Levitus S.,East-West Center |
Levitus S.,World Data Center for Oceanography |
Matishov G.,Russian Academy of Sciences |
Smolyar I.,East-West Center |
And 10 more authors.
Data Science Journal | Year: 2013
We document the geographical and temporal distributions of oceanographic vertical profile observations made during World War II (1939-1945) that are included in the "World Ocean Database" (WOD). The WOD is a product of the NOAA/National Oceanographic Data Center, USA and its co-located ICSU World Data Center for Oceanography. The WOD is the largest collection of ocean profile data available internationally without restriction. All data shown in this paper are available online without restriction and at no cost. The WOD is built upon the international exchange of oceanographic data with contributions of data received from many countries. Most of the data shown in this paper and the data within the WOD in which these data reside in a uniform format were gathered under the auspices of the International Oceanographic Data and Information Exchange (IODE) committee of the Intergovernmental Oceanographic Commission (IOC) of UNESCO and the ICSU (International Council of Science) World Data Center system, which is now part of the ICSU World Data System. The WOD contains 112,714 ocean station data casts and 45,003 mechanical bathythermograph profiles for 1939-1945.
Ma X.,Physical Oceanography Laboratory |
Ma X.,Texas A&M University |
Jing Z.,Physical Oceanography Laboratory |
Jing Z.,Texas A&M University |
And 14 more authors.
Nature | Year: 2016
Current climate models systematically underestimate the strength of oceanic fronts associated with strong western boundary currents, such as the Kuroshio and Gulf Stream Extensions, and have difficulty simulating their positions at the mid-latitude ocean's western boundaries. Even with an enhanced grid resolution to resolve ocean mesoscale eddies-energetic circulations with horizontal scales of about a hundred kilometres that strongly interact with the fronts and currents-the bias problem can still persist; to improve climate models we need a better understanding of the dynamics governing these oceanic frontal regimes. Yet prevailing theories about the western boundary fronts are based on ocean internal dynamics without taking into consideration the intense air-sea feedbacks in these oceanic frontal regions. Here, by focusing on the Kuroshio Extension Jet east of Japan as the direct continuation of the Kuroshio, we show that feedback between ocean mesoscale eddies and the atmosphere (OME-A) is fundamental to the dynamics and control of these energetic currents. Suppressing OME-A feedback in eddy-resolving coupled climate model simulations results in a 20-40 per cent weakening in the Kuroshio Extension Jet. This is because OME-A feedback dominates eddy potential energy destruction, which dissipates more than 70 per cent of the eddy potential energy extracted from the Kuroshio Extension Jet. The absence of OME-A feedback inevitably leads to a reduction in eddy potential energy production in order to balance the energy budget, which results in a weakened mean current. The finding has important implications for improving climate models' representation of major oceanic fronts, which are essential components in the simulation and prediction of extratropical storms and other extreme events, as well as in the projection of the effect on these events of climate change. © 2016 Macmillan Publishers Limited. All rights reserved.
Zhang N.,CSIRO |
Feng M.,CSIRO |
Du Y.,CAS South China Sea Institute of Oceanology |
Lan J.,Physical Oceanography Laboratory |
Journal of Geophysical Research: Oceans | Year: 2016
In this study, seasonal and interannual variations of the mixed layer salinity (MLS) in the southeast tropical Indian Ocean (SETIO) are analyzed using satellite observations, historical data sets, and data-assimilating ocean model outputs. On the seasonal cycle, the MLS in the SETIO becomes fresher in austral winter and saltier in austral summer: between the Java-Lesser Sunda coast and the South Equatorial Current (SEC, 12°S), where positive entrainment and fresh advections counterbalance each other, the annual cycle of the MLS closely follows the variation of the air-sea freshwater forcing; off the northwest and west Australian coasts, the MLS variations are influenced by the annual cycles of the Indonesian Throughflow (ITF) and Leeuwin Current (LC) transports as well as the air-sea freshwater forcing, with eddy fluxes acting to freshen the MLS along the SEC, the Eastern Gyral Current, and the LC. On the interannual-scale, El Niño (La Niña) events are typically associated with saltier (fresher) MLS in the SETIO. Composite and budget analyses reveal that interannual variations in precipitations drive the MLS anomalies off the Java-Lesser Sunda coast; between 12°S and the northwest Australian coast, the MLS variations are influenced by both advection anomalies and local precipitation anomalies; whereas anomalous meridional currents contribute to the MLS variations off the west Australian coast. Both enhanced local precipitations and the ITF transport anomalies have substantial contributions to the drastic freshening of the Indonesian-Australian Basin between the Java-Lesser Sunda coast and the northwest Australian coast during the extended La Niña events in 1999-2001 and 2010-2012. © 2016. American Geophysical Union.
Lan J.,Physical Oceanography Laboratory |
Wang Y.,Physical Oceanography Laboratory |
Cui F.,Physical Oceanography Laboratory |
Zhang N.,Physical Oceanography Laboratory
Journal of Geophysical Research C: Oceans | Year: 2015
The previous studies show that the SCS deep circulation is featured by a basin-scale cyclonic gyre. On the basis of the Hybrid Coordinate Ocean Model (HYCOM) and the Simple Ocean Data Assimilation (SODA), this study attempts to examine its seasonal variability and to investigate the driving mechanism. During summer season, the basin-scale cyclonic gyre is dominant and strong, corresponding to higher value of the deepwater overflow transport. During winter season, the basin-scale cyclonic gyre can hardly be identified, corresponding to lower value of the deepwater overflow transport. The control run and the SODA show the similar results. Two sensitivity experiments are designed to investigate what could be possible responsible for the seasonal variation in the SCS deep circulation. The results reveal that the deepwater overflow through the Luzon Strait contributes to the seasonal variability of the SCS deep circulation, and the seasonal variation of the surface forcings have less influence on that. The mechanism is related to the potential vorticity flux by the deepwater overflow. © 2015. American Geophysical Union.