upper limit for a is 0.115 g carbon [g chlorophyll] h [ yE m S ] 



(Piatt and Jassby, 1976). A theoretical upper limit for P of 24 g 



-1 -1 

 carbon g chlorophyll h has been calculated based on the turnover 



rates of photosynthetic units ( Falkowske , 1982). A large suite of both 



laboratory and field data for phytoplankton and higher plants document 



empirical confirmation of these values as upper limits (cf., Malone and 



Neale , 1981). 



These theoretical maxima are important for remotely sensed determina- 

 tions of marine primary productivity because they place an upper bound 

 on primary production calculations based on color scanner chlorophyll 

 concentrations. Specific environmental conditions including 

 temperature, nutrients, light intensity, and light history set the 

 actual lower values for computing instantaneous primary productivity 

 rates from biomass. Results of research over the last several years on 

 phytoplankton physiology have advanced our understanding of the effects 

 of temperature, nutrients, and both present light intensity and recent 

 light history on photosynthesis. These results provide mechanisms for 

 assigning realistic values within the theoretical maximal rates for pri- 

 mary productivity per unit of chlorophyll biomass sensed by buoys, air- 

 craft, and satellites . 



With the availability of other remotely sensed environmental data, e.g., 

 ocean temperature, incident light intensity arriving at the sea surface, 

 wind stress (Tables 2-2 and 2-3), the precision for resolving instan- 

 taneous rates of primary productivity can be further enhanced. 

 Biological, enzyme-mediated reactions exhibit a temperature dependency 

 which is often expressed by the Arrhenius equation for temperature regu- 

 lation of a chemical rate reaction 



In k = -E (RT)" 1 + C 



where k is a rate constant in units of t , t is time, E is a tempera- 

 ture characteristic (calories mole)" , R is the universal gas constant 

 (calories °K" mole)" , T is absolute temperature (degrees Kelvin), and 

 C is a constant. The maximal photosynthetic rate, P , is enzymatically 

 determined, and hence, is affected by temperature; this contrasts with 



4-8 



