Schmidt, A.; Alard, F.; Handrich, Y. (2006). Changes in body temperatures in king penguins at sea: the result of fine adjustments in peripheral heat loss? Am. J. Physiol. Regul. Integr. Comp. Physiol., 291(3), R608–618.
Abstract: To investigate thermoregulatory adjustments at sea, body temperatures (the pectoral muscle and the brood patch) and diving behavior were monitored during a foraging trip of several days at sea in six breeding king penguins Aptenodytes patagonicus. During inactive phases at sea (water temperature: 4-7{degrees}C), all tissues measured were maintained at normothermic temperatures. The brood patch temperature was maintained at the same values as those measured when brooding on shore (38{degrees}C). This high temperature difference causes a significant loss of heat. We hypothesize that high-energy expenditure associated with elevated peripheral temperature when resting at sea is the thermoregulatory cost that a postabsorptive penguin has to face for the restoration of its subcutaneous body fat. During diving, mean pectoral temperature was 37.6 {+/-} 1.6{degrees}C. While being almost normothermic on average, the temperature of the pectoral muscle was still significantly lower than during inactivity in five out of the six birds and underwent temperature drops of up to 5.5{degrees}C. Mean brood patch temperature was 29.6 {+/-} 2.5{degrees}C during diving, and temperature decreases of up to 21.6{degrees}C were recorded. Interestingly, we observed episodes of brood patch warming during the descent to depth, suggesting that, in some cases, king penguins may perform active thermolysis using the brood patch. It is hypothesized that functional pectoral temperature may be regulated through peripheral adjustments in blood perfusion. These two paradoxical features, i.e., lower temperature of deep tissues during activity and normothermic peripheral tissues while inactive, may highlight the key to the energetics of this diving endotherm while foraging at sea.
Programme: 394
|
Fahlman, A.; Handrich, Y.; Woakes, A.J.; Bost, C.-A.; Holder, R.; Duchamp, C.; Butler, P.J. (2004). Effect of fasting on the VO2-fh relationship in king penguins, Aptenodytes patagonicus. Am. J. Physiol. Regul. Integr. Comp. Physiol., 287(4), R870–877.
Abstract: King penguins (Aptenodytes patagonicus) may fast for up to 30 days during their breeding period. As such extended fasting may affect the relationship between the rate of O2 consumption (O2) and heart rate (fH), five male king penguins were exercised at various speeds on repeated occasions during a fasting period of 24-31 days. In addition, O2 and fH were measured in the same animals during rest in cold air and water (4{degrees}C). O2 and fH at rest and O2 during exercise decreased with fasting. There was a significant relation between O2 and fH (r2 = 0.56) that was improved by including speed, body mass (Mb), number of days fasting (t), and a cross term between fH and t (r2 = 0.92). It was concluded that there was a significant change in the O2-fH relationship with fasting during exercise. As t is measurable in the field and was shown to be significant and, therefore, a practical covariate, a regression equation for use when birds are ashore was obtained by removing speed and Mb. When this equation was used, predicted O2 was in good agreement with the observed data, with an overall error of 3.0%. There was no change in the O2-fH relationship in penguins at rest in water.
Programme: 131;137;394
|
|
Alexander, C. M. O., Maurette, M., Swan, P., & Walker, R. M. (1992). Studies of Antarctic micrometeorites. Abstracts of the Lunar and Planetary Science Conference, 23, 7.
|
|
Gasparini, J., Roulin, A., Gill, V., Hatch, S.A. & Boulinier, T. (2006). In kittiwakes food availability partially explains the seasonal decline in humoral immunocompetence. Functional ecology, 20, 457–463.
|
|
Gasparini, J., McCoy, K.D., Staszewski, V., Haussy, C. & Boulinier, T. (2006). Dynamics of anti-Borrelia antibodies in kittiwake chicks (Rissa tridactyla) suggests a maternal educational effect. Can. J. Zool., 84, 623–627.
|
Boulinier, T., Betoulle, S., Caza, F., St Pierre, Y., Tornos, J., Gamble, A. &Amp; Tasiemski, A. (2020). Panorama des recherches et des derniers résultats sur les pathogènes en milieu polaire. Bachelor's thesis, , .
Abstract: Approches complémentaires des interactions hôte-parasite en zones polaire: de la détection de parasites et agents infectieux à l'étude fonctionnelle, écologique et évolutive de leurs interactions avec leurs hôtes.
Programme: 333,1151
|
Viblanc Va, Stier A, Bize P, Schull Q, Criscuolo F, Groscolas R, Robin Jp. (2021). The ecophysiology of king penguins : responses to a fluctuating environment. Bachelor's thesis, , .
Abstract: Penguins are sea...birds. These highly evolved marine predators thrive in the oceanic habitat. Yet, they are conflicted – confronted to the duality of a life spent partly at sea, partly on-land. This life style has them subject to a number of very different ecological pressures. The ECONERGY polar project (IPEV #119) seeks to understand how king penguin cope with the constraints they face while living on-land, and the underlying physiological adaptations that allow them to do so. This includes studies dealing with fasting, parasites, predators, aggressive neighbors, climate and human disturbance. I will present some of the advances our project has made over the past decades, and where we will proceed in the years to come with a new project. We aim to understand bird stress from an integrative perspective, building a long-term observatory of penguin physiological responses to a changing world, and determining how breeding performances on land and foraging performances at sea are related.
Programme: 119
|
Cécile Agosta, Charles Amory, Christoph Kittel, Anais Orsi, Vincent Favier, Hubert Gallée, Michiel R. van den Broeke, Jan T. M. Lenaerts, Jan Melchior van Wessem, Willem Jan van de Berg, Xavier Fettweis. (2019). Estimation of the Antarctic surface mass balance using the regional climate model MAR (1979–2015) and identification of dominant processes (Vol. 13). Bachelor's thesis, , .
Abstract: The Antarctic Ice Sheet Mass Balance Is A Major Component Of The Sea Level Budget And Results From The Difference Of Two Fluxes Of A Similar Magnitude: Ice Flow Discharging In The Ocean And Net Snow Accumulation On The Ice Sheet Surface, I.e. The Surface Mass Balance (Smb). Separately Modelling Ice Dynamics And Smb Is The Only Way To Project Future Trends. In Addition, Mass Balance Studies Frequently Use Regional Climate Models (Rcms) Outputs As An Alternative To Observed Fields Because Smb Observations Are Particularly Scarce On The Ice Sheet. Here We Evaluate New Simulations Of The Polar Rcm Mar Forced By Three Reanalyses, Era-interim, Jra-55, And Merra-2, For The Period 1979–2015, And We Compare Mar Results To The Last Outputs Of The Rcm Racmo2 Forced By Era-interim. We Show That Mar And Racmo2 Perform Similarly Well In Simulating Coast-to-plateau Smb Gradients, And We Find No Significant Differences In Their Simulated Smb When Integrated Over The Ice Sheet Or Its Major Basins. More Importantly, We Outline And Quantify Missing Or Underestimated Processes In Both Rcms. Along Stake Transects, We Show That Both Models Accumulate Too Much Snow On Crests, And Not Enough Snow In Valleys, As A Result Of Drifting Snow Transport Fluxes Not Included In Mar And Probably Underestimated In Racmo2 By A Factor Of 3. Our Results Tend To Confirm That Drifting Snow Transport And Sublimation Fluxes Are Much Larger Than Previous Model-based Estimates And Need To Be Better Resolved And Constrained In Climate Models. Sublimation Of Precipitating Particles In Low-level Atmospheric Layers Is Responsible For The Significantly Lower Snowfall Rates In Mar Than In Racmo2 In Katabatic Channels At The Ice Sheet Margins. Atmospheric Sublimation In Mar Represents 363 Gt Yr−1 Over The Grounded Ice Sheet For The Year 2015, Which Is 16 % Of The Simulated Snowfall Loaded At The Ground. This Estimate Is Consistent With A Recent Study Based On Precipitation Radar Observations And Is More Than Twice As Much As Simulated In Racmo2 Because Of Different Time Residence Of Precipitating Particles In The Atmosphere. The Remaining Spatial Differences In Snowfall Between Mar And Racmo2 Are Attributed To Differences In Advection Of Precipitation With Snowfall Particles Being Likely Advected Too Far Inland In Mar.
Programme: 411,1169
|
Tijl Verhoelst, Steven Compernolle, Gaia Pinardi, Jean-Christopher Lambert, Henk J. Eskes, Kai-Uwe Eichmann, Ann Mari Fjæraa, José Granville, Sander Niemeijer, Alexander Cede, Martin Tiefengraber, François Hendrick, Andrea Pazmiño, Alkiviadis Bais, Ariane Bazureau, K. Folkert Boersma, Kristof Bognar, Angelika Dehn, Sebastian Donner, Aleksandr Elokhov, Manuel Gebetsberger, Florence Goutail, Michel Grutter de la Mora, Aleksandr Gruzdev, Myrto Gratsea, Georg H. Hansen, Hitoshi Irie, Nis Jepsen, Yugo Kanaya, Dimitris Karagkiozidis, Rigel Kivi, Karin Kreher, Pieternel F. Levelt, Cheng Liu, Moritz Müller, Monica Navarro Comas, Ankie J. M. Piters, Jean-Pierre Pommereau, Thierry Portafaix, Olga Puentedura, Richard Querel, Julia Remmers, Andreas Richter, John Rimmer, Claudia Rivera Cárdenas, Lidia Saavedra de Miguel, Valery P. Sinyakov, Kimberley Strong, Michel Van Roozendael, J. Pepijn Veefkind, Thomas Wagner, Folkard Wittrock, Margarita Yela González, Claus Zehner. (2020). Ground-based validation of the Copernicus Sentinel-5p TROPOMI NO2 measurements with the NDACC ZSL-DOAS, MAX-DOAS and Pandonia global networks. Bachelor's thesis, , .
Abstract: This Paper Reports On Consolidated Ground-based Validation Results Of The Atmospheric No2 Data Produced Operationally Since April 2018 By The Tropomi Instrument On Board Of The Esa/eu Copernicus Sentinel-5 Precursor (S5p) Satellite. Tropospheric, Stratospheric, And Total No2 Column Data From S5p Are Compared To Correlative Measurements Collected From, Respectively, 19 Multi-axis Doas (Max-doas), 26 Ndacc Zenith-scattered-light Doas (Zsl-doas), And 25 Pgn/pandora Instruments Distributed Globally. The Validation Methodology Gives Special Care To Minimizing Mismatch Errors Due To Imperfect Spatio-temporal Co-location Of The Satellite And Correlative Data, E.g., By Using Tailored Observation Operators To Account For Differences In Smoothing And In Sampling Of Atmospheric Structures And Variability, And Photochemical Modelling To Reduce Diurnal Cycle Effects. Compared To The Ground-based Measurements, S5p Data Show, On An Average: (I) A Negative Bias For The Tropospheric Column Data, Of Typically −23 To −37 % In Clean To Slightly Polluted Conditions, But Reaching Values As High As −51 % Over Highly Polluted Areas; (Ii) A Slight Negative Bias For The Stratospheric Column Data, Of About −0.2 Pmolec/cm2, I.e. Approx. −2 % In Summer To −15 % In Winter; And (Iii) A Bias Ranging From Zero To −50 % For The Total Column Data, Found To Depend On The Amplitude Of The Total No2 Column, With Small To Slightly Positive Bias Values For Columns Below 6 Pmolec/cm2 And Negative Values Above. The Dispersion Between S5p And Correlative Measurements Contains Mostly Random Components, Which Remain Within Mission Requirements For The Stratospheric Column Data (0.5 Pmolec/cm2), But Exceed Those For The Tropospheric Column Data (0.7 Pmolec/cm2). While A Part Of The Biases And Dispersion May Be Due To Representativeness Differences, It Is Known That Errors In The S5p Tropospheric Columns Exist Due To Shortcomings In The (Horizontally Coarse) A-priori Profile Representation In The Tm5-mp Chemistry Transport Model Used In The S5p Retrieval, And To A Lesser Extent, To The Treatment Of Cloud Effects. Although Considerable Differences (Up To 2 Pmolec/cm2 And More) Are Observed At Single Ground-pixel Level, The Near-real-time (Nrti) And Off-line (Offl) Versions Of The S5p No2 Operational Data Processor Provide Similar No2 Column Values And Validation Results When Globally Averaged, With The Nrti Values Being On Average 0.79 % Larger Than The Offl Values.
Programme: 209
|
Franz Slemr, Lynwill Martin, Casper Labuschagne, Thumeka Mkololo, Hélène Angot, Olivier Magand, Aurélien Dommergue, Philippe Garat, Michel Ramonet, Johannes Bieser. (2020). Atmospheric mercury in the Southern Hemisphere – Part 1: Trend and inter-annual variations in atmospheric mercury at Cape Point, South Africa, in 2007–2017, and on Amsterdam Island in 2012–2017 (Vol. 20). Bachelor's thesis, , .
Abstract: The Minamata Convention On Mercury (Hg) Entered Into Force In 2017, Committing Its 116 Parties (As Of January 2019) To Curb Anthropogenic Emissions. Monitoring Of Atmospheric Concentrations And Trends Is An Important Part Of The Effectiveness Evaluation Of The Convention. A Few Years Ago (In 2017) We Reported An Increasing Trend In Atmospheric Hg Concentrations At The Cape Point Global Atmosphere Watch (Gaw) Station In South Africa (34.3535∘ S, 18.4897∘ E) For The 2007–2015 Period. With 2 More Years Of Measurements At Cape Point And The 2012–2017 Data From Amsterdam Island (37.7983∘ S, 77.5378∘ E) In The Remote Southern Indian Ocean, A More Complex Picture Emerges: At Cape Point The Upward Trend For The 2007–2017 Period Is Still Significant, But No Trend Or A Slightly Downward Trend Was Detected For The Period 2012–2017 At Both Cape Point And Amsterdam Island. The Upward Trend At Cape Point Is Driven Mainly By The Hg Concentration Minimum In 2009 And Maxima In 2014 And 2012. Using Ancillary Data On 222rn, Co, O3, Co2, And Ch4 From Cape Point And Amsterdam Island, The Possible Reasons For The Trend And Its Change Are Investigated. In A Companion Paper This Analysis Is Extended For The Cape Point Station By Calculations Of Source And Sink Regions Using Backward-trajectory Analysis.
Programme: 416,1028
|
