Cold front induced changes on the Florida panhandle shelf during October 2008 Public Deposited

http://ir.library.oregonstate.edu/concern/defaults/6w924c19w

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • A significant step transition between seasonally stratified and destratified hydrographic conditions occurred during an October 2008 cruise to the Florida Panhandle Shelf along a cross-shelf transect that was sampled before and after a cold front passed through the area. Meteorological measurements from nearby ocean and land-based stations characterized the event. Cross-shelf continuous Acrobat profiles and discrete CTD stations characterized water column hydrographic patterns, while mid-shelf multi- corer and box corer samples characterized sediment texture and nutrients.Water samples collected from selected depths biased toward the sediment interface were analyzed for nutrient content and phytoplankton community composition. Pre-front, the cross-shelf water column exhibited vertical stratification with complex temperature and salinity patterns. A prominent near-bottom chlorophyll a maximum of ~1.5 μg L⁻¹ between the 25–35 m isobaths occurred with the 1% light level at ~18 m depth and a near-bottom nitrate+ nitrite (NO₃ + NO₂⁻) maximum > 3 μM between the 30–40 m isobaths. HPLC-determined phytoplankton community composition in the near-bottom chlorophyll a maximum consisted of gyroxanthin-containing dinoflagellates (Kareniabrevis) and less abundant diatoms, both verified by FlowCAM analysis, mixed with detectable cryptophytes and chlorophytes. Sediment trends based on limited core replicates suggested the sediments were a potential source of nutrients to near-bottom populations of K. brevis and that shell hash could provide abundant pore space for K. brevis incursions. Between the 40–50 m isobaths, diatoms, cryptophytes and chlorophytes dominated near-bottom,gyroxanthin-containing dinoflagellates and prasinophytes occurred throughout the water column, and cyanophytes dominated near-surface. Post-front, the cross-shelf water column exhibited destratification with temperature and salinity increasing offshore. Achlorophyll a maximum of ~0.75 μg Chl a L⁻¹ left the sediment between 25–35 m isobaths and extended offshore especially in the lower water column with the 1% light level at ~15 m depth and NO₃ + NO₂⁻ concentrations ~2 μM to the 60 m isobath. HPLC-determined phytoplankton community composition of the offshore plume retained the signature of gyroxanthin-containing dinoflagellates and chloro- phytes. Between the 30–50 m isobaths, prasinophytes increased in the lower water column, while cyanophytes increased at all depths across the shelf. The observed step transition from stratification to destratification on the Florida Panhandle Shelf contributed to altered phytoplankton community patterns in response to predominant downwelling favorable winds. Pre-front, K. brevis cells were broadly distributed cross-shelf, but concentrated near-bottom between the 25–35 m isobaths and staged for prolific bloom seeding in response to the upwelling favorable west winds more typical of spring-summer. Post-front, K. brevis cells were mixed throughout the mid-shelf water column and were staged for diffuse bloom seeding in response to either the downwelling or upwelling favorable winds occurring fall-winter. Cyanophytes located predominantly near-surface offshore pre-front, were ubiquitous cross-shelf and more closely associated with K. brevis post-front.
Resource Type
DOI
Date Available
Date Issued
Citation
  • Kamykowski, D., Pridgen, K., Morrison, J., McCulloch, A., Nyadjro, E., Thomas, C., & Sinclair, G. (2013). Cold front induced changes on the florida panhandle shelf during october 2008. Continental Shelf Research, 54, 52-66. doi:10.1016/j.csr.2012.12.006
Non-Academic Affiliation
Series
Rights Statement
Related Items
Funding Statement (additional comments about funding)
Publisher
Peer Reviewed
Language
Replaces
Additional Information
  • description.provenance : Submitted by Deborah Campbell (deborah.campbell@oregonstate.edu) on 2013-04-23T16:29:26ZNo. of bitstreams: 1McCullochAAHMSCColdFrontInduced.pdf: 3417104 bytes, checksum: 6b553d5dcf8554172d928fa37fd8ecd4 (MD5)
  • This is the publisher’s final pdf. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work.
  • description.provenance : Approved for entry into archive by Deborah Campbell(deborah.campbell@oregonstate.edu) on 2013-04-23T16:29:56Z (GMT) No. of bitstreams: 1McCullochAAHMSCColdFrontInduced.pdf: 3417104 bytes, checksum: 6b553d5dcf8554172d928fa37fd8ecd4 (MD5)
  • description.provenance : Made available in DSpace on 2013-04-23T16:29:56Z (GMT). No. of bitstreams: 1McCullochAAHMSCColdFrontInduced.pdf: 3417104 bytes, checksum: 6b553d5dcf8554172d928fa37fd8ecd4 (MD5) Previous issue date: 2013-01-16

Relationships

Parents:

This work has no parents.

Last modified

Downloadable Content

Download PDF

Items