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Ocean Surface Topography Altimetry by Large Baseline Cross-Interferometry from Satellite Formation
remote sensing Article Ocean Surface Topography Altimetry by Large Baseline Cross-Interferometry from Satellite Formation Weiya Kong 1,2, Bo Liu 2,*, Xiaohong Sui 2, Running Zhang 3 and Jinping Sun 1 1 School of Electronic and Information Engineering, Beihang University, Beijing 100191, China; [email protected] (W.K.); [email protected] (J.S.) 2 Qian Xuesen Laboratory of Space and Technology, Beijing 100094, China; [email protected] 3 Beijing Institute of Spacecraft System Engineering, Beijing 100094, China; [email protected] * Correspondence: [email protected]; Tel.: +86-010-6811-3401 Received: 21 September 2020; Accepted: 26 October 2020; Published: 27 October 2020 Abstract: Imaging Radar Altimeter (IRA) is the current development tendency for ocean surface topography (OST) altimetry,which utilizes Synthetic Aperture Radar (SAR) and interferometry to improve the spatial resolution of OST to several kilometers or even better. Meanwhile, centimetric altimetry accuracy should be guaranteed for applications such as geostrophic currents or marine gravity anomaly inversion. However, the baseline length of IRA which determines the altimetric sensitivity is confined by the satellite platform, in consideration of baseline vibration and payload capability. Therefore, the baseline length from a single satellite can extend to only tens of meters, making it difficult to achieve centimetric accuracy. Referring to the successful experience from TerraSAR-X/TanDEM-X, satellite formation can easily extend the baseline length to hundreds or thousands of meters, depending on the helix orbit. Therefore, we propose the large baseline IRA (LB-IRA) from satellite formation for OST altimetry: the carrier frequency shift (CFS) is brought in to compensate for the severe baseline decorrelation, and the helix orbit is carefully selected to prevent severe time decorrelation from along-track baseline. -
Role of Regional Ocean Dynamics in Dynamic Sea Level Projections by the End of the 21St Century Over Southeast Asia
EGU21-8618, updated on 25 Sep 2021 https://doi.org/10.5194/egusphere-egu21-8618 EGU General Assembly 2021 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Role of Regional Ocean Dynamics in Dynamic Sea Level Projections by the end of the 21st Century over Southeast Asia Dhrubajyoti Samanta1, Svetlana Jevrejeva2, Hindumathi K. Palanisamy2, Kristopher B. Karnauskas3, Nathalie F. Goodkin1,4, and Benjamin P. Horton1 1Nanyang Technological University, Singapore ([email protected]) 2Centre for Climate Research Singapore, Singapore 3University of Colorado Boulder, USA 4American Museum of Natural History, USA Southeast Asia is especially vulnerable to the impacts of sea-level rise due to the presence of many low-lying small islands and highly populated coastal cities. However, our current understanding of sea-level projections and changes in upper-ocean dynamics over this region currently rely on relatively coarse resolution (~100 km) global climate model (GCM) simulations and is therefore limited over the coastal regions. Here using GCM simulations from the High-Resolution Model Intercomparison Project (HighResMIP) of the Coupled Model Intercomparison Project Phase 6 (CMIP6) to (1) examine the improvement of mean-state biases in the tropical Pacific and dynamic sea-level (DSL) over Southeast Asia; (2) generate projection on DSL over Southeast Asia under shared socioeconomic pathways phase-5 (SSP5-585); and (3) diagnose the role of changes in regional ocean dynamics under SSP5-585. We select HighResMIP models that included a historical period and shared socioeconomic pathways (SSP) 5-8.5 future scenario for the same ensemble and estimate the projected changes relative to the 1993-2014 period. -
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Vol. 62 Bollettino Vol. 62 - SUPPLEMENT 1 pp. 327 di Geofisica An International teorica ed applicata Journal of Earth Sciences IMDIS 2021 International Conference on Marine Data and Information Systems 12-14 April, 2021 Online Book of Abstracts SUPPLEMENT 1 Guest Editors: Michèle Fichaut, Vanessa Tosello, Alessandra Giorgetti BOLLETTINO DI GEOFISICA teorica ed applicata 210109 - OGS.Supp.Vol62.cover_08dorso19.indd 3 03/05/21 10:54 EDITOR-IN-CHIEF D. Slejko; Trieste, Italy EDITORIAL COUNCIL SUBSCRIPTIONS 2021 A. Camerlenghi, N. Casagli, F. Coren, P. Del Negro, F. Ferraccioli, S. Parolai, G. Rossi, C. Solidoro; Trieste, Italy ASSOCIATE EDITORS A. SOLID EaRTH GeOPHYsICs N. Abu-Zeid; Ferrara, Italy J. Ba; Nanjing, China R. Barzaghi; Milano, Italy J. Boaga; Padova, Italy C. Braitenberg; Trieste, Italy A. Casas; Barcelona, Spain G. Cassiani; Padova, Italy F. Cavallini; Trieste, Italy A. Del Ben; Trieste, Italy P. dell’Aversana; San Donato Milanese, Italy C. Doglioni; Roma, Italy F. Ferrucci, Vibo Valentia, Italy E. Forte; Trieste, Italy M.-J. Jimenez; Madrid, Spain C. Layland-Bachmann, Berkeley, U.S.A. Bollettino di Geofisica Teorica ed Applicata G. Li; Zhoushan, China c/o Istituto Nazionale di Oceanografia P. Paganini; Trieste, Italy e di Geofisica Sperimentale V. Paoletti, Naples, Italy Borgo Grotta Gigante, 42/c E. Papadimitriou; Thessaloniki, Greece 34010 Sgonico, Trieste, Italy R. Petrini; Pisa, Italy e-mail: [email protected] M. Pipan; Trieste, Italy G. Seriani; Trieste, Italy http-server: bgta.eu A. Shogenova; Tallin, Estonia E. Stucchi; Milano, Italy S. Trevisani; Venezia, Italy M. Vellico; Trieste, Italy A. Vesnaver; Trieste, Italy V. Volpi; Trieste, Italy A. -
Shallow Water Waves and Solitary Waves Article Outline Glossary
Shallow Water Waves and Solitary Waves Willy Hereman Department of Mathematical and Computer Sciences, Colorado School of Mines, Golden, Colorado, USA Article Outline Glossary I. Definition of the Subject II. Introduction{Historical Perspective III. Completely Integrable Shallow Water Wave Equations IV. Shallow Water Wave Equations of Geophysical Fluid Dynamics V. Computation of Solitary Wave Solutions VI. Water Wave Experiments and Observations VII. Future Directions VIII. Bibliography Glossary Deep water A surface wave is said to be in deep water if its wavelength is much shorter than the local water depth. Internal wave A internal wave travels within the interior of a fluid. The maximum velocity and maximum amplitude occur within the fluid or at an internal boundary (interface). Internal waves depend on the density-stratification of the fluid. Shallow water A surface wave is said to be in shallow water if its wavelength is much larger than the local water depth. Shallow water waves Shallow water waves correspond to the flow at the free surface of a body of shallow water under the force of gravity, or to the flow below a horizontal pressure surface in a fluid. Shallow water wave equations Shallow water wave equations are a set of partial differential equations that describe shallow water waves. 1 Solitary wave A solitary wave is a localized gravity wave that maintains its coherence and, hence, its visi- bility through properties of nonlinear hydrodynamics. Solitary waves have finite amplitude and propagate with constant speed and constant shape. Soliton Solitons are solitary waves that have an elastic scattering property: they retain their shape and speed after colliding with each other. -
Global Observations of Fine-Scale Ocean Surface Topography with the Surface Water and Ocean Topography (SWOT) Mission
fmars-06-00232 May 13, 2019 Time: 15:5 # 1 REVIEW published: 15 May 2019 doi: 10.3389/fmars.2019.00232 Global Observations of Fine-Scale Ocean Surface Topography With the Surface Water and Ocean Topography (SWOT) Mission Rosemary Morrow1*, Lee-Lueng Fu2, Fabrice Ardhuin3, Mounir Benkiran4, Bertrand Chapron3, Emmanuel Cosme5, Francesco d’Ovidio6, J. Thomas Farrar7, Sarah T. Gille8, Guillaume Lapeyre9, Pierre-Yves Le Traon4, Ananda Pascual10, Aurélien Ponte3, Bo Qiu11, Nicolas Rascle12, Clement Ubelmann13, Jinbo Wang2 and Edward D. Zaron14 1 Centre de Topographie des Océans et de l’Hydrosphère, Laboratoire d’Etudes en Géophysique et Océanographie Spatiale, CNRS, CNES, IRD, Université Toulouse III, Toulouse, France, 2 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States, 3 Laboratoire d’Océanographie Physique et Spatiale, Centre National de la Edited by: Recherche Scientifique – Ifremer, Plouzané, France, 4 Mercator Ocean, Ramonville-Saint-Agne, France, 5 Institut des Fei Chai, Géosciences de l’Environnement, Université Grenoble Alpes, Grenoble, France, 6 Sorbonne Université, CNRS, IRD, MNHN, Second Institute of Oceanography, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France, State Oceanic Administration, China 7 Woods Hole Oceanographic Institution, Woods Hole, MA, United States, 8 Scripps Institution of Oceanography, University 9 Reviewed by: of California, San Diego, La Jolla, CA, United States, Laboratoire de Météorologie Dynamique (LMD-IPSL), -
An Unconditionally Stable Scheme for the Shallow Water Equations*
810 MONTHLY WEATHER REVIEW VOLUME 128 An Unconditionally Stable Scheme for the Shallow Water Equations* MOSHE ISRAELI Computer Science Department, Technion, Haifa, Israel NAOMI H. NAIK AND MARK A. CANE Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York (Manuscript received 24 September 1998, in ®nal form 1 March 1999) ABSTRACT A ®nite-difference scheme for solving the linear shallow water equations in a bounded domain is described. Its time step is not restricted by a Courant±Friedrichs±Levy (CFL) condition. The scheme, known as Israeli± Naik±Cane (INC), is the offspring of semi-Lagrangian (SL) schemes and the Cane±Patton (CP) algorithm. In common with the latter it treats the shallow water equations implicitly in y and with attention to wave propagation in x. Unlike CP, it uses an SL-like approach to the zonal variations, which allows the scheme to apply to the full primitive equations. The great advantage, even in problems where quasigeostrophic dynamics are appropriate in the interior, is that the INC scheme accommodates complete boundary conditions. 1. Introduction is easy to code and boundary conditions for the discre- The two-dimensional linearized shallow water equa- tized equations are fairly natural to impose. At the other tions represent the evolution of small perturbations in end of the spectrum, the CP algorithm is speci®cally the ¯ow ®eld of a shallow basin on a rotating sphere. designed with the characteristics of the physics of the Our interest in these model equations arises from our equatorial ocean dynamics in mind. By separating the interest in solving for the motions in a linear beta-plane free modes into the eastward propagating Kelvin mode deep ocean. -
Climate-Change–Driven Accelerated Sea-Level Rise Detected in the Altimeter Era
Climate-change–driven accelerated sea-level rise detected in the altimeter era R. S. Nerema,1, B. D. Beckleyb, J. T. Fasulloc, B. D. Hamlingtond, D. Mastersa, and G. T. Mitchume aColorado Center for Astrodynamics Research, Ann and H. J. Smead Aerospace Engineering Sciences, Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309; bStinger Ghaffarian Technologies Inc., NASA Goddard Space Flight Center, Greenbelt, MD 20771; cNational Center for Atmospheric Research, Boulder, CO 80305; dOld Dominion University, Norfolk, VA 23529; and eCollege of Marine Science, University of South Florida, St. Petersburg, FL 33701 Edited by Anny Cazenave, Centre National d’Etudes Spatiales, Toulouse, France, and approved January 9, 2018 (received for review October 2, 2017) Using a 25-y time series of precision satellite altimeter data from acceleration estimate by 0.033 mm/y2, resulting in a final “climate- TOPEX/Poseidon, Jason-1, Jason-2, and Jason-3, we estimate the change–driven” acceleration of 0.084 mm/y2. Climate-change–driven climate-change–driven acceleration of global mean sea level over in this case means we have tried to adjust the GMSL measurements the last 25 y to be 0.084 ± 0.025 mm/y2. Coupled with the average for as many natural interannual and decadal effects as we can to try climate-change–driven rate of sea level rise over these same 25 y of to isolate the longer-term, potentially anthropogenic, acceleration–– 2.9 mm/y, simple extrapolation of the quadratic implies global mean any remaining effects are considered in the error analysis. sea level could rise 65 ± 12 cm by 2100 compared with 2005, roughly We also must consider the impact of errors in the altimeter in agreement with the Intergovernmental Panel on Climate Change measurements, especially instrument drift. -
Geophysical Fluid Dynamics, Nonautonomous Dynamical Systems, and the Climate Sciences
Geophysical Fluid Dynamics, Nonautonomous Dynamical Systems, and the Climate Sciences Michael Ghil and Eric Simonnet Abstract This contribution introduces the dynamics of shallow and rotating flows that characterizes large-scale motions of the atmosphere and oceans. It then focuses on an important aspect of climate dynamics on interannual and interdecadal scales, namely the wind-driven ocean circulation. Studying the variability of this circulation and slow changes therein is treated as an application of the theory of nonautonomous dynamical systems. The contribution concludes by discussing the relevance of these mathematical concepts and methods for the highly topical issues of climate change and climate sensitivity. Michael Ghil Ecole Normale Superieure´ and PSL Research University, Paris, FRANCE, and University of California, Los Angeles, USA, e-mail: [email protected] Eric Simonnet Institut de Physique de Nice, CNRS & Universite´ Coteˆ d’Azur, Nice Sophia-Antipolis, FRANCE, e-mail: [email protected] 1 Chapter 1 Effects of Rotation The first two chapters of this contribution are dedicated to an introductory review of the effects of rotation and shallowness om large-scale planetary flows. The theory of such flows is commonly designated as geophysical fluid dynamics (GFD), and it applies to both atmospheric and oceanic flows, on Earth as well as on other planets. GFD is now covered, at various levels and to various extents, by several books [36, 60, 72, 107, 120, 134, 164]. The virtue, if any, of this presentation is its brevity and, hopefully, clarity. It fol- lows most closely, and updates, Chapters 1 and 2 in [60]. The intended audience in- cludes the increasing number of mathematicians, physicists and statisticians that are becoming interested in the climate sciences, as well as climate scientists from less traditional areas — such as ecology, glaciology, hydrology, and remote sensing — who wish to acquaint themselves with the large-scale dynamics of the atmosphere and oceans. -
2019 Ocean Surface Topography Science Team Meeting Convene
2019 Ocean Surface Topography Science Team Meeting Convene Chicago 16 West Adams Street, Chicago, IL 60603 Monday, October 21 2019 - Friday, October 25 2019 The 2019 Ocean Surface Topography Meeting will occur 21-25 October 2019 and will include a variety of science and technical splinters. These will include a special splinter on the Future of Altimetry (chaired by the Project Scientists), a splinter on Coastal Altimetry, and a splinter on the recently launched CFOSAT. In anticipation of the launch of Jason-CS/Sentinel-6A approximately 1 year after this meeting, abstracts that support this upcoming mission are highly encouraged. Abstracts Book 1 / 259 Abstract list 2 / 259 Keynote/invited OSTST Opening Plenary Session Mon, Oct 21 2019, 09:00 - 12:35 - The Forum 12:00 - 12:20: How accurate is accurate enough?: Benoit Meyssignac 12:20 - 12:35: Engaging the Public in Addressing Climate Change: Patricia Ward Science Keynotes Session Mon, Oct 21 2019, 14:00 - 15:45 - The Forum 14:00 - 14:25: Does the large-scale ocean circulation drive coastal sea level changes in the North Atlantic?: Denis Volkov et al. 14:25 - 14:50: Marine heat waves in eastern boundary upwelling systems: the roles of oceanic advection, wind, and air-sea heat fluxes in the Benguela system, and contrasts to other systems: Melanie R. Fewings et al. 14:50 - 15:15: Surface Films: Is it possible to detect them using Ku/C band sigmaO relationship: Jean Tournadre et al. 15:15 - 15:40: Sea Level Anomaly from a multi-altimeter combination in the ice covered Southern Ocean: Matthis Auger et al. -
The Difference of Sea Level Variability by Steric Height and Altimetry In
remote sensing Letter The Difference of Sea Level Variability by Steric Height and Altimetry in the North Pacific Qianran Zhang 1, Fangjie Yu 1,2,* and Ge Chen 1,2 1 College of Information Science and Engineering, Ocean University of China, Qingdao 266100, China; [email protected] (Q.Z.); [email protected] (G.C.) 2 Laboratory for Regional Oceanography and Numerical Modeling, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266200, China * Correspondence: [email protected]; Tel.: +86-0532-66782155 Received: 4 December 2019; Accepted: 22 January 2020; Published: 24 January 2020 Abstract: Sea level variability, which is less than ~100 km in scale, is important in upper-ocean circulation dynamics and is difficult to observe by existing altimetry observations; thus, interferometric altimetry, which effectively provides high-resolution observations over two swaths, was developed. However, validating the sea level variability in two dimensions is a difficult task. In theory, using the steric method to validate height variability in different pixels is feasible and has already been proven by modelled and altimetry gridded data. In this paper, we use Argo data around a typical mesoscale eddy and altimetry along-track data in the North Pacific to analyze the relationship between steric data and along-track data (SD-AD) at two points, which indicates the feasibility of the steric method. We also analyzed the result of SD-AD by the relationship of the distance of the Argo and the satellite in Point 1 (P1) and Point 2 (P2), the relationship of two Argo positions, the relationship of the distance between Argo positions and the eddy center and the relationship of the wind. -
MAR 542 – Fundamentals of Atmosphere and Ocean Dynamics Instructor: Marat Khairoutdinov Room: 158 Endeavour Time: Tuesdays and Thursday 11:30 AM – 12:50 PM
MAR 542 – Fundamentals of Atmosphere and Ocean Dynamics Instructor: Marat Khairoutdinov Room: 158 Endeavour Time: Tuesdays and Thursday 11:30 AM – 12:50 PM Text: Atmosphere, Ocean, and Climate Dynamics: An Introductory Text By John R. Marshall and R. Alan Plumb, Academic Press 2008 This course serves as an introduction to atmosphere and ocean dynamics. It is required of first-year atmospheric science graduate students, and it is recommended for first-year physical oceanography students. It assumes a working knowledge of differential and integral calculus, including partial derivatives and simple differential equations. Its purpose is to prepare students in atmospheric sciences and physical oceanography to move onto more advanced courses in these areas, as well as to acquaint each other with some fundamental aspects of dynamics applied to geophysical fluids outside your area of specialization. It is anticipated that the entire book will be covered. The chapter contents of this text are as follows, but some other topics will also be covered. 1. Characteristics of the atmosphere 2. The global energy balance 3. The vertical structure of the atmosphere 4. Convection 5. The meridional structure of the atmosphere 6. The equations of fluid motion 7. Balanced flow 8. The general circulation of the atmosphere 9. The ocean and its circulation 10. The wind-driven circulation 11. The thermohaline circulation of the ocean 12. Climate and climate variability • !"#$"%"&'"()*"+(,&-.)*/*0-",+--"1-"2*3&4"5$"6,7" • 8+9:";&<*/-"+2&=(">$"%"&'"()*"?+/()0-"-=/'+;*7" • @)*"+<*/+A*":*.()"&'"()*"&;*+9-"1-"+2&=("B"6,7" • !C$"%"&'"()*"?+/()0-"3+9:"1-"19"()*"D&/()*/9"E*,1-.)*/*7" Atmosphere is very thin: 99.9% of mass is below 50 km Compared to the Earth’s radius (6500 km), it is only 1% which is comparable to the thickness of an apple’s skin Thus, the synoptic-scale systems are quasi-two-dimensional! Vertical structure of the atmosphere Pressure (mb) 0.001 0.01 0.1 1 10 100 1000 Permanent vs. -
Lesson Plans Graphing Sea Level Slopes and Surface Currents
My NASA Data - Lesson Plans Graphing Sea Level Slopes and Surface Currents Purpose Students analyze the relationship between sea surface height and ocean surface currents by graphing sea height using satellite data. Note: This lesson is modified from NASA's TOPEX/Poseidon lesson plan. Learning Objectives Describe the use of a radar altimeter to measure sea surface height. Plot sea surface height data. Describe the relationship between the slope of the sea surface and the direction and speed of ocean surface currents. Why Does NASA Study This Phenomenon? The ocean surface is not level but has broad, gradual hills and valleys created by surface winds and density differences. Surface currents flow around the sides of these hills and valleys. Measuring this sea surface topography is a challenging task. One measuring device is the TOPEX/Poseidon radar altimeter mounted on an Earth-orbiting satellite. This device sends radar beams down to the sea surface, where they are reflected back to the satellite. The round-trip travel times for the beams allow 1 / 7 scientists to measure the satellite to sea surface distance to within a few centimeters. The satellite- derived sea surface elevations are then compared to those that the sea surface would have if the oceans were still (no currents, waves, etc.). Specifically, the elevations of the imaginary still ocean are subtracted from those calculated from the satellite's data. The height differences show where the ocean's hills and valleys are and the slope of the surface between them. The following activity uses some of these sea height differences, calculated from TOPEX/Poseidon data to investigate the relationship between sea surface topography and ocean surface currents.