Primary production in Antarctic sea ice

Science

Volumn 276, Issue 5311, 1997, Pages 394-397

  Arrigo, Kevin R ^a   Worthen, Denise L ^b   Lizotte, Michael P ^c   Dixon, Paul ^d   Dieckmann, Gerhard ^e  

^a NASA GODDARD SPACE FLIGHT CENTER   (United States)

^b SCIENCE SYSTEMS AND APPLICATIONS INC   (United States)

^c UNIVERSITY OF WISCONSIN OSHKOSH   (United States)

^d UNIVERSITY OF CALIFORNIA   (United States)

^e ALFRED WEGENER INSTITUTE FOR POLAR AND MARINE RESEARCH   (Germany)

Author keywords

[No Author keywords available]

Indexed keywords

ICE; SNOW;

ALGA; ANTARCTICA; ARTICLE; CARBON DIOXIDE FIXATION; ECOSYSTEM; ENVIRONMENTAL TEMPERATURE; LIGHT; PRIORITY JOURNAL; SEA; SURFACE PROPERTY;

ICE ALGAE; PRIMARY PRODUCTION; SEA ICE;

ANTARCTICA;

EID: 0030620489     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.276.5311.394     Document Type: Article

References (22)

1. H. J. Zwally et al., Antarctic Sea Ice, 1973-1976: Satellite Passive Microwave Observations (SP-459, NASA, Washington, DC, 1983).
2. K. R. Arrigo et al., Mar. Ecol. Prog. Ser. 98, 173 (1993).
3. K. R. Arrigo et al., ibid. 127, 255 (1995).
4. J. J. Stretch et al., ibid. 44, 131 (1988).
5. -3. The model was run with 1-hour time steps at a vertical resolution of 0.5 cm in the infiltration layer and 1 cm in the freeboard layer.
6. K. R. Arrigo et al., J. Geophys. Res. 98, 6929 (1993).
7. K. R. Arrigo and C. W. Sullivan, Limnol. Oceanogr. 39, 609 (1994).
8. In the infiltration layer, nutrients were supplied continuously whenever the snow density and thickness were sufficient to force the sea ice below sea level (the ice surface flooded). Nutrients were supplied to the interior freeboard layer when sea ice brine volume, a function of temperature and sea ice salinity, exceeded 70 per mil (the sea ice became permeable) as well as when the surface flooded. If these criteria were not met, the nutrient supply was cut off until the surface flooded or the ice became permeable again.
9. L. Legendre et al., Polar Biol. 12, 429 (1992).
10. 2 pixel was consistent with the log-normal frequency distribution observed in situ. The multiplier applied to a given grid point was shifted at most one step to the right or left of the previous multiplier in the array every 4 days to simulate temporal changes in snow thickness at each grid point. The array was ordered such that the difference between adjacent elements was minimized, which ensured that temporal changes in snow thickness at each grid point were not too abrupt. For example, after a multiplier of 0.721 was applied to a grid point, the potential multipliers that could be applied subsequently were 1.305, 0.721, or 0.427, with the actual multiplier chosen at random. Production was calculated independently for each grid point, and all grid points within a pixel were averaged to obtain the productivity for that pixel. Spatial variation in nutrient concentrations within seawater, which supplies the sea ice, were obtained from annual climatologies (79). Seawater salinity was obtained from (20). Cloud cover, sea-level air pressure, relative humidity, and sea-level air temperature used in the atmospheric model were obtained from (21). Total column ozone was calculated as the averaged monthly climatologies from years 1989 to 1991 of the total ozone mapping spectrometer data. Total column precipitable water was calculated as the averaged monthly climatologies from years 1985 to 1988 of the TIROS operational vertical sounder data. All monthly climatologies were interpolated daily during the model integration.
11. -1. However, because sea ice in the southwestern Pacific Ocean was constantly disappearing and reforming (on average, sea ice at a given location there attained a maximum age of 20 days), rates of production in the freeboard layer were ∼50% lower than in the rest of the ice pack.
12. Similar proportions of submerged sea ice in the Weddell Sea were reported by P. Wadhams et al. [J. Geophys. Res. 92, 14535 (1987)].
13. Our estimate of primary production within sea ice must be considered conservative. Pack ice consists of ice of varied age, thickness, diameter, and structural irregularities (for example, rafted ice floes, snow drifts, and refrozen leads), which adds to the potential sites for algal colonization and may result in higher estimates of production.
14. S. Mathot et al., Eos 76 (no. 3), OS143 (1996).
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16. T. K. Frazer, L. B. Quetin, R. M. Ross, in Antarctic Communities: Species, Structure and Survival, B. Battaglia, J. Valencia, D. W. H. Walton, Eds. (Cambridge Univ. Press, Cambridge, 1997), pp. 107-111.
17. S. S. Jacobs and J. C. Comiso, Geophys. Res. Lett. 20, 1171 (1993).
18. K. R. Arrigo et al., NASA Tech. Memo. 104640 (1996).
19. M. E. Conkright et al., World Ocean Atlas 1994, vol. 1, Nutrients (NOAA Atlas NESDIS 1, U.S. Department of Commerce, Washington, DC, 1994).
20. S. Levitus et al., World Ocean Atlas 1994, vol. 3, Salinity [National Oceanic and Atmospheric Administration (NOAA) Atlas NESDIS 3, U.S. Department of Commerce, Washington, DC, 1994].
21. A. M. da Silva, C. C. Young, S. Levitus, Atlas of Surface Marine Data 1994, vol. 1, Algorithms and Procedures (NOAA Atlas NESDIS 6, U.S. Department of Commerce, Washington, DC, 1994).
22. We thank S. Fiegles for assistance with SSM/I imagery; S. Ackley, D. Robinson, and C. Fritsen for helpful discussions and technical advice; and W. Olson, C. McClain, W. Esaias, L. Harding, and A. Schnell for editorial comments. Supported by NSF grant OPP 95-25805 (K.R.A. and M.P.L.) and NASA grants 971-438-20-10 and 971-148-65-56 (K.R.A.).