N. The overall goal was to investigate
the capability of the ERS 1 type active microwave sensors
to measure marine variables such as near-surface wind,
waves and ocean surface current and their interaction in weather
conditions ranging from moderate to extreme.
The primary objectives of NORCSEX included studies of SAR imaging of surface current features, SAR imaging of ocean surface gravity waves, combined airborne SAR and ship-mounted scatterometer measurements of near-surface wind fields, radar altimeter measurements of sea surface topography, significant wave height, and wind speed, integrated use of SAR and radar altimeter for significant wave height measurements, and comparison and validation of numerical ocean circulation model results to remote sensing and in situ observations. See Johannessen (1991).
W and 30 N in the western North
Atlantic Ocean. It includes the Sohm Abyssal Plain to
the northeast, the Hatteras Abyssal Plain to the west,
and the Nares Abyssal Plain (or Nares Deep) to the southeast.
Other prominent features in this basin include
the Vema Gap, the Blake-Bahama
Outer Ridge, and Blake-Bahama Basin and the Puerto Rico
Trench.
See Fairbridge (1966).
NADW originates in the northern North Atlantic in the GIN Sea. The main sources in are the dense overflows on either side of Iceland from intermediate depths in the Nordic Seas, the lower part of the Labrador Sea Water (LSW) layer including both a recirculating and an entraining component, and a recirculating Antarctic Bottom Water (AABW) derivative of southerly origins in the deepest layers of either basin.
The total direct transport of the dense overflows is about 5.6 Sv, about equally divided east and west of Iceland over the various sections of the Greenland-Scotland Ridge. The sill depth in the Denmark Strait to the east of Iceland is 600 m. To the west is is 450 m on the Iceland-Faroe Ridge and 850 m in the Faroe Bank Channel. The most saline of the overflows in through the Faroe Bank Channel which, although it overflows as a relatively fresh source, mixes intensely with overlying warm saline water from the local thermocline to become more saline. This water has been labeled by some as Northeast Atlantic Deep Water (NEADW). The coldest and densest of the overflows is the Denmark Strait Overflow, which has a characteristic salinity minimum. This overflow has been sometimes labeled as Northwest Atlantic Bottom Water.
The AABW component passes into the eastern
GIN Sea basin through the Vema Fracture Zone at 11 N
at a rate of about 2.0-2.5 Sv. This eventually combines
with the overflows east of Iceland to give an estimated
6.6 Sv of flow west through the Charlie Gibbs Fracture Zone.
This flows west to combine with the overflow west of Iceland,
which has mixed with the LSW to contribute to a total eventual
southward flow of NADW east of Newfoundland of about 13 Sv.
The recirculation and entrainment processes that increase the
5.6 Sv of overflow water to the 13 Sv of NADW flowing south
are the least well known parts of NADW formation.
See Dickson and Brown (1994) for
the present best summary of NADW formation processes.
The resulting mixture, as it moves south, is conventionally separated into upper, middle and lower NADW. Upper NADW comes from Mediterranean outflow spreading into the Central and North Atlantic at depths of 1000 to 1500m, while middle NADW is formed by ocean convection in the Labrador Sea flowing into the Western North Atlantic Basin. Lower NADW is formed by a complex series of mixing flows over the Greenland-Scotland Ridge and thereafter, and comprises the bulk of the totality of NADW. The middle and lower forms of NADW are additionally identified by two oxygen maxima in the subtropics at 2000-3000 m and 3500-4000 m, respectively. See Warren (1981).
S along
around 35 W. Geostrophic calculations (relative to
1000 m) show a broad (300 km wide), northwestward current
transporting about 37 Sv at 5 S. It is concentrated
in a subsurface core at 100-200 m depth.
It continues as
a coherent feature until the subthermocline layers retroflect
at between 3 and 5 N to feed the
North Equatorial Undercurrent (NEUC) and then the
upper layers retroflect at between 5 and 8 N to feed the
North Equatorial Countercurrent (NECC).
The NBC originates south of the equator where the
South Equatorial Current approaches the coast.
Historically, it was thought to be simply the northward
flowing part of the bifurcation of the
Central South Equatorial Current (CSEC) at near 5 S (with
the Brazil Current (BC) the
southward flowing part), but
recent investigations have shown a more complicated picture.
The simple view was prompted by surface current distributions
obtained from ship drift and surface drifter trajectories,
which turn out to have obscured the overall geostrophic
flow patterns.
Geostrophic calculations have shown that the NBC originates
just south of 10 30' S where the convergence of the
southern branch of the CSEC with part of the
Southern South Equatorial Current results in a transport
(relative to 1000 m) of about 21 Sv at near 10 S.
It continues north from there and eventually merges with
the northern branch of the CSEC just north of 5 S
where the transport has increased to the aforementioned
37 Sv.
See da Silveira (1994).
N. It is located between the
NEC and the SEC and
called a countercurrent because it flows counter to the direction
of the easterly trade winds.
The NECC is strongest during July and August and weak in the northern
winter and spring, and is known to migrate from a northernmost
position in the northern summer to a position closest to the
equator in the northern winter.
Some evidence indicates that during this latter
period the NECC is discontinuous and may even vanish in parts
of the eastern Pacific. Even so, it is the most well developed
of any of the equatorial currents. In the Indian Ocean this and
the NEC are seasonally controlled by the
monsoon circulation patterns.
See Leetmaa et al. (1981),
N. In the Indian Ocean this and
the NECC are seasonally controlled by the
monsoon circulation patterns.
See Leetmaa et al. (1981),
N) to
become part of the
flow in the Polar Front.
in the subtropical gyre
in the North Pacific. The low salinity signature is
taken as evidence of ventilation of the subtropical
gyre by waters of subpolar origin.
See Talley (1993).
, has an average depth of
94 m, and a volume of 54,000 km 
.
See Fairbridge (1966) and Lee (1970).
N in the North Pacific Ocean.
It flows between the eastward flowing
North Equatorial Countercurrent (NECC) to the north and the
westward flowing
South Equatorial Current (SEC) to the south.
See Gouriou and Toole (1993).
, has a volume of
2,408,000 km , and a mean depth of 1742 m.
The term Norwegian Sea has also been used to collectively refer to the
sea described here along with the
Greenland Sea and the
Iceland Sea.
See Hopkins (1991) and Fairbridge (1966).
C isotherm traditionally used as the
upper limit of NSDW. Most is colder than -0.4 C
with typically NSDW -0.5 to -1.1 and 34.92.
See Swift (1986).
m in
diameter and its production mechanism is by gas-to-particle
conversion (GPC).
See Jaenicke (1993b).
N.
See Ho et al. (1995).
where 
is the sampling interval. It is the
maximum frequency that can be detected from data sampled
at time spacing . Higher frequencies are
subject to aliasing which can
cause the spectrum to differ from the true spectrum.
See Nyquist theorem.
See Peixoto and Oort (1992).
, where 
is the maximum frequency present in
the series. In other words, the Nyquist frequency must be higher than the maximum frequency present
in the series. See Peixoto and Oort (1992).