Kn-Kz

Knight Inlet

A fjord located on the west coast of Canada approximately 300 km north of Vancouver. It exhibits the characteristic steep sides, deep basins, and sills of a fjord estuary, and first reaches inland eastward from the mouth to Sallie Point and after an abrupt turn reaches sinuously northward to the head. Two sills - on 64 m deep at the mouth and the other 68 m deep about 72 km from the head - separate the inlet's 120 km length into two basins. The outer basin has a maximum depth of 250 m and the inner basin 540 m.

According to Baker and Pond (1995):

Heavy precipitation (rain at lower elevations and snow higher) during the fall and winter leads to a year-round stratified water column with a peak freshet during the summer. This stratification governs the inlet dynamics, with a surface outflow above the pycnocline that entrains saltwater as it flows seaward and a salt compensating inflow below. A tidal range of 4 to 8 m, the seasonal availability of replenishment water for deep-water renewal, and strong winds all modulate this general circulation pattern.

See Farmer and Freeland (1983) and Baker and Pond (1995).

knot

A speed of 1 nautical mph. It is equal to 1.15 mph or 1.85 kph and used in navigation and meteorology.

KNOT

Acronym for Kyodo North Pacific Ocean Time Series, an ocean time series station established in 1998 at the southwestern margin of the subarctic gyre at 44$^\circ$N, 155$^\circ$E. The objectives include studies of CO$_2$ uptake and its relationship to biological activity in the seasonally variable ocean. The planned measurements include CTD sampling, JGOFS core measurements, deployment of moored sediment traps at 1.3 and 5 km, a shallow optical buoy, and free-drifting sediment traps.

[http://ads.smr.uib.no/jgofs/ghligh.htm]

Knudsen, Martin (?-?)

A Danish physicist who worked on a set of tables for the determination of chlorinity, salinity, temperature, and density from in situ measurements. He suggested at the ICES meeting in 1899 that such tables should be published to facilitate the standardization of hydrographic work. He also suggested that Standard or Normal Water (i.e. water of known and unvarying salinity) be distributed to oceanographic laboratories as a standard against which all other salinities could be compared. Knudsen set up a Hydrographic Laboratory for ICES in Copenhagen for the purpose of producing such standard water samples. He and his co-workers also improved the accuracy of measurements by devising special burettes and pipettes with which to perform the measurements. See Schlee (1973).

Knudsen buret

A buret developed (along with a pipet) by Knudsen and others to obtain salinity values sufficiently accurate enough for oceanographic use via the chlorine titration method. See Dietrich (1963).

Knudsen pipet

See Knudsen buret.

Knudsen number

More later.

Knudsen's Tables

A series of tables published in 1901 that allowed one to find the density of a sea water sample (relative to pure water) as a function of its measured chlorinity ($Cl$), salinity ($S$) and temperature ($T$). These tables allowed the easy determination of the density (at atmospheric pressure and in situ salinity and temperature, i.e. $\sigma_t$) and the thermosteric anomaly from measured quantities.

The complete Tables consisted of seven tables. These were:

1. Table of the corresponding values of $Cl$, $S$, $\sigma_0$ and $\rho_{17.5}$ where $Cl$ is the weight of chlorine (in grams) in 1000 grams of sea water, $S$ is the total weight of salt in grams in 1000 grams of sea water and calculated from $Cl$ as $S = 0.030\,+\,1.8050\,Cl$, ${\sigma_0}\,=\,({s_0} - 1)$ where $s_0$ is the specific gravity of sea water at 0$^\circ$ C referred to distilled water at 4$^\circ$, calculated as:

   $$\begin{split}{\sigma_0}\,=\,&-0.069 + 1.4708 Cl - 0.001570 {Cl^2}\\ &+ 0.0000398 {Cl^3}, \end{split}$$

   
   
   $\rho_{17.5} = (s_{17.5}/{\sf s}_{17.5} - 1)$ where $s_{17.5}$ is the specific gravity of sea water at 17.5$^\circ$ C referred to distilled water at 4$^\circ$ C and ${\sf s}_{17.5}$ is the specific gravity of distilled water at 17.5$^\circ$ C in proportion to distilled water at 4$^\circ$ C, with $\rho_{17.5}$ calculated as

   $$\begin{split}{\rho_{17.5}}\,=\,&(0.1245 + {\sigma_0} - 0.0595... ...a_0} \\ & + 0.000155{{\sigma_0}^2})\times 1.00129. \end{split}$$

   
   

2. Table of titration for the correction $k$ to be added to the titration reading for finding the amount of chlorine $(Cl)$.
3. Table of constants $\Sigma_t$, $A_t$ and $B_t$ for the exact calculation of the density $s_t$ of sea water when $\sigma_0$ and the temperature are given. The density $s_t$ is calculated from

   $${s_t} = 1 + ({\sigma_t}/1000)$$

   
   
   where $\sigma_t$ is given by

   $$\begin{split}{\sigma_t} = {\Sigma_t} &+ ({\sigma_0} + 0.1324)[1 - {A_t} \\ & + {B_t}({\sigma_0} - 0.1324)]. \end{split}$$

   
   
   The constant ${\Sigma_t} = ({\sf s}_t - 1)\times 1000$ where ${\sf s}_t$ is the density of distilled water at $t^\circ$ referred to distilled water at 4$^\circ$ C can be calculated from

   $$\Sigma_t \,= \,-{ {{(t - 3.98^\circ )}^2} \over 503.570 } { {t + 283^\circ} \over {t + 67.26^\circ} }$$

   
   
   and the constants $A_t$ and $B_t$ from

   $$\begin{split}{A_t} & = t (4.7867 - 0.098185 t \\ & + 0.0010843 {t^2})\times {10}^{-3}, \end{split}$$

   
   

   $$\begin{split}{B_t} & = t (18.030 - 0.8164 t \\ & + 0.01667 {t^2})\times {10}^{-6} \end{split}$$

   
   

4. Table of $D = {\sigma_0} - {\sigma_t}$ for the calculation of $\sigma_t$ when $\sigma_0$ and $t$ are given.
5. Table of $D = {\sigma_0} - {\sigma_t}$ for the calculation of $\sigma_0$ when $\sigma_t$ and $t$ are given.
6. Hydrometer corrections $K$ with regard to normal glasses 16$^{III}$. $K$ is to be added to the hydrometer reading $\alpha_t$ to obtain $\rho_{17.5}$.
7. Table of the correction $K'$ which is added to $K$ to obtain the corrections for other kinds of hydrometer glasses. The table gives $K'$ for different reading temperatures and different coefficients of cubical expansion $\gamma$. For normal glass (i.e. 59$^{III}$) this is given by

   $$\gamma = 10^{-6} [17.039 + 0.00746 (t + 17.5)]$$

   
   

KODC

Abbreviation for Korean Oceanographic Data Center.

[http://www.nfrda.re.kr/kodc/e-index.html]

Kolmogorov scale

A length scale at which viscous and inertial forces are of the same order of magnitude. It is defined as:

$${L_K}\,=\,{{\left({\nu^3}/\varepsilon\right)}^{1/4}}$$

where $\nu$ is the kinematic viscosity of seawater and $\varepsilon$ is the rate at which turbulent kinetic energy is lost, i.e.

$$\varepsilon\,=\,2\nu {{e_{ij}}^2}$$

where

$$e_{ij}\,=\,{1\over 2}\left({u_{ij}}\,+\,{u_{ji}}\right)$$

is the rate of strain tensor (with units of ${m^2}{s^{-3}}$ or $W {kg^{-1}}$). See McDougall et al. (1987).

Kolmogorov spectrum

See Phillips (1991).

KORDI

Acronym for Korean Ocean Research and Development Institute.

[http://key.kordi.re.kr/]

Krümmel, Otto (1854-1912)

A German professor of geography (at the University of Kiel) considered by some as the first research-oriented academic oceanographer in the modern sense. Among his research accomplishments were a description of the seasonal variability of what is now known as North Equatorial Countercurrent (NEC) in the Atlantic, the first detailed investigation of the Falkland Current that determined it to be an unambiguous, deep-reaching current, and the first explicit description of what is now known as the Subtropical Front.

In 1887 Krümmel published the monumental Handbuch der Ozeanographie, which immediately attained status as the standard reference source for physical oceanographic information. The Handbuch contained a global chart of the ocean surface circulation that depicted all of the major currents in the proper locations. This chart also showed the monsoonal cycle in the northern Indian Ocean via an inset, a new cartographic technique that has since come into wide use. Extensive descriptions of surface circulation features were included, although theory was dealt with from a historical point of view as the field was still in its nascent stages in the latter part of the nineteenth century. He did discuss the work of William Ferrel and Henrik Mohn regarding the effects of the earth's rotation, although the results of some tank experiments led him to believe that the deflecting force would be relatively small in most cases. See Peterson et al. (1996).

Kruzenshtern Strait

See Okhotsk Sea.

krypton-85

A radiactive inert gas with a half-life of 10.76 years that is useful as a tracer in ocean studies. It forms when uranium and plutonium undergo fission, making its chief atmospheric sources nuclear weapons testing and nuclear reactors used for commercial power and weapons plutonium production. Most of the krypton-85 sources are located in the northern hemisphere which, due to slow mixing across the ITCZ, has about a 20% higher atmospheric concentration than does the southern hemisphere.

Its source to the ocean is well known due to extensive measurements of the atmospheric concentrations over time. This, along with its chemical inertness, are valuable properties for an ocean tracer to have. It enters the ocean by gas exchange, equilibrating with surface water on a time scale of about one month. This equilibrium concentration can be calculated from krypton solubility, a function of temperature and salinity, and from the atmospheric krypton concentration. This procedure won't apply in regions of rapid vertical mixing since the surface water doesn't have time to come into equilibrium with the atmosphere, but direct measurements in those regions can alleviate this problem. A measurement requires a water volume of 250 l, and the dynamic range of the measurement of krypton-85 (i.e. the ratio of the surface water concentration to the minimum detectable amount) is around 100. Measurement precision is +/- 4% for surface samples and +/- 25% for samples with concentrations 3% that of surface water.

Kr-85 is used as a tracer for study processes that occur on a decadal time scale, e.g. thermocline ventilation, mixing, circulation, and deep water mass formation, due to it being introduced to the atmosphere only in the last 35-40 years. See Sarmiento (1988) and Broecker and Peng (1982).

Kuroshio Current

In oceanography, a western boundary current located in the western North Pacific Ocean. The Kuroshio begins where the North Equatorial Current approaches the Philippines and continues northward east of Taiwan. It then crosses a ridge between Kyushu and the Okinawa Islands, responding by forming the East China Sea meander, and proceeds through the Tokara Strait, after which it takes a sharp turn to the left (north).

At this point is takes one of two paths, commonly called the large-meander (LM) and non-large-meander (NLM) paths. The LM path is located offshore, while the NLM path is close to the Japanese coast west of the Kii peninsula. The paths diverge offshore of Aburatsu, where the LM begins an offshore loop extending to about 31$^\circ$S, after which it loops back towards Japan, flowing to the west of the Izu Ridge and rejoining the typical path of the NLM north of Miyake-jima. The path of the NLM undergoes another variation further downstream. It usually passes over the Izu Ridge north of Miyake-jima, keeping close to the main island, but occasionally shifts such that it loops offshore and passes over the ridge south of Hachijo-jima, looping back to rejoin the reunited LM/NLM path at around 141$^\circ$E, 35$^\circ$N.

The development of an LM path is apparently related to the current velocity of the Kuroshio. An LM path originates with the generation of a small meander southeast of Kyushu and its downstream (eastward) propagation to the Kii Peninsula, where it develops into a Large Meander. The generation of the initial small meander is associated with a maximum in the velocity of the Kuroshio. The Kuroshio velocity usually decreases after its formation and remains small throughout the period of propagation of the small meander and for several months after the formation of the large meander. The decay of the LM phases seems to be associated with large Kuroshio velocities, particularly for the process of the eastward shift of the large meander to lie over the Izu Ridge. The LM formation process is also associated with the position of the Kuroshio in the Tokara Strait, with the LM path usually beginning about four months after the Kuroshio shifts north in the Strait, and terminating four or five months after it returns to the south. The lag time corresponds to the formation (i.e. the propagation of the small meander) and decay periods of the large meander.

After the LM/NLM paths merge, the Kuroshio separates from the coast and turns east at about 35$^\circ$ N, at which point it technically changes into the Kuroshio Extension. The Kuroshio Current is part of the overall wind-driven subtropical gyre circulation cell that exists in the North Pacific Ocean. This has also been called the Black Stream and the Japan Stream. See Stommel and Yoshida (1972), Tomczak and Godfrey (1994), Kawabe (1995) and Kawai (1998).

Kuroshio Extension

That which the Kuroshio Current becomes when it separates from the continental rise at about 35$^\circ$ N in the western North Pacific Ocean. It flows eastward from this point as a strong jet which, given the proclivities of such things, evinces a strong instability. This is seen in two regions of north- and south-ward shift called the ``First Crest'' and the ``Second Crest'', centered at approximately 140$^\circ$ E and 152$^\circ$ E, respectively, with a node near 147$^\circ$ E. East of these features the Shatsky Rise produces another region of alternate (but less regular) paths, followed by a passage over the Emperor Seamounts where it breaks up into filaments which partly comprise the North Pacific Current. The Kuroshio Extension is part of the overall wind-driven subtropical gyre circulation cell that exists in the North Pacific Ocean. See Stommel and Yoshida (1972) (especially Kawai (1972)), Tomczak and Godfrey (1994) and Hurlburt and Metzger (1998).

Kuroshio Deep Water (KDW)

A water mass found in the East China Sea. KDW is usually located at depths of 900-100 m in the Okinawa Trough, and originates mainly from the passage between the Okinawa islands. The temperature and salinity are fairly stable at, respectively, 3.7$^\circ$ C and 34.48. KDW is formed mainly via convection. See Yu-song and Xue-chuan (1994).

Kuroshio Intermediate Water (KIW)

A water mass found in the East China Sea. KIW originates from northwest Pacific water, with the major part entering from east of Taiwan and most of the rest from between Okinawa and Miyako-Jima. It is located at around 900-1000 m and has a thickness range of 500-600 m, with the latter rapidly decreasing in the shallow area of the Okinawa Trough. The temperature and salinity ranges and averages of KIW are, respectively, 5.8$^\circ$-9.5$^\circ$ C (7.8$^\circ$ C) and 34.26-34.38 (34.32). A major feature is a low salinity core with small variations in temperature and salinity. Some KIW upwells on the continental slope. See Yu-song and Xue-chuan (1994).

Kuroshio Subsurface Water (KSSW)

A water mass found in the East China Sea. KSSW originates from the near-surface water of the subtropical North Pacific, although in the winter its upper boundary is the sea surface as it merges with the Kuroshio Surface Water (KSW). In the summer the upper boundary ranges from 50-75 m depth with the lower boundary at about 400 m and shallowing towards the upper slope. The temperature decreases with depth from $>$20$^\circ$ C to about 15$^\circ$ C, and a salinity maximum is found between 125-200 m. The temperature and salinity range of this salinity core are, respectively, 17.0$^\circ$-23.2$^\circ$ C and 34.67-34.97. See Yu-song and Xue-chuan (1994).

Kuroshio Surface Water (KSW)

A water mass found in the East China Sea. KSW exists only in the warm half of the year. It is modified and merges with Kuroshio Subsurface Water (KSSW) via strong convective interaction during the cold half. This is the warmest water mass in the East China Sea, and is usually located in the upper 75 m although seasonal variations can push this up to 100 m. Its salinity is less than that of the underlying KSSW due to rainfall and runoff. The annual temperature and salinity ranges and means are, respectively, 21.9$^\circ$-29.6$^\circ$ (25.60$^\circ$) and 33.95-34.95 (34.44). See Yu-song and Xue-chuan (1994).

Kuroshio Water Mass

A group of water masses produced by modified Pacific water in the Kuroshio area in the eastern East China Sea. The four water masses comprising this are, from top to bottom: Kuroshio Surface Water (KSW), Kuroshio Subsurface Water (KSSW), Kuroshio Intermediate Water (KIW), and Kuroshio Deep Water (KDW). All four layers only exists in summer, as the KSW merges with the KSSW in winter. See Yu-song and Xue-chuan (1994).

kymatology

The science of waves and wave motion.