TEACHER PAGES
LESSON THREE
Chlorophyll
Time,
Temperature,
a
Does sea surface temperature affect chlorophyll a concentrations?
A partnership between California Current Ecosystem Long Term Ecological Research (CCE LTER) and Ocean Institute (OI)
Beth Simmons, Education and Outreach Coordinator, CCE LTER, Scripps Institution of Oceanography,
Christy Millsap, Teacher, Rancho Bernardo High School, San Diego, California.
Introduction: Scientists with the California Current Ecosystem Long
Chlorophyll a Concentrations
Term Ecological Research program (CCE LTER) have been collecting
(mg Chl/m³)
data on phytoplankton abundance and chlorophyll a concentrations
Satellite data are analyzed using an equation (or
algorithm) that manipulates specific values like ocean
using water sampling techniques for decades. It is time-consuming and
color and chlorophyll a concentration and translates
expensive to collect these samples offshore, so they are generally
them into pixel values (like pixels of a photograph).
collected only once every three months. For the past twenty-five years,
Each pixel represents the chlorophyll concentration
from a certain place in the ocean. These pixels are
scientists have been able to supplement their data collection with
then projected onto a map so that scientists can see
satellite images. These images allow scientists to see changes in
how much chlorophyll is in a particular place. A color
phytoplankton abundance and chlorophyll a concentrations over short
scale is created to represent a range of values for
periods of time and over large areas of the ocean at once.
chlorophyll concentration. Since each pixel represents
a specific value, scientists can study an entire image and
Integrating technology like NASA satellites complements CCE LTER’s
begin to understand the health of a specific location.
ship-based measurements. These satellites are equipped with SeaWiFS
and MODIS remote sensing technology. This technology creates images
that help scientists visualize the abundance of phytoplankton in a given area.
It works by measuring the color of the ocean surface. Chlorophyll a absorbs
particular wavelengths of light. Lower concentrations of phytoplankton, and
therefore chlorophyll a, result in the water appearing more purple or blue. As the concentration of phytoplankton (and
chlorophyll a) increases, the water appears more green, yellow, or even red. Images of chlorophyll a concentrations can
be coupled with satellite images of sea surface temperatures (SST) in the same area at the same time. When these two
variables are examined together, scientists can assess how increasing sea surface temperatures relates to phytoplankton
abundance. Why is this important?
In many instances, phytoplankton abundances are higher in cold, nutrient-rich waters. In the California Current Ecosystem,
these nutrient-rich waters are the result of upwelling. Upwelling occurs when the prevailing winds blow south along the
coastline. This results in the surface water moving
westward away from the coast (caused by Ekman
transport). As the warm, surface water moves away
from the coast, cold, deep water comes in to fill the
space. This deep water is full of nutrients, which
allows for large numbers of phytoplankton to flourish. As ocean surface temperatures increase, upwelling tends to decrease. Decreased upwelling can lead
to lower phytoplankton abundance. The effects of
this decrease can be widespread and change local
ecosystem dynamics. In light of this, scientists from
the CCE LTER continue to track phytoplankton
abundance as an indicator of the health of the California Current Ecosystem.
1
Created by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
LESSON THREE
TEACHER PAGES
Time,
Temperature,
Chlorophyll
a
Does sea surface temperature affect chlorophyll a concentrations?
CA standards addressed:
Target students: Grade 9-12 Biology, Marine Science, Environmental
Science, or Ecology students
Life Science standards
6b students know how to analyze changes in an
ecosystem resulting from changes in climate...
Time Frame: ~ 60 minute class period
Purpose: To determine if there is a relationship between sea surface
temperature, chlorophyll a concentrations and phytoplankton abundance.
Objectives:
✓ analyze changes in an ecosystem resulting from changes in climate, human
activity or changes in phytoplankton abundance
✓ determine if sea surface temperature affects chlorophyll a concentrations
and phytoplankton abundance
✓ recognize that technology enhances scientific observations
✓ understand the cumulative nature of science
Materials: CCE LTER satellite images of Santa Barbara coastal waters
(provided)
Investigation and Experimentation
1d Formulate explanations by using logic and evidence
1k Recognize the cumulative nature of scientific
evidence
National Science Standards:
NS.9-12.1 SCIENCE AS INQUIRY
- Abilities necessary to do scientific inquiry
investigations and understand scientific inquiry
- Identify questions and concepts that guide scientific
investigations.
NS.9-12.6 PERSONAL AND SOCIAL PERSPECTIVES Environmental quality
NS.9-12.7 HISTORY AND NATURE OF SCIENCE Nature of scientific knowledge
Prior Knowledge:
✓ Students should review the process of photosynthesis.
✓ Students should understand the role of photosynthesis in the carbon cycle.
Hypothesis: Have students take on the role of a CCE LTER scientist by developing a testable hypothesis examining the
relationships between chlorophyll a, sea surface temperature and phytoplankton abundance.
Procedure Part One:
1. Divide the class into groups of four. Have each student write a hypothesis.
2. Within each group, designate two students as phytoplankton ecologists studying chlorophyll and two students as
physical oceanographers studying sea surface temperature (SST).
3. Give the phytoplankton ecologists the chlorophyll satellite image 1a worksheet (chlorophyll a values 10/4-10/8/08) and
give the physical oceanographers the sea surface temperature data image 1b worksheet (sea surface temperature
10/4-10/10/08).
4. Have the students pair off and make some initial observations with their partner, and then respond to the questions
underneath each of the images.
5. After each group has examined the images and responded to the questions, have them come back as a group of four
to discuss their results, encouraging the phytoplankton ecologists and the physical oceanographers to compare their
images (1a and 1b). Have them:
a. Share their findings and together write a statement describing what kind of relationship(s) might exist between
chlorophyll a concentrations (1a) and sea surface temperature (1b).
b. Write a possible explanation for why a relationship might exist between the two variables supporting the explanation
with scientific concepts. For example: Chlorophyll a appears to increase when the surface water is cooler because
cooler water carries more nutrients for the phytoplankton, which need nutrients and sunlight to grow. The nutrients
fuel phytoplankton production which means more chlorophyll a.
2
Created by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
LESSON THREE
TEACHER PAGES
Time, Temperature, Chlorophyll a
Does sea surface temperature affect chlorophyll a concentrations?
Procedure Part Two:
6. After completing the first set of observations have students pair back up with their chlorophyll / SST partners.
Distribute the second set of images, giving image 2a to the chlorophyll students, and image 2b to the SST students. Have
them look at the images with their partners and respond to the questions underneath each of the images.
7. Have students return to their group of four to compare images 2a and 2b, and have them discuss their findings with
the others by responding to the following prompts:
a. Was your hypothesis supported or rejected, or is more research required to make a statement?
b. Write a possible explanation as to why the images (1 and 2) changed so drastically over such a short span of
time.
8. After groups have completed their discussions using the prompts, engage the class in a discussion. Does sea surface
temperature influence chlorophyll a concentrations? What causes the sea surface temperature to change? During this
discussion, ask students to consider the role that wind might play in moving warm surface water away from shore and
how cold, nutrient-rich, deep water rises up to replace it (upwelling). This explains why the inshore water is cooler.
Upwelling is vital in that it brings nutrients (like nitrogen, phosphorus, etc.) that phytoplankton need to grow and be
productive at the surface. Point out to the students that in-between the timing of images 1 and 2 there was a storm
with strong winds. The result was that a large amount of warm surface water moved away from the shore allowing
cold, deep, nutrient-rich water to replace it. A rapid response by phytoplankton followed, causing a phytoplankton
bloom.
Conclusion:
Based on the data that have been analyzed, have the students write their scientific findings in a concluding paragraph.
Have them include in this paragraph:
✓ Their original hypothesis and whether it was supported or rejected based on the images that they have seen.
✓ A statement clearly explaining the relationship that exists between phytoplankton abundance, chlorophyll a
and sea surface temperature.
✓ What influences sea surface temperature change on a daily, weekly and monthly basis.
✓ The long-term effects of increasing sea surface temperatures on phytoplankton abundance.
Additional resources:
1. Kay, Jane (2006) Ocean warming's effect on phytoplankton / NASA satellite data show how global climate
change hurts marine food chain, Chronicle Environment Writer:
http://articles.sfgate.com/2006-12-07/news/17327061_1_phytoplankton-climate-pacific-ocean
2. The Incredible Glowing Algae: http://earthobservatory.nasa.gov/Features/glowingalgae/.
3
Created by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
TEACHER ANSWER SHEET
Time, Temperature, Chlorophyll a
Does sea surface temperature affect chlorophyll a concentrations?
Possible Student Answers
1.
2.
3.
4.
1. 2.
3.
4.
5.
6. Chlorophyll Image 1a:
The values for chlorophyll a are highest closest to the shore, on the north side of Point Conception and
between Point Conception and the Channel Islands. The chlorophyll values are lowest offshore.
Answers will vary. This is a region of coastal upwelling. This upwelling brings cool, nutrient-rich waters to the
surface, enabling phytoplankton to use those nutrients for growth.
As sea surface temperatures increase, chlorophyll a concentrations decrease. They are inversely related.
Answers will vary depending on how much background students have. Colder ocean water often contains more
nutrients, which phytoplankton require for photosynthesis. The warmer the water, the fewer the nutrients are
generally available and the probability for the formation of phytoplankton blooms decreases.
Chlorophyll Image 2a:
Chlorophyll a is high inshore and around the Channel Islands, but
there is also a large concentration of chlorophyll offshore. The lowest chlorophyll concentrations are to the
south and far offshore.
Answers will vary depending on how much background students have. This is a region of coastal upwelling
where cold, nutrient-rich water reaches the surface and allows plankton to grow.
Image 2a shows a much larger area of chlorophyll a concentration. It has expanded from the initial
coastal region to much further offshore.
The SST images should show a relationship between areas of low SST and high chlorophyll a concentration.
a. Was your prediction correct or incorrect? Answers will vary.
b. During this time span, there was a storm, which included a high-wind event. The storm caused cooler,
nutrient-rich water to move into the area (through upwelling) and stimulated a phytoplankton bloom, due to
the sudden availability of nutrients.
Research results must be communicated. Use a writing rubric to score student’s conclusions. Did
students clearly articulate a relationship between sea surface temperature, chlorophyll a concentrations and
phytoplankton abundance? Did they mention the value of advancements in technology that enhance scientific
exploration? Did students understand the cumulative nature of science?
4
Created by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
TEACHER ANSWER SHEET
Time, Temperature, Chlorophyll a
Does sea surface temperature affect chlorophyll a concentrations?
Possible Student Answers
Vocabulary:
Abundance: The number of a particular type
of organism within a specific community.
Biomass: The amount of living organisms.
Chlorophyll a: A pigment that all plants
contain, which allows them to perform
photosynthesis. It absorbs blue light and emits
or fluoresces, red light. This green pigment
can be directly measured and is used as the
primary indicator of algal biomass.
Ekman transport: The net movement of the
surface layer of the ocean in a direction 90° to
the right of the direction of the wind.
Nutrients: Elements that are required by
phytoplankton for growth. Those of greatest
importance are nitrogen, phosphorus and iron.
Photosynthesis: Chemical process by which
plants convert light energy into chemical
energy (glucose). 6CO2 + 6H2O + light
energy ➪ C6H12O6 + 6O2
Phytoplankton: Microscopic algae that live in
water and produce their own food through
the process of photosynthesis. Collectively,
phytoplankton are the foundation of the
marine food web.
Primary productivity: The amount of material
(biomass) produced by plants (primary
producers) through the process of
photosynthesis.
SEAWIFS/MODIS: Sea-viewing Wide Field-ofview (SEAWIFS) Sensor that provides data
received from an Earth-orbiting color satellite
sensor loaded with Moderate Resolution
Imaging Spectroradiometer (MODIS)
instrument that collects the data.
Upwelling: The process where by sustained
winds move warm surface water offshore and
cold, nutrient- rich deep water rises up to
replace it.
Sea Surface Temperature Image 1b:
1. The values for sea surface temperature are lowest closest to the shore, on the
north side of Point Conception and between Point Conception and the Channel
Islands. Values are higher offshore and to the coastal south.
2. Answers will vary. This is a region of coastal upwelling. This upwelling brings
cool, nutrient-rich waters to the surface along coastlines due to prevailing wind
patterns and Ekman transport.
3. As sea surface temperatures increase, chlorophyll a concentrations decrease. They
are inversely related.
4. Answers will vary depending on how much background students have. Colder
ocean water often contains more nutrients, which phytoplankton require for
photosynthesis. The warmer the water, the fewer nutrients are generally available,
thus the probability for the formation of phytoplankton blooms decreases.
Sea Surface Temperature Image 2b:
1. Sea surface temperature is high inshore along the coastal south and around the
Channel Islands, with a large area offshore. Highest sea surface temperatures are to
the south.
2. Answers will vary depending on how much background students have. This is a
region of coastal upwelling where cold, nutrient-rich water reaches the surface due to
prevailing winds and Ekman transport.
3. Image 2b shows a much larger area of cool sea surface temperatures. It has
expanded from the initial coastal region to much further offshore.
4. The second satellite image of chlorophyll a should show high concentrations in the
same locations where sea surface temperatures are low.
a. Was your prediction correct or incorrect? Answers will vary.
b. Possible explanation: During this time span, there was a storm, which
included a high-wind event. The storm caused cooler, nutrient-rich water to
move into the area (through upwelling) and stimulated a phytoplankton
bloom, due to the sudden availability of nutrients.
5. Conclusions: (see above)
5
(STUDENT WORKSHEET) for TEACHER
Time, Temperature, Chlorophyll a
Does sea surface temperature affect chlorophyll a concentrations?
The satellite imagery below is taken using different filters to detect chlorophyll a concentrations. When looking at the chlorophyll a images, warmer colors
indicate higher concentrations of chlorophyll a (and thus phytoplankton) and cooler colors indicate lower concentrations. Black lines indicate satellite drifter
tracks. Source: http://spg.ucsd.edu/Satellite_Data/California_Current/2008/CCE-LTER/
IMAGE 1a: Chlorophyll a concentrations
Point Conception
Chl mg/m³
Channel Islands
CCE LTER Satellite Image off the coast of Santa Barbara 10/04/08 - 10/08/08
Phytoplankton ecologists respond to the following:
Write a hypothesis to explain a possible relationship between sea surface temperature, chlorophyll a concentration and
phytoplankton abundance.
My hypothesis:
1. Looking at image 1a, describe where chlorophyll a concentrations are the highest and where they are lowest.
2. With your partner, write a statement describing why there are many phytoplankton in some areas and few in other
areas.
3. Share your findings with the physical oceanographers and together write a statement describing what kind of
relationship(s) might exist between chlorophyll a (1a) and sea surface temperature (1b).
4. Write a possible explanation for why a relationship between the two measurements may exist, and support the
explanation with scientific concepts.
6
Created by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
(STUDENT WORKSHEET) for TEACHER
Time, Temperature, Chlorophyll a
Does sea surface temperature affect chlorophyll a concentrations?
The satellite imagery below is taken using different filters to detect chlorophyll a concentrations. When looking at the chlorophyll a images, warmer colors
indicate higher concentrations of chlorophyll a (and thus phytoplankton) and cooler colors indicate lower concentrations. Black lines indicate satellite
drifter tracks. Source: http://spg.ucsd.edu/Satellite_Data/California_Current/2008/CCE-LTER/
IMAGE 2a: Chlorophyll
(STUDENT WORKSHEET) for TEACHER
Chl mg/m³
Chan-
CCE LTER Satellite Image off the coast of Santa Barbara 10/15/08 - 10/28/08
Phytoplankton ecologists respond to the following:
1. Looking at image 2a, describe where chlorophyll a concentrations are the highest and where they are lowest.
2. Write a possible explanation for the pattern you see. Why are there many phytoplankton in some areas and few in others?
3. Write a statement describing how images 1a and 2a are different.
4. Based on this satellite image, predict what the corresponding image of SST might look like.
5. As a group, discuss your observations relating chlorophyll a concentrations and SST. Answer the following questions on the back
side of this paper:
a. Was your prediction for sea surface temperature correct?
b. Give a possible explanation as to why images 1a and 2a changed so drastically over such a short time span.
6. Conclusion: Based on the data that have been analyzed, write your scientific findings in a concluding paragraph. Include in this
paragraph:
✓ Your original hypothesis, and whether it was supported or not, based on the images that you have seen,
✓ A statement clearly explaining the relationship that exists between phytoplankton abundance, chlorophyll a concentration and sea
surface temperature.
✓ What influences sea surface temperature changes on a daily, weekly and monthly basis.
✓ The long-term effects of increasing sea surface temperatures on phytoplankton abundance.
7
Created by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
(STUDENT
for
WORKSHEET)
TEACHER
Time, Temperature, Chlorophyll a
Does sea surface temperature affect chlorophyll a concentrations?
The satellite imagery below shows sea surface temperature (SST). Warmer colors indicate warmer sea surface temperatures and cooler colors indicate
cooler temperatures. Black lines indicate satellite drifter tracks. Source: http://spg.ucsd.edu/Satellite_Data/California_Current/2008/CCE-LTER/
IMAGE 1b: Sea Surface Temperature
Point Conception
◦C
Channel Islands
CCE LTER Satellite Image off the coast of Santa Barbara 10/04/08 - 10/08/08
Physical Oceanographers respond to the following:
Write a hypothesis to explain a possible relationship between sea surface temperature, chlorophyll a concentration and
phytoplankton abundance.
My hypothesis:
1. Looking at image 1b, describe where sea surface temperature (SST) is the highest and where it is the lowest.
2. Write a possible explanation for the pattern you see. Why is the surface of the ocean warm in some areas and cool in
others?
3. Share your findings with the phytoplankton ecologists and together write a statement describing the relationship
between sea surface temperature (1b) and chlorophyll a (1a).
4. Write a possible explanation for why this relationship may exist and support the explanation with scientific concepts.
8
Created by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately
(STUDENT
for
WORKSHEET)
TEACHER
Time, Temperature, Chlorophyll a
The satellite imagery below shows sea surface temperature (SST). Warmer colors indicate warmer sea surface temperatures and cooler colors indicate
cooler temperatures. Black lines indicate satellite drifter tracks. Source: http://spg.ucsd.edu/Satellite_Data/California_Current/2008/CCE-LTER/
IMAGE 2b: Sea Surface Temperature
Point Conception
◦C
Channel Islands
CCE LTER Satellite Image off the coast of Santa Barbara 10/15/08 - 10/18/08
Physical Oceanographers respond to the following:
1. Looking at image 2b, describe where sea surface temperature (SST) is the highest and where it is the lowest.
2. Write a possible explanation for the pattern you see. Why is sea surface temperature high in some areas and low in others?
3. Write a statement describing how images 1b and 2b are different.
4. Based on this SST image, predict what the corresponding chlorophyll a image might look like.
5. Now, as a group discuss your observations correlating chlorophyll a concentrations and SST. Answer the following questions on the
back side of this paper:
a. Was your prediction for chlorophyll concentration correct?
b. Give a possible explanation as to why images 1b and 2b changed so drastically over such a short time span.
6. Conclusion: Based on the data that have been analyzed, write your scientific findings in a concluding paragraph. Include in this
paragraph:
✓ Your original hypothesis and whether it was supported or not, based on the images you have seen.
✓ A statement clearly explaining the relationship that exists between phytoplankton abundance, chlorophyll a concentration and sea
surface temperature.
✓ What influences sea surface temperature change on a daily, weekly and monthly basis?
✓ The long-term effects of increasing sea surface temperatures on phytoplankton abundance.
9
Created by: Beth E. Simmons © 2009 (Revised 2011)
Education & Outreach Coordinator CCE Long Term Ecological Research (LTER)
Disclaimer: May be reproduced for educational purposes; cite appropriately