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Author Serdal Ayhan, Mario Pauli, Steffen Scherr, Benjamin Göttel, Akanksha Bhutani, Sven Thomas, Timo Jaeschke, Jean-Michel Panel, Frédéric Vivier, Laurence Eymard, Alain Weill, Nils Pohl, Thomas Zwick doi  openurl
  Title Millimeter-Wave Radar Sensor for Snow Height Measurements Type Journal
  Year 2017 Publication IEEE Transactions on Geoscience and Remote Sensing Abbreviated Journal  
  Volume 55 Issue 2 Pages 854-861  
  Keywords Frequency-modulated continuous-wave (FMCW) radar high accuracy Laser radar Measurement by laser beam millimeter wave Millimeter wave radar Radar measurements range detection Snow snow height snow thickness Temperature measurement  
  Abstract A small and lightweight frequency-modulated continuous-wave (FMCW) radar system is used for the determination of snow height by measuring the distance to the snow surface from a platform. The measurements have been performed at the Centre des Études de la Neige (Col de Porte), which is located near Grenoble in the French Alps. It is shown that the FMCW radar at millimeter-wave frequencies is an extremely promising approach for distance measurements to snow surfaces, e.g., in the mountains or in an Arctic environment. The characteristics of the radar sensor are described in detail. The relevant accuracy to measure the distance to a snow layer is shown at different heights and over an extended time duration. A dedicated laser snow telemeter is used as reference. In addition, the reflection from different types of snow is shown.  
  Programme 1015  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1558-0644 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial (down) 8161  
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Author Rochelle Constantine, Debbie Steel, Judy Allen, Megan Anderson, Olive Andrews, C. Scott Baker, Peta Beeman, Daniel Burns, Jean-Benoît Charrassin, Simon Childerhouse, Michael Double, Paul Ensor, Trish Franklin, Wally Franklin, Nick Gales, Claire Garrigue, Nadine Gibbs, Peter Harrison, Nan Hauser, Amanda Hutsel, Curt Jenner, Micheline-Nicole Jenner, Greg Kaufman, Anne Macie, David Mattila, Carlos Olavarría, Adrian Oosterman, David Paton, Michael Poole, Jooke Robbins, Natalie Schmitt, Peter Stevick, Alden Tagarino, Kirsten Thompson, Juney Ward doi  openurl
  Title Remote Antarctic feeding ground important for east Australian humpback whales Type Journal
  Year 2014 Publication Marine Biology Abbreviated Journal  
  Volume 161 Issue 5 Pages 1087-1093  
  Keywords  
  Abstract Understanding the dynamics of population recovery is particularly complex when an organism has multiple, remote breeding and feeding grounds separated by one of the longest known migration routes. This study reports on the most comprehensive assessment of humpback whale (Megaptera novaeangliae) movements between remote Antarctic waters south of New Zealand and east Australia (EA), and the migratory corridors and breeding grounds of Australia and Oceania. A total of 112 individual whales were identified; 57 from microsatellites and 61 by fluke with 23 % (n = 26) matched to sites outside Antarctica. Despite large datasets from other southern regions being included in the comparison, the whales were predominantly linked to EA (n = 24). Only two matches to the Oceania catalogues directly north was surprising; therefore the primary feeding grounds of these endangered whales still remain unknown. The confirmation of the Balleny Islands as an important feeding ground for EA whales could provide an insight into reasons behind the rapid recovery of this population. Determining the feeding grounds of Oceania’s whales may explain whether prey energetics or migration length are limiting factors to their recovery and will allow an understanding of future ecosystem changes in these whales.  
  Programme 1014  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1432-1793 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial (down) 8160  
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Author Ivo G. S. van Hooijdonk, Herman J. H. Clercx, Carsten Abraham, Amber M. Holdsworth, Adam H. Monahan, Etienne Vignon, Arnold F. Moene, Peter Baas, Bas J. H. van de Wiel file  doi
openurl 
  Title Near-Surface Temperature Inversion Growth Rate during the Onset of the Stable Boundary Layer Type Journal
  Year 2017 Publication Journal of the Atmospheric Sciences Abbreviated Journal  
  Volume 74 Issue 10 Pages 3433-3449  
  Keywords  
  Abstract Abstract This study aims to find the typical growth rate of the temperature inversion during the onset of the stable boundary layer around sunset. The sunset transition is a very challenging period for numerical weather prediction, since neither accepted theories for the convective boundary layer nor those for the stable boundary layer appear to be applicable. To gain more insight in this period, a systematic investigation of the temperature inversion growth rate is conducted. A statistical procedure is used to analyze almost 16 years of observations from the Cabauw observational tower, supported by observations from two additional sites (Dome C and Karlsruhe). The results show that, on average, the growth rate of the temperature inversion (normalized by the maximum inversion during the night) weakly declines with increasing wind speed. The observed growth rate is quantitatively consistent among the sites, and it appears insensitive to various other parameters. The results were also insensitive to the afternoon decay rate of the net radiation except when this decay rate was very weak. These observations are compared to numerical solutions of three models with increasing complexity: a bulk model, an idealized single-column model (SCM), and an operational-level SCM. It appears only the latter could reproduce qualitative features of the observations using a first-order closure. Moreover, replacing this closure with a prognostic TKE scheme substantially improved the quantitative performance. This suggests that idealized models assuming instantaneous equilibrium flux-profile relations may not aid in understanding this period, since history effects may qualitatively affect the dynamics.  
  Programme 1013,1176  
  Campaign  
  Address  
  Corporate Author Thesis Bachelor's thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-4928, 1520-0469 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial (down) 8159  
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Author Alexandre Cauquoin, Camille Risi, Étienne Vignon file  doi
openurl 
  Title Importance of the advection scheme for the simulation of water isotopes over Antarctica by atmospheric general circulation models: A case study for present-day and Last Glacial Maximum with LMDZ-iso Type Journal
  Year 2019 Publication Earth and Planetary Science Letters Abbreviated Journal  
  Volume 524 Issue Pages 115731  
  Keywords advection AGCM Antarctica isotope–temperature gradient water stable isotopes  
  Abstract Atmospheric general circulation models (AGCMs) are known to have a warm and isotopically enriched bias over Antarctica. We test here the hypothesis that these biases are partly consequences of a too diffusive advection. Exploiting the LMDZ-iso model, we show that a less diffusive representation of the advection, especially on the horizontal, is very important to reduce the bias in the isotopic contents of precipitation above this area. The choice of an appropriate representation of the advection is thus essential when using GCMs for paleoclimate applications based on polar water isotopes. Too much diffusive mixing along the poleward transport leads to overestimated isotopic contents in water vapor because dehydration by mixing follows a more enriched path than dehydration by Rayleigh distillation. The near-air surface temperature is also influenced, to a lesser extent, by the diffusive properties of the advection scheme directly via the advection of the air and indirectly via the radiative effects of changes in high cloud fraction and water vapor. A too diffusive horizontal advection increases the temperature and so also contributes to enrich the isotopic contents of water vapor over Antarctica through a reduction of the distillation. The temporal relationship, from Last Glacial Maximum (LGM) to present-day conditions, between the mean annual near-air surface temperature and the water isotopic contents of precipitation for a specific location can also be impacted, with significant consequences on the paleo-temperature reconstruction from observed changes in water isotopes.  
  Programme 1013,1149,1176  
  Campaign  
  Address  
  Corporate Author Thesis Bachelor's thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0012-821X ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial (down) 8158  
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Author Florence Naaim-Bouvet, Hervé Bellot, Kouichi Nishimura, Christophe Genthon, Cyril Palerme, Gilbert Guyomarc’h, Vincent Vionnet doi  openurl
  Title Detection of snowfall occurrence during blowing snow events using photoelectric sensors Type Journal
  Year 2014 Publication Cold Regions Science and Technology Abbreviated Journal  
  Volume 106-107 Issue Pages 11-21  
  Keywords Alps Blowing snow Drifting snow Precipitation Sensor Snowfall  
  Abstract There is a strong need to identify blowing snow events with and without concurrent falling snow and to estimate solid precipitation amounts in mountainous areas and polar regions. For these purposes, we first developed a method using the concomitant analysis of an anemometer and a drifting snow sensors (SPC-S7 and Wenglor/YH03PCT8-YH08PCT8). Photoelectric sensors, such as the SPC-S7 (Snow Particle Counter), specially designed for studying drifting snow, or a simpler photoelectric counter manufactured by Wenglor, were chosen because they had already been tested in previous studies for measuring solid precipitation. They were set up at Lac Blanc Pass, an experimental site dedicated to the study of drifting snow in the French Alps. The data set obtained was compared with the independent database of blowing snow events with or without falling snow collected at the same experimental site, i.e. data on the precipitation amount stemming from heated precipitation gauge and SAFRAN modeling output. The analysis of snow flux and mean diameter according to wind speed allowed us to separate blowing snow events with and without precipitation for moderate wind speed. To reduce the uncertainty at high wind speed, the SPC-S7 must be set up at least 4m above the snow surface. Similar preliminary results were obtained with the simpler Wenglor photoelectric counter, despite the minimum observable diameter being 200μm and the particle size distribution unavailable. These results must be confirmed by further experiments. The SPC-S7- estimated precipitation amount is in relatively good agreement with modeled precipitation given the many uncertainties due to the calculation hypotheses. Since the particle size distribution is not available for the simpler photoelectric counter and there are too many uncertainties and hypotheses in calculating solid precipitation, we concluded that the solid precipitation amount cannot be reliably estimated by the simple photoelectric counter.  
  Programme 1013  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0165-232X ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial (down) 8157  
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Author Claudio Tomasi, Boyan H. Petkov, Elena Benedetti doi  openurl
  Title Annual cycles of pressure, temperature, absolute humidity and precipitable water from the radiosoundings performed at Dome C, Antarctica, over the 2005–2009 period Type Journal
  Year 2012 Publication Antarctic science Abbreviated Journal  
  Volume 24 Issue 6 Pages 637-658  
  Keywords Antarctic tropopause atmospheric water radiosonde data seasonal temperatures temperature inversion  
  Abstract A four-year set of vertical profiles of pressure, temperature and relative humidity derived from 1113 radiosoundings performed at Dome C (Antarctica) at 12h00 UT of each day, from late March 2005 to the end of March 2009, was examined by following a complex procedure for removing the most important lag errors and dry biases from the temperature and moisture data. The analysis provides evidence of annual cycles over the four years, characterizing the pressure and temperature conditions at the surface and at the various troposphere and low stratosphere levels, with maxima in summer and wide minima in winter for both parameters. Specific studies of the thermal parameters characterizing the ground layer and the tropopause region are also presented to describe their annual average variations. The analysis of moisture parameters indicates that absolute humidity varies regularly with season within the low troposphere, presenting well marked peaks in the summer months. Consequently, precipitable water was found to vary regularly during the year, from values of 0.2–0.4 mm in the winter to more than 0.6 mm in summer. The main year-to-year variations characterizing the monthly mean vertical profiles of pressure, temperature and moisture parameters are also described.  
  Programme 1013  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0954-1020, 1365-2079 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial (down) 8156  
Permanent link to this record
 

 
Author Carsten Abraham, Adam H. Monahan doi  openurl
  Title Climatological Features of the Weakly and Very Stably Stratified Nocturnal Boundary Layers. Part I: State Variables Containing Information about Regime Occupation Type Journal
  Year 2019 Publication Journal of the Atmospheric Sciences Abbreviated Journal  
  Volume 76 Issue 11 Pages 3455-3484  
  Keywords  
  Abstract Abstract The atmospheric nocturnal stable boundary layer (SBL) can be classified into two distinct regimes: the weakly SBL (wSBL) with sustained turbulence and the very SBL (vSBL) with weak and intermittent turbulence. A hidden Markov model (HMM) analysis of the three-dimensional state-variable space of Reynolds-averaged mean dry static stability, mean wind speed, and wind speed shear is used to classify the SBL into these two regimes at nine different tower sites, in order to study long-term regime occupation and transition statistics. Both Reynolds-averaged mean data and measures of turbulence intensity (eddy variances) are separated in a physically meaningful way. In particular, fluctuations of the vertical wind component are found to be much smaller in the vSBL than in the wSBL. HMM analyses of these data using more than two SBL regimes do not result in robust results across measurement locations. To identify which meteorological state variables carry the information about regime occupation, the HMM analyses are repeated using different state-variable subsets. Reynolds-averaged measures of turbulence intensity (such as turbulence kinetic energy) at any observed altitude hold almost the same information as the original set, without adding any additional information. In contrast, both stratification and shear depend on surface information to capture regime transitions accurately. Use of information only in the bottom 10 m of the atmosphere is sufficient for HMM analyses to capture important information about regime occupation and transition statistics. It follows that the commonly measured 10-m wind speed is potentially a good indicator of regime occupation.  
  Programme 1013  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-4928, 1520-0469 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial (down) 8155  
Permanent link to this record
 

 
Author Carsten Abraham, Adam H. Monahan doi  openurl
  Title Climatological Features of the Weakly and Very Stably Stratified Nocturnal Boundary Layers. Part II: Regime Occupation and Transition Statistics and the Influence of External Drivers Type Journal
  Year 2019 Publication Journal of the Atmospheric Sciences Abbreviated Journal  
  Volume 76 Issue 11 Pages 3485-3504  
  Keywords  
  Abstract Abstract In a companion paper hidden Markov model (HMM) analyses have been conducted to classify the nocturnal stably stratified boundary layer (SBL) into weakly stable (wSBL) and very stable (vSBL) conditions at different tower sites on the basis of long-term Reynolds-averaged mean data. The resulting HMM regime sequences allow analysis of long-term (climatological) SBL regime statistics. In particular, statistical features of very persistent wSBL and vSBL nights, in which a single regime lasts for the entire night, are contrasted with those of nights with SBL regime transitions. The occurrence of very persistent nights is seasonally dependent and more likely in homogeneous surroundings than in regions with complex terrain. When transitions occur, their timing is not seasonally dependent, but transitions are enhanced close to sunset (for land-based sites). The regime event durations depict remarkably similar distributions across all stations with peaks in transition likelihood approximately 1–2 h after a preceding transition. At Cabauw in the Netherlands, very persistent wSBL and vSBL nights are usually accompanied by overcast conditions with strong geostrophic winds Ugeo or clear-sky conditions with weak Ugeo, respectively. In contrast, SBL regime transitions can neither be linked to magnitudes in Ugeo and cloud coverage nor to specific tendencies in Ugeo. However, regime transitions can be initiated by changes in low-level cloud cover.  
  Programme 1013  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-4928, 1520-0469 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial (down) 8154  
Permanent link to this record
 

 
Author Carsten Abraham, Adam H. Monahan doi  openurl
  Title Climatological Features of the Weakly and Very Stably Stratified Nocturnal Boundary Layers. Part III: The Structure of Meteorological State Variables in Persistent Regime Nights and across Regime Transitions Type Journal
  Year 2019 Publication Journal of the Atmospheric Sciences Abbreviated Journal  
  Volume 76 Issue 11 Pages 3505-3527  
  Keywords  
  Abstract Abstract The evolution of profiles of meteorological state variables during nights with and without transitions in the nocturnal stably stratified boundary layer (SBL) between weakly stable (wSBL) and very stable (vSBL) regimes, as classified by a hidden Markov model, is examined at nine different tower sites. During wSBL-to-vSBL transitions, inversion strengths increase, near-surface winds decelerate, and atmospheric layers vertically decouple. Turbulence kinetic energy (TKE) steadily decreases before wSBL-to-vSBL transitions and fluctuations of the vertical velocity become weak. In contrast to land-based sites where wSBL-to-vSBL transitions are normally caused by surface cooling, at sea-based stations the transitions generally are initiated by advection of warm air aloft. The vSBL-to-wSBL transition is characterized by a fast breakdown of the inversion strength, acceleration of wind profiles, and a restored vertical coupling of the atmospheric flow. TKE recovers on time scales of minutes first in atmospheric levels between 50 and 100 m. Profiles of state variables for the two different regimes during very persistent nights (nights without SBL regime transitions) are clearly separated and similar to structures during nights with transitions away from transition times. During very persistent nights the wind conditions stay relatively steady. Similarly, the temperature is steady after an initial adjustment time at sunset (wSBL) or shortly after sunset (vSBL). Even though nights with and without transitions are a common feature of the SBL, there is no clear indicator in Reynolds-averaged mean variables that distinguishes very persistent nights from nights with transitions.  
  Programme 1013  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-4928, 1520-0469 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial (down) 8153  
Permanent link to this record
 

 
Author C. Amory, F. Naaim-Bouvet, H. Gallée, E. Vignon doi  openurl
  Title Brief communication: Two well-marked cases of aerodynamic adjustment of sastrugi Type Journal
  Year 2016 Publication The Cryosphere Abbreviated Journal  
  Volume 10 Issue 2 Pages 743-750  
  Keywords  
  Abstract

Abstract. In polar regions, sastrugi are a direct manifestation of drifting snow and form the main surface roughness elements. In turn, sastrugi alter the generation of atmospheric turbulence and thus modify the wind field and the aeolian snow mass fluxes. Little attention has been paid to these feedback processes, mainly because of experimental difficulties. As a result, most polar atmospheric models currently ignore sastrugi over snow-covered regions. This paper aims at quantifying the potential influence of sastrugi on the local wind field and on snow erosion over a sastrugi-covered snowfield in coastal Adélie Land, East Antarctica. We focus on two erosion events during which sastrugi responses to shifts in wind direction have been interpreted from temporal variations in drag and aeolian snow mass flux measurements during austral winter 2013. Using this data set, it is shown that (i) neutral stability, 10 m drag coefficient (CDN10) values are in the range of 1.3–1.5 × 10−3 when the wind is well aligned with the sastrugi, (ii) as the wind shifts by only 20–30° away from the streamlined direction, CDN10 increases (by 30–120 %) and the aeolian snow mass flux decreases (by 30–80 %), thereby reflecting the growing contribution of the sastrugi form drag to the total surface drag and its inhibiting effect on snow erosion, (iii) the timescale of sastrugi aerodynamic adjustment can be as short as 3 h for friction velocities greater than 1 m s−1 and during strong drifting snow conditions and (iv) knowing CDN10 is not sufficient to estimate the snow erosion flux that results from drag partitioning at the surface because CDN10 includes the contribution of the sastrugi form drag.

 
  Programme 1013  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1994-0416 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial (down) 8152  
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