Connections among ice, runoff and atmospheric forcing in the Beaufort Gyre

Macdonald, R. W.; Carmack, Eddy C.; McLaughlin, Fiona A.; Falkner, Kelly K.; Swift, James H.

doi:10.1029/1999gl900508

Cited by 161 publications

(141 citation statements)

References 23 publications

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“…According to our observations, the river plume extended far from the western channel of the river mouth to the northwest direction over 150 km. This result is consistent with that reported by Macdonald et al (1999). The slope of a CDOM (440) versus salinity in the present study was significantly different from that of Bélanger et al (2006) (p < 0.0001; Fig.…”

Section: Linkages Among Cdom Absorption Doc Concentrations and Hydrsupporting

confidence: 83%

Tracing the transport of colored dissolved organic matter in water masses of the Southern Beaufort Sea: relationship with hydrographic characteristics

et al. 2012

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Abstract. Light absorption by colored dissolved organic matter (CDOM) [a CDOM (λ)] plays an important role in the heat budget of the Arctic Ocean, contributing to the recent decline in sea ice, as well as in biogeochemical processes. We investigated a CDOM (λ) in the Southern Beaufort Sea where a significant amount of CDOM is delivered by the Mackenzie River. In the surface layer, a CDOM (440) showed a strong and negative correlation with salinity, indicating strong river influence and conservative transport in the river plume. Below the mixed layer, a weak but positive correlation between a CDOM (440) and salinity was observed above the upper halocline, resulting from the effect of removal of CDOM due to brine rejection and lateral intrusion of Pacific summer waters into these layers. In contrast, the relationship was negative in the upper and the lower haloclines, suggesting these waters originated from Arctic coastal waters. DOC concentrations in the surface layer were strongly correlated with a CDOM (440) (r 2 = 0.97), suggesting that this value can be estimated in this area, using a CDOM (440) that is retrieved using satellite ocean color data. Implications for estimation of DOC concentrations in surface waters using ocean color remote sensing are discussed.

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Section: Linkages Among Cdom Absorption Doc Concentrations and Hydrsupporting

confidence: 83%

Tracing the transport of colored dissolved organic matter in water masses of the Southern Beaufort Sea: relationship with hydrographic characteristics

et al. 2012

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“…For example, Guay and Falkner (1997) concluded, based on the dissolved barium concentration, that large amount of river discharge was present near the North American continental slope in 1993. Several studies (McPhee et al, 1998;Macdonald et al, 1999;Kadko and Swart, 2004) conducted at the SHEBA observation site in 1997 reported anomalously low salinities. The freshening in 1997 was traced to partly originate in the Mackenzie discharge, which likely contributes also to the elevated freshwater (Fig.…”

Section: The 1990smentioning

confidence: 99%

Time and space variability of freshwater content, heat content and seasonal ice melt in the Arctic Ocean from 1991 to 2011

et al. 2013

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Abstract. Changes in the hydrography of the Arctic Ocean have recently been reported. The upper ocean has been freshening and pulses of warm Atlantic Water have been observed to spread into the Arctic Ocean. Although these changes have been intensively studied, salinity and temperature variations have less frequently been considered together. Here hydrographic observations, obtained by icebreaker expeditions conducted between 1991 and 2011, are analyzed and discussed. Five different water masses in the upper 1000 m of the water column are examined in five sub-basins of the Arctic Ocean. This allows for studying the variations of the distributions of the freshwater and heat contents in the Arctic Ocean not only in time but also laterally and vertically. In addition, the seasonal ice melt contribution is separated from the permanent, winter, freshwater content of the Polar Mixed Layer. Because the positions of the icebreaker stations vary between the years, the icebreaker observations are at each specific point in space and time compared with the Polar Science Center Hydrographic Climatology to separate the effects of space and time variability on the observations. The hydrographic melt water estimate is discussed and compared with the potential ice melt induced by atmospheric heat input estimated from the ERA–Interim and NCEP/NCAR reanalyses. After a period of increased salinity in the upper ocean during the 1990s, both the Polar Mixed Layer and the upper halocline have been freshening. The increase in freshwater content in the Polar Mixed Layer is primarily driven by a decrease in salinity, not by changes in Polar Mixed Layer depth, whereas the freshwater is accumulating in the upper halocline mainly through the increasing thickness of the halocline. This is especially evident in the Northern Canada Basin, where the most substantial freshening is observed. The warming, and to some extent also the increase in salinity, of the Atlantic Water during the early 1990s extended from the Nansen Basin into the Amundsen and Makarov basins, while the warm and saline inflows occurring during the 2000s appear to be confined to the Nansen Basin, suggesting that the warm and saline inflow through Fram Strait largely recirculates in the Nansen Basin.

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“…10), may have been generated either if dense waters were being formed inshore or if other sources of higher salinity waters existed inshore and were leaking out across the shelf [60][61][62]. We did not sample further inshore than the stations shown, so conditions further inshore are unknown.…”

Section: Vertical Sections and Salinitymentioning

confidence: 99%

“…It has been suggested that the northern Chukchi Sea, the Beaufort Sea, and the southern Canada Basin all have oligotrophic productivities because the surface waters lack high nutrient concentrations and the strong primary pycnocline prevents significant input of deep-water nutrients [27,62,63]. Our vertical sections (Fig.…”

Section: The Mesoscale Distribution Of Nitratementioning

confidence: 99%

Mesoscale Distribution of Springtime Waters and Nutrients near the Continental Shelf Break, Beaufort Sea, Alaska~!2010-05-13~!2010-06-25~!2010-09-08~!

Christensen¹

2010

TOOCEAJ

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Forty two sites on the Alaskan Beaufort Sea shelf break were sampled by helicopter in April 2003 for hydrographic parameters and nutrients. Mesoscale maps delineated two eddies and the Beaufort shelf break current. Higher-salinity nutrient-rich waters upwelled onto the shelf, and the depth of the main pycnocline shoaled to <22 m. A plume of 31.40-31.80 salinity water at 10 m was flowing off the shelf, and maps of Brunt Vaisala frequencies and Richardson numbers showed that its presence weakened the pycnocline stability. The high shelf-break nutrient concentrations could support a spring-bloom productivity of 23 g-C m -2 y -1 , which, when added to previous summertime productivity measurements, demonstrated significant production along the Beaufort Sea shelf break.

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Connections among ice, runoff and atmospheric forcing in the Beaufort Gyre

Cited by 161 publications

References 23 publications

Tracing the transport of colored dissolved organic matter in water masses of the Southern Beaufort Sea: relationship with hydrographic characteristics

Tracing the transport of colored dissolved organic matter in water masses of the Southern Beaufort Sea: relationship with hydrographic characteristics

Time and space variability of freshwater content, heat content and seasonal ice melt in the Arctic Ocean from 1991 to 2011

Mesoscale Distribution of Springtime Waters and Nutrients near the Continental Shelf Break, Beaufort Sea, Alaska~!2010-05-13~!2010-06-25~!2010-09-08~!

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