Light

Question 1

Energy of a photon

Answer 1

h*v (plank’s constant * frequency)

Question 2

Septrum of Solar Radiation (shortest to longest wavelength)

Answer 2

UV –> visible light –> infrared

Question 3

Visible Light

Answer 3

between 400-700 nm wavelength. shorter to longer (VBGYOR)

Question 4

PAR

Answer 4

photosynthetically active radiation (visible light)

Question 5

Infrared Radiation

Answer 5

700-3000 nm. HEATS LAKES

Question 6

Ultraviolet Radiation

Answer 6

100-400 nm. high energy most UV is between 320-400 nm (UV-A)

Question 7

Light Attenuation Coefficient

Answer 7

Higher in more eutrophic lakes (less light gets through). Units of 1/length. approximated by (1.7/secchi depth)

Question 8

Light absorbed quickest in water?

Answer 8

red light

Question 9

Light absorbed slowest in water?

Answer 9

blue light

Question 10

Secchi Disc

Answer 10

white and black disc used to measure depth

Question 11

Secchi Depth

Answer 11

about 10% of surface light

Question 12

Euphotic Zone

Answer 12

Where photosynthesis can occur (max depth = secchi depth * 3)

Question 13

Aphotic Zone

Answer 13

begins where 1% of surface light reaches and goes to the bottom of the lake

Question 14

Colored Dissolved Organic Matter (CDOM)

Answer 14

absorbs most wavelengths of light (heat and visible light)

Question 15

Clarity in Lakes

Answer 15

affected by organic color, algae, and suspended sediment