The ColoroftheOcean Dr. Garver Geography GEO 410
Why Study Ocean Color? • Globally • Critical for the study of oceanprimary 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
Carbon Cycle CO2
Carbon Cycle • Phytoplankton; • First link in food chain • critical part of ocean chemistry • CO2 in atmosphere in balance with CO2in oceans. • During photosynthesis phytoplankton remove CO2from sea water and release O2 as by-product. • Oceans absorb additional CO2from atmosphere. • If less phytoplankton existed, atm. CO2 would increase.
Carbon Cycle • Phytoplankton also affect CO2levels 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.
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.
Time Monthly mean atmospheric carbon dioxide - longest record of CO2 measurements in atm. David Keeling -1958
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.
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.
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.
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.
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
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.
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.
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.
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.
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
Orbiting Sensor • Launched in summer, 1997 • Can view every square kilometer of cloud-free ocean every 48 hours
-----Original Message-----From: gene carl feldman [mailto:email@example.com] Sent: Monday, February 14, 2011 11:57 AMTo: firstname.lastname@example.orgCc: email@example.com; firstname.lastname@example.org; email@example.com; firstname.lastname@example.org; Runge.Howard@orbital.com; McCarthy.John@orbital.comSubject: [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
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.
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
SeaWIFS Imagery - Detailed maps of ocean color Reflected light will be directly related to the particulates and dissolved materials in it.
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.
Surface plumes along Gaviota Coast March 3, 1998 (Santa Barbara News Press).
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.
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.
Characterizing the Urban Ocean using Remotely Sensed Imagery Case study: Santa Monica Bay
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 ………
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?
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
Ballona Creek Discharge 1996/97 vs. 1997/98 Malibu Creek Discharge 1996/97 vs. 1997/98 February February Rainfall significantly above average - Feb. ‘98 +13 in.
Bacteria Counts Dissolved & Suspended Solids
10.00 1.00 0.10 Low Precipitation Month Chlorophyll Content January 22, 1998 mg m3 <1 mg m3 for most of Santa Monica Bay, with +1 mg m3 near the mouth of Ballona Creek.
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
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
Characterizing the Southern California Coastal Urban Ocean Geography majors Kelley McMurry and DeShawn Leiataua First Place – Student Poster Competition California Geographical Society Annual Meeting Salinas, CA
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.