Oscar Schofield x 548, you are better off just walking in if you need help, if I can’t I will let you know, but it is quicker then trying to make a formal appointment, ask Judy I am a schedule- organization disaster……
Light and Photosynthesis 1)Light in the Ocean I)Intensity II)Color III)Inherent Optical Properties IV)Apparent Optical Properties V)Remote Sensing 2)Photosynthesis I)Light Absorption II)Light Reactions III)Dark Reactions
For satellite remote sensing the wavelength is the key to what you want to measure. c = = h hc
Figure 6
I) Light Z (meters) Irradiance Intensity Lambert Beers Law Ed 2 = Ed 1 e - z*Kd Ed 2 Ed 1 z1z1 z2z2 zz 1)Because of Lambert Beers Law the ocean is dim 2)Plant life is dependent on light 3) The 1% light level for the majority of the is 100 m or less? 2500 mol photons m -2 s mol photons m -2 s -1
Alexander the Great Early Optics
The color of the sea shows a great deal of variability from the deep violet-blue of the open ocean to degrees of green and brown in coastal regions. Before the advent of sensitive optical instruments, color was determined by visual comparison against standard reference standards such as the Forel Ule Color scale.
Your future will include robots patrolling the waters for you as optical instruments are now small
74:1074:0073:5073:4073:3073:2073:10 16-Sep :00: Sep :57:27 Temperature b b (532)/c(532) b b Now we can study during storms Depth-Averaged Currents Surface Currents Tropical Storm Ivan
What kind of measurements are there? Inherent Optical Properties: Those optical properties that are fundamental to the piece of water, not dependent on the geometric structure of the light field. (absorption, scattering, attenuation) Apparent Optical Properties: Those optical properties that are fundamental to the piece of water and are dependent on the geometric structure of the light field. (light intensity, reflectance)
Why IOP Measurements? Absorption, a color Scattering, b clarity Beam attenuation, c (transmission) a + b = c The IOPs tell us something about the particulate and dissolved substances in the aquatic medium; how we measure them determines what we can resolve
Why IOP Measurements? Absorption, a colorAbsorption, a color Photo S. Etheridge
Why IOP Measurements? Absorption, a Scattering, b clarity
Review of IOP Theory oo Incident Radiant Flux No attenuation Transmitted Radiant Flux tt
Review of IOP Theory Attenuation tt oo Incident Radiant Flux Transmitted Radiant Flux
Loss due to absorption a Absorbed Radiant Flux oo Incident Radiant Flux tt Transmitted Radiant Flux
Loss due to scattering b Scattered Radiant Flux oo Incident Radiant Flux tt Transmitted Radiant Flux
Loss due to beam attenuation (absorption + scattering) a Absorbed Radiant Flux b Scattered Radiant Flux tt oo Incident Radiant Flux Transmitted Radiant Flux
Conservation of radiant flux a Absorbed Radiant Flux b Scattered Radiant Flux o = t + a + b tt oo Incident Radiant Flux Transmitted Radiant Flux
Beam Attenuation Measurement Theory tt aa bb c = fractional attenuance per unit distance, attenuation coefficient c = C/ x c x = - / c x = - ln( t / o ) c (m -1 ) = (-1/x) ln( t / o ) oo xx 0 c dx = - 0 d / xx c(x-0) = -[ ln( x )-ln( 0 )] c x = -[ ln( t )-ln( o )]
1m Underwater Eye Chart 11:40 TIME Optical Mooring c53213:4015:4018:20 19:25
Phytoplankton CDOM-Rich Water Suspended Sediments Benthic Plants 1/Kd Optically-ShallowOptically-Deep Micro-bubbles Whitecaps Shallow Ocean Floor 1)Collect a signal, about 95% of the signal is determined by the atmosphere. 2) Relate the reflectance to the physics, chemistry, and/or biology in the water. R = B b /(a+B b )
Phytoplankton Dissolved organics Changing the relative proportions of materials in the water column also impacts color of the water
Distance (km) 01 Absorption (m -1 ) 00.03Backscatter (m -1 ) Depth (m) Depth (m) Distance (km) Distance (km) Distance (km) Depth (m) Depth (m) B b 488 B b 589 a490a550
a490/a B b 488/B b 589 Distance (km) Ratio
That Pristine Blue NJ Water
Courtesy of Hans Graber, Rich Garvine, Bob Chant, Andreas Munchow, Scott Glenn and Mike Crowley
Target 3 m Based on Surface Values Influence of Optical Properties on Laser Performance
Changes in the color of the reflectance as the load of material changes in the water column. Water Leaving Radiance Reflectance
Color variability at multiple scales around Tasmania from CZCS image Causes? Strong winds, strong currents, bottom togography, etc. GSFC, NASA Tasmania
wavelength (nm) phytoplankton absorption (m -1 )
chl a chl b chl c PSC PPC wavelength (nm) absorption coefficient (m 2 mg -1 )
Wavelength (nm) Spectral Irradiance ( W cm -2 nm -1 ) chl a chl b chl c chl b carotenoids phycobilins Relative Absorption chl a-chl c-carotenoids chl a-chl b-carotenoids chl a-phycobilins
Chlorophyll a : all phytoplankton (used as a measure of concentrations) Chlorophyll b : green algae Chlorophyll c : chromophytes (dinoflagellates, diatoms, coccolithophorrids) Carotenoids : fucoxanthin (dinoflagellates, diatoms, coccolithophorrids) 19’-hexanoyfucoxanthin (coccolithophorrids) alloxanthin (cryptophytes) peridinin (dinoflagellates)
Energy hv Ground State Different Excitation Orbitals In a molecule Heat Fluorescence Photosynthesis Energy gained
PAR Light-Harvesting Pigments RC IIRC I e - QAQA QBQB 2H + PQH 2 2H + Fd CO 2 CH 2 O P680 + z 2H 2 O O 2 + 4H + Fluorescence
THYLAKOIDMEMBRANE STROMA CYTOSOL LHCLHC 1/2 O 2 + 2H + H2OH2O 4Mn Yz e-e- 2H + PQ QbQb QbQb Cytochrome b 6 -f-Fe nn 2H + PC/ cyt c 6 Photosystem I CHLOROPLAST P700 A0A0 FxFx Fa/ FbFa/ Fb FdFd ATP synthase complex CF 0 CF 1 3/2ADP + 3/2Pi 3/2ATP + 3/2Pi NADPH H + + NADP + 6H + 1/2CH 2 O + 3/2ADP + 3/2Pi H + + 1/2CO 2 THYLAKOID LUMEN E P680 Pheo e-e- e-e- Photosystem II D2 D1 E QaQa QbQb 2 x e - PH Minutes to Hours NUCLEUS P LHC gene Repressor proteins Days to Weeks fluorescence
light intensity oxygen evolution quantum yield of oxygen evolution Pmax
Irradiance Intensity Z (meters) IkIk Photosynthesis Biomass Nutrients