How do you calculate mixed layer depth?
- MLD in temperature with a fixed threshold criterion (0.2°C)
- MLD_DT02 = depth where (θ = θ10m ± 0.2 °C)
- MLD in density with a fixed threshold criterion (0.03kg/m3)
- MLD_DR003 = depth where(σ0 = σ010m+ 0.03 kg.m-3)
- MLD in density with a variable threshold criterion (equivalent to a 0.2°C decrease)
How is ocean mixed layer depth calculated?
[23] An estimate of the mixing layer depth was made using a threshold criterion of 0.1°C from the temperature closest to the surface. The criterion applied in our temperature-based climatology, a 0.2°C threshold difference from 10 m, was calculated, along with similar 0.5 and 0.8°C MLDs.
What is the approximate thickness of the mixed layer?
This is because the thickness of the surface mixed layer is typically 100 m or less. The pycnocline acts as a porous boundary that allows some kinetic energy to penetrate into deep water.
What is the mixed layer in the ocean?
The oceanic surface mixed layer is the layer of almost uniform density resulting from the interaction between stratifying and destratifying processes. The mixed layer extends from the surface of the ocean to the top of the pycnocline (see illustration).
Which variables are constant in a mixed layer?
The mixed layer is a zone where turbulence, caused by surface currents and wind has so thoroughly mixed the water that temperature, density, and salinity are relatively constant throughout the layer.
What is mixing depth?
mixing depth Measured from the surface of the Earth, the extent of an atmospheric layer (usually a sub-inversion layer) in which convection and turbulence lead to mixing of the air and of any pollutants in it. A Dictionary of Ecology. “mixing depth .”
Does surface mixing reach ocean depths?
Mixing of the Surface and Deep Oceans Because the surface and deep ocean layers are of very different densities (due to salt content and temperature), these layers of the ocean do not mix easily. On average, it takes the waters in the ocean’s mixed layer and deep ocean about 1,000 years (or more) to completely mix.
What are the ocean depth levels?
The ocean is divided into five zones: the epipelagic zone, or upper open ocean (surface to 650 feet deep); the mesopelagic zone, or middle open ocean (650-3,300 feet deep); the bathypelagic zone, or lower open ocean (3,300-13,000 feet deep); the abyssopelagic zone, or abyss (13,000-20,000 feet deep); and the …
What is the mixed layer of the ocean?
[2] A striking and nearly universal feature of the open ocean is the surface mixed layer within which salinity, temperature, and density are almost vertically uniform. This oceanic mixed layer is the manifestation of the vigorous turbulent mixing processes which are active in the upper ocean.
Is there a global seasonal estimation of barrier layer thickness?
A new global seasonal estimation of barrier layer thickness is also provided. An interesting result is the prevalence in mid- and high-latitude winter hemispheres of vertically density-compensated layers, creating an isopycnal but not mixed layer. Consequently, we propose an optimal estimate of MLD based on both temperature and density data.
When was the 2 resolution global climatology of the mixed layer depth published?
Received 10 March 2004; revised 17 August 2004; accepted 13 September 2004; published 4 December 2004. [1]A new 2 resolution global climatology of the mixed layer depth (MLD) based on individual profiles is constructed. Previous global climatologies have been based on temperature or density-gridded climatologies.
What is the indexterms of Oceanography?
INDEXTERMS: 4572 Oceanography: Physical: Upper ocean processes; 4568 Oceanography: Physical: Turbulence, diffusion, and mixing processes; 4227 Oceanography: General: Diurnal, seasonal, and annual cycles; KEYWORDS: mixed layer, mixed layer depth criterion, density compensation
0