Network For the
Detection of Atmospheric Composition Change (NDACC)
NASA Jet Propulsion Laboratory (JPL)
What does this program measure?
Stratospheric Ozone profiles (15-55km),
Stratospheric Temperature profiles (15-80km),
Stratospheric Aerosol profiles (15-40km)
How does this program work?
The experiment uses high-power, ultraviolet lasers. The laser wavelengths 308 and 353 nm are transmitted into the atmosphere. Radiation back scattered by the atmosphere at these wavelengths and also at 332 and 385 nm from atmospheric nitrogen Raman scattering is monitored. Ozone is measured by differential absorption lidar (DIAL), temperature by Rayleigh and Raman lidar, and aerosols by elastic backscatter (Mie) lidar. Observations occur 3-4 times per week at MLO.
Why is this research important?
The primary goals are to make the earliest possible identification of changes in the ozone layer and to discern the causes of the changes; to provide an independent calibration of satellite sensors of the atmosphere, and to obtain data that can be used to test and improve multidimensional stratospheric chemical and dynamical models.
Are there any trends in the data?
The following discussion and results are taken from a special section of NOAA CMDL Annual Report #27
As Figure 1 shows below, there is a significant positive correlation between ozone that was locally measured by lidar over Mauna Loa Observatory and the potential vorticity from ECMWF observed during the summer of 2002 near the tropopause. The signature of Rossby wave breaking events was easily identified as high PV intrusions over the Hawaiian Islands associated with the high values of ozone measured by lidar.
How does this program fit into the big picture?
What is it's role in global climate change?
The MLO location is a strongly active Stratosphere-Troposphere Exchange (STE) region due to the particular configuration of the circulation over the Pacific Ocean at the exit of the Asian monsoon upper circulation.
Comments and References
Dr. John E. Barnes