koty: Ocean

Evidence: 100 • authority: 72

The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as oceans (in descending order by area: the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Antarctic/Southern Ocean, and the Arctic Ocean), and are themselves mostly divided into seas, gulfs, and subsequent bodies of water. The ocean contains 97% of Earth's water and is the primary component of Earth's hydrosphere, acting as a huge reservoir of heat for Earth's energy budget, as well as for its carbon cycle and water cycle, forming the basis for climate and weather patterns worldwide. The ocean is essential to life…

Evidence: 52 • authority: 88

A robust empirical model for deriving depth-integrated N ₂ fixation rates from surface measurements in the global open ocean. Abstract. Marine dinitrogen (N2) fixation (NF) is a critical nitrogen source supporting ocean productivity, yet its global quantification remains challenging because vertically resolved measurements are logistically demanding. To address this, we developed an empirical model to predict depth-integrated NF (INF, μmol N m−2 d−1) within the euphotic zone directly from surface NF (SNF, μmol N m−3 d−1) measurements. Using 690 measured NF profiles from the global open ocean, we established a robust relationship: log10INF = 1.85 + 0.84 × log10SNF (R2 = 0.82, RMSE…

Evidence: 45 • authority: 90

Rare Earth Elements in the surface Ocean under the Saharan dust belt. The supply of trace metals to the surface ocean via dust \ndeposition is important for primary productivity and the global \nbiogeochemical cycle of many elements. Here we utilise the \nsystematic variation of the chemical properties of yttrium and \nthe rare earth elements (YREE) to investigate trace metal \nrelease from dust in the equatorial Atlantic Ocean. We present \nYREE data for the dissolved (<0.45 μm) and suspended \nparticulate matter (SPM) collected from the mixed layer \nduring Polarstern cruise ANT-XXIII/1 in Oct-Nov 2005. \n \nSaharan dust can be traced with the Al content of the SPM \nrevealing a broad max…

Evidence: 45 • authority: 90

Tracing carbon and nitrogen incorporation and pathways in the microbial community of a photic subtidal sand. The pathways and fate of C and N in the microbial compartment of a coastal permeable sandy sediment in the photic zone were studied in a pulse-chase experiment. 13C-bicarbonate and 15N-nitrate were added to the water column on top of 5 sediment cores incubated in 4 transparent and 1 opaque laboratory chambers. After 9 h of labelling in the light and dark, stable isotope incorporation by microphytobenthos (MPB) and bacteria was quantified over a period of 4 d through the analysis of phospholipid-derived fatty acids (PLFA) and hydrolysable amino acids (HAA). 13C was fixed by MPB, and m…

Evidence: 29 • authority: 90

Observations of a splitting ocean cyclone resulting in subduction of surface waters. Earth's oceans contain large numbers of cyclonic eddies, 10 to 25 kilometers in diameter and unresolved in climate simulations. However, we lack observations of these features due to their small size and fast evolution. Here, we present in situ observations of one such cyclonic eddy with intense chlorophyll at its center as it spontaneously splits into two smaller cyclonic eddies over a few days. This splitting rapidly transports surface waters to depth, with sustained vertical velocities of 60 meters per day, primarily from the center of the eddy where carbon concentrations are largest, facilitating effici…

Evidence: 21 • authority: 80

Mixed layer depth parameterization and ocean surface cooling induced by tropical cyclones

Evidence: 21 • authority: 88

Photic zone changes in the North West Pacific Ocean from MIS 4-5e. Abstract. In comparison to other sectors of the marine system, the palaeoceanography of the subarctic North Pacific Ocean is poorly constrained. New diatom isotope records of δ13C, δ18O, δ30Si (δ13Cdiatom, δ18Odiatom, δ30Sidiatom), are presented alongside existing geochemical and isotope records to document changes in photic zone conditions, including nutrient supply and the efficiency of the soft-tissue biological pump, between Marine Isotope Stage (MIS) 4 and MIS 5e. Peaks in opal productivity in MIS 5b/c and MIS 5e are both associated with the breakdown of the regional halocline stratification and increased nutrient suppl…

Evidence: 21 • authority: 90

Climatology of surface chlorophyll a, autumn‐winter and spring blooms in the southwest Pacific Ocean. Ocean color data from the 13 year Sea‐viewing Wide Field‐of‐view Sensor mission are used to examine the distribution of surface chlorophyll a in the southwest Pacific Ocean. The mean surface chlorophyll field is similar to that found by previous workers, with elevated levels in the Subtropical Front and around the subantarctic islands that have an associated shelf. The annual cycle in surface chlorophyll shows a ubiquitous summer bloom in subantarctic water, with autumn, winter, and spring blooms variously in subtropical water and across the Subtropical Front. The autumn blooms progress equ…

Evidence: 21 • authority: 72

Ocean heat content (OHC) or ocean heat uptake (OHU) is the energy absorbed and stored by oceans. It is an important indicator of global warming. Ocean heat content is calculated by measuring ocean temperature at many different locations and depths, and integrating the areal density of a change in enthalpic energy over an ocean basin or entire ocean. Between 1971 and 2018, a steady upward trend in ocean heat content accounted for over 90% of Earth's excess energy from global warming. Scientists estimate a 1961–2022 warming trend of 0.43 ± 0.08 W/m², accelerating at about 0.15 ± 0.04 W/m² per decade. By 2020, about one third of the added energy had propagated to depths below 700 meters. The f…