The Color of the Ocean

1
The Color of the Ocean

• Dr. Garver
• Geography
• GEO 410

2
Why Study Ocean Color?

• Globally
• Critical for the study of ocean primary
  production and global biogeochemistry.
• Carbon Cycle Marine plants remove carbon from
  the atmosphere at a rate equivalent to
  terrestrial plants.
• But knowledge of interannual variability is very
  poor.
• production of organic compounds from atmospheric
  or aquatic carbon dioxide, principally through
  the process of photosynthesis.
• study of the chemical, physical, geological, and
  biological processes and reactions that govern
  the composition of the natural environment

3
Carbon Cycle
CO2
4
Carbon Cycle

• Phytoplankton
• First link in food chain
• critical part of ocean chemistry
• CO2 in atmosphere in balance with CO2 in oceans.
• During photosynthesis phytoplankton remove CO2
  from sea water and release O2 as by-product.
• Oceans absorb additional CO2 from atmosphere.
• If less phytoplankton existed, atm. CO2 would
  increase.

5
Carbon Cycle

• Phytoplankton also affect CO2 levels when they
  die.
• Phytoplankton - composed of carbon-based
  substances.
• Dead phytoplankton sink to ocean floor.
• Covered by other material sinking to ocean
  bottom.
• Oceans act as a sink for global carbon which
  otherwise would accumulate in the atmosphere as
  CO2.

6
Carbon Cycle

• Carbon dioxide acts as a "greenhouse" gas in
  atmosphere.
• Sources of CO2 in atmosphere - decomposition of
  organic matter (such as trees), carbon dioxide
  that animals and people exhale, volcanic
  activity, burning of fossil fuels.
• No one knows how much carbon oceans and land can
  absorb.
• Nor do we know how Earth's environment will
  adjust to increasing amounts of CO2 in
  atmosphere.
• Studying distribution and changes in global
  phytoplankton using ocean color and other tools
  will help scientists find answers to these
  questions.

7
Monthly mean atmospheric carbon dioxide - longest
record of CO2 measurements in atm. David Keeling
-1958

• Time

8

• Regionally
• Knowledge of suspended and dissolved materials is
  critical for monitoring marine resources.
• Detailed ocean color modeling required if coastal
  zone managers are to take advantage of global
  investments in satellite-borne ocean color
  sensors.

9

• Coastal Zone Color Scanner (CZCS)
• First instrument devoted to measurement of ocean
  color
• Other instruments optimized for land or
  meteorological use and had limited sensitivity
  over oceans.
• Objective was to determine if satellite remote
  sensing of ocean color could be used to identify
  and quantify material suspended or dissolved in
  ocean waters.
• discriminate between organic and inorganic
• determine quantity of material and discriminate
  between different organic particulate types.

10

• Coastal Zone Color Scanner
• Measurements allowed oceanographers to infer the
  global distribution of phytoplankton for the
  first time.
• "proof-of-concept" experiment
• Showed that satellite ocean color measurements
  could be reliably used to derive products such as
  chlorophyll and sediment concentrations.
• Provided justification for future ocean color
  missions such as SeaWiFS.

11
CZCS

• One of eight instruments flown on Nimbus-7
  spacecraft
• Launched October 24th, 1978 ended in 1985
• 6 bands
• Thermal Band - infrared temperature sensor
  (channel 6, 10.5-12.5 microns) never functioned
  satisfactorily.
• Detector lost sensitivity rapidly - reasons for
  failure never determined.

12
(No Transcript)
13
(No Transcript)
14
Colored dissolved organic matter (CDOM) Detritus

• The optically measurable component of the
  dissolved organic matter in water.
• Also known as yellow substance and gelbstoff
• occurs naturally in aquatic environments as a
  result of decaying detritus.
• detritus is non-living particulate organic
  material
• The color of water will range through green,
  yellow-green, and brown as CDOM and detritus
  increases.
• can have significant effect on biological
  activity
• inhibit growth of phytoplankton and
  photosynthesis

15
Colored dissolved organic matter and Detritus

• Interferes with the use of satellite
  spectrometers to remotely estimate phytoplankton
  population distributions.
• Chlorophyll is key indicator of phytoplankton
  activity.
• However, difficult to differentiate between
  CDOM/Detritus and chlorophyll.

16

• CZCS - really was a COASTAL ZONE color scanner
  with heavy emphasis on sampling coastal waters
  (northern hemisphere).
• Persistent cloud cover in regions like the ITCZ
  and other factors influence the patterns of
  coverage
• CZCS was scheduled to collect data over specific
  regions rather than follow a uniform global
  distribution of sampling as is the case with
  SeaWiFS.

17

• Environmental awareness was just coming of age in
  the 70's at the time of the CZCS mission and
  people's attentions were focused along the coasts
  and the impacts of humankind on these regions.
• The decades of the 80's and 90's saw the focus
  shift to a more global approach to environmental
  studies.

18
SeaWiFS Project

• Part of NASA's Mission to Planet Earth (MTPE)
• Goal Provide quantitative data on global ocean
  bio-optical properties to the Earth science
  community.
• Follow on ocean color visible sensor to the CZCS
  sensor which operated from 1978-1985.

19
SeaWiFS Wavebands

• Band Wavelength Region (nm) Resolution (km)
• 1 402-422 (blue) 1.13
• 2 433-453 (blue) 1.13
  
• 3 480-500 (cyan) 1.13
• 4 500-520 (green) 1.13
• 5 545-565 (green) 1.13
• 6 660-680 (red) 1.13
• 7 745-785 (near-IR) 1.13
• 8 845-885 (near-IR) 1.13

20
Characteristics of sensors
Parameters Landsat-ETM SeaWiFS
Spatial resolution 15, 30, 60 m 1.1 km
Temporal resolution 16 days 1 day
Radiometric resolution 8 bits 256 DN values 10 bits 1024 DN values
Spectral resolution 8 Bands 8 Bands
21
Orbiting Sensor

• Launched in summer, 1997
• Can view every square kilometer of cloud-free
  ocean every 48 hours

22

• -----Original Message-----From gene carl
  feldman mailtogene_at_seawifs.gsfc.nasa.gov
  Sent Monday, February 14, 2011 1157 AMTo
  ocean-color_at_seawifs.gsfc.nasa.govCc
  staff_at_seawifs.gsfc.nasa.gov mhf_at_nasa.gov
  compton.j.tucker_at_nasa.gov mcleave_at_verizon.net
  Runge.Howard_at_orbital.com McCarthy.John_at_orbital.co
  mSubject ocean-color the end of an incredible
  era
•  
• Folks,
• I am very sorry to have to report the news that
  after nearly two months of intensive research and
  numerous attempts at communication with the
  spacecraft, it has been determined that the
  SeaWiFS mission is no longer recoverable. While
  this is certainly not the outcome that we were
  all hoping for, the international scientific
  community certainly could not have asked for a
  more tenacious little spacecraft and instrument
  that has served us so well for the past 13
  years.
• Not bad for a spacecraft and mission that so
  many people thought would never get off the
  ground let alone make it through the projected 5
  year mission life.
• We will be putting together a feature this week
  on the OceanColor website about this wonderful
  little instrument but I wanted to pass along a
  couple of photographs that gave us our last look
  at the spacecraft and instrument as it was being
  prepared for launch on a hot summer day back in
  August 1997.
• Thanks to everyone for all their incredible
  support over the years and I have no doubt that
  this data set will continue to provide new
  discoveries and insights into the workings of
  this incredible planet that we call home.
• With my very best regards,
• gene

23
(No Transcript)
24
Phytoplankton

• Pigment concentration can be derived from
  satellite observations
• Ocean color in the visible light region varies
  with the concentration of chlorophyll and other
  plant pigments present.
• The greater the concentration of pigments, the
  greener the water.

25
(No Transcript)
26
(No Transcript)
27
CZCS Bands
28
SeaWiFS Bands
29

• Plumes and Blooms Project (UCSB/ICESS)
• R/V Ballena conducts transect cruises
• Optical, chemical and biological measurements
• Temperature, salinity, ocean color spectra,
  suspended particulate load and phytoplankton
  abundance

30
PNB STATION LOCATIONS
31
SeaWIFS Imagery - Detailed maps of ocean color

• Reflected light will be directly related to the
  particulates and dissolved materials in it.

32
Example Impacts of Large El Nino Driven Storms
on the California Coastal Environment (Warrick
and Mertes)

• Feb. 1998, El Nino driven storms blanketed the
  coast of California.
• Storm water inundated coastal waters, blanketing
  approximately 6,000 km2.
• Following week, the PnB project sampled 38
  locations in the Channel in an effort to
  quantify the impact of large storm water runoff
  events.

33

• Surface plumes along Gaviota Coast March 3, 1998
  (Santa Barbara News Press).

34
SeaWiFS true color image 2/10/98 (A) California
coast (B) Santa Barbara Channel. Between 2/4/98
and 2/8/98, 28 cm of precipitation fell in the
City of Santa Barbara. Aerial photographs of
plumes in the Santa Barbara Channel (C and D)
taken on 2/10/98.
35

• A spectral mixture analysis was applied to the
  February 9, 1998, SeaWiFS image to yield a
  sediment plume map for the Southern California
  region.
• Satellite data was calibrated using field
  measuremnets of TSM.

36
Characterizing the Urban Ocean using Remotely
Sensed Imagery

• Case study Santa Monica Bay

37
(No Transcript)
38
Look at storm water runoff by focusing on 2-3
episodes during last El Nino, winter 97- 98.

• Stormwater Pollution
• Untreated, contaminated water
• Drains from LA streets through municipal storm
  drain system and

39
How does storm water spread? Is an anthropogenic
signal detectable? What comes out of the mouths
of rivers? Spatial extent and duration of
episodes? Surface or subsurface?
40
Data

• 1) Ocean color imagery
• 2) Storm water runoff measurements
• Storm water runoff data - LA DWP
• Two major monitoring stations Ballona Creek and
  Malibu Creek.
• 1) Bacteria
• 2) Toxic metals
• 3) Biotic content

41
Rainfall significantly above average - Feb. 98
13 in.
42
Bacteria Counts
Dissolved Suspended Solids
43
Low Precipitation Month Chlorophyll
Content January 22, 1998
mg m3
lt1 mg m3 for most of Santa Monica Bay, with 1 mg
m3 near the mouth of Ballona Creek.
44
High Precipitation Month Chlorophyll Content
February 24, 1998
mg m3
up to 10 mg m3 along coastline, esp. near mouth
of Malibu Creek.
0.05 mg m3
45
Results

• 1997-98 El Nino event - excellent case study to
  examine storm water runoff.
• Clear environmental signal related to storm
  water and changes in chlorophyll concentration

46
Characterizing the Southern California Coastal
Urban Ocean Geography majors Kelley McMurry and
DeShawn Leiataua
First Place Student Poster Competition Californi
a Geographical Society Annual Meeting Salinas, CA
47
SeaWiFS 1-km resolution mapped images for the
California Current area
48
El-Chichon volcano erupted March/April 1982 -
spewed large amount of ash and gaseous products
into atmosphere.Gaseous products, particularly,
SO2 was converted into sulfuric acid and resides
in stratosphere for several yearsEffect of
eruption was observed in satellite-measurements
of geophysical parameters including SST by
(AVHRR) and ozone measurements. SST was biased
by, as much as 2.5o C.