Megacities Carbon Project - Los Angeles observing network

This animation shows a global map of fossil-fuel CO2 emissions and the world's largest cities. Cities and their power plants are the largest sources of greenhouse gas emissions from human activity. As of 2010, urbanization has concentrated more than half of the world's population, at least 70% of fossil fuel carbon dioxide (CO2) emissions, and a significant amount of methane into a small fraction of the Earth's land surface. Currently the world's 40 largest cities together represent the third largest emitter of fossil fuel CO2 after China and the US. This trend is expected to grow in the future with increasing urbanization.This animation shows a global map of fossil-fuel CO2 emissions for the year 2010 derived from satellite imagery of night-lights and other data (courtesy Tom Oda - CSU/NOAA in collaboration with NIES). A global urban carbon monitoring system would combine surface measurement networks in the world's largest cities (highlighted here) and satellite observations of nearly all urban areas. The surface grid squares illustrate the surface footprint of future geostationary satellites that could be focused on the 2-3% of land surface area producing the majority of emissions.The Megacities Carbon Project will develop and test methods for monitoring the greenhouse gas emissions of the largest human contributors to climate change. For More InformationSee [http://megacities.jpl.nasa.gov/portal/](http://megacities.jpl.nasa.gov/portal/) Related pages

This animation shows an artist concept of the CLARS instrument on Mt Wilson scanning the LA basin for carbon dioxide and other greenhouse gases. The Megacities Carbon Project is developing and testing methods for monitoring the greenhouse gas emissions of cities, the largest human contributors to climate change. One of the sites in the Megacities monitoring network for Los Angeles is the California Laboratory for Atmospheric Remote Sensing (CLARS) located on Mt Wilson. From an altitude of nearly 6000 ft, CLARS makes frequent scans during daylight hours across the LA basin. In this animation, the CLARS telescope mirror points sequentially to different pre-programmed points to sample sunlight scattering off the Earth's surface. The CLARS spectrometer splits the light from each reflection point into a spectrum (like colors in a rainbow) to reveal the unique "fingerprints" of carbon dioxide, methane and other gases in the atmosphere. The lines in the spectrum are due to absorption from the various gases - analysis of which is used to reveal the concentration of a given gas in a column of air for a given location. CLARS serves as a prototype for a future geostationary satellite instrument that may someday serve as a "carbon weather satellite" - providing frequent wall-to-wall mapping of greenhouse gases across entire cities and broader regions.CLARS was developed by JPL with support from the NASA Earth Science Technology Office. CLARS operations are funded jointly by NASA and NIST. For More InformationSee [http://megacities.jpl.nasa.gov/portal/](http://megacities.jpl.nasa.gov/portal/) Related pages

This movie is a combined visualization of PBL and wind dynamics over the LA basin for a one month period. This movie is a visualization of PBL over the LA basin for a one month period. This movie is a visualization of winds over the LA basin for a one month period. The Megacities Carbon Project is developing and testing methods for monitoring the greenhouse gas emissions of cities, the largest human contributors to climate change. Observations of the concentrations of carbon dioxide (CO2), methane, and other gases in the atmosphere can be used to estimate the locations and strengths of different emission sources. Interpreting measurements of gas concentrations at one location to infer an emission source at another location is complicated by the effects of the Earth's atmosphere which is always in motion. For example, increasing concentrations of CO2 at a given location can either be due to increasing emissions or stagnant or sinking air whereas decreasing concentrations of CO2 can either be due to decreasing emissions or strong winds or rising air.This visualization shows the output of a high-resolution model of the atmosphere over Los Angeles (courtesy Meemong Lee and Zhijin Li, NASA/JPL). The model is based on meteorological measurements for one month in the spring of 2010 at a resolution of 1 km and 3 hours. Vertical motion of the Earth's Planetary Boundary Layer (PBL) - the lowest part of the atmosphere that hugs the surface of the Earth - is represented by the gray "blanket". The height of the PBL is largely driven by convection associated with the changing surface temperature of the Earth (for example, rising during the day and sinking at night). The colored arrows represent the strength and direction of winds at different altitudes. The Megacities Carbon Project includes measurements and models of PBL dynamics and winds to help interpret measurements of greenhouse gas abundances at different locations around the basin. Measurement systems include wind speed and direction indicators and laser detection and ranging (lidar) instruments to track the changing PBL height. For More InformationSee [http://megacities.jpl.nasa.gov/portal/](http://megacities.jpl.nasa.gov/portal/) Related pages