Physicochemical sea ice and water characteristics near Point Barrow 2005-2006 ...

• Main Authors: Manes, Sarah Story, Gradinger, Rolf
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2009
• Subjects: International Polar Year 2007-2008 IPY; Barrow; Chukchi; Chukchi Sea; ice algae; International Polar Year; IPY; Point Barrow; Sea ice; Alaska
• Online Access: https://dx.doi.org/10.1594/pangaea.815928; https://doi.pangaea.de/10.1594/PANGAEA.815928

Photosynthetic parameters of phytoplankton and sea ice algae from landfast sea ice of the Chukchi Sea off Point Barrow, Alaska, were assessed in spring 2005 and winter through spring 2006 using Pulse Amplitude Modulated (PAM) fluorometry including estimates of maximum quantum efficiency (Fv/Fm), maximum relative electron transport rate (rETRmax), photosynthetic efficiency (alpha), and the photoadaptive index (Ek). The use of centrifuged brine samples allowed to document vertical gradients in ice algal acclimation with 5 cm vertical resolution for the first time. Bottom ice algae (0-5 cm from ice-water interface) expressed low Fv/Fm (0.331-0.426) and low alpha (0.098-0.130 /(µmol photons/m**2/s)) in December. Fv/Fm and alpha increased in March and May (0.468-0.588 and 0.141-0.438 /(µmol photons/m**2/s), respectively) indicating increased photosynthetic activity. In addition, increases in rETRmax (3.3-16.4 a.u.) and Ek (20-88 µmol photons/m**2/s) from December to May illustrates a higher potential for primary ... : Data extracted in the frame of a joint ICSTI/PANGAEA IPY effort, see http://doi.pangaea.de/10.1594/PANGAEA.150150 ...