1,721,031 research outputs found
Ocean Heat Content
No full textEstimates (OCCA2, ECCO4) of global ocean heat content (OHC) anomaly from 2004-2006 climatology. ECCO4 is a closed heat budget estimate. ECCO4 release 5 is used here that covers 1992-2019. OCCA2 was derived by 1. extending ECCO4 (r2) to 1980-2022 and 2. adding a gridded adjustment to Argo over 2004-2022. The 2004-2006 climatologies were subtracted separately before combining anomalies over 1992-2019
Earth Energy Imbalance Assessment Workshop (2023)
No full textContents include materials prepared for the 2023 Earth Energy Imbalance Assessment Workshop :
1. temperature averages from ECCOv4r5 for the 0-300m, 0-1000m, and 0-2000m layers on a regular half degree grid (T_from_0_to_300m.nc etc)
2. same as 1 but including regions where sea floor depth is less than layer bottom depth (T_from_0_to_300m_or_less.nc, etc)
3. sea floor depth in ECCOv4r5
4. net heat flux across sea surface, or top of seaice/snow (SIatmQnt.nc)
5. net heat flux across free surface, or bottom of seaice (oceQnet.nc
Pathways of seawater carried by the Gulf Stream, based on the ECCO4 estimate
No full text Virtual particles, on a computer, are released near Florida Strait and then move forward following the Ocean flow fields as estimated in the ECCO climatology.
Details
10000 particles are initially released, all at time 0, in depth range D
particles are released in D = 0-110m , 110-380m, or 380-860m
flow fields are three-dimensional, global, and time invariant
ocean flow field estimate : ECCO4, release 2, 20-year time mean
the duration of each simulation is 10 years
particles are gradually, periodically reset to their original positions
background map : Blue Marble: Next Generation + Topography and Bathymetry
particle tracking software : IndividualDisplacements.jl to compute particle trajectories
visualization software (included) : PlottingFunctions.jl created the plots (png) & movies (mp4)
in the included graphs, particle colors indicate depth
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Argo / MITprof 2023 release
No full text- MITprof files were created using ArgoData.jl
- copy of the Argo GDAC downloaded on 20230415 was used
<https://github.com/euroargodev/ArgoData.jl#readme
Effective Ocean Heat Transport Estimates
No full textEstimates presented in the Figures and Tables of Forget, G. and Ferreira, D. (2019) Global ocean heat transport dominated by heat export from the tropical Pacific. Nature Geoscience. ISSN 1752-0894 (In Press
Effective Ocean Heat Transport Estimates
No full textEstimates presented in the Figures and Tables of Forget, G. and Ferreira, D. (2019) Global ocean heat transport dominated by heat export from the tropical Pacific. Nature Geoscience. ISSN 1752-0894 (In Press
Global Workshop on Earth Observation with Julia 2023
No full textFor use at the JuliaEO2023, Global Workshop on Earth Observation with Julia, workshop.
- Regional subsets of sea level & topography data for the region of the Azores.
- Docker image for attendees & others to reproduce workshop notebook results.
Workshop website is https://aircentre.github.io/JuliaEO
Mapping Ocean Observations in a Dynamical Framework: A 2004-06 Ocean Atlas
No full textThis paper exploits a new observational atlas for the near-global ocean for the best-observed 3-yr period from December 2003 through November 2006. The atlas consists of mapped observations and derived quantities. Together they form a full representation of the ocean state and its seasonal cycle. The mapped observations are primarily altimeter data, satellite SST, and Argo profiles. GCM interpolation is used to synthesize these datasets, and the resulting atlas is a fairly close fit to each one of them. For observed quantities especially, the atlas is a practical means to evaluate free-running GCM simulations and to put field experiments into a broader context. The atlas-derived quantities include the middepth dynamic topography, as well as ocean fluxes of heat and salt–freshwater. The atlas is publicly available online (www.ecco-group.org). This paper provides insight into two oceanographic problems that are the subject of vigorous ongoing research. First, regarding ocean circulation estimates, it can be inferred that the RMS uncertainty in modern surface dynamic topography (SDT) estimates is only on the order of 3.5 cm at scales beyond 300 km. In that context, it is found that assumptions of “reference-level” dynamic topography may yield significant errors (of order 2.2 cm or more) in SDT estimates using in situ data. Second, in the perspective of mode water investigations, it is estimated that ocean fluxes (advection plus mixing) largely contribute to the seasonal fluctuation in heat content and freshwater/salt content. Hence, representing the seasonal cycle as a simple interplay of air–sea flux and ocean storage would not yield a meaningful approximation. For the salt–freshwater seasonal cycle especially, contributions from ocean fluxes usually exceed direct air–sea flux contributions
Determining the Origins of Advective Heat Transport Convergence Variability in the North Atlantic
No full textA recent state estimate covering the period 1992–2010 from the Estimating the Circulation and Climate of the Ocean (ECCO) project is utilized to quantify the roles of air–sea heat fluxes and advective heat transport convergences in setting upper-ocean heat content anomalies H in the North Atlantic Ocean on monthly to interannual time scales. Anomalies in (linear) advective heat transport convergences, as well as Ekman and geostrophic contributions, are decomposed into parts that are due to velocity variability, temperature variability, and their covariability. Ekman convergences are generally dominated by variability in Ekman mass transports, which reflect the instantaneous response to local wind forcing, except in the tropics, where variability in the temperature field plays a significant role. In contrast, both budget analyses and simple dynamical arguments demonstrate that geostrophic heat transport convergences that are due to temperature and velocity variability are anticorrelated, and thus their separate treatment is not insightful. In the interior of the subtropical gyre, the sum of air–sea heat fluxes and Ekman heat transport convergences is a reasonable measure of local atmospheric forcing, and such forcing explains the majority of H variability on all time scales resolved by ECCO. In contrast, in the Gulf Stream region and subpolar gyre, ocean dynamics are found to be important in setting H on interannual time scales. Air–sea heat fluxes damp anomalies created by the ocean and thus are not set by local atmospheric variability.United States. National Oceanic and Atmospheric Administration (Grant NA10OAR4310199)United States. National Oceanic and Atmospheric Administration (Grant NA10OAR4310134)United States. National Oceanic and Atmospheric Administration (Grant NA10OAR4310135)National Oceanographic Partnership Program (U.S.) (United States. National Aeronautics and Space Administration Grant NNX08AV89G
A Comparison of Atmospheric Reanalysis Surface Products over the Ocean and Implications for Uncertainties in Air–Sea Boundary Forcing
No full textThis paper investigates the uncertainties related to atmospheric fields from reanalysis products used in forcing ocean models. Four reanalysis products, namely from 1) the interim ECMWF Re-Analysis (ERA-Interim), 2) version 2 of the Common Reference Ocean–Ice Experiments (CORE2), 3) the 25-Year Japanese Reanalysis Project (JRA-25), and 4) NCEP–NCAR, are evaluated against satellite-derived observations for eight different fields (zonal and meridional winds, precipitation, specific humidity, continental discharge, surface air temperature, and downwelling longwave and shortwave radiation fluxes). No single product is found to agree better in all fields with satellite-derived observations. Reanalysis products are mostly comparable to each other because of their similar physical assumptions and assimilation of common observations. Adjusted atmospheric fields from the Estimating the Circulation and Climate of the Ocean (ECCO) optimizations are also in agreement with other reanalysis products. Time-mean and time-variable errors are estimated separately and mapped globally in space, based on 14-day average fields to focus on monthly to interannual periods. Time-variable errors are larger in comparison to the signal than time-mean errors for most fields, thus justifying the need to separate them for studying uncertainties as well as formulating optimization procedures. Precipitation and wind stress fields show significant time-mean and time-variable errors whereas downwelling radiation, air temperature, and humidity fields show small time-mean errors but large time-variable errors, particularly in the tropics. Uncertainties based on evaluating multiple products presented here are considerably larger than uncertainties based on single product pairs.National Science Foundation (U.S.) (Grant ARC-1022733
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