1 / 15

Height of the Planetary Boundary Layer During ICEALOT 2008

Height of the Planetary Boundary Layer During ICEALOT 2008. Virginia Sawyer Advisors: Ruth Varner, Judd Welton August 5-6, 2009. Free Troposphere. Mixed Layer. Planetary Boundary Layer. The transition between well-mixed surface air and the free atmosphere aloft, typically ~1 km

geraldine-salinas
Download Presentation

Height of the Planetary Boundary Layer During ICEALOT 2008

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Height of the Planetary Boundary Layer During ICEALOT 2008 Virginia Sawyer Advisors: Ruth Varner, Judd Welton August 5-6, 2009

  2. Free Troposphere Mixed Layer Planetary Boundary Layer • The transition between well-mixed surface air and the free atmosphere aloft, typically ~1 km • Usually maintained by a temperature inversion, which is buoyantly stable. • Mixed layer: high aerosol concentrations, nearly uniform with height • Free troposphere: less polluted, more vertical stratification

  3. Aerosols in the Arctic • Solid or liquid particulate in the atmosphere • Affects global climate both before and after removal from the atmosphere • Affects air quality and visibility • Major source of anthropogenic pollution to the Arctic, including trace metals

  4. PBL Transport and the PBL • Aerosol that remains below the PBL settles out within a few kilometers of its origin • Aerosol that reaches the free troposphere can enter long-range transport, and eventually deposit thousands of kilometers away • Areas with few local emission sources are still subject to pollutants that have crossed the PBL

  5. ICEALOT and the Arctic Haze • Arctic air pollution peaks in spring: the Arctic haze • Triggered by polar sunrise, dissipated by precipitation in summer • R/V Knorr 19 March-24 April • NOAA funded project to study atmospheric chemistry for IPY

  6. Lidar with MPLNET • 527-nm laser beamed upward from the ground (or the deck of the ship) • Photons deflected by aerosol are detected with return time; yields height of particle • Vertical backscatter profile approximately corresponds to aerosol concentration with height

  7. Other Sources of PBL Data • ICEALOT balloon sondes • Temperature profiles • Up to 4 launches per day • Overpasses by CALIPSO satellite • Aerosol lidar • April 7th, 11th, 19th, and 21st http://www.nasa.gov/mission_pages/calipso/main/

  8. PBL Detection Algorithm Wavelet covariance transform using the Haar function z = altitude a = dilation b = translation

  9. Algorithm sometimes chooses elevated cloud or aerosol signal rather than PBL • 3-km threshold introduced to exclude high features

  10. PBL and Climate

  11. Comparison to Sonde-Derived PBL Height RMSE 0.497 km

  12. April 11, 2008 – approaching Tromsø, Norway http://mplnet.gsfc.nasa.gov/data.html

  13. Conclusions • Most anthropogenic aerosol in the Arctic depends on PBL behavior for transport, mixing, and removal • Aerosols in the Arctic affect global atmospheric chemistry and climate • Aerosol lidar can detect the PBL height with much better time resolution than direct observation (i.e. sondes), enough to watch changes develop • Future work: CALIPSO, mechanism for mixing through the Arctic marine PBL

  14. Acknowledgments Peter Kelly Ruth Varner Doug Vandemark Judd Welton Dan Wolfe Bob Talbot R/V Knorr and ICEALOT crew AIRMAP MPLNET at NASA-GSFC Research & Discover Committee Members

More Related