26 results on '"John M Lyman"'
Search Results
2. CERESMIP: a climate modeling protocol to investigate recent trends in the Earth's Energy Imbalance
- Author
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Gavin A. Schmidt, Timothy Andrews, Susanne E. Bauer, Paul J. Durack, Norman G. Loeb, V. Ramaswamy, Nathan P. Arnold, Michael G. Bosilovich, Jason Cole, Larry W. Horowitz, Gregory C. Johnson, John M. Lyman, Brian Medeiros, Takuro Michibata, Dirk Olonscheck, David Paynter, Shiv Priyam Raghuraman, Michael Schulz, Daisuke Takasuka, Vijay Tallapragada, Patrick C. Taylor, and Tilo Ziehn
- Subjects
CMIP6 ,climate modeling ,earth's energy balance ,aerosols ,cloud feedbacks ,AMIP ,Environmental sciences ,GE1-350 - Abstract
The Clouds and the Earth's Radiant Energy System (CERES) project has now produced over two decades of observed data on the Earth's Energy Imbalance (EEI) and has revealed substantive trends in both the reflected shortwave and outgoing longwave top-of-atmosphere radiation components. Available climate model simulations suggest that these trends are incompatible with purely internal variability, but that the full magnitude and breakdown of the trends are outside of the model ranges. Unfortunately, the Coupled Model Intercomparison Project (Phase 6) (CMIP6) protocol only uses observed forcings to 2014 (and Shared Socioeconomic Pathways (SSP) projections thereafter), and furthermore, many of the ‘observed' drivers have been updated substantially since the CMIP6 inputs were defined. Most notably, the sea surface temperature (SST) estimates have been revised and now show up to 50% greater trends since 1979, particularly in the southern hemisphere. Additionally, estimates of short-lived aerosol and gas-phase emissions have been substantially updated. These revisions will likely have material impacts on the model-simulated EEI. We therefore propose a new, relatively low-cost, model intercomparison, CERESMIP, that would target the CERES period (2000-present), with updated forcings to at least the end of 2021. The focus will be on atmosphere-only simulations, using updated SST, forcings and emissions from 1990 to 2021. The key metrics of interest will be the EEI and atmospheric feedbacks, and so the analysis will benefit from output from satellite cloud observation simulators. The Tier 1 request would consist only of an ensemble of AMIP-style simulations, while the Tier 2 request would encompass uncertainties in the applied forcing, atmospheric composition, single and all-but-one forcing responses. We present some preliminary results and invite participation from a wide group of models.
- Published
- 2023
- Full Text
- View/download PDF
3. Evaluating Twenty-Year Trends in Earth’s Energy Flows from Observations and Reanalyses
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Norman G Loeb, Michael Mayer, Seiji Kato, John T Fasullo, Hao Zuo, Retish Senan, John M Lyman, Gregory C Johnson, and Magdalena Balmaseda
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Earth Resources And Remote Sensing - Abstract
Satellite, reanalysis, and ocean in situ data are analyzed to evaluate regional, hemispheric and global mean trends in Earth’s energy fluxes during the first twenty years of the 21st century. Regional trends in net top-of-atmosphere (TOA) radiation from the Clouds and the Earth’s Radiant Energy System (CERES), ECMWF Reanalysis 5 (ERA5), and a model similar to ERA5 with prescribed sea surface temperature (SST) and sea ice differ markedly, particularly over the Eastern Pacific Ocean, where CERES observes large positive trends. Hemispheric and global mean net TOA flux trends for the two reanalyses are smaller than CERES, and their climatological means are half those of CERES in the southern hemisphere (SH) and more than nine times larger in the northern hemisphere (NH). The regional trend pattern of the divergence of total atmospheric energy transport (TEDIV) over ocean determined using ERA5 analyzed fields is similar to that inferred from the difference between TOA and surface fluxes from ERA5 short-term forecasts. There is also agreement in the trend pattern over ocean for surface fluxes inferred as a residual between CERES net TOA flux and ERA5 analysis TEDIV and surface fluxes obtained directly from ERA5 forecasts. Robust trends are observed over the Gulf Stream associated with enhanced surface-to-atmosphere transfer of heat. Within the ocean, larger trends in ocean heating rate are found in the NH than the SH after 2005, but the magnitude of the trend varies greatly among datasets.
- Published
- 2022
- Full Text
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4. Global High-Resolution Random Forest Regression Maps of Ocean Heat Content Anomalies Using In Situ and Satellite Data
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John M. Lyman and Gregory C. Johnson
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Atmospheric Science ,Ocean Engineering - Abstract
The ocean, with its low albedo and vast thermal inertia, plays key roles in the climate system, including absorbing massive amounts of heat as atmospheric greenhouse gas concentrations rise. While the Argo array of profiling floats has vastly improved sampling of ocean temperature in the upper half of the global ocean volume since the mid-2000s, they are not sufficient in number to resolve eddy scales in the oceans. However, satellite sea surface temperature (SST) and sea surface height (SSH) measurements do resolve these scales. Here we use random forest regressions to map ocean heat content anomalies (OHCA) using in situ training data from Argo and other sources on a 7-day × 1/4° × 1/4° grid with latitude, longitude, time, SSH, and SST as predictors. The maps display substantial patterns on eddy scales, resolving variations of ocean currents and fronts. During the well-sampled Argo period, global integrals of these maps reduce noise relative to estimates based on objective mapping of in situ data alone by roughly a factor of 3 when compared to time series of CERES (satellite data) top-of-the-atmosphere energy flux measurements and improve correlations of anomalies with CERES on annual time scales. Prior to and early on in the Argo period, when in situ data were sparser, global integrals of these maps retain low variance, and do not relax back to a climatological mean, avoiding potential deficiencies of various methods for infilling data-sparse regions with objective maps by exploiting temporal and spatial patterns of OHCA and its correlations with SST and SSH. Significance Statement We use a simple machine learning technique to improve maps of subsurface ocean warming by exploiting the relationships between subsurface ocean temperature both sea surface temperature and sea level. Mapping ocean warming is important because it contributes to sea level rise through thermal expansion; impacts marine life through marine heatwaves and changes in mixing, oxygen, and carbon dioxide levels; increases energy available to tropical cyclones; and stores most of the energy building up in Earth’s climate system owing to the accumulation of anthropogenic greenhouse gases in the atmosphere. Our new estimates generally have lower noise energy and higher correlations than other products when compared with global energy fluxes at the top of the atmosphere measured by satellite.
- Published
- 2023
5. State of the Climate in 2020: Global Oceans
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Gregory C Johnson, Rick Lumpkin, Simone R Alin, Dillon J Amaya, Molly O Baringer, Tim Boyer, Peter Brandt, Brendan R Carter, Ivona Cetinić, Don P Chambers, Lijing Cheng, Andrew U Collins, Cathy Cosca, Ricardo Domingues, Shenfu Dong, Richard A Feely, Eleanor Frajka-Williams, Bryan A Franz, John Gilson, Gustavo Goni, Benjamin D Hamlington, Josefine Herrford, Zeng-Zhen Hu, Boyin Huang, Masayoshi Ishii, Svetlana Jevrejeva, John J Kennedy, Marion Kersalé, Rachel E Killick, Peter Landschützer, Matthias Lankhorst, Eric Leuliette, Ricardo Locarnini, John M Lyman, John J Marra, Christopher S Meinen, Mark A Merrifield, Gary T Mitchum, Ben I Moat, R Steven Nerem, Renellys C Perez, Sarah G Purkey, James Reagan, Alejandra Sanchez-Franks, Hillary A Scannell, Claudia Schmid, Joel P Scott, David A Siegel, David A Smeed, Paul W Stackhouse, William Sweet, Philip R Thompson, Joaquin A Triñanes, Denis L Volkov, Rik Wanninkhof, Robert A Weller, Caihong Wen, Toby K Westberry, Matthew J Widlansky, Anne C Wilber, Lisan Yu, and Huai-Min Zhang
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Meteorology and Climatology - Abstract
This chapter details 2020 global patterns in select observed oceanic physical, chemical, and biological variables relative to long-term climatologies, their differences between 2020 and 2019, and puts 2020 observations in the context of the historical record. In this overview we address a few of the highlights, first in haiku, then paragraph form: La Niña arrives, shifts winds, rain, heat, salt, carbon: Pacific—beyond. Compiled by NOAA’s National Centers for Environmental Information, "State of the Climate in 2020" is based on contributions from scientists from around the world. It provides a detailed update on global climate indicators, notable weather events, and other data collected by environmental monitoring stations and instruments located on land, water, ice, and in space. The full report is available from: https://doi.org/10.1175/2021BAMSStateoftheClimate.1.
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- 2021
- Full Text
- View/download PDF
6. Argo Data 1999–2019: Two Million Temperature-Salinity Profiles and Subsurface Velocity Observations From a Global Array of Profiling Floats
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Annie P. S. Wong, Susan E. Wijffels, Stephen C. Riser, Sylvie Pouliquen, Shigeki Hosoda, Dean Roemmich, John Gilson, Gregory C. Johnson, Kim Martini, David J. Murphy, Megan Scanderbeg, T. V. S. Udaya Bhaskar, Justin J. H. Buck, Frederic Merceur, Thierry Carval, Guillaume Maze, Cécile Cabanes, Xavier André, Noé Poffa, Igor Yashayaev, Paul M. Barker, Stéphanie Guinehut, Mathieu Belbéoch, Mark Ignaszewski, Molly O'Neil Baringer, Claudia Schmid, John M. Lyman, Kristene E. McTaggart, Sarah G. Purkey, Nathalie Zilberman, Matthew B. Alkire, Dana Swift, W. Brechner Owens, Steven R. Jayne, Cora Hersh, Pelle Robbins, Deb West-Mack, Frank Bahr, Sachiko Yoshida, Philip J. H. Sutton, Romain Cancouët, Christine Coatanoan, Delphine Dobbler, Andrea Garcia Juan, Jerôme Gourrion, Nicolas Kolodziejczyk, Vincent Bernard, Bernard Bourlès, Hervé Claustre, Fabrizio D'Ortenzio, Serge Le Reste, Pierre-Yve Le Traon, Jean-Philippe Rannou, Carole Saout-Grit, Sabrina Speich, Virginie Thierry, Nathalie Verbrugge, Ingrid M. Angel-Benavides, Birgit Klein, Giulio Notarstefano, Pierre-Marie Poulain, Pedro Vélez-Belchí, Toshio Suga, Kentaro Ando, Naoto Iwasaska, Taiyo Kobayashi, Shuhei Masuda, Eitarou Oka, Kanako Sato, Tomoaki Nakamura, Katsunari Sato, Yasushi Takatsuki, Takashi Yoshida, Rebecca Cowley, Jenny L. Lovell, Peter R. Oke, Esmee M. van Wijk, Fiona Carse, Matthew Donnelly, W. John Gould, Katie Gowers, Brian A. King, Stephen G. Loch, Mary Mowat, Jon Turton, E. Pattabhi Rama Rao, M. Ravichandran, Howard J. Freeland, Isabelle Gaboury, Denis Gilbert, Blair J. W. Greenan, Mathieu Ouellet, Tetjana Ross, Anh Tran, Mingmei Dong, Zenghong Liu, Jianping Xu, KiRyong Kang, HyeongJun Jo, Sung-Dae Kim, and Hyuk-Min Park
- Subjects
global ,ocean ,pressure ,temperature ,salinity ,Argo ,Science ,General. Including nature conservation, geographical distribution ,QH1-199.5 - Abstract
In the past two decades, the Argo Program has collected, processed, and distributed over two million vertical profiles of temperature and salinity from the upper two kilometers of the global ocean. A similar number of subsurface velocity observations near 1,000 dbar have also been collected. This paper recounts the history of the global Argo Program, from its aspiration arising out of the World Ocean Circulation Experiment, to the development and implementation of its instrumentation and telecommunication systems, and the various technical problems encountered. We describe the Argo data system and its quality control procedures, and the gradual changes in the vertical resolution and spatial coverage of Argo data from 1999 to 2019. The accuracies of the float data have been assessed by comparison with high-quality shipboard measurements, and are concluded to be 0.002°C for temperature, 2.4 dbar for pressure, and 0.01 PSS-78 for salinity, after delayed-mode adjustments. Finally, the challenges faced by the vision of an expanding Argo Program beyond 2020 are discussed.
- Published
- 2020
- Full Text
- View/download PDF
7. Ocean Warming: From the Surface to the Deep in Observations and Models
- Author
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Paul J. Durack, Peter J. Gleckler, Sarah G. Purkey, Gregory C. Johnson, John M. Lyman, and Tim P. Boyer
- Subjects
ocean warming ,global climate system ,greenhouse gas ,Oceanography ,GC1-1581 - Abstract
The ocean is the primary heat sink of the global climate system. Since 1971, it has been responsible for storing more than 90% ofthe excess heat added to the Earth system by anthropogenic greenhouse-gas emissions. Adding this heat to the ocean contributes substantially to sea level rise and affects vital marine ecosystems. Considering the global ocean’s large role in ongoing climate variability and change, it is a good place to focus in order to understand what observed changes have occurred to date and, by using models, what future changes might arise under continued anthropogenic forcing of the climate system. While sparse measurement coverage leads to enhanced uncertainties with long-term historical estimates of change, modern measurements are beginning to provide the clearest picture yet of ongoing global ocean change. Observations show that the ocean is warming from the near-surface through to the abyss, a conclusion that is strengthened with each new analysis. In this assessment, we revisit observation- and model-based estimates of ocean warming from the industrial era to the present and show a consistent, full-depth pattern of change over the observed record that is likely to continue at an ever-increasing pace if effective actions to reduce greenhouse-gas emissions are not taken.
- Published
- 2018
- Full Text
- View/download PDF
8. Global Oceans
- Author
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Gregory C. Johnson, Rick Lumpkin, Tim Boyer, Francis Bringas, Ivona Cetinić, Don P. Chambers, Lijing Cheng, Shenfu Dong, Richard A. Feely, Baylor Fox-Kemper, Eleanor Frajka-Williams, Bryan A. Franz, Yao Fu, Meng Gao, Jay Garg, John Gilson, Gustavo Goni, Benjamin D. Hamlington, Helene T. Hewitt, William R. Hobbs, Zeng-Zhen Hu, Boyin Huang, Svetlana Jevrejeva, William E. Johns, Sato Katsunari, John J. Kennedy, Marion Kersalé, Rachel E. Killick, Eric Leuliette, Ricardo Locarnini, M. Susan Lozier, John M. Lyman, Mark A. Merrifield, Alexey Mishonov, Gary T. Mitchum, Ben I. Moat, R. Steven Nerem, Dirk Notz, Renellys C. Perez, Sarah G. Purkey, Darren Rayner, James Reagan, Claudia Schmid, David A. Siegel, David A. Smeed, Paul W. Stackhouse, William Sweet, Philip R. Thompson, Denis L. Volkov, Rik Wanninkhof, Robert A. Weller, Caihong Wen, Toby K. Westberry, Matthew J. Widlansky, Josh K. Willis, Lisan Yu, and Huai-Min Zhang
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Atmospheric Science - Published
- 2022
9. Global Oceans
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T. C. Lee, A. Sanchez-Franks, Lijing Cheng, David A. Smeed, Boyin Huang, Bryan A. Franz, Ben Moat, Uwe Send, M.B. Bif, S.M. Bushinsky, Y. Takeshita, John M. Lyman, Matthew J. Widlansky, Deborah J. Misch, Jessicca Griffin, William Sweet, E. Frajka-Williams, Eric Leuliette, R.S. Nerem, Matthias Lankhorst, Catia M. Domingues, Masayoshi Ishii, Paul W. Stackhouse, Toby K. Westberry, James Reagan, John J. Marra, Ricardo A. Locarnini, N. Rome, Denis Volkov, Shenfu Dong, Philip R. Thompson, Sara W. Veasey, Timothy P. Boyer, Robert A. Weller, Zeng-Zhen Hu, Claudia Schmid, Gustavo Goni, Christopher S. Meinen, Rick Lumpkin, Lisan Yu, Ivona Cetinić, A. Andersen, S.E. Love-Brotak, Didier Monselesan, Rik Wanninkhof, Kenneth S. Johnson, Don P. Chambers, Svetlana Jevrejeva, A.J. Fassbender, Merrifield, William E. Johns, Anne C. Wilber, Brendan R. Carter, John Kennedy, David A. Siegel, Darren Rayner, Molly O. Baringer, M. Visbeck, Joaquin Trinanes, J.P. Scott, Gregory Hammer, Deborah B. Riddle, Benjamin D. Hamlington, John Gilson, W. Yu, M. Dai, Sarah G. Purkey, Gregory C. Johnson, Gary T. Mitchum, S. Speich, F. Li, Susan Wijffels, Rachel Killick, M. Kersalé, E. Lindstrom, S. Chiba, Richard A. Feely, R.C. Perez, Peter Landschützer, S. Lozier, and Huai Min Zhang
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Atmospheric Science ,010504 meteorology & atmospheric sciences ,State (polity) ,Climatology ,media_common.quotation_subject ,0211 other engineering and technologies ,Environmental science ,02 engineering and technology ,01 natural sciences ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,media_common - Abstract
State of the climate in 2019
- Published
- 2020
10. Warming trends increasingly dominate global ocean
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John M. Lyman and Gregory C. Johnson
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0303 health sciences ,Research groups ,010504 meteorology & atmospheric sciences ,Effects of global warming on oceans ,Global warming ,Environmental Science (miscellaneous) ,Physical oceanography ,01 natural sciences ,03 medical and health sciences ,Sea surface temperature ,Climatology ,Period (geology) ,Environmental science ,Ocean heat content ,Social Sciences (miscellaneous) ,Pacific decadal oscillation ,030304 developmental biology ,0105 earth and related environmental sciences - Abstract
The ocean takes up about 93% of the global warming heat entering Earth’s climate system. In addition, the associated thermal expansion contributes substantially to sea-level rise. Hence, quantifying the oceanic heat uptake rate and its statistical significance has been a research focus. Here we use gridded ocean heat content maps to examine regional trends in ocean warming for 0–700 m depth from 1993–2019 and 1968–2019, periods based on sampling distributions. The maps are from four research groups, three based on ocean temperature alone and one combining ocean temperature with satellite altimeter sea-level anomalies. We show that use of longer periods results in larger percentages of ocean area with statistically significant warming trends and less ocean area covered by statistically significant cooling trends. We discuss relations of these patterns to climate phenomena, including the Pacific Decadal Oscillation, the Atlantic Meridional Overturning Circulation and global warming. A large proportion of anthropogenic heat energy is being taken up by ocean warming. Analysis of yearly 0–700 m ocean heat content maps from four different estimates shows that the longer the period over which regional trends are estimated, the larger the area of statistically significant warming.
- Published
- 2020
11. Quantifying Spread in Spatiotemporal Changes of Upper-Ocean Heat Content Estimates: An Internationally Coordinated Comparison
- Author
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Timothy P. Boyer, Will Hobbs, Rebecca Cowley, Susan Wijffels, Simon J. Marsland, Abhishek Savita, John M. Lyman, Josh K. Willis, Masayoshi Ishii, John A. Church, Viktor Gouretski, Didier Monselesan, Gregory C. Johnson, Catia M. Domingues, and Peter Dobrohotoff
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Earth system science ,Atmospheric Science ,Indian ocean ,Research groups ,Frontal regions ,Climatology ,Anomaly (natural sciences) ,Environmental science ,Ocean heat content ,Bathythermograph ,Pacific ocean - Abstract
The Earth system is accumulating energy due to human-induced activities. More than 90% of this energy has been stored in the ocean as heat since 1970, with ∼60% of that in the upper 700 m. Differences in upper-ocean heat content anomaly (OHCA) estimates, however, exist. Here, we use a dataset protocol for 1970–2008—with six instrumental bias adjustments applied to expendable bathythermograph (XBT) data, and mapped by six research groups—to evaluate the spatiotemporal spread in upper OHCA estimates arising from two choices: 1) those arising from instrumental bias adjustments and 2) those arising from mathematical (i.e., mapping) techniques to interpolate and extrapolate data in space and time. We also examined the effect of a common ocean mask, which reveals that exclusion of shallow seas can reduce global OHCA estimates up to 13%. Spread due to mapping method is largest in the Indian Ocean and in the eddy-rich and frontal regions of all basins. Spread due to XBT bias adjustment is largest in the Pacific Ocean within 30°N–30°S. In both mapping and XBT cases, spread is higher for 1990–2004. Statistically different trends among mapping methods are found not only in the poorly observed Southern Ocean but also in the well-observed northwest Atlantic. Our results cannot determine the best mapping or bias adjustment schemes, but they identify where important sensitivities exist, and thus where further understanding will help to refine OHCA estimates. These results highlight the need for further coordinated OHCA studies to evaluate the performance of existing mapping methods along with comprehensive assessment of uncertainty estimates.
- Published
- 2022
12. GOSML: A Global Ocean Surface Mixed Layer Statistical Monthly Climatology: Means, Percentiles, Skewness, and Kurtosis
- Author
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Gregory C. Johnson and John M. Lyman
- Subjects
Geophysics ,Space and Planetary Science ,Geochemistry and Petrology ,Earth and Planetary Sciences (miscellaneous) ,Oceanography - Published
- 2022
13. Equatorial Pacific 1,000‐dbar Velocity and Isotherm Displacements From Argo Data: Beyond the Mean and Seasonal Cycle
- Author
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John M. Lyman, Hannah Zanowski, and Gregory C. Johnson
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Geophysics ,Space and Planetary Science ,Geochemistry and Petrology ,Climatology ,Earth and Planetary Sciences (miscellaneous) ,Rossby wave ,Oceanography ,Seasonal cycle ,Argo ,Geology - Published
- 2019
14. Global Oceans
- Author
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Gregory C. Johnson, Rick Lumpkin, Simone R. Alin, Dillon J. Amaya, Molly O. Baringer, Tim Boyer, Peter Brandt, Brendan R. Carter, Ivona Cetinić, Don P. Chambers, Lijing Cheng, Andrew U. Collins, Cathy Cosca, Ricardo Domingues, Shenfu Dong, Richard A. Feely, Eleanor Frajka-Williams, Bryan A. Franz, John Gilson, Gustavo Goni, Benjamin D. Hamlington, Josefine Herrford, Zeng-Zhen Hu, Boyin Huang, Masayoshi Ishii, Svetlana Jevrejeva, John J. Kennedy, Marion Kersalé, Rachel E. Killick, Peter Landschützer, Matthias Lankhorst, Eric Leuliette, Ricardo Locarnini, John M. Lyman, John J. Marra, Christopher S. Meinen, Mark A. Merrifield, Gary T. Mitchum, Ben I. Moat, R. Steven Nerem, Renellys C. Perez, Sarah G. Purkey, James Reagan, Alejandra Sanchez-Franks, Hillary A. Scannell, Claudia Schmid, Joel P. Scott, David A. Siegel, David A. Smeed, Paul W. Stackhouse, William Sweet, Philip R. Thompson, Joaquin A. Triñanes, Denis L. Volkov, Rik Wanninkhof, Robert A. Weller, Caihong Wen, Toby K. Westberry, Matthew J. Widlansky, Anne C. Wilber, Lisan Yu, and Huai-Min Zhang
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Atmospheric Science - Published
- 2021
15. Satellite and Ocean Data Reveal Marked Increase in Earth’s Heating Rate
- Author
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Seiji Kato, John M. Lyman, Fred G. Rose, Norman G. Loeb, Gregory C. Johnson, and Tyler J. Thorsen
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Geophysics ,Meteorology ,General Earth and Planetary Sciences ,Environmental science ,Satellite ,Earth (classical element) - Published
- 2021
16. Subsurface Evolution and Persistence of Marine Heatwaves in the Northeast Pacific
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John M. Lyman, Gregory C. Johnson, Hillary A. Scannell, Stephen C. Riser, and LuAnne Thompson
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Geophysics ,Oceanography ,010504 meteorology & atmospheric sciences ,General Earth and Planetary Sciences ,Environmental science ,010502 geochemistry & geophysics ,01 natural sciences ,Pacific ocean ,The Blob ,Argo ,0105 earth and related environmental sciences ,Late summer - Abstract
The reappearance of a northeast Pacific marine heatwave (MHW) sounded alarms in late summer 2019 for a warming event on par with the 2013–2016 MHW known as The Blob. Despite these two events having...
- Published
- 2020
17. Subsurface Evolution and Persistence of Marine Heatwaves in the Northeast Pacific
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Hillary A. Scannell, Gregory C. Johnson, LuAnne Thompson, John M. Lyman, and Stephen C. Riser
- Published
- 2020
18. Antarctic Bottom Water Warming in the Brazil Basin: 1990s Through 2020, From WOCE to Deep Argo
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Gregory C. Johnson, Chanelle Cadot, Kristene E. McTaggart, John M. Lyman, and Elizabeth L. Steffen
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Geophysics ,Oceanography ,Antarctic Bottom Water ,Effects of global warming on oceans ,General Earth and Planetary Sciences ,Structural basin ,Argo ,Geology - Published
- 2020
19. Heat stored in the Earth system: Where does the energy go? The GCOS Earth heat inventory team
- Author
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Didier Monselesan, John Gilson, Almudena García-García, Masayoshi Ishii, Valentin Aich, Leopold Haimberger, Hugo Beltrami, Sarah G. Purkey, Gregory C. Johnson, Rachel Killik, John M. Lyman, Michael Mayer, Timothy P. Boyer, Pierre Gentine, Ben Marzeion, Nicolas Kolodziejczyk, Fiammetta Straneo, Caterina Tassone, Matthew D. Palmer, Dean Roemmich, Susan Wijffels, Catia M. Domingues, Mary-Louise Timmermans, Gottfried Kirchengast, Francisco José Cuesta-Valero, Donald Slater, Karina von Schuckmann, Damien Desbruyères, Maximilian Gorfer, Susheel Adusumilli, Axel Schweiger, Sonia I. Seneviratne, Brian A. King, Lijing Cheng, Maeva Monier, Andrew Shepherd, and Andrea K. Steiner
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010504 meteorology & atmospheric sciences ,Effects of global warming on oceans ,Global warming ,Climate change ,010502 geochemistry & geophysics ,Atmospheric sciences ,01 natural sciences ,Earth system science ,Atmosphere ,Solar gain ,Cryosphere ,Environmental science ,Sea level ,0105 earth and related environmental sciences - Abstract
Human-induced atmospheric composition changes cause a radiative imbalance at the top-of-atmosphere which is driving global warming. This Earth Energy Imbalance (EEI) is a fundamental metric of climate change. Understanding the heat gain of the Earth system from this accumulated heat – and particularly how much and where the heat is distributed in the Earth system – is fundamental to understanding how this affects warming oceans, atmosphere and land, rising temperatures and sea level, and loss of grounded and floating ice, which are fundamental concerns for society. This study is a Global Climate Observing System (GCOS) concerted international effort to update the Earth heat inventory, and presents an updated international assessment of ocean warming estimates, and new and updated estimates of heat gain in the atmosphere, cryosphere and land over the period 1960–2018. The study obtains a consistent long-term Earth system heat gain over the past 58 years, with a total heat gain of 393 ± 40 ZJ, which is equivalent to a heating rate of 0.42 ± 0.04 W m−2. The majority of the heat gain (89 %) takes place in the global ocean (0–700 m: 53 %; 700–2000 m: 28 %; > 2000 m: 8 %), while it amounts to 6 % for the land heat gain, to 4 % available for the melting of grounded and floating ice, and to 1 % for atmospheric warming. These new estimates indicate a larger contribution of land and ice heat gain (10 % in total) compared to previous estimates (7 %). There is a regime shift of the Earth heat inventory over the past 2 decades, which appears to be predominantly driven by heat sequestration into the deeper layers of the global ocean, and a doubling of heat gain in the atmosphere. However, a major challenge is to reduce uncertainties in the Earth heat inventory, which can be best achieved through the maintenance of the current global climate observing system, its extension into areas of gaps in the sampling, as well as to establish an international framework for concerted multi-disciplinary research of the Earth heat inventory. Earth heat inventory is published at DKRZ (https://www.dkrz.de/) under the doi: https://doi.org/10.26050/WDCC/GCOS_EHI_EXP (von Schuckmann et al., 2020).
- Published
- 2020
20. Ocean Warming: From the Surface to the Deep in Observations and Models
- Author
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P. J. Gleckler, Paul J. Durack, Sarah G. Purkey, Gregory C. Johnson, Timothy P. Boyer, and John M. Lyman
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Surface (mathematics) ,010504 meteorology & atmospheric sciences ,global climate system ,Effects of global warming on oceans ,010502 geochemistry & geophysics ,Oceanography ,01 natural sciences ,ocean warming ,lcsh:Oceanography ,greenhouse gas ,Environmental science ,lcsh:GC1-1581 ,0105 earth and related environmental sciences - Abstract
The ocean is the primary heat sink of the global climate system. Since 1971, it has been responsible for storing more than 90% ofthe excess heat added to the Earth system by anthropogenic greenhouse-gas emissions. Adding this heat to the ocean contributes substantially to sea level rise and affects vital marine ecosystems. Considering the global ocean’s large role in ongoing climate variability and change, it is a good place to focus in order to understand what observed changes have occurred to date and, by using models, what future changes might arise under continued anthropogenic forcing of the climate system. While sparse measurement coverage leads to enhanced uncertainties with long-term historical estimates of change, modern measurements are beginning to provide the clearest picture yet of ongoing global ocean change. Observations show that the ocean is warming from the near-surface through to the abyss, a conclusion that is strengthened with each new analysis. In this assessment, we revisit observation- and model-based estimates of ocean warming from the industrial era to the present and show a consistent, full-depth pattern of change over the observed record that is likely to continue at an ever-increasing pace if effective actions to reduce greenhouse-gas emissions are not taken.
- Published
- 2018
21. Measuring Global Ocean Heat Content to Estimate the Earth Energy Imbalance
- Author
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Masayoshi Ishii, Tristan L'Ecuyer, Rebecca Cowley, Dean Roemmich, Susan Wijffels, N. V. Zilberman, Steve Piotrowicz, Viktor Gouretski, Detlef Stammer, Donata Giglio, John Abraham, Matthew D. Palmer, Sabrina Speich, Felix W. Landerer, Maria Z. Hakuba, Gongjie Wang, Lijing Cheng, Abhishek Savita, Rémy Roca, John A. Church, John M. Lyman, Seiji Kato, Catia M. Domingues, Karina von Schuckmann, Anny Cazenave, William Llovel, Benoit Meyssignac, Timothy P. Boyer, Alejandro Blazquez, David Legler, Graeme L. Stephens, Sarah G. Purkey, Rachel Killick, Zhongxiang Zhao, Gregory C. Johnson, Armin Köhl, Michael Ablain, Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Applied Physics Laboratory [Seattle] (APL-UW), University of Washington [Seattle], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Center for Earth System Research and Sustainability (CEN), Universität Hamburg (UHH), NASA Langley Research Center [Hampton] (LaRC), Department of Atmospheric and Oceanic Sciences [Madison], University of Wisconsin-Madison, Collecte Localisation Satellites (CLS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National d'Études Spatiales [Toulouse] (CNES), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Météo France-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Institute of Marine Sciences, University of Hamburg, Centre National d'Études Spatiales [Toulouse] (CNES), Climate Change Research Centre [Sydney] (CCRC), University of New South Wales [Sydney] (UNSW), Institute for Marine and Antarctic Studies and Centre for Marine Socioecology, University of Tasmania (UTAS), Cancer Genetics Branch, National Institute of Health (NIH)-National Human Genome Research Institute (NHGRI), National Oceanic and Atmospheric Administration (NOAA), University of California, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Laboratoire de physique des océans (LPO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
0106 biological sciences ,010504 meteorology & atmospheric sciences ,lcsh:QH1-199.5 ,ocean surface fluxes ,Climate change ,Ocean Engineering ,Aquatic Science ,sea level ,lcsh:General. Including nature conservation, geographical distribution ,Oceanography ,Atmospheric sciences ,01 natural sciences ,Atmosphere ,ARGO ,GRACE ,altimetry ,ocean heat content ,ocean mass ,14. Life underwater ,Altimeter ,lcsh:Science ,Sea level ,Argo ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Water Science and Technology ,Global and Planetary Change ,010604 marine biology & hydrobiology ,Earth Energy Imbalance ,13. Climate action ,Greenhouse gas ,[SDE]Environmental Sciences ,Environmental science ,Satellite ,lcsh:Q ,Ocean heat content - Abstract
The energy radiated by the Earth toward space does not compensate the incoming radiation from the Sun leading to a small positive energy imbalance at the top of the atmosphere (0.4-1 Wm(-2)). This imbalance is coined Earth's Energy Imbalance (EEI). It is mostly caused by anthropogenic greenhouse gas emissions and is driving the current warming of the planet. Precise monitoring of EEI is critical to assess the current status of climate change and the future evolution of climate. But the monitoring of EEI is challenging as EEI is two orders of magnitude smaller than the radiation fluxes in and out of the Earth system. Over 93% of the excess energy that is gained by the Earth in response to the positive EEI accumulates into the ocean in the form of heat. This accumulation of heat can be tracked with the ocean observing system such that today, the monitoring of Ocean Heat Content (OHC) and its long-term change provide the most efficient approach to estimate EEI. In this community paper we review the current four state-of-the-art methods to estimate global OHC changes and evaluate their relevance to derive EEI estimates on different time scales. These four methods make use of: (1) direct observations of in situ temperature; (2) satellite-based measurements of the ocean surface net heat fluxes; (3) satellite-based estimates of the thermal expansion of the ocean and (4) ocean reanalyses that assimilate observations from both satellite and in situ instruments. For each method we review the potential and the uncertainty of the method to estimate global OHC changes. We also analyze gaps in the current capability of each method and identify ways of progress for the future to fulfill the requirements of EEI monitoring. Achieving the observation of EEI with sufficient accuracy will depend on merging the remote sensing techniques with in situ measurements of key variables as an integral part of the Ocean Observing System.
- Published
- 2019
22. Sensitivity of Global Upper-Ocean Heat Content Estimates to Mapping Methods, XBT Bias Corrections, and Baseline Climatologies*
- Author
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J. Antonov, Catia M. Domingues, Masayoshi Ishii, Josh K. Willis, John A. Church, Viktor Gouretski, John M. Lyman, Timothy P. Boyer, Rebecca Cowley, Susan Wijffels, Nathaniel L. Bindoff, Gregory C. Johnson, and Simon A. Good
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,010505 oceanography ,Climate change ,01 natural sciences ,Sea level rise ,Climatology ,Environmental science ,Bias correction ,Sensitivity (control systems) ,Ocean heat content ,Bathythermograph ,Baseline (configuration management) ,0105 earth and related environmental sciences - Abstract
Ocean warming accounts for the majority of the earth’s recent energy imbalance. Historic ocean heat content (OHC) changes are important for understanding changing climate. Calculations of OHC anomalies (OHCA) from in situ measurements provide estimates of these changes. Uncertainties in OHCA estimates arise from calculating global fields from temporally and spatially irregular data (mapping method), instrument bias corrections, and the definitions of a baseline climatology from which anomalies are calculated. To investigate sensitivity of OHCA estimates for the upper 700 m to these different factors, the same quality-controlled dataset is used by seven groups and comparisons are made. Two time periods (1970–2008 and 1993–2008) are examined. Uncertainty due to the mapping method is 16.5 ZJ for 1970–2008 and 17.1 ZJ for 1993–2008 (1 ZJ = 1 × 1021 J). Uncertainty due to instrument bias correction varied from 8.0 to 17.9 ZJ for 1970–2008 and from 10.9 to 22.4 ZJ for 1993–2008, depending on mapping method. Uncertainty due to baseline mean varied from 3.5 to 14.5 ZJ for 1970–2008 and from 2.7 to 9.8 ZJ for 1993–2008, depending on mapping method and offsets. On average mapping method is the largest source of uncertainty. The linear trend varied from 1.3 to 5.0 ZJ yr−1 (0.08–0.31 W m−2) for 1970–2008 and from 1.5 to 9.4 ZJ yr−1 (0.09–0.58 W m−2) for 1993–2008, depending on method, instrument bias correction, and baseline mean. Despite these complications, a statistically robust upper-ocean warming was found in all cases for the full time period.
- Published
- 2016
23. Informing Deep Argo Array Design Using Argo and Full-Depth Hydrographic Section Data
- Author
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Sarah G. Purkey, Gregory C. Johnson, and John M. Lyman
- Subjects
Atmospheric Science ,Section (archaeology) ,Climatology ,Ocean Engineering ,Ocean heat content ,Scale (map) ,Longitude ,Hydrography ,Sea level ,Geology ,Argo ,Latitude - Abstract
Data from full-depth closely sampled hydrographic sections and Argo floats are analyzed to inform the design of a future Deep Argo array. Here standard errors of local decadal temperature trends and global decadal trends of ocean heat content and thermosteric sea level anomalies integrated from 2000 to 6000 dbar are estimated for a hypothetical 5° latitude × 5° longitude × 15-day cycle Deep Argo array. These estimates are made using temperature variances from closely spaced full-depth CTD profiles taken during hydrographic sections. The temperature data along each section are high passed laterally at a 500-km scale, and the resulting variances are averaged in 5° × 5° bins to assess temperature noise levels as a function of pressure and geographic location. A mean global decorrelation time scale of 62 days is estimated using temperature time series at 1800 dbar from Argo floats. The hypothetical Deep Argo array would be capable of resolving, at one standard error, local trends from −1 in the quiescent abyssal North Pacific to about 26 m °C decade−1 below 2000 dbar along 50°S in the energetic Southern Ocean. Larger decadal temperature trends have been reported previously in these regions using repeat hydrographic section data, but those very sparse data required substantial spatial averaging to obtain statistically significant results. Furthermore, the array would provide decadal global ocean heat content trend estimates from 2000 to 6000 dbar with a standard error of ±3 TW, compared to a trend standard error of ±17 TW from a previous analysis of repeat hydrographic data.
- Published
- 2015
24. Anomalous eddy heat and freshwater transport in the Gulf of Alaska
- Author
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John M. Lyman and Gregory C. Johnson
- Subjects
geography ,geography.geographical_feature_category ,Continental shelf ,Temperature salinity diagrams ,Sea-surface height ,Oceanography ,Geophysics ,Eddy ,Space and Planetary Science ,Geochemistry and Petrology ,Anticyclone ,Ocean gyre ,Earth and Planetary Sciences (miscellaneous) ,Ocean heat content ,Geology ,Argo - Abstract
Characteristics of eddies in the Gulf of Alaska are assessed from January 2003 through April 2012. Ensemble statistics for eddy subsurface water properties on isopycnals are computed using temperature and salinity profiles from Argo profiling floats located within eddies, which are identified in sea-surface height using objective techniques. Ninety cyclonic and 154 anticyclonic eddies are identified during this period. The anticyclonic eddies are strongly nonlinear and exhibit significant warm subsurface temperature anomalies and associated salty anomalies on isopycnals while no clear distinguishing subsurface anomalies on isopycnals are detected in association with the cyclonic eddies. Heat and freshwater fluxes for the eddies are estimated from integrations in depth coordinates. The anticyclonic eddies transport heat both westward off the continental shelf into the Subarctic Gyre and westward within the Alaskan Stream. However, they transport salt into the Subarctic Gyre and freshwater within the Alaskan Stream. In both pathways eddy heat and freshwater transport show possible year-to-year fluctuations, varying from 0 to 50.4 × 1018 J a−1 and −16.8 to +7.4 km3 a−1, respectively. The anticyclonic eddies are capped by relatively fresh water year-round.
- Published
- 2015
25. Improving estimates of Earth's energy imbalance
- Author
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Gregory C. Johnson, Norman G. Loeb, and John M. Lyman
- Subjects
010504 meteorology & atmospheric sciences ,Meteorology ,0211 other engineering and technologies ,Climate change ,02 engineering and technology ,Environmental Science (miscellaneous) ,Physical oceanography ,Atmospheric sciences ,01 natural sciences ,Environmental science ,Earth (chemistry) ,Social Sciences (miscellaneous) ,Energy (signal processing) ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences - Published
- 2016
26. Where's the heat?
- Author
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Gregory C. Johnson and John M. Lyman
- Subjects
Oceanography ,Meteorology ,Climatology ,Effects of global warming on oceans ,Environmental science ,Satellite ,Environmental Science (miscellaneous) ,Ocean heat content ,Physics::Atmospheric and Oceanic Physics ,Social Sciences (miscellaneous) ,Physics::Geophysics - Abstract
In recent decades, over nine-tenths of Earth's top-of-the-atmosphere energy imbalance has been stored in the ocean, which is rising as it warms. Combining satellite sea-level data with ocean mass data or model results allows insights into ocean warming.
- Published
- 2014
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