Lecture 19 : Linking in situ IOP with biogeochemistry, case studies (multi-instructor presentation and discussion). Concept of optical proxies. Proxies itunes. Variable interacts with light Volts or Counts IOP or AOP Proxy Variable –> real thing ( = phytoplankton, etc.).
Concept of optical proxies
Volts or Counts
IOP or AOP
Variable –> real thing
( = phytoplankton, etc.)Optical Properties as Proxies
Variable IOP or AOP
How to measure the variable (combination of proxies?)
Biogenic minerals (coccoliths)
What information does the IOP/AOP contain (multiple variables)?
absorption coefficientdirect IOP or inversion from AOPs: but – phytoplankton is only part of total aphyt, all pigments aps photosynthetically competent pigments fluorescencequasi-IOP or AOP (solar fluorescence)caution because of variable fdetermine pigment, then what? Convert to carbon? Use for physiology or PP model?
Variable: phytoplankton biomass – carbonIOPs: c – phytoplankton is only part b – phytoplankton is only part bb – phytoplankton is only part AOPs: bb – phytoplankton is only part Can bb/b or bb/c ratio help to better resolve if c, b or bb is dominated by organics ?
Variable: phytoplankton functional grouping eg: SIZE or TAXONIOP: spectrum beam c – mean particle size VSF – particle size distributionAOP: inversion spectrum bb – mean particle size-dependence of a – pigment packaging –> pico vs. microplankton; key groups
Ancillary data to guide interpretation/model/etc.* temperature – algal growth rate, carbon flux, nutrient effects, etc.* salinity – terrestrial CDOM, stratification * winds – mixing, storms* depth – MLD, euphotic depth, water column depth* geographic regime and distance from shore* what else?