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Wood JD, Sadler EJ, Fox NI, Greer ST, Gu L, Guinan PE, Lupo AR, Market PS, Rochette SM, Speck A, White LD. Land-Atmosphere Responses to a Total Solar Eclipse in Three Ecosystems With Contrasting Structure and Physiology. J Geophys Res Atmos 2019; 124:530-543. [PMID: 31080699 PMCID: PMC6505711 DOI: 10.1029/2018jd029630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 12/21/2018] [Indexed: 06/09/2023]
Abstract
Mid-Missouri experienced up to 2 min 40 s of totality at around solar noon during the total eclipse of 2017. We conducted the Mid-Missouri Eclipse Meteorology Experiment to examine land-atmosphere interactions during the eclipse. Here, research examining the eclipse responses in three contrasting ecosystems (forest, prairie, and soybeans) is described. There was variable cloudiness around first and fourth contacts (i.e., the start and end of partial solar obscuration) at the forest and prairie; however, solar irradiance (K ↓) signals during the eclipse were relatively clean. Unfortunately, the eclipse forcing at the soybean field was contaminated by convective activity, which decreased K ↓ beginning about an hour before first contact and exposed the field to cold outflow ~30 min before second contact. Turbulence was suppressed during the eclipse at all sites; however, there was also an amplified signal at the soybean field during the passage of a gust front. The standard deviations of the horizontal and vertical wind velocities and friction velocities decreased by ~75% at the forest (aerodynamically rough), and ~60% at the prairie (aerodynamically smooth). The eddy fluxes of energy were highly coherent with the solar forcing with the latent and sensible heat fluxes approaching 0 W/m2 and changing in direction, respectively. For the prairie site, we estimated a canopy-scale time constant for the surface conductance light response of 10 min. Although the eclipse imparted large forcings on surface energy balances, the air temperature response was relatively muted (1.5-2.5 °C decrease) due to the absence of topographic effects and the relatively moist land and atmosphere.
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Affiliation(s)
- J. D. Wood
- School of Natural Resources, University of Missouri, Columbia, Missouri, USA
| | - E. J. Sadler
- Cropping Systems and Water Quality Research Unit, USDA-ARS, Columbia, Missouri, USA
| | - N. I. Fox
- School of Natural Resources, University of Missouri, Columbia, Missouri, USA
| | - S. T. Greer
- School of Natural Resources, University of Missouri, Columbia, Missouri, USA
| | - L. Gu
- Environmental Sciences Division and Climate Change Institute, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - P. E. Guinan
- School of Natural Resources, University of Missouri, Columbia, Missouri, USA
| | - A. R. Lupo
- School of Natural Resources, University of Missouri, Columbia, Missouri, USA
| | - P. S. Market
- School of Natural Resources, University of Missouri, Columbia, Missouri, USA
| | - S. M. Rochette
- Department of Earth Sciences, The College at Brockport, State University of New York, Brockport, New York, USA
| | - A. Speck
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri, USA
| | - L. D. White
- Department of Chemistry, Physics, and Atmospheric Science, Jackson State University, Jackson, Mississippi, USA
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Zelzer B, Speck A, Langenbucher A, Eppig T. Theoretical model for design and analysis of protectional eyewear. Z Med Phys 2013; 23:120-8. [DOI: 10.1016/j.zemedi.2013.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 02/05/2013] [Accepted: 02/05/2013] [Indexed: 10/27/2022]
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Gabrielse G, Kolthammer WS, McConnell R, Richerme P, Wrubel J, Kalra R, Novitski E, Grzonka D, Oelert W, Sefzick T, Zielinski M, Borbely JS, Fitzakerley D, George MC, Hessels EA, Storry CH, Weel M, Müllers A, Walz J, Speck A. Centrifugal separation of antiprotons and electrons. Phys Rev Lett 2010; 105:213002. [PMID: 21231298 DOI: 10.1103/physrevlett.105.213002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2010] [Indexed: 05/30/2023]
Abstract
Centrifugal separation of antiprotons and electrons is observed, the first such demonstration with particles that cannot be laser cooled or optically imaged. The spatial separation takes place during the electron cooling of trapped antiprotons, the only method available to produce cryogenic antiprotons for precision tests of fundamental symmetries and for cold antihydrogen studies. The centrifugal separation suggests a new approach for isolating low energy antiprotons and for producing a controlled mixture of antiprotons and electrons.
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Affiliation(s)
- G Gabrielse
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
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Gabrielse G, Larochelle P, Le Sage D, Levitt B, Kolthammer WS, McConnell R, Richerme P, Wrubel J, Speck A, George MC, Grzonka D, Oelert W, Sefzick T, Zhang Z, Carew A, Comeau D, Hessels EA, Storry CH, Weel M, Walz J. Antihydrogen production within a Penning-Ioffe trap. Phys Rev Lett 2008; 100:113001. [PMID: 18517780 DOI: 10.1103/physrevlett.100.113001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Indexed: 05/26/2023]
Abstract
Slow antihydrogen (H) is produced within a Penning trap that is located within a quadrupole Ioffe trap, the latter intended to ultimately confine extremely cold, ground-state H[over ] atoms. Observed H[over ] atoms in this configuration resolve a debate about whether positrons and antiprotons can be brought together to form atoms within the divergent magnetic fields of a quadrupole Ioffe trap. The number of detected H atoms actually increases when a 400 mK Ioffe trap is turned on.
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Affiliation(s)
- G Gabrielse
- Department of Physics, Harvard University, Cambridge, MA 02138, USA.
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Gabrielse G, Larochelle P, Le Sage D, Levitt B, Kolthammer WS, Kuljanishvili I, McConnell R, Wrubel J, Esser FM, Glückler H, Grzonka D, Hansen G, Martin S, Oelert W, Schillings J, Schmitt M, Sefzick T, Soltner H, Zhang Z, Comeau D, George MC, Hessels EA, Storry CH, Weel M, Speck A, Nillius F, Walz J, Hänsch TW. Antiproton confinement in a Penning-Ioffe trap for antihydrogen. Phys Rev Lett 2007; 98:113002. [PMID: 17501048 DOI: 10.1103/physrevlett.98.113002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Indexed: 05/15/2023]
Abstract
Antiprotons (p[over]) remain confined in a Penning trap, in sufficient numbers to form antihydrogen (H[over ) atoms via charge exchange, when the radial field of a quadrupole Ioffe trap is added. This first demonstration with p[over] suggests that quadrupole Ioffe traps can be superimposed upon p[over] and e(+) traps to attempt the capture of H[over] atoms as they form, contrary to conclusions of previous analyses.
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Affiliation(s)
- G Gabrielse
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
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Kohlhaas M, Spoerl E, Speck A, Schilde T, Sandner D, Pillunat LE. Eine neue Behandlung der Keratektasie nach LASIK durch Kollagenvernetzung mit Riboflavin/UVA-Licht. Klin Monbl Augenheilkd 2005; 222:430-6. [PMID: 15912463 DOI: 10.1055/s-2005-857950] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Keratectasia is one of the most severe complications after refractive laser surgery. Usually penetrating keratoplasty is the treatment of choice to achieve an optical rehabilitation in such cases. PATIENTS AND METHODS We report on a female patient who developed keratectasia in both eyes 4 weeks after LASIK. Due to a severe keratectasia 10 months after LASIK, a treatment with riboflavin/UVA cross-linking was performed. RESULTS Due to the induced collagen cross-linking the biomechanical status of the cornea was stabilized and a progression of the keratectasia was prevented. The postoperative refraction and corneal topography have been stable for 18 months. CONCLUSION Collagen cross-linking leads to a stiffening of the anterior parts of the corneal stroma. The increase of biomechanical stability can stop the progression of a keratectasia after LASIK by means of a simple procedure.
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Affiliation(s)
- M Kohlhaas
- Universitäts-Augenklinik Carl Gustav Carus, Dresden.
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Storry CH, Speck A, Le Sage D, Guise N, Gabrielse G, Grzonka D, Oelert W, Schepers G, Sefzick T, Pittner H, Herrmann M, Walz J, Hänsch TW, Comeau D, Hessels EA. First laser-controlled antihydrogen production. Phys Rev Lett 2004; 93:263401. [PMID: 15697977 DOI: 10.1103/physrevlett.93.263401] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2004] [Indexed: 05/24/2023]
Abstract
Lasers are used for the first time to control the production of antihydrogen (H ). Sequential, resonant charge exchange collisions are involved in a method that is very different than the only other method used so far-producing slow H during positron cooling of antiprotons in a nested Penning trap. Two attractive features are that the laser frequencies determine the H binding energy, and that the production of extremely cold H should be possible in principle-likely close to what is needed for confinement in a trap, as needed for precise laser spectroscopy.
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Affiliation(s)
- C H Storry
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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Gabrielse G, Speck A, Storry CH, LeSage D, Guise N, Grzonka D, Oelert W, Schepers G, Sefzick T, Pittner H, Walz J, Hänsch TW, Comeau D, Hessels EA. First measurement of the velocity of slow antihydrogen atoms. Phys Rev Lett 2004; 93:073401. [PMID: 15324235 DOI: 10.1103/physrevlett.93.073401] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2004] [Indexed: 05/24/2023]
Abstract
The speed of antihydrogen atoms is deduced from the fraction that passes through an oscillating electric field without ionizing. The weakly bound atoms used for this first demonstration travel about 20 times more rapidly than the average thermal speed of the antiprotons from which they form, if these are in thermal equilibrium with their 4.2 K container. The method should be applicable to much more deeply bound states, which may well be moving more slowly, and should aid the quest to lower the speed of the atoms as required if they are to be trapped for precise spectroscopy.
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Affiliation(s)
- G Gabrielse
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
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Gabrielse G, Bowden NS, Oxley P, Speck A, Storry CH, Tan JN, Wessels M, Grzonka D, Oelert W, Schepers G, Sefzick T, Walz J, Pittner H, Hänsch TW, Hessels EA. Driven production of cold antihydrogen and the first measured distribution of antihydrogen states. Phys Rev Lett 2002; 89:233401. [PMID: 12485006 DOI: 10.1103/physrevlett.89.233401] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2002] [Indexed: 05/24/2023]
Abstract
Cold antihydrogen is produced when antiprotons are repeatedly driven into collisions with cold positrons within a nested Penning trap. Efficient antihydrogen production takes place during many cycles of positron cooling of antiprotons. A first measurement of a distribution of antihydrogen states is made using a preionizing electric field between separated production and detection regions. Surviving antihydrogen is stripped in an ionization well that captures and stores the freed antiproton for background-free detection.
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Affiliation(s)
- G Gabrielse
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
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Gabrielse G, Bowden NS, Oxley P, Speck A, Storry CH, Tan JN, Wessels M, Grzonka D, Oelert W, Schepers G, Sefzick T, Walz J, Pittner H, Hänsch TW, Hessels EA. Background-free observation of cold antihydrogen with field-ionization analysis of its states. Phys Rev Lett 2002; 89:213401. [PMID: 12443407 DOI: 10.1103/physrevlett.89.213401] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2002] [Indexed: 05/24/2023]
Abstract
A background-free observation of cold antihydrogen atoms is made using field ionization followed by antiproton storage, a detection method that provides the first experimental information about antihydrogen atomic states. More antihydrogen atoms can be field ionized in an hour than all the antimatter atoms that have been previously reported, and the production rate per incident high energy antiproton is higher than ever observed. The high rate and the high Rydberg states suggest that the antihydrogen is formed via three-body recombination.
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Affiliation(s)
- G Gabrielse
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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Speck A. Ein Fall von „Pseudohaematemesis”. Dtsch Med Wochenschr 1913. [DOI: 10.1055/s-0028-1128478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Speck A. Kühlkisten zur Kühlung der Säuglingsmilch im Hause. Dtsch Med Wochenschr 1905. [DOI: 10.1055/s-0029-1188277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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