errors in the estimates of the 81-day running average of the Zurich sunspot numbers. The report presents: (1) the best estimates for sunspot cycles 20 and 21, (2) a comparison of the ADAPT performance with conventional techniques,...
Topics: NASA Technical Reports Server (NTRS), SOLAR CYCLES, SUNSPOTS, ALGORITHMS, PREDICTIONS, REGRESSION...
Living With a Star is a NASA initiative employing the combination of dedicated spacecraft with targeted research and modeling efforts to improve what we know of solar effects of all kinds on the Earth and its surrounding space environment, with particular emphasis on those that have significant practical impacts on life and society. The highest priority among these concerns is the subject of this report: the potential effects of solar variability on regional and global climate, including the...
Topics: NASA Technical Reports Server (NTRS), SOLAR TERRESTRIAL INTERACTIONS, NASA PROGRAMS, CLIMATOLOGY,...
Forecasts of solar and geomagnetic activity are critical since these quantities are such important inputs to the thermospheric density models. At this time in the history of solar science there is no way to make such a forecast from first principles. Physical theory applied to the Sun is developing rapidly, but is still primitive. Techniques used for forecasting depend upon the observations over about 130 years, which is only twelve solar cycles. It has been noted that even-numbered cycles...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC DENSITY, ATMOSPHERIC MODELS, GEOMAGNETISM, SOLAR...
The NASA/MSFC method of forecasting is more formal than NOAA's. The data is smoothed by the Lagrangian method and linear regression prediction techniques are used. The solar activity period is fixed at 11 years--the mean period of all previous cycles. Interestingly, the present prediction for the time of the next solar minimum is February or March of 1987, which, within the uncertainties of two methods, can be taken to be the same as the NOAA result.
Topics: NASA Technical Reports Server (NTRS), DATA SMOOTHING, LINEAR PREDICTION, REGRESSION ANALYSIS, SOLAR...
Preliminary results of measurements made during 1979-1980 are discussed. Variability in the radius measurements of 0.4 pi is found, of unknown origin.
Topics: NASA Technical Reports Server (NTRS), SECULAR VARIATIONS, SOLAR DIAMETER, VARIABILITY, RADII, SOLAR...
The mechanism we wish to demonstrate exploits chemical, radiative, and dynamical sensitivities in the stratosphere to affect the climate of the troposphere. The sun, while its variability in total radiative output over the course of the solar cycle is on the order of 0.1%, exhibits variability in the UV output on the order of 5%. We expect to show that a substantially decreased solar UV output lessened the heating of the Earth's stratosphere during the Maunder Minimum, through decreased...
Topics: NASA Technical Reports Server (NTRS), CLIMATE CHANGE, SOLAR ACTIVITY EFFECTS, TROPOSPHERE, SOLAR...
Solar cycle predictions are needed to plan long-term space missions; just like weather predictions are needed to plan your next vacation. Fleets of satellites circle the Earth collecting many types of science data, protecting astronauts, and relaying information. All of these satellites are sensitive at some level to solar cycle effects. Predictions of drag on LEO spacecraft are one of the most important. Launching a satellite with less propellant can mean a higher orbit, but unanticipated...
Topics: NASA Technical Reports Server (NTRS), PREDICTIONS, SOLAR ACTIVITY, SOLAR CYCLES, SPACE MISSIONS,...
Some observational facts about the large-scale patterns formed by solar negative polarity magnetic fields during the 19th and 20th cycles of solar activity are presented. The close relation of the position of occurrence of very large flares accompanied by cosmic ray and PCA events as well as other phenomena of solar activity during the declining part of the 19th cycle of the regularities in the internal structure of large scale negative polarity features are demonstrated.
Topics: NASA Technical Reports Server (NTRS), PARTICLE EMISSION, SOLAR CYCLES, SOLAR FLARES, SOLAR MAGNETIC...
Geomagnetic field sudden increases or storm sudden commencements are compared with measurements of electron content of the solar wind. The latter data are obtained by a radio propagation experiment, which measures the electron content along a radio path between transmitters on the ground and several spacecraft in solar orbit. Measurements were examined during time periods that included 40 of the geomagnetic disturbances (gmd) reported between January 1, 1966, and June 30, 1969. These studies...
Topics: NASA Technical Reports Server (NTRS), ELECTRON DENSITY (CONCENTRATION), MAGNETIC STORMS, SOLAR...
Measurements of radial and latitudinal gradients of galactic cosmic rays and anomalous components now cover radii from 0.3 to 40 AU from the sun and latitudes up to 30 deg above the ecliptic plane for particle energies from approx. 10 MeV/n up to relativistic energies. The most accurate measurements cover the period 1972 through 1987, which includes more than one full 11 year cycle of solar activity. Radial gradients for glactic cosmic rays of all energies and species are small (similar to less...
Topics: NASA Technical Reports Server (NTRS), GALACTIC COSMIC RAYS, GRADIENTS, RADIATION MEASUREMENT, SOLAR...
The primary purpose of the Theory and Modeling Group meeting was to identify scientists engaged or interested in theoretical work pertinent to the Max '91 program, and to encourage theorists to pursue modeling which is directly relevant to data which can be expected to result from the program. A list of participants and their institutions is presented. Two solar flare paradigms were discussed during the meeting -- the importance of magnetic reconnection in flares and the applicability of...
Topics: NASA Technical Reports Server (NTRS), ASTRONOMICAL MODELS, SOLAR FLARES, SOLAR PHYSICS,...
The solar wind structure is reviewed based on experimental space measurements acquired over approximately the last decade. The character of the interplanetary medium is considered from the viewpoint of the temporal behavior of the solar wind over increasingly longer time intervals, the average properties of the various solar wind parameters and their interrelationships. A brief discussion is included of interplanetary-terrestrial relationships and the expected effects of heliographic latitude...
Topics: NASA Technical Reports Server (NTRS), SOLAR ACTIVITY EFFECTS, SOLAR WIND, INTERPLANETARY MEDIUM,...
The probability with which any given proton fluence level will be exceeded during a space mission is computed for missions to be flown during the active phase of the next solar cycle (1977-1983). This probability is a function of fluence level, proton energy threshold, and mission duration. Data on the major solar proton events of 1966-1972 are given; it is argued that only this data set (and not that of the previous solar cycle) is appropriate for estimating next-cycle fluences. Probable...
Topics: NASA Technical Reports Server (NTRS), FLUENCE, SOLAR CYCLES, SOLAR PROTONS, SPACE FLIGHT,...
Using NSO/KP magnetograms, the pattern and rate of the emergence of magnetic flux and the development of the large-scale patterns of unipolar fields are considered in terms of the solar magnetic cycle. Magnetic flux emerges in active regions at an average rate of 2 x 10(exp 21) Mx/day, approximately 10 times the estimated rate in ephemeral regions. Observations are presented that demonstrate that the large-scale unipolar fields originate in active regions and activity nests. For cycle 21, the...
Topics: NASA Technical Reports Server (NTRS), MAGNETIC FLUX, SOLAR CYCLES, SOLAR MAGNETIC FIELD, DIPOLE...
Two changes in recording the sunspot record have occurred in recent years. First, in 1976, the longer-than-100-yr daily photographic record of the Royal Greenwich Observatory (RGO), used for determination of numbers and positions of sunspot groups and sunspot areas ended, and second, at the end of 1980, after more than 130 years, Zurich s Swiss Federal Observatory stopped providing daily sunspot numbers. To extend the sunspot record beyond 1976, use of United States Air Force/National Oceanic...
Topics: NASA Technical Reports Server (NTRS), SUNSPOTS, OBSERVATORIES, SOLAR CYCLES, DATA BASES,...
Time variations in the flux of galactic cosmic rays are the result of changing conditions in the solar wind. Maximum cosmic ray fluxes, which occur when solar activity is at a minimum, are well defined. Reductions from this maximum level are typically systematic and predictable but on occasion are rapid and unexpected. Models relating the flux level at lower energy to that at neutron monitor energy are typically accurate to 20 percent of the total excursion at that energy. Other models,...
Topics: NASA Technical Reports Server (NTRS), GALACTIC COSMIC RAYS, SOLAR CYCLES, SOLAR FLARES, SUN, TIME,...
Solar sunspot cycles 8 through 21 are reviewed. Mean time intervals are calculated for maximum to maximum, minimum to minimum, minimum to maximum, and maximum to minimum phases for cycles 8 through 20 and 8 through 21. Simple cosine functions with a period of 132 years are compared to, and found to be representative of, the variation of smoothed sunspot numbers at solar maximum and minimum. A comparison of cycles 20 and 21 is given, leading to a projection for activity levels during the...
Topics: NASA Technical Reports Server (NTRS), SOLAR CYCLES, SOLAR FLARES, SPACELAB, SUNSPOTS, COSINE...
494
494
Jul 12, 2010
07/10
by
Churchill, G. B.; Dugan, D. C
texts
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The effective use of simulation from issuance of the request for proposal through conduct of a flight test program for the XV-15 Tilt Rotor Research Aircraft is discussed. From program inception, simulation complemented all phases of XV-15 development. The initial simulation evaluations during the source evaluation board proceedings contributed significantly to performance and stability and control evaluations. Eight subsequent simulation periods provided major contributions in the areas of...
Topics: LUMINOSITY, SOLAR PHYSICS, STELLAR MOTIONS, THEORETICAL PHYSICS, MATHEMATICAL MODELS, OSCILLATIONS,...
