Light driven seasonal patterns of chlorophyll and nitrate in the lower euphotic zone of the North Pacific Subtropical Gyre Public Deposited

http://ir.library.oregonstate.edu/concern/defaults/t435gf715

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • The euphotic zone below the deep chlorophyll maximum layer (DCML) at Station ALOHA (a long-term oligotrophic habitat assessment; 22º45′N, 158º00′W) transects the nearly permanently stratified upper thermocline. Hence, seasonal changes in solar radiation control the balance between photosynthesis and respiration in this lightlimited region. Combining profiles of radiance reflectance, algal pigments, and inorganic nutrients collected between January 1998 and December 2000, we explore the relationships between photosynthetically available radiation (PAR), phytoplankton biomass (chlorophyll a), and the position of the upper nitracline in the lower euphotic zone. Seasonal variations in the water-column PAR attenuation coefficient displace the 1% sea-surface PAR depth from approximately 105 m in winter to 121 m in summer. However, the seasonal depth displacement of isolumes (constant daily integrated photon flux strata) increases to 31 m due to the added effect of changes in sea-surface PAR. This variation induces a significant deepening of the DCML during summertime with a concomitant increase in chlorophyll a and the removal of 36 mmol m22 inorganic nitrogen [NO–3 NO–2] in the 90–200-m depth range, equivalent to approximately 34% of the annual flux of particulate nitrogen collected in sediment traps placed at 150 m. We conclude that in this oceanic region the annual light cycle at the base of the euphotic zone induces an increase in the phototrophic biomass analogous to a spring bloom event.
Resource Type
Date Available
Date Issued
Citation
  • Limnol. Oceanogr., 49(2), 2004, 508–519
Table of Contents
  • Methods; Results; Discussion
Rights Statement
Funding Statement (additional comments about funding)
Publisher
Language
Replaces
Additional Information
  • description.provenance : Approved for entry into archive by Linda Lamb(llamb@coas.oregonstate.edu) on 2009-10-01T23:09:09Z (GMT) No. of bitstreams: 1 2004.pdf: 1080176 bytes, checksum: 414d5a9b259efa6269105779c58c2845 (MD5)
  • description.provenance : Made available in DSpace on 2009-10-01T23:09:09Z (GMT). No. of bitstreams: 1 2004.pdf: 1080176 bytes, checksum: 414d5a9b259efa6269105779c58c2845 (MD5) Previous issue date: 2004
  • description.provenance : Submitted by Linda Lamb (llamb@coas.oregonstate.edu) on 2009-09-30T15:38:01Z No. of bitstreams: 1 2004.pdf: 1080176 bytes, checksum: 414d5a9b259efa6269105779c58c2845 (MD5)
ISSN
  • 0024-3590

Relationships

In Administrative Set:
Last modified: 07/21/2017

Downloadable Content

Download PDF
Citations:

EndNote | Zotero | Mendeley

Items