195 research outputs found
Increased variability of the Arctic summer ice extent in a warmer climate
No full textSimulations performed with general circulation models and a model of intermediate complexity show that the variability of the September sea ice extent in the Arctic of the 21st century increases first when the mean extent decreases from present-day values. A maximum of the variance is found when the mean September ice extent is around 3 million km(2). For lower extents, the variance declines with the mean extent. The behavior is clearly different in Antarctica where the variance always decreases as the mean ice extent decreases, following roughly a square-root law compatible with very simple geometric arguments. Several mechanisms are responsible for the non-linear behavior of the Arctic. However, the strong interhemispheric contrast suggests that the difference in geometrical setting, with an open ocean in the south and a semi-closed basin in the north, plays a significant role. Citation: Goosse, H., O. Arzel, C. M. Bitz, A. de Montety, and M. Vancoppenolle (2009), Increased variability of the Arctic summer ice extent in a warmer climate, Geophys. Res. Lett., 36, L23702, doi: 10.1029/2009GL040546
THE MIXED-PHASE ARCTIC CLOUD EXPERIMENT (M-PACE)
No full textMixed-Phase Arctic Cloud Experiment (M-PACE) at temperatures down to –30°C. S ignificant and interrelated atmospheric, oceanic, and terrestrial changes have been occurring in the Arctic in recent decades (SEARCH SSC 2001; ACIA 2005). These changes are broad ranging, im-pacting every part of the Arctic environment. The Arctic is observed to be warming at a rate approxi-mately twice that of the global average (ACIA 2005). Indeed, Overpeck et al. (2005) conclude, based on observations and model simulations, that the Arctic is heading toward a new climate state characterized by substantially less permanent ice. The uncertainty in the model projections, however, is larger in the Arctic than over the rest of the globe (Holland and Bitz 2003; Kattsov and Källén 2004). The underlying causes of this enhanced warming and scatter among models i
1958 Jay-Cee-An BJC - Page [61]
No full textPhotographs of BJC FreshmenRow1: G. Tschider. K. Knudson, 1. Guon, R. Long, M. Entzel.
Row2: T. Guttenburg, M. Doppler, D. Melarvie.
Row 1: R. Bailey. N. Herner, G. Hagstrom.
Row2: L. Seeger, E. Thompson, D. Wurm, L. Bitz.
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Row1: L. Botton, C. Hughes, J. Olson, L. Hinkel.
Row2: D. Durant, M. Dutt, H. Hinkel
lettie-roach/analysis_antarctic-asym: Code for journal article
No full textAnalysis code, processed observational data and climate model output required to produce figures for the journal article
Roach, L. A., Eisenman, I., Wagner, T. J., Blanchard-Wrigglesworth, E., and Bitz, C. M.. Asymmetry in the seasonal cycle of Antarctic sea ice due to insolation (2022). Nature Geoscience. https://doi.org/10.1038/s41561-022-00913-
Optical study on ultrathin InAs/InP single quantum wells
No full textOur interest is centred on the very thin layers consisting of only one or a few monolayers of InAs. The optical transition energies, measured by photoluminescence spectroscopy, are compared with theoretical calculations obtained in envelope function approximation and through an empirical tight-binding method. This comparison yields values for the not well-known valence band offset at the InAs/InP interface, and the luminescence lines observed at different energies could be assigned to layers between one and 13 monolayers thick.LASPELOEQEcole normale super lyon, cecam, f-69364 lyon 07, france. univ pavia, ist fis a volta, i-27100 pavia, italy. ecole polytech fed lausanne, phb ecublens, inst micro & optoelectr, ch-1015 lausanne, switzerland. Bitz, A, ECOLE POLYTECH FED LAUSANNE, PHB ECUBLENS, INST PHYS APPL, CH-1015 LAUSANNE, SWITZERLAND.ISI Document Delivery No.: UB294Cited Reference Count: 13Cited References:ANDREANI LC, 1990, PHYS REV B, V42, P8928GAMMON D, 1991, PHYS REV LETT, V67, P1547KE SH, 1994, PHYS REV B, V49, P10495KOPF RF, 1991, APPL PHYS LETT, V58, P631MADER KA, 1992, P INT M OPT EXC CONFMIAUTON L, 1995, THESISOHLER C, 1994, PHYS REV B, V50, P7833PEOPLE R, 1990, PHYS REV B, V41, P8431RUDRA A, 1994, J CRYST GROWTH, V136, P1STORCH DR, 1992, J APPL PHYS, V72, P3041VANDEWALLE CG, 1988, MATER RES SOC S P, V102, P565WALDROP JR, 1991, J APPL PHYS, V69, P372WYSER A, 1994, THESI
Modeling the salinity profile of undeformed Arctic sea ice
No full textThe salinity of sea ice affects its physical and ecological properties. Here, a multilayer one-dimensional halo-thermodynamic sea ice model is used to simulate the vertical salinity profile of undeformed Arctic sea ice. The model successfully reproduces the desalination pattern observed in first-year (FY) and multi-year (MY) ice. The model can also be integrated with a prescribed, time-independent salinity profile. Substantial differences in the simulated mass balance and ice-ocean salt flux arise depending on the salinity. After 10 years into the simulation, the annual mean ice thickness is 2.85 m with the interactive halodynamic component, compared to 2.53 m (2.29 m) with a prescribed, time-independent, vertically varying (constant) salinity profile. Modelling sea ice salinity is especially important when sea ice is transitioning from a MY to FY ice regime. Thus including a halodynamic component in sea ice models would significantly improve simulations of future climate
Antarctic Climate Response to Stratospheric Ozone Depletion in a Fine Resolution Ocean Climate Model
No full textWe investigate the impact of stratospheric ozone depletion on Antarctic climate, paying particular attention to the question of whether eddy parameterizations in the ocean fundamentally alter the results. This is accomplished by contrasting two versions of the Community Climate System Model (version 3.5), one at 0.1° ocean and sea ice resolution and the other at 1° with parameterized ocean eddies. At both resolutions, pairs of integrations are performed: one with high (1960) and one with low (2000) ozone levels. We find that the effect of ozone depletion is to warm the surface and the ocean to a depth of 1000 m and to significantly reduce the sea ice extent. While the ocean warming is somewhat weaker when the eddies are resolved, the total loss of sea ice area is roughly the same in the fine and coarse resolution cases
Optical properties of ultrathin GaAs layers embedded in AlxGa1-xAs
No full textWe present a comparison between the predictions of two theoretical models and experimental results on ultrathin GaAs layers with a thickness in the range from 1 to 8 ML embedded in bulk (AlxGa1-x)As, 0.30 less than or equal to x less than or equal to 0.34. The theoretical predictions, obtained from an empirical tight-binding Green's-function approach and from the usual effective-mass approximation, are compared to photoluminescence and photoluminescence excitation data of a set of multiple quantum-well samples grown by metal-organic vapor-phase epitaxy on substrates with different misorientations. We find that the optical transitions are narrower in samples with slightly misoriented substrates, although their spectral position remains unchanged. This suggests that the substrate misorientation favors a good quality of the ternary alloy. The observed optical transitions of our thin layers compare well with the predictions of both models. However, the lack of a reliable exciton theory for such ultrathin layers becomes apparent.LOEQEcole Polytech Fed Lausanne, Dept Phys, PH Ecublens, CH-1015 Lausanne, Switzerland. Univ Leipzig, Fak Phys & Chem, D-04103 Leipzig, Germany. Univ Munich, DESY, Hasylab, Dop, D-22603 Hamburg, Germany. Bitz, A, Ecole Polytech Fed Lausanne, Dept Phys, PH Ecublens, CH-1015 Lausanne, Switzerland.ISI Document Delivery No.: YV536Cited Reference Count: 19Cited References:ALTARELLI M, 1986, HETEROJUNCTIONS SEMI, P12ANDREANI LC, 1990, PHYS REV B, V42, P8928ATANASOV R, 1994, PHYS REV B, V50, P14381BARONI S, 1989, NATO ADV STUDY I B, V206, P251BASTARD G, 1992, WAVE MECH APL SEMICOBITZ A, 1995, NUOVO CIMENTO D, V17, P1367BOSIO C, 1988, PHYS REV B, V38, P3263CATALANO IM, 1990, PHYS REV B, V41, P12937DIVENTRA M, 1996, P 23 INT C PHYS SEM, V3, P1719DIVENTRA M, 1997, PHYS REV B, V55, P13148IOTTI RC, 1997, PHYS REV B, V56, P3922MADER KA, 1992, P INT M OPT EXC CONF, P341MILLER RC, 1985, J LUMIN, V30, P526OELGART G, 1994, PHYS REV B, V49, P10456PIAO ZS, 1996, PHYS REV B, V53, P1485PROCTOR MJ, 1993, THESIS ECOLE POLYTECSCHWABE R, 1995, J APPL PHYS, V77, P6295VOLIOTIS V, 1995, PHYS REV B, V52, P10725WANG PD, 1994, PHYS REV B, V50, P160
1972 Jay-Cee-An BJC -- Page [102]
No full textPhotographs of BJC freshmenFRESHMEN
Aberle, Patrick P.
Ackerman, La Vern L.
Ackerman, Linda K.
Agard, Joseph L.
Aho, Vicki R.
Aipperspach, Dolores J.
A Ibrecht, Linda C.
Alderin, Vickie S.
Amderson, Patricia T.
Anderson, Deborah A.
Anderson, Gary J.
Anderson, Jill L.
Anderson, Mary L.
Anderson, Wesley A.
Anton, Alan
Askew, Jeffrey J.
A uch, Garrie E.
Baesler, Dwight D.
Bahmiller, Gary
Baltzer, Terrence R.
Baltzer, Timothy J.
Balzer, Stephen
Banker, Gary P.
Basaraba, Betty J.
Barth, Deborah K.
Becker, Gerald S.
Becker, Susan R.
Bender, Carlotte
Bergendahl, Bart S.
Bibelheimer, Paul R.
Bitz, Brenda L.
Bitz, Ken
Biwer, Thomas D.
Blaeser, Kevin M.
Blakemore, Charles B.
Blanc, Devra K.
Blotske, Diane
Boehm, Bruce C.
Bohn, Gregory A.
Bohn, Maralee E.
Bornhoef, William
Borth, Peggy J.
Bosch, Dennis J.
Bosch, Kenneth R.
Bosch, Lynette
Bosworth, Joel F.
Botnen, Ralph B.
Boxeth, Gwendolyn
Boxeth, Jacquelyn
Braun, Sandy L.
Brennan, Kevin F.
Brew, Vern O.
Briss, Dwight P.
Boeckel, Paulette A.
Brown, Carl W.
Brown, Ralph C.
Brunelle, Margaret L.
Bunmeier, Eldora K.
Buchholz, Rolf
Buehler, Elizabeth A.
Bullinger, Melvin J.
Burcham, Susan D.
Burke, Claudia A
1956 Jay-Cee-An - Page 34
No full textPhotographs of BJC nursing studentsST. ALEXIUS HOSPIT AL STUDENT NURSES
ROW ONE: V. Obritschkew itsch, M.
Woychik, M. Woychik, M. Schaan, P.
Oliver. ROW TWO: R. Thies, D.
Rauchwater, H. Bares, D. Maichel, 1.
Clooten. ROW THREE: M. Speey, M.
Gabe, A. Schwartz, G. Sempson, E.
Rising.
The first year students of the St. Alexius and Bismarck Schools of
Nursing attend classes at Bismarck Junior College and participate in
the college's outside activities. One student from each hospital is
elected to serve on the Student Association of the college for the year.
The students also have classes at the Nurses' Homeand work in
the hospital. Their many activities include glee club, school plays,
dances, parties, and outside activities.
ROW ONE: M. Feien, M. Fischer,
B. Emineth, 1. Heileman, L.
Schl ittenhard, E. Silk, H. Deich-ert.
ROW TWO: M. Stowman, H.
Brien, K. Wolf, D. Staff, R. Bitz.
ROW THREE: B. Hassa, K. Tim-mers,
C. Baumgartner, H. Well,
1. Baumgartner.
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