"PIRANAs and PIRATAs Remote Sensing the Amazon River Plume" Guest Scientist: Ajit Subramanian

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"PIRANAs and PIRATAs -- Remote Sensing the Amazon
River Plume" Guest Scientist Ajit Subramanian

• Earth2Class Workshops
• Originally Presented 23 Oct 2004

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Dr. Ajit Subramanian

• is interested in the use of remote sensing,
  ocean optics, phytoplankton physiology,
  biological and physical oceanography and
  geographical information systems to better
  understand how the marine ecosystem works and can
  be managed.
• uses bio-optics and remote sensing as tools
  for monitoring coastal water quality.

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Much of his work focuses on understanding the
Nitrogen cycle in the global ocean system
http//shell.pubnix.net/spond/filter/nitrogen.htm
l
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Here is another way to represent the Nitrogen
Cycle
http//users.rcn.com/jkimball.ma.ultranet/BiologyP
ages/N/NitrogenCycle.html
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The Nitrogen Cycle in the Oceans

• Recent research reveals that human impacts have
  greatly enhanced the rate at which nitrogen moves
  from land to sea
• In effect, we have doubled the amount of nitrogen
  fertilizers in the marine system

http//scicom.ucsc.edu/SciNotes/9801/ice/nitro.htm
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Much of this is taken up by the wide variety of
marine phytoplankton
http//seawifs.gsfc.nasa.gov/SEAWIFS/sanctuary_4.h
tml
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One of the most effective nitrogen-fixers is
Trichodesmium

• This cyanobacterium (blue-green algae) possesses
  nitrogenase enzymes
• Much research is underway to learn how Fe, Mo,
  and other elements may serve as bio-limiting
  factors

• Trichodesmium

http//www.princeton.edu/cebic/N-cycle-intro1.htm
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Among the effects may be algal blooms, which
can now be observed from space
CZCS Image of the Po River
Shuttle Photograph of the Po River
http//daac.gsfc.nasa.gov/CAMPAIGN_DOCS/OCDST/clas
sic_scenes/10_classics_rivers.html
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HAB Harmful Algae Blooms

• Although most phytoplankton are harmless, some
  species contain toxins
• The misnomer red tide has been used for blooms
  of these dangerous organisms

http//www.whoi.edu/redtide/
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http//www.whoi.edu/redtide/whathabs/whathabs.html
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How Can We Observe Earth from Space?

• NASA provides an educational web site to
  explain remote sensing and other spatial
  information technologies at
• http//education.ssc.nasa.gov/fad/default.asp
• The site includes a tutorial, lesson plans,
  and links to additional Internet resources.

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SeaWIFS

• The Sea-viewing Wide Field-of-view Sensor
  provides quantitative data on global ocean
  bio-optical properties.

http//seawifs.gsfc.nasa.gov/SEAWIFS/BACKGROUND/
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• SeaWIFS can detect subtle changes in ocean
  color that signify various types and quantities
  of marine phytoplankton (microscopic marine
  plants), the knowledge of which has both
  scientific and practical applications.

http//seawifs.gsfc.nasa.gov/SEAWIFS/BACKGROUND/SE
AWIFS_BACKGROUND.html
http//seawifs.gsfc.nasa.gov/SEAWIFS/IMAGES/SEAWIF
S_GALLERY.html
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Techniques for studying plankton from space are
explained at

• Created by Bigelow Labs, this site describes how
  NASAs ocean color satellite instruments are used
  to study phytoplankton.
• http//www.bigelow.org/foodweb/

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Dr. Ajit Subramanian

• will provide much more information about remote
  sensing and the nitrogen cycle in marine
  ecosystems.
• His personal web site is
• http//www.ldeo.columbia.edu/ajit/
• He also recommends
• http//www.usc.edu/dept/LAS/biosci/tricho/trichoho
  me/