Figure 6.2 a & b. Data taken from Aerosol Pollution and its Sources in Major Cities of China, Zhang, Y., S. Xie, M. Shao, L. Zeng, M. Hu, W. Wang, and M. Bergin,
https://www.giss.nasa.gov/meetings/pollution2002/d1_zhang.html

Footnote 6. Arctic Monitoring and Assessment Program (AMAP), Arctic Pollution, 2009, a downloadable report from www.amap.no

Additional Resources

5.     NASA, Earth data, https://earthdata.nasa.gov/, accessed April 2017 and http://disc.sci.gsfc.nasa.gov/data-holdings/PIP/aerosol_index.shtml

6.     Goddard Space Flight Centre, AERONET, http://aeronet.gsfc.nasa.gov/

7.     NASA, NEO (NASA Earth Observations), http://neo.sci.gsfc.nasa.gov/