2022

Informations à venir 

 

2021

Gautier, C., Langlois, A., Johnson C. A. and Sasseville, V. 2021. Étude des mouvements saisonniers du caribou de Peary (Rangifer tarandus pearyi) sur la glace de mer et les îles de l’Archipel Arctique Canadien, à l’aide d’un modèle thermodynamique de neige et des connaissances traditionnelles. Centre d’études nordiques, conférence annuelle, Février 2021.

Crevier, C., Langlois, A., Roy, A. and Derksen, C. 2021. Détection du gel/dégel du sol en Arctique à partir d’imageries radar à synthèse d’ouverture (RSO) multicapteur en bande C. Centre d’études nordiques, conférence annuelle, Février 2021.

Holtzman, N., Anderegg, L.D.L., Kraatz, S., Mavrovic, A., Sonnentag, O., Pappas, C., Cosh, M.H., Langlois, a., Lakhankar, T., Tesser, D., Steiner, N., Colliander, A., Roy, A. and Konings, G. 2021. L-band vegetation optical depth as an indicator of plant water potential in a temperate deciduous forest stand. European Geosciences Union, April 2021.

Crevier, C., Langlois, A., Roy, A. and Derksen, C. 2021. Freeze/thaw detection in arctic environment from multisensor C-band SAR time series. 42nd Canadian Symposium on Remote Sensing, June 2021.

Billecocq, P., Madore, J.-B., Wendleder, A., Montpetit, B. and Langlois, A. 2021. A multi-frequency SAR polarimetric analysis of British Columbia seasonal snowpack. 42nd Canadian Symposium on Remote Sensing, June 2021.

Sasseville, V., Langlois, A. and Brucker, L. 2021. Patterns and trend analysis of rain-on-snow events using passive microwave satellite data over the Canadian Arctic Archipelago since 1979. 42nd Canadian Symposium on Remote Sensing, June 2021.

Voglimacci CSRS2021

 

2020

Meloche, J., Royer, A., Langlois, a. Rutter, N. and Sasseville, V. 2020. Improvement of microwave emissivity of frozen Arctic soils using roughness measurements derived from automated computer vision photogrammetry. American Geophysical Union, December 2020.

Gautier, C., Langlois, A., Johnson, C.-A., Sasseville, V. 2020. Study of seasonal movements of Peary caribou (Rangifer tarandus pearyi) on sea-ice and islands of the Canadian Arctic Archipelago, using a thermodynamic model of snow and traditional Inuit knowledge, Arctic Change 2020, December 2020.

Gautier, C., Langlois, A., Johnson, C.-A., Sasseville, V., Neave, E. 2020. Study of habitat quality along Peary caribou’s migratory routes, using a thermodynamic snow model and indigenous knowledge (IK). Annual meeting: Centre d’études nordiques, Montréal, Québec, February 13-14th, 2020.

Voglimacci-Stephanopoli, J., Langlois, A., Lantuit, H.,Sasseville, V., Wendleder, A., and Stettner, S., 2019. Deriving Snow State Variables Mapping Approach Using Radar Satellite Observations and Multisource In-Situ Data. TerraSAR-X / TanDEM-X Science Team Meeting, Oberpfaffenhofen, Germany October 21 – 24th, 2019.

Voglimacci-Stephanopoli, J., Langlois, A., Lantuit, H.,Sasseville, V., Wendleder, A., and Stettner, S., 2020. Caractérisation de l’état du couvert nival arctique à haute résolution au moyen de TerraSAR-X (bande X): étude du cas Qikitaruk-Herschel (Yukon). Annual meeting: Centre d’études nordiques, Montréal, Québec, February 13-14th, 2020.

Sasseville, V., Gautier, C., Langlois, A., Théau, J and Johnson, C-A. 2020. Implementation of a habitat quality index for the Peary caribou using snow geophysical properties retrived from satellite remote sensing and modeling. Annual meeting: Centre d’études nordiques, Montréal, Québec, February 13-14th, 2020.

Blanchette, A., Madore, J.B., Langlois, A. and Billecocq, P. 2020. Sensibilité  du  modèle  SNOWPACK  à  la  paramétrisation  de  la  phase  de  précipitation  dans  un contexte de stabilité du couvert nival. Annual meeting: Centre d’études nordiques, Montréal, Québec, February 13-14th, 2020.

Mavrovic, A., Roy, A., Lemmetyinen, J., Langlois, A. and Sonnentag, O. 2020. Suivi des flux de carbone hivernaux en régions arctiques par télédétection. Annual meeting: Centre d’études nordiques, Montréal, Québec, February 13-14th, 2020.

 

2019

Kramer, D., Meloche, J., Langlois, A., Royer, A., Cliché, P. and McLennan, D. Describing Arctic snow and ice with a small Ka-band radar. Eastern Snow Conference, Lake Morey, VT, June 2019.

Couture, G., Langlois, A., Howell, S. and Montpetit, B. Spatiotemporal polynya formation trends in the Canadian Arctic Archipelago using sea ice charts from 1968 onwards. Eastern Snow Conference, Lake Morey, VT, June 2019.

Meloche, J., Kramer, D., Langlois, A. and Royer, A. High resolution snow depth mapping with Unmanned Aerial Vehicle (UAV) using Structure-from-Motion (SfM) and kinematic dGPS: Comparison of two methods for arctic application. Eastern Snow Conference, Lake Morey, VT, June 2019.

Holtzman, N., Anderegg, L.D., Kraatz, S., Mavrovic, A., Roy, A., Sonnentag, O., Pappas, C., Cosh, M.H., Steiner, N., Langlois, A., Lakhankar, T., Colliander, A., and Konings, A.G. 2019. Microwave Radiometry for Remote Sensing of Plant Water Status Dynamics: Stand-Scale Evaluation in a Temperate Deciduous Forest. American Geophysical Union, San Francisco, USA, December 9-13 2019.

Langlois, A., Johnson, C.-A., Dolant, C., Martineau, C., Brucker, L. and Royer, A. 2019. An Overview of Monitoring Winter Extreme Events using Remote Sensing and Modeling in the Arctic: an Ecological Perspective for Ungulates Habitat Characterization. American Geophysical Union, San Francisco, USA, December 9-13 2019.

 

2018

Langlois, A., Dolant, C., Montpetit, B., Brucker, L., Roy, A. and Royer, A. 2018. Changing Arctic Snow Cover: Rain-on-Snow and Ice Layer Detection. International Symposium on Cryosphere and Biosphere. Kyoto, Japan, March 14-19 2018.

Royer, A., Larue, F., Vargel, C., Roy, A., Langlois, A., Vionnet, V., Picard, G. and Cosme, E. 2018. Improved subarctic and arctic SWE retrieval using passive microwave over Canada. POLAR 2018, Davos, Switzerland, June 2018.

Kramer, D., Langlois, A., Royer, A. and McLennan, D. 2018. Retrieving ice parameters with a UAV-mounted RADAR. POLAR 2018, Davos, Switzerland, June 2018.

Vuyovich, C., Langlois, A., Roy, A., Letcher, t., Jacobs, J., Parno, J., Kraatz, S., Courville, Z. and Cho, E. 2018 Hubbard Brook Field Experiment: Snow observations in a north-eastern U.S. forested region. Eastern Snow Conference, College Park, Maryland, USA, June 2018.

Letcher, T., Vuyovich, C., Langlois, A. and Roy, A. 2018. Improving the understanding and uncertainty of snow radiative transfer modeling using snowpack information of varying complexity. Eastern Snow Conference, College Park, Maryland, USA, June 2018.

Roy, A., Langlois, A., Dolant, C., Brucker, L. and Royer, A. 2018. SnowEx 2017 In-situ passive microwave measurements: analysis of wet snow microwave emission. International Geoscience and Remote Sensing Symposium, Valencia, Spain, July 2018.

Brucker, L. et al. 2018. NASA SnowEx’17 in-situ measurements and ground-based remote sensing. International Geoscience and Remote Sensing Symposium, Valencia, Spain, July 2018.

Roy, A., Langlois, A., Dolant, C., Brucker, L. and Royer, A. 2018. SnowEx 2017 In-situ passive microwave measurements: Analysis of wet snow microwave emission. 75^th Eastern Snow Conference, Washington, June 2018.

Couture, G., Langlois, A., Howell, S. and Montpetit, B. 2018. Development of a polynya climatology in the Canadian Arctic Archipelago using RADARSAT imagery from 1997 to 2018. ArcticNet Annual Meeting, Ottawa, December 2018.

Gautier, C., Langlois, A., Johnson, C.-A. and Martineau, C. 2018. Study of habitat quality and migratory patterns of Peary caribou (Rangifer tarandus pearyi) using a thermodynamic model of snow and traditional knowledge. ArcticNet Annual Meeting, Ottawa, December 2018.

Kramer, D., Meloche, J., Langlois, A. and McLennan, D. 2018. Developing a low-cost DIY unmanned-aerial-vehicle (UAV) for arctic snow and ice monitoring. ArcticNet Annual Meeting, Ottawa, December 2018.

Levasseur, S., Langlois, A. and Brown, K. 2018. Modeling snowmelt runoff and analysis of its impact on geochemical elements transport in the Arctic. ArcticNet Annual Meeting, Ottawa, December 2018.

Meloche, J., Kramer, D. and Langlois, A. 2018. High resolution mapping of snow depth using UAS and kinematic dGPS in the Canadian Arctic. ArcticNet Annual Meeting, Ottawa, December 2018.

Sasseville, V., Langlois, A., Théau, J. and Royer, A. 2018. Implementation of a habitat quality index for the Peary caribou using snow geophysical properties retrieved from satellite remote sensing and modeling. ArcticNet Annual Meeting, Ottawa, December 2018.

Voglimacci, J., Langlois, A. and Lantuit, H. 2018. Development of a snow depth mapping approach using radar satellite data and multisource in-situ data. ArcticNet Annual Meeting, Ottawa, December 2018.

Madore, J.-B., Mavrovic, A., Langlois, A., Laliberté, J. and Royer, A. 2018. Testing and comparing a new 1.2 GHz coaxial sensor for liquid water content in snow. International Snow Science Workshop, Innsbruck, Austria, October 2018.

Laliberté, J., Langlois, A., Royer, A., Madore, J.-B. and Gauthier, F. 2018. Retrieving snow stratigraphic information using a frequency modulated continuous wave (FMCW) Ka-band radar. International Snow Science Workshop, Innsbruck, Austria, October 2018.

 

2017

Langlois, A., Roy, A., Derksen, C.., Lundquist, J., Marsh, P., Kelly, R., Pomeroy, J., Royer, A., Belair, S., Garnaud, C., Carrera, M. and Brucker, L. 2017. Overview of SnowEx 2017 in-situ passive microwave measurements : a context for SWE assimilation. SnowEx scientific meeting, Longmont, CO, August 2017.

Dolant, C., Langlois, A., Brucker, L., Royer, A., Roy, A. and Montpetit, B. 2017. Detection and evolution of rain-on-snow events in the Canadian Arctic Archipelago using passive microwave radiometry. Eastern Snow conference, Ottawa, ON, June 2017.

Madore, J.-B., Langlois, A., Van Wierts, S., and Borghini, S. 2017. Identification of snow accumulation zones and cornices using LiDAR Unmanned Aerial Vehicles (UAVs) in an avalanche forecasting context: A case study. Eastern Snow conference, Ottawa, ON, June 2017.

Kramer, D. and Langlois, A. 2017. Snow Depth retrieval via Unmanned Aerial Vehicles (UAV). Eastern Snow conference, Ottawa, ON, June 2017.

Martineau, C., Langlois, F., Johnson, C.-A., Neave, E. and Ouellet, F. 2017. Adaptation and validation of the SNOWPACK model to Arctic conditions. Eastern Snow conference, Ottawa, ON, June 2017.

Dolant, C., Langlois, A., Brucker, L., Royer, A., Roy, A. and Montpetit, B. 2017. Meteorological inventory of rain-on-snow events and detection assessment in the canadian arctic archipelago using passive microwave radiometry. IEEE International Geoscience and Remote Sensing Symposium, Fort Worth, Texas, July 2017.

Brucker, L., …, Langlois, A. and co-authors. 2017. A first overview of SnowEx ground-based remote sensing activities.  IEEE International Geoscience and Remote Sensing Symposium, Fort Worth, Texas, July 2017.

 

2016

Madore, J.-B. and Langlois, A. 2016. Evaluation of SNOWPACK metamorphism and microstructure in a Canadian context: A case study for snow stability assessment. International Snow Science Worksop, Breckenridge, CO, October 2016.

Langlois, A. and the Snow school team. 2016. 2nd European Snow Science Winter School. Eastern Snow Conference, Columbus, OH, June 2016.

Langlois, A., Johnson, C.-A., Montpetit, B., Royer, A., Richerds, A., Neave, E., Dolant, C., Roy, A., Arhonditis, g., Kim, D.K., Kaluskar, S. and Brucker, L. 2016. Detection of rain-on-snow (ROS) events and ice layer formation using passive microwave radiometry: A context for Peary caribou habitat in the Canadian Arctic. Eastern Snow Conference, Columbus, OH, June 2016.

Langlois A., and the iSWGR Team. 2016. NASA (international) Snow Working Group for Remote Sensing: iSWGR. Eastern Snow Conference, Columbus, OH, June 2016.

St-Jean Rondeau, O., Royer, A., Roy, A., Langlois, A. and Madore, J.-B. 2016. Parameterization of snow microstructure for passive microwave radiometry. Eastern Snow Conference, Columbus, OH, June 2016.

Dolant C. 1, 2, Langlois A.1, 2, Brucker L.,3, 4, Montpetit B.5 and Royer A.1, 2. 2016. Detection of raon-on-snow events in the Canadian Arctic archipelago between 1980-2014 using passive microwave radiometry. Eastern Snow Conference, Columbus, OH, June 2016.

Langlois, A., Royer, A., Montpetit, B. and Roy, A.2016. Snow grain size and shape distributions in northern Canada. American Geophysical union Fall meeting, San Francisco, CA, December 2016.

Royer, A., Marchand, N., Ottlé, C., Krinner, G., Roy, A. and Langlois, A. 2016. Continuous ground surface temperature measurements over the Arctic: a key parameter for the monitoring of permafrost evolution. European Space Agency Earth Observation and Cryosphere Science, Prague, Czech Republic, May 2016.

Larue, F., Royer, A., De Sève, D., Langlois, A., Roy, A. and St-Jean Rondeau, O. 2016. Simulations of a Canadian snowpack brightness temperatures  using SURFEX-Crocus. European Geosciences Union Spring meeting, Vienna, Austria, April 2016.

Roy, A., Toose, P., Derksen, c., Royer, A., Mavrovic, Berg, A., Arnold, L., Williamson, M., Rowlandson, T., Lemmetyinen, J., Langlois, A., Teltock, e. and Sonnentag, O. 2015. Analysis of L-band brightness temperatures response to freeze/thaw in two prairie environments from surface-based radiometer measurements. IEEE International Geoscience and Remote Sensing Symposium, Beijing, China, July 2016.

 

2015

Papasodoro, C., Royer, A., Langlois, A. and Berthier, E. 2015. SAR RADARSAT-2 and optical Pléiades stereo imagery for monitoring the melt of Baffin Island ice caps (Nunavut, Canada). Eastern Snow Conference, Sherbrooke, Qc, June 2015.

Ouellet, F., Langlois, A., Johnson, C.-A. and Richards, A. 2015. Spatialization of the SNOWPACK Snow Model in the Canadian Arctic for Peary Caribou Winter Grazing conditions assessment. Eastern Snow Conference, Sherbrooke, Qc, June 2015.

Larue, F., Royer, A., De Sève, D., Lozac’h, L., Langlois, a., Roy, a. and Derksen, C. 2015. Preliminary validation analysis of the GlobSnow2 database over Eastern Canada.. Eastern Snow Conference, Sherbrooke, Qc, June 2015.

Côté, K., Madore, J.-B. and Langlois, A. 2015. Assessing accuracy of simulated and spatialized snow profiles from SNOWPACK and Alpine3D driven by insitu and predicted meteorological data for avalanche forecasting in Canada. Eastern Snow Conference, Sherbrooke, Qc, June 2015.

Madore, J.-B., Côté, K. and Langlois, A. 2015. Improvement of snow grain simulations from the multi-layered thermodynamic snow model SNOWPACK: implications to avalanche risk assessment.  Eastern Snow Conference, Sherbrooke, Qc, June 2015.

Busseau, B.-C., Royer, A. and Langlois, A. 2015. Analysis of the Interactions Between Snow and Shrub Ecosystem of the Taiga in Nunavik. Eastern Snow Conference, Sherbrooke, Qc, June 2015.

Langlois, A., Dolant, C., Ouellet, F., Brucker, L., Richards, A., Johnson, c.-A. and Royer, a. 2015. Changing arctic snow cover : rain-on-snow detection and caribou grazing conditions in Canada. IEEE Geoscience and Remote Sensing Society meeting, Milan, Italy, July 2015.

Roy, A., Toose, P., Derksen, C., Royer, A., Berg, a., Arnold, L., Willamson, M., Rowlandson, T., Langlois, A. and Tetlock, B. 2015. Response of L-band brightness temperatures to prairie soil and snow properties from surface-based radiometer measurements. IEEE Geoscience and Remote Sensing Society meeting, Milan, Italy, July 2015.

Langlois, A., Côté, K. and Madore, J.-B. 2015. Improving snow stability prediction through improved microstructure simulations. Canadian Avalanche Association Spring meeting, Penticton, BC, May 2015.

Ouellet, F., Langlois, A., Johnson, C.-A. and Richards, A. 2015. Spatialization of the SNOWPACK snow model in the Canadian Arctic for Peary caribou winter grazing conditions assessment. Canadian Meteorological and Oceanographic Society meeting, Whistler, BC, June 2015.

Langlois, A., Royer, A., Roy, A., St-Jean Rondeau, O., Montpetit, B., Larue, F. and Dolant, C. 2015. Avancées dans l’étude de la télédétection micro-onde du couvert nival. Association Québécoise de Télédétection congress, Québec, QC, October 2015.

Roy, A., Royer, A., Montpetit, B. and Langlois, A. 2015. Microwave snow emission modeling of boreal forest environments. . IEEE Geoscience and Remote Sensing Society meeting, Milan, Italy, July 2015.

Langlois, A., Montpetit, B., Dolant, C., Brucker, L., Ouellet, F., Johnson, C.A., Richards, A., Roy, A. and Royer, A. 2015. Rain-on-snow and ice layer formation detection using passive microwave radiometry: An arctic perspective. American Geophysical Union Fall meeting, San Francisco, CA, December 2015.

 

2014

Madore, J.-B., Côté, K. and Langlois, A. 2014. Improvement of snow grain simulations from the multi-layered thermodynamic snow model SNOWPACK : implications to avalanche risk assessment. International Snow Science Worksop, Banff, AB, Canada, October 2014.

Côté, K., Madore, J.-B. and Langlois A. 2014. Evaluating the potential of using SNOWPACK and alpine-3D in three Canadian mountain climates. International Snow Science Worksop, Banff, AB, Canada, October 2014.

Langlois, A. and the iSWGR team. 2014. NASA Snow Working Group – Remote Sensing (NASA SWGR). Eastern Snow Conference, Boone, NC, June 2014.

Dolant, C., Langlois, A., Todorovic, V., Montpetit, B., Roy, A. and Royer, A. 2014. Detection of a rain-on-snow event (ROS) using an empirical algorithm using passive microwave radiometry.  Eastern Snow Conference, Boone, NC, June 2014.

Pachon, C., Langlois, A., Royer, A., Brown, R. and Harvey, R. 2014. Improvement of the parameterization of the precipitation phase in the CRCM4 from the Canadian Land Surface Scheme (CLASS 2.7 and 3.5) in Northern Québec, Canada. Eastern Snow Conference, Boone, NC, June 2014.

Thériault, N., Royer, A., Langlois, A., Harvey, R. and Brown, R. 2014. Improving snow albedo simulations in arctic and subarctic regions with the Canadian LAnd Surface Scheme (CLASS). Eastern Snow Conference, Boone, NC, June 2014.

Royer, A., Rodrigue, S. and Langlois, A. 2014. Analysis of the joint snow and ecosystem evolutions in Nunavik tundra and taiga areas (Québec Canada) over the last 35 years using satellite data. Arctic Change 2014, Ottawa, ON, December 2014.

Royer, A., Montpetit, B. and Langlois, A. 2014. A Short-Wave Infrared Camera (SWIR cam) to retrieve the snow grain SSA and the snowpack stratigraphy. Intercomparison of Snow Grain Size Measurements Workshop. Davos, Switzerland, March 2014.

Royer, A., Roy, A., Montpetit, B. and Langlois, A. 2014. Coupling the Canadian Land Surface Scheme to a microwave model to simulate the snow microwave brightness temperature under boreal forest. Workshop on Microstructure in Snow Microwave Radiative Transfer MICROSNOW, Reading, UK, August 2014.

Brucker, L., Royer, A., Picard, G., Langlois, A. and fily, M. 2014. Simulation of Seasonal Snow Microwave TB Using Coupled Multi-Layered Snow Evolution and Microwave Emission Models. Workshop on Microstructure in Snow Microwave Radiative Transfer MICROSNOW, Reading, UK, August 2014.

 

2013

Langlois, A. and Royer, A. 2013. Improving snow properties retrievals in thermodynamic snow models for satellite remote sensing. International Snow Science Workshop, Grenoble, France, October 2013.

Langlois, A., Royer, A. and Montpetit, B. 2013. Seasonal measurements of snow physical and radiometric properties during rain-on-snow events (ROS) over Eastern Canada. IEEE Geoscience and Remote Sensing Society meeting, Melbourne, Australia, July 2013.

Royer, A., Leconte, R., Langlois, A., Trudel, M. and Goita, K. 2013. Amélioration du suivi de l’équivalent en eau du couvert nival dans un contexte hydrologique par télédétection. RHQ2013, Québec, QC, février 2013.

Royer, A., Langlois, A., Cliche, P., Marchand, N., Montpetit, B., Thériault, N., Roy, A., Lefebvre, E., Lesaffre, B., Picard, G. and Fily, M. Amélioration de la modélisation de l’émission micro-onde de la neige par un suivi saisonnier des propriétés radiométriques et in-situ de la neige à la Baie James, Québec. Association Québécoise de Télédétection congress, Rimouski, QC, September 2013.

Langlois, A., Pachon, C., Montpetit, B., Royer, A. and Roy, A. Detection of a rain-on-snow event using passive microwaves: A case study. Eastern Snow Conference, Waterloo, ON, June 2013.

 

2012

Langlois, A., Bergeron, J., Harvey, R., Brown, R., Derksen, C., and Royer, A.. 2012. Evaluating CRCM4 snow cover properties simulations from the Canadian Land Surface Scheme (CLASS 2.7 and 3.5) in Northern Québec, Canada. Eastern Snow Conference, Frost Valley, NY, June 2012.

Montpetit B., Royer, A., Roy, A., Langlois, A. and Derksen, C. 2012. Snow microwave emission modeling of ice lenses within the snowpack using the Microwave Emission Model for Layered Snowpacks (MEMLS). Eastern Snow Conference, Frost Valley, NY, June 2012.

Langlois, A., Bergeron, J., Harvey, R., Brown, R., Derksen, C., Frigon, A., Royer, A., Thériault, N., and Dupras-Tessier, O. 2012. Evaluating CRCM4 snow cover properties simulations from the Canadian Land Surface Scheme (CLASS 2.7 and 3.5) in Northern Québec, Canada. Ouranos Scientific Symposium, Montréal, QC, November 2012.

Royer, A., Langlois, A., Derksen, C., Roy, A., Montpetit, B., Bergeron, J., Picard, G., Brucker, L., Arnaud, L. and  Goïta, K. 2012. Improvements in snow monitoring using microwave space-based observations. International Polar Year Symposium, Québec, QC, April 2012.

Langlois, A., Royer, A., Derksen, C., Montpetit, B., Dupont, F. and Goïta, K. 2012. Coupling of the snow thermodynamic model SNOWPACK with the Microwave Emission Model for Layered Snowpacks (MEMLS) for subarctic and arctic Snow Water Equivalent retrievals. American Geophysical Union Fall meeting, San Francisco, CA, December 2012.

Langlois, A., Bergeron, J., Brown, R., Royer, A., Harvey, R., Wang, L., Derksen, C. 2012. Evaluating CRCM4 snow cover properties simulations from the Canadian Land Surface Scheme (CLASS 2.7 and 3.5) in Northern Québec, Canada. American Geophysical Union Fall meeting, San Francisco, CA, December 2012.

Royer, A., Langlois, A., Derksen, C., Montpetit, B., Dupont, f. and goita, K. 2012. Coupling of the snow thermodynamic model SNOWPACK with the Microwave Emission Model for Layered Snowpacks (MEMLS) for subarctic and arctic Snow Water Equivalent retrievals. American Geophysical Union Fall meeting, San Francisco, CA, December 2012.