The oceans cover 71% of the Earth’s surface and are critical to life on our planet. At ESR, many of our scientists specialize in physical oceanography, which is the study of the physical properties of the Earth‘s ocean such as its motion, the distribution of heat and salt, and the transfer of heat between the ocean, atmosphere, and sea ice.
Surface Currents: The Ocean Surface Current Analyses Real-time (OSCAR) project is an ongoing NASA funded research project and global ocean surface current database developed and run by scientists at ESR. OSCAR produces surface currents, based on ocean physics and satellite fields, available from 1993 until present day. The currents are provided freely through the Physical Oceanography NASA data center (podaac.jpl.nasa.gov). The research goal of the OSCAR project is to understand better how surface currents are generated by global winds. OSCAR has a broad user interest. For example, OSCAR has a strong user base in the boating community. The data are also in use for fishery resource management research, marine animal migrations studies, and other maritime applications. OSCAR can also be used indirectly in determining wind stress and bulk air-sea fluxes since in air-sea flux algorithms the wind stress and heat fluxes depend upon wind relative to surface flow. The OSCAR analyses have been used extensively in climate studies
Surface Salinity: ESR scientists provide systematic estimation and assessment of satellite sea surface salinity over the global ocean and use salinity observations to study ocean phenomena. Salinity (the amount of salt in the water) changes the density of seawater, which influences global circulation patterns. It is also a great tracer of the global water cycle: As water evaporates from the ocean, it leaves behind saltier, denser water, while rainfall over the oceans and riverine outflows lead to freshening. These processes can lead to stratification, or layering, of lighter (less dense) water masses on top of denser water. Stratification has a significant impact on air-sea fluxes, such as how much carbon dioxide is being taken up by the ocean. It can also affect how sea ice is formed in polar regions and its thickness and extent. All of these have very important implications for climate (learn more.
ESR scientists track trends in ocean properties to better understand variability associated with natural and anthropogenic forcing.
Our scientists monitor the evolution of the El Niño/Southern Oscillation (ENSO) signal in the tropical Pacific Ocean and the Pacific Decadal Oscillation (PDO). We provide daily updates to current signals in the Pacific, and provide the current status of the ENSO INDEX and PDO INDEX. ESR scientists also participate in Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP) cruises which collect climate quality measurements of temperature, salinity, the carbonate system, and other critical variables throughout the world’s oceans. An essential part of our global ocean/climate observing system, GO-SHIP repeat hydrography brings together scientists with interests in physical oceanography, the carbon cycle, marine biogeochemistry and ecosystems.
Tides can have a critical impact on the world’s oceans and the transfer of heat and salt. In regions of strong tidal currents, the tidal contribution to ocean mixing becomes an important process that modified water masses. ESR researchers focus on understanding tides and their effects in the polar oceans. To do this, we develop tide models, analyze satellite-derived measurements of sea surface height changes, and contribute to data bases of polar ocean tide heights and currents.
Computer models are critical tools for investigating ocean circulation and water mass properties, and expected changes in future climate conditions. ESR scientists use models the study how the ocean, atmosphere sea ice and ice shelves interact with each other. The models provide a way to learn about what is happening in regions that are very remote and hard to sample, including under Antarctica’s massive ice shelves. We use national High Performance Computing (HPC) facilities to run large models at high enough resolution to resolve critical features of these environments.