In situ measurements of HCN and CH3CN over the Pacific Ocean: Sources, sinks, and budgets

AbstractThe impact of data assimilation on the transports of eastward-flowing Equatorial Undercurrent (EUC) and North Equatorial Countercurrent (NECC) in the Pacific Ocean from 145°E to 95°W during 2004–05 and 2009–11 was assessed. Two Estimating the Circulation and Climate of the Ocean, Phase II (ECCO2), solutions were analyzed: one with data assimilation and one without. Assimilated data included satellite observations of sea surface temperature and ocean surface topography, in which the sampling patterns were approximately uniform over the 5 years, and in situ measurements of subsurface salinity and temperature profiles, in which the sampling patterns varied considerably in space and time throughout the 5 years. Velocity measurements were not assimilated. The impact of data assimilation was considered significant when the difference between the transports computed with and without data assimilation was greater than 5.5 × 106 m3 s−1 (or 5.5 Sv; 1 Sv ≡ 106 m3 s−1) for the EUC and greater than 5.0 Sv for the NECC. In addition, the difference of annual-mean transports computed from 3-day-averaged data was statistically significant at the 95% level. The impact of data assimilation ranged from no impact to very substantial impact when data assimilation increased the EUC transport and decreased the NECC transport. The study’s EUC results had some correspondence with other studies and no simple agreement or disagreement pattern emerged among all studies of the impact of data assimilation. No comparable study of the impact of data assimilation on the NECC has been made.

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The rare deep-living hyperiid amphipod Megalanceoloides remipes (Barnard, 1932): complementary description and symbiosis

Zootaxa ◽

10.11646/zootaxa.4178.1.7 ◽

2016 ◽

Vol 4178 (1) ◽

pp. 138 ◽

Cited By ~ 2

Author(s):

REBECA GASCA ◽

STEVEN H.D. HADDOCK

Keyword(s):

Pacific Ocean ◽

Indian Ocean ◽

Gulf Of California ◽

South Atlantic ◽

Symbiotic Association ◽

The Pacific ◽

The Indian Ocean ◽

The Pacific Ocean ◽

In Situ Observations

A female ovigerous specimen of the rare deep-living hyperiid Megalanceoloides remipes (Barnard, 1932) was collected with a remotely operated submersible (ROV) at a depth of 2,094 m in the Farallon Basin, Gulf of California. The specimen was found to be symbiotically associated with the siphonophore Apolemia sp. Eschscholtz, 1829. Hitherto, this species was known only from two other specimens, one from the South Atlantic and another from the Indian Ocean; the present record is the first from the Pacific Ocean. Previous descriptions lacked morphological details of different appendages; these data are provided here. In addition, we present the first data on its symbiotic association from in situ observations. The colors of the hyperiid and of some parts of the Apolemid were very similar, thus supporting the notion that some hyperiids tend to mimic the color of its host.

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In situ observations of trophic behaviour and locomotion of Princaxelia amphipods (Crustacea: Pardaliscidae) at hadal depths in four West Pacific Trenches

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315411000452 ◽

2011 ◽

Vol 92 (1) ◽

pp. 143-150 ◽

Cited By ~ 16

Author(s):

Alan J. Jamieson ◽

Anne-Nina Lörz ◽

Toyonobu Fujii ◽

Imants G. Priede

Keyword(s):

Pacific Ocean ◽

Japan Trench ◽

Predatory Behaviour ◽

The Pacific ◽

Close Range ◽

Burst Swimming ◽

The Pacific Ocean ◽

In Situ Observations ◽

Made In

The genus Princaxelia, Pardaliscidae, is a rarely recorded, infrequently collected and hitherto observed benthic amphipod, typically found at hadal depths (>6000 m) in the Pacific Ocean trenches. Little is known about the behaviour or physiology of this genus. Using a baited camera lander, observations of Princaxelia jamiesoni were made in the Japan Trench (7703 m) and Izu–Ogasawara Trench (9316 m) and of Princaxelia aff. abyssalis in the Kermadec Trench (7966 m) and Tonga Trench (8798 m). These amphipods rapidly intercepted the bait and preyed upon smaller lysianassoid amphipods. Mean absolute swimming speeds for P. jamiesoni and P. aff. abyssalis were 4.16 cm.s−1 ± 1.8 SD and 4.02 cm.s−1 ± 0.87 SD respectively. These amphipods have the capacity for long range swimming, high manoeuvrability in close range, and efficient predatory behaviour. Burst swimming speeds for P. aff. abyssalis were 9 and 10 cm.s−1 with accelerations up to 22–25 cm.s−2.

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