- jackknife method
- A statistical procedure in which, in its simplest form, estimates
are formed of a parameter based on a set of N observations
by deleting each observation in turn to obtain, in addition to
the usual estimate base d on N observations, N estimates each
based on N-1 observations. Combinations of these give estimates
of both bias and variance valid under a wide range of parent
distributions. This method has deposed distribution-based methods
in many applications due to its simplicity, its applicability in
complicated situations, and its lack of distributional assumptions,
resulting in greater reliability in practice. An elementary review
can be found in Efron and Gong (1983)
and the extension of such methods
to time series analysis (with several geophysical examples) is
reviewed in Thomson and Chave (1991).
- Jacobsen's method
- A method suggested by Jacobsen (1927)
to compute eddy coefficients using
See Neumann and Pierson (1966).
- See Fieux et al. (1994) and
Molcard et al. (1994).
- Acronym for Japan Maritime Research Institute.
- Acronym for Japan Marine Science and Technology Center.
- Jan Mayen Current (JMC)
- An eastward flow emanating from the
East Greenland Current (EGC)
in the Greenland Sea.
Its axis is north of Jan Mayen and centered on
Its position in the winter is often associated with an
ice odden, a persistent eastward extension of the
East Greenland Ice Stream.
The upper layer baroclinic flow shows that about half of the
JMC is a wide meander in the EGC and about half continues
eastward to close the Greenland Gyre system on the south.
Beneath the halocline the meander dissipates and the flow
becomes more barotropic, with the barotropic flow steered
to the east by the Jan Mayen Fracture Zone. This has also
been called the Jan Mayen Polar Current.
See van Aken (1995) and
Bourke et al. (1992).
- Acronym for Japanese Pacific Climate Study.
- Japan Sea
- A marginal sea of the western Pacific Ocean bounded on the
east by the Japanese islands, the west and southwest by
Korea, and the north and northwest by the former Soviet
Union. It is connected to the
East China Sea in the south,
the Okhotsk Sea in the north,
and the Pacific Ocean in the east via narrow passages whose
sill depths don't exceed 100 m. It comprises the Japan
Basin (with depths exceeding 3500 m) north of about 40 N,
and the Yamato Basin
(with depths around 2500 m) south of 40 N, the the
basins separated by
the Yamato Ridge. The dimensions are are about 1600 by 900 km,
an area of 978,000 km, the average depth
1750 m, and a maximum depth of about 3700 m.
The Japan Sea is a meeting place for warm currents from
the south and cold currents from the north, with the confluence
being the Polar Front.
Prominent circulation features in the Japan Sea include
the Tshushima Current,
the Tsugaru Current, the
Liman Current, the
North Korea Current and
the Mid-Japan Sea or
Maritime Province Current. Water masses found there include
Japan Sea Middle Water
(or Intermediate Water) and
Japan Sea Proper Water.
The Tsushima Warm Current (TWC) transports
warm, salty water into the sea through the Tsushima Strait.
It either splits into three branches, takes a single meandering path,
or takes both patterns alternately.
In the contemporary literature, these branches are called (from east
to west), the Nearshore Branch,
the Offshore Branch and the
East Korean Warm Current (EKWC).
The Nearshore Branch flows eastward along the coast of Honshu and exits
into the Pacific via the Tsugaru Strait.
The more variable Offshore Branch flows along the continental shelf.
The EKWC flows northward along the continental slope off the east
coast of Korea up to about 37-38N, where it meets the southward
North Korea Cold Current (NKCC).
At their confluence, the currents separate from the coast and flow
east-northeast toward the Tsugaru Strait along the Polar Front.
Most of the flow exists via the Strait, while the rest continues north
as an eastern boundary current along the coast of Hokkaido called
the Soya Warm Current (SWC).
Some of the SWC flows into the
Okhotsk Sea, while the rest flows southward
along the Siberian coast as the
Liman Cold Current (LCC) (or
Primoriye Current) and (south of
Vladivostok) as the NKCC.
This forms a cyclonic gyre in the northern part of the basin.
See Tomczak and Godfrey (1994),
Preller and Hogan (1998) and
Chu et al. (2001).
- Japan Sea Bottom Water (JSBW)
- See Japan Sea Proper Water.
- Japan Sea Deep Water (JSDW)
- See Japan Sea Proper Water.
- Japan Sea Middle Water (JSMW)
- A water mass found in the
Japan Sea. It is found in the
depth range 25-200 m and characterized by a rapid drop
in temperature from 17 to 2 C as well as an oxygen
maximum of 8 ml/l near 200 m depth. The warmer layers
are advected in by the Kuroshio and the colder layers
formed by sinking at the Polar Front and on the shelf
to the north.
- Japan Sea Proper Water (JSPW)
- A water mass in the Japan Sea
that comprises all the water below 200 m (and thus the
Japan Sea Middle Water).
It is characterized by uniform temperature (1-2 C) and
salinity (34.1) which result from its isolation from other
basins by shallow sills. It is formed via winter
convection facilitated by the salt imported by the
Tsushima Current, with
the instabilities in the Polar Front serving to transport
this salt into the northern formation regions. Some authors
differentiate Japan Sea Deep Water (JSDW) (200 - 2000 m) and
Japan Sea Bottom Water (JSBW) (2000 m - bottom), and occasionally
the entire water mass is referred to as Japan Sea Deep Water.
See Tomczak and Godfrey (1994) and
Kawamura and Wu (1998).
- Japan Stream
- See Kuroshio Current.
- Abbreviation for Joint Archive for Shipboard
ADCP, a collaboration between the E. Firing
ADCP Laboratoary at the University of Hawaii and the
NODC. This center, formerly known as the
Shipboard ADCP Center (SAC), is responsible for the acquisition,
review, documentation, archiving, and distribution of shipboard
ADCP data sets. It primarily handles U.S. national cruises, but
also supports such multi-national programs as TOGA COARE,
WEPOCS, and US-PRC cruises. The JASADCP is also a
Data Assembly Center for WOCE in
collaboration with the JODC.
- Acronym for the Joint Air-Sea Interaction experiment.
See Nicholls et al. (1983) and
- Acronym for the Joint Air-Sea Monsoon INteraction Experiment, a cruise
taking place in the east Indian Ocean and the Bay of Bengal between
April 7 and June 8, 1999.
The goal of JASMINE was to observe the atmosphere and ocean environment
during a monsoon onset event, including both an active and break period,
to understand the conditions responsible for the variability of the
monsoon season on short time and space scales.
- A shallow body of water located in the southwestern part of
the Australasian Mediterranean Sea. Centered
at about 114 E and 5 S, it has average depths
of around 40-50 m, and an area ranging from 367,000 to
433,000 km depending on where the boundaries are specified.
It is connected to the
Sulawesi Sea to the northeast
by the Makassar Strait, adjoins
the Flores Sea to the east,
connects to the South China Sea
to the northwest via the
Karimata Strait, and abuts the
Bali Sea to the south and
Kalimantan to the north.
It is sometimes grouped together with the shelf sector of
the South China Sea
as the SundaSea, and also variously
spelled as Jawa Sea.
The Java Sea was formed when two large river systems,
now forming shallow channels in the shallow sea floor,
were drowned out at the end of the last ice age. The
circulation and hydrography are determined by the annual
cycle of monsoon winds, with currents flowing westward
from June to August and eastward during the rest of the
year. During this latter period a tongue of high salinity
water from the South China Sea pushes salinity values of
32 as far east as 112 E.
See Tomczak and Godfrey (1994).
- Jawa Sea
- See Java Sea.
- In oceanography, an acronym for the Joint Effects of Baroclinicity
And Relief, a term that arises from the derivation of the vertically
integrated vorticity equation.
See Huthnance (1984),
Mertz and Wright (1992),
Slordal and Weber (1996) and
Cane et al. (1998).
- Acronym for Japan and East China Seas Study.
- Jeffreys' theorem
- A theorem that concerns the conditions under which hydrostatic
equilibrium obtains. It states that hydrostatic equilibrium is
impossible if density variaitons occur on
See Hide (1978).
- Acronym for Japanese El Niño Experiment.
- Jerlov water types
- A scheme for classifying the optical properties of various
waters based on their irradiance transmissivity in the
upper 10 m. The scheme divides them into oceanic (Types I to III)
and coastal (Types 1 to 9) categories.
See Jerlov (1976).
- jet stream
- A well-defined core of strong wind, ranging from 200-300 miles
(320-480 km) wide with wind speeds up to 200 mph (320 kph),
that occurs in the vicinity of the tropopause.
See Reiter (1963).
- Acronym for Joint Global Ocean Flux Study, a subprogram of the
IGBP whose goal is to improve our
knowledge of the processes controlling carbon fluxes between
the atmosphere, surface ocean, ocean interior and its continental
margins, and the sensitivity of these fluxes to climate changes.
JGOFS originated in Feb. 1987 when SCOR
sponsored a meeting of experts in Paris where the goals, scientific
elements, topics of emphasis, and organizational structure of
JGOFS was established.
An international planning Committee for JGOFS was established in
Oct. 1987, which met for the first time in Jan. 1988.
The first JGOFS regional process study was the 1989 North
Atlantic Pilot Study, which involved Germany, UK, Netherlands,
USA and Canada. Soon after this, links were established with
WOCE and TOGA.
In 1989, an agreement between SCOR and
ICSU established JGOFS as a core project
of IGBP, although it would be responsible
directly to SCOR.
- Abbreviation for Joint Ice Center, a U.S.
Navy/NOAA facility that produces sea ice
analyses and forecasts on global, regional, and local scales.
There are global analyses for both the northern and southern
hemispheres with consist of a determination of the ice edge,
the concentration of the ice, leads in the ice, and an estimation
of the age of the ice. Regional ice analyses are produced twice
per week for the Bering, Chuckchi and Beaufort Seas. Local scale
analyses are available for ships operating in the Antarctic during
the Austral summer. The JIC also produces 7- and 30-day ice
forecasts as well as long-range outlooks. The 7-day forecasts
are produced weekly for the eastern and western Arctic and give
the expected position of the ice edge, while the 30-day forecasts
are produced twice a month for the predicted ice edge position
and ice concentrations in the eastern and western arctic.
The long-range outlooks forecast the expected severity of ice
conditions and are verified about 90 days after issuance.
- Acronym for
Joint Institute for Marine and Atmospheric Research.
- Acronym for
Joint Institute for the Study of the Atmosphere and
- Abbreviation for Japan Ocean Data Center, established in the Hydrographic
Department of the Maritime Safety Agency in 1965 to fulfill the role
of the marine data bank of Japan, acquiring marine data sets obtained
by various research institutes and providing users with the data.
JODC Web site.
- Acronym for Joint Oceanographic Institutions, a consortium of U.S.
academic institutions for organizing the collective capabilities
of the individual oceanographic institutions on research planning
and management of the ocean sciences.
JOI was established as a private, non-profit organization in
- Acronym for Joint Oceanographic Institutions for Deep Earth Sampling,
a program to obtain cores of deep ocean sediments.
- Joint Institute for Marine and Atmospheric Research (JIMAR)
- A Joint Institute formed in 1977 between the University of
Hawaii and the NOAA ERL.
The purpose of JIMAR is to increase the effectiveness of oceanic,
atmospheric, and geophysical research of mutual interest to NOAA
and the University, with the principal research interests being
equatorial oceanography, tsunamis, fisheries oceanography, and
climate and global change.
JIMAR Web site.
- Joint Institute for the Study of the Atmosphere and
the Ocean (JISAO)
- A Joint Institute formed in 1980 between the University of
Washington and the NOAA ERL.
This was established in 1980 and has five core research
areas: (1) climate variability; (2) global environmental
chemistry; (3) estuaries; (4) recruitment of fish stock;
and (5) policy, impact and response strategies with respect
to climate variability.
JISAO Web site.
- Joint Skagerrak Expedition
- An ICES sponsored 1966 program to further knowledge
of the hydrography of the Skagerrak as a
transition zone between the
Baltic Sea and
the North Sea.
The expedition took place from June 20 to July 15, 1966 and involved
Germany, Finland, Norway, the UK and Sweden.
The particulars included:
The data from the expedition were published in 1969 as ``Joint Skagerrak
Expedition 1966'' Vols. 1-4 in the "ICES Oceanographic Data Lists" series,
with the expedition atlas following as Vol. 5 in 1970.
- measurements of temperature, salinity, oxygen and phosphate - and in
some cases pH and silicate - made at 21 sections covering 233 stations,
most of which were repeated;
- current measurements made at 7 anchor sations, 8 drifting stations, and
by 17 self-recording current meters laid out over periods of up to
- about 100 vertical soundings of temperature and chlorinity (via
bathysonde), temperature and salinity (via membrane salinometer),
temperature (via bathythermograph) and transparency;
- continuous recordings of the surface layer temperature between 0
and 70 m via Delphin towing gear covering 36 profiles of nearly 1200
nm total length; and
- use of the vessels Skagerak, G. O. Sars and Meteor.
- Acronym for Joint North Sea Data Acquisition Project, a cooperative
data collection program begun in 1970 by the countries bordering the
The first phase of JONSDAP involved the systematic collection of
data from moored stations and coastal observation sites in the
North Sea from 1971 to 1973.
The second phase, JONSDAP 73, was a program of tide and current
measurement in the Southern Bight of the North Sea from September
to October 1973. The third phase, JONSDAP 76, consisted of two
intensive measurement programs:
- FLEX, the Fladen Ground Experiment to study the development
of the thermocline and the dynamics of the plankton bloom; and
- INOUT, a program concerning the general circulation of the
North Sea and the storm surge problem.
- Acronym for Joint North Sea Information System.
- Acronym for JOint North Sea WAve Project.
See Hasselmann et al. (1973).
- JONSWAP spectrum
- A wave spectrum developed for fetch-limited
wind waves. This is basically the
multipled by an extra peak enhancement factor and fetch-dependent
See Hasselmann et al. (1973).
- Abbreviation for Joint Panel on Oceanographic Tables and
Standards, a panel sponsored by UNESCO,
and SCOR which first met in 1962 (in an earlier form
not yet called JPOTS) to study and decide upon standards
to measure the properties of sea water.
- Jutland Current
- See North Sea and