OSEANOGRAFI FISIKA VI

Kecepatan Cahaya :

Di vakum 300.ooo km/dtk

Di Alam tgtg λ dan frek (v) c = λ.c

Peran sinar matahari di laut : Memanaskan air laut

Menghangatkan lapisan permukaan

Energi untuk phytplankton

Navigasi hewan dekat permukaan

Pemetaan backscatter ex: klorofil

Sun Earth~1026 cal/s 2,00 cal/cm2 min

Berfluktuasi : Aphelion (1,93)Perihelion (2,08)

Kenapa Jumlahnya berbeda?? Adsorption H2O, CO2, O3

UV (λ<0,29μ) ter-Cut off oleh O3

IR (λ 0,7-10 μ) terserap oleh H2O, CO2

Energi yang terserap diubah jadi bahang dan mjdheat budget atm

Scattering Refraksi and difraksi

Molekul udara dan turbid material (debu,

tetesan air, asap, dkk)

Radiasi gel panjang (Thermal wave) emisi awan danatm

Garis Fraunhofer

Dalam sifat optik air laut yang dikaji hanya rad. matahari pada gel. pendek yang tiba di muka laut (Io).

Dimana Is = radiasi langsung

Id = radiasi angkasa diffuse

Is dan Id bervariasi :

ketinggian matahari

komposisi atm

Short-Wave Back Radiation from Water to Air

Skema Short-Wave back Radiation (Ib)

Reflected & Scattered

Interface

Udara

Air

Menambah fluks ke atm(Ib)

Ib depends on

Amount of scatter and reflected radiation within the water, that is, on turbidity (Suspended matter, plankton, dust, air bubbles, etc)

Sun altitude (angle of direct solar)

Measurement of Iu (undersurface) easy made than Ib

(surface) agitated by wave

Extinction of Solar RadiationRadiation that penetrates of surface progressively diminished by extinction as result of:

Adsorption by pure water (k)

Adsorption by suspended and dissolved matter (kω)

Scattering in pure water (Є)

Scattering (diffraction, reflection) by suspended and dissolved matter (Єω)

These Component Which determine the extinction coefficient (α) depend on λ

Total intensity (Iz) at a depth (z) given by :

Where Is total intensity in surface

For Individual Wavelength

What is the conclusions you get from the figure 3.18 ??

Extinction of light in Pure Water Pure water before Salt Water

0,47μ

Extinction of Light In Sea Water of Different Turbidity Scattering (Є ωλ) and adsorption (k ω) by turbid water contribution in α fluctuating by place and time

In open ocean, turbidity depend on :

Origin of water masses

General oceanic circulation

αs observed extinction coefficient

αω extinction coefficient in pure water

Atlantic water

Figure 3.21 Distribution of vertical extinction coefficient of surface water in theAtlantic Ocean. The value are multiple by 100

Figure 3.22 Decrease of light intensity with depth at different location

Sargasso Sea

Continental Slope

Continental Shelf

Costal Area

Character of light extinction in different type of ocean water

Turbid Costal water (green-yelow)

Oceanic water (blue)

Increasing turbidity in open ocean and costal extinction short-wave become more significant it’s result from “Yellow Substance”

Spectral extinction in costal water (1) before and (2) after filtering , in (3) Comparison with double-distilled water

Spectral extinction in Oceanic water (1) before and (2) after filtering , in (3) Comparison with double-distilled water

Differences cause by FPTM (FilterPassing Turbidity Material) Ex Dissolved Organic Substance

The Color Of The Sea Coefficient Extinction of sun radiation

Depth Shallow or Depth Water

Organism Red Sea

Sediment Yellow Sea