Accession Number : ADA258803


Title :   Upper Ocean Mixing: The Use of Algal Pigments as Biological Tracers for Turbulent Diffusion.


Descriptive Note : Final rept. 1 Jul 1987-31 Dec 1990


Corporate Author : MOSS LANDING MARINE LABS CA


Personal Author(s) : Welschmeyer, Nicholas


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a258803.pdf


Report Date : 23 Sep 1992


Pagination or Media Count : 4


Abstract : The goal of lhe proposed research was to develop an in situ method for determining upper-ocean mixing rates using algal pigments as natural biological tracers. The work focused specifically on xanthophyll-cycling, a well known series of reversible, light-sensitive pigment transformations that occur in all higher land plants and many marine phytoplankton species. Laboratory work was initiated to define the rate constants for xanthophyll-cycling in microalgal cultures, and to develop a. quantitative understanding of the influence of light intensity on the xanthophyll-cycling process. Field work was completed which verified that xanthophyll-cycling processes measured in natural phytoplankton populations indeed reproduced our laboratory observations. A Monte-Carlo computer model was developed in order to study the influence of xanthophyll- cycling on algal pigmentation under known conditions of simulated mixing. The collective results from physiological experimentation and simulation modeling were used to develop a field method for calculating ocean mixing rates (Welschmeyer and Hoepffner, 1991; Welschmeyer 1991). The work has now identified previously unrecognized relationships between xanthophyll- cycling and cellular fluorescence, which are of potential importance in exploiting single-cell characteristics as novel tracers of ocean mixing. This new work is continuing in our laboratory.


Descriptors :   *OCEANS , *PIGMENTS , *PHYTOPLANKTON , *TRACER STUDIES , *TURBULENT DIFFUSION , SIMULATION , LABORATORY TESTS , FLUORESCENCE , MODELS , COMPUTERS , CELLS , OBSERVATION , INTENSITY , LIGHT , RATES , OCEANOGRAPHIC DATA , REVERSIBLE , LIMESTONE , NAVAL RESEARCH , MARINE BIOLOGY , LABORATORIES , MIXING , MOSAICS(LIGHT SENSITIVE) , CAROTENOIDS , OCEANOGRAPHY , FLUORESCENT SCREENS , TRANSFORMATIONS , CULTURES(BIOLOGY) , CULTURE , DIFFUSION


Subject Categories : Biology
      Radiation and Nuclear Chemistry
      Physical and Dynamic Oceanography


Distribution Statement : APPROVED FOR PUBLIC RELEASE