胡焕庸线：更多的卫星图片

（1）Figure 2. (a) Solar-induced chlorophyll fluorescence (SIF) as retrieved from GOSAT from June 2009 to December 2011. (b) Modeled gross primary production (GPP) for the same time period and locations.3, 4 GOSAT: Global Greenhouse Gas Observation by Satellite. sr: Steradian. MPI-BGC: Max Planck Institute for Biogeochemistry.

Figure 2 shows a global average of SIF as well as a corresponding map of modeled GPP, revealing strong correlations between both parameters.8These observations are directly linked to photosynthesis, provide new information not available from greenness indices, and enable an entirely new perspective on the global carbon cycle. Observations of SIF can, therefore, have an important role in carbon cycle research and alleviate the large uncertainties in GPP measurements.

（2） Figure 1. (a) Global map of plant chlorophyll fluorescence as measured by the GOSAT satellite from June 2009 to May 2010. The fluorescence is measured at a spectral wavelength of 757 nanometers and superimposed on a 2°x 2° grid. Areas of higher and lower plant activity can be seen in different parts of the world. (b) Time variations in the fluorescence signal given off by vegetation, from June 2009 to August 2010. A pronounced seasonal variation can be seen that reflects the growing season in the northern hemisphere and seasonal vegetation shifts in the tropics.

相关链接：

[1] 2014-12-24，胡焕庸线：清晰可见（美国极轨道碳观测者卫星2号OCO-2的荧光图）

http://blog.sciencenet.cn/blog-107667-853546.html

[2] Christian Frankenberg, Joseph Berry, Luis Guanter and Joanna Joiner, 15 February 2013, Remote sensing of terrestrial chlorophyll fluorescence from space.

http://spie.org/x92267.xml

[3] Amber Jenkins, Jet Propulsion Laboratory, February 29, 2012, Watching the planet breathe

http://climatesciences.jpl.nasa.gov/news-release/2012-02-earth-breathe