Earth Observations from Space The First 50 Years of Scientific Achievements (2008) / Chapter Skim
Currently Skimming:
9 Ecosystems and the Carbon Cycle
9 Ecosystems and the Carbon Cycle
Pages 73-83
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 73... ...
higher trophic levels. Since the discovery of the importance of carbon dioxide as a greenhouse gas, the estimation of Terrestrial Primary Productivity global carbon fixed by photosynthetic processes has become a central quest in global carbon cycle research and an integral New awareness of the relationship between microclipart of climate models.
|
From page 74... ...
These early studies established that red and near-infrared satellite bands could track changes in plant growth and development. the plant canopy used to estimate functional process rates of nological patterns among six global terrestrial biome types.
|
From page 75... ...
or line through the canopy and counting the number of leaves that were contacted. With the development of red and near Marine Primary Productivity infrared indices such as normalized difference vegetation index (NDVI)
|
From page 76... ...
Although clouds prevent ocean color sensors to see the entire ocean surface on each orbital pass, a global picture of the distribution of photosynthetic plant biomass emerges from averaging data over several consecutive days or weeks. The first ocean color sensor was the Coastal Zone Color Scanner (CZCS)
|
From page 77... ...
CZCS = Coastal Zone Color Scanner; GAC = Global Area Coverage; LAC = Local Area Coverage; MERIS = Medium Resolution Imaging Spectrometer; MODIS = Moderate Resolution Imaging Spectroradiometer; MOS = Maritime Observation Satellite; OCI = Ocean Color Imager; OCTS = Ocean Color and Temperature Sensor; SeaWiFS = Sea-Viewing Wide Field-of-View Sensor; IRS = Indian Remote Sensing Satellite; ADEOS = Advanced Earth Observing Satellite; SST = Sea Surface Temperature. NPP (grams C m-2 year-2)
|
From page 78... ...
satellite data to estimate global net primary production, Prior to the introduction of satellite observations, esti- combining both terrestrial and oceanic models. Within a few mates of oceanic primary production depended on relatively years they used a linked ocean-terrestrial model that comfew labor-intensive ship-based incubations using the 14C bined an 8-year Advanced Very High Resolution Radiometer technique that had become the standard method for measur- (AVHRR)
|
From page 79... ...
Because AVHRR p roductivity, the oceanic component of the carbon cycle will was not designed for observing the terrestrial biosphere and respond more quickly to climate changes. the 1- to 8-km scale of AVHRR pixels was significantly For example, there are vast areas of the Pacific and larger than theoretical understanding of ecosystem processes, Southern Oceans, where phytoplankton productivity might scientists were initially skeptical about whether biospheric be limited by iron (Martin et al.
|
From page 80... ...
To estimate actual NPP in the presence of environmenwere strongly correlated with daily dynamics of terrestrial tal stressors, researchers developed methods to remotely IPAR (intercepted photosynthetically active radiation) and estimate regulatory plant biochemicals.
|
From page 81... ...
They used a time series of NDVI, a measure of the photosynthetic activity of vegetation canopies, derived from the daily AVHRR satellite data, and showed an increase in length of the growing season in the boreal region (north of 45º) of 12 days (8 days in spring and 4 days in autumn)
|
From page 82... ...
the synergistic advent of new sensor capabilities such as FIGURE 9.6 A map of invasive species in the Hawaiian rainforest, measured using NASA's AVIRIS data and impacts of invasive species and plant functional types on biogeochemical cycles. SOURCE: Modified from Asner and Vitousek (2005)
|
From page 83... ...
Jubata invaded chaparral Intact chaparral Intact scrub Iceplant invaded scrub chaparral Iceplant invaded chaparral Blue gum Masked Road Coastline FIGURE 9.7 Distribution of three invasive species -- iceplant, jubata grass, and blue gum -- in two native shrub eco systems -- coastal sage scrub and Burton Mesa chaparral -- on the central coast of California. The map was produced from a mosaic of flightlines acquired from airborne NASA AVIRIS data, a 224-band imaging spectrometer measuring from the visible through the solar infrared (400-2,500 nm)
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.