Light and Photosynthesis 1 2 Light in the

Light and Photosynthesis 1) 2) Light in the Ocean I) Intensity II) Color III) Inherent Optical Properties IV) Apparent Optical Properties V) Remote Sensing Photosynthesis I) Light Absorption II) Light Reactions III) Dark Reactions I need a work study student (library work, will pay) Oscar Schofield (oscar@ahab. rutgers. edu)

For satellite remote sensing the wavelength is the key to what you want to measure. c = l/u e = hu = hc/l

Figure 6

I) Light Irradiance Intensity 2500 mmol photons m-2 s-1 z 1 Z (meters) Ed 1 Dz 5. 0 mmol photons m-2 s-1 z 2 Ed 2 Lambert Beers Law Ed 2 = Ed 1 e-Dz*Kd 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?

Early Optics Alexander the Great

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.

January 2003 Today Robot-mounted Hyperspectral Absorption meter

Your future will include robots patrolling the waters for you as optical instruments are now small

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 color Photo S. Etheridge

Why IOP Measurements? • Absorption, a • Scattering, b clarity

Review of IOP Theory Fo Incident Radiant Flux Ft Transmitted Radiant Flux No attenuation

Review of IOP Theory Fo Incident Radiant Flux Ft Transmitted Radiant Flux Attenuation

Loss due to absorption Fa Absorbed Radiant Flux Fo Incident Radiant Flux Ft Transmitted Radiant Flux

Loss due to scattering Fb Scattered Radiant Flux Fo Incident Radiant Flux Ft Transmitted Radiant Flux

Loss due to beam attenuation (absorption + scattering) Fb Scattered Radiant Flux Fa Absorbed Radiant Flux Fo Incident Radiant Flux Ft Transmitted Radiant Flux

Conservation of radiant flux Fb Scattered Radiant Flux Fa Absorbed Radiant Flux Fo Incident Radiant Flux Ft Transmitted Radiant Flux Fo = Ft + Fa + Fb

Beam Attenuation Measurement Theory c = fractional attenuance per unit distance, attenuation coefficient c = DC/Dx Fb Fa Fo Ft c Dx = - DF/F x x 0 c dx = - 0 d. F/F c(x-0) = -[ ln(Fx)-ln(F 0)] c x = -[ ln(Ft)-ln(Fo)] c x = - ln(Ft/Fo) Dx c (m-1) = (-1/x) ln(Ft/Fo)

Swimmer Visibility Model REAL TIME – Camera at NODE A Linking VIDEO and Vertical profile with Optical Products and Swimmer. Visibility Air Force Targets 19: 25 15: 40 13: 40 18: 20 Optical Mooring 11: 40 c 532 1 m Plans to return July 00 with NAVO. TIME

1) Collect a signal, about 95% of the signal 2) is determined by the atmosphere. 3) 2) Relate the reflectance to the physics, chemistry, 4) and/or biology in the water. R = Bb/(a+Bb) Optically-Deep Optically-Shallow Whitecaps Micro-bubbles Shallow Ocean Floor Suspended Sediments Phytoplankton 1/Kd Benthic Plants CDOM-Rich Water

Changing the relative proportions of materials in the water column also impacts color of the water Dissolved organics Phytoplankton 0. 7 Absorption (1/m) 0. 6 0. 5 0. 4 0. 3 0. 2 0. 1 0 400 -0. 1 450 500 550 600 wavelength (nm) 650 700

0 Absorption (m-1) 0 Depth (m) 0 6 12 2 4 6 8 Distance (km) 0 10 Backscatter (m-1) 2 4 6 8 Distance (km) 10 0. 03 Depth (m) 0 6 0 a 550 0 0 12 6 12 a 490 0 Depth (m) 1 12 Bb 488 2 6 4 6 8 Distance (km) 10 Bb 589 0 2 4 6 8 Distance (km) 10

2 Ratio 1. 5 1 0. 5 a 490/a 550 0 Bb 488/Bb 589 5 Distance (km) 10

That Pristine Blue NJ Water

Courtesy of Hans Graber, Rich Garvine, Bob Chant, Andreas Munchow, Scott Glenn and Mike Crowley

Influence of Optical Properties on Laser Performance Target 3 m Based on Surface Values

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

phytoplankton absorption (m-1) 0. 3 0. 2 0. 1 0 400 500 600 wavelength (nm) 700

absorption coefficient (m 2 mg-1) 0. 08 chl a chl b chl c PSC PPC 0. 06 0. 04 0. 02 0. 0 400 450 500 550 600 wavelength (nm) 650 700

chl a chl c chl b phycobilins carotenoids 1. 0 15 0. 75 10 5 0. 25 0 0 400 450 500 550 600 Wavelength (nm) 650 700 m. W cm-2 nm-1) 0. 50 Spectral Irradiance ( chl a-chl c-carotenoids 20 chl a-chl b-carotenoids chl a-phycobilins 1. 25 Relative Absorption chl b chl a

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)

Photosynthesis Heat Fluorescence Energy Different Excitation Orbitals In a molecule Energy gained hv Ground State

Q Fd A Fluorescence e QB - 2 H+ PQH 2 RC II P 680 + z RC I 2 H+ Light-Harvesting Pigments 2 H 2 O O 2 + 4 H+ PAR CO 2 CH 2 O

NUCLEUS P LHC gene CYTOSOL CHLOROPLAST H+ + 1/2 CO 2 1/2 CH 2 O + 3/2 ADP + 3/2 Pi Qb PQ Qb Qb PQ PQ PQ Qa LHC THYLAKOID MEMBRANE D 1 e. D 2 e- P 680 PH E e- e nc ce 1/2 O 2 + 2 H+ es H 2 O Yz or 4 Mn LHC PC/ cyt c 6 flu Minutes to Hours Pheo CF 1 Fx Photosystem I 2 x Fa/ Fb PQ e- Cytochrome b 6 -f-Fenn STROMA Fd 2 H+ 6 H+ 3/2 ADP + 3/2 Pi 3/2 ATP + 3/2 Pi 2 H+ A 0 P 700 2 H+ THYLAKOID LUMEN CF 0 E ATP synthase complex H+ + NADPH Photosystem II Days to Weeks Repressor proteins

0. 08 Pmax 2. 5 0. 06 0. 04 1. 5 0. 02 0. 5 0 0 50 100 150 200 light intensity 250 0 300 quantum yield of oxygen evolution 3. 5

Biomass Nutrients Photosynthesis Irradiance Intensity Ik Z (meters)