Raymond M. Hoff


 

Professor of Physics
Director of the Joint Center for Earth Systems Technology
Director of the Goddard Earth Science and Technology Center

A. B. University of California, Berkeley (Physics) 1970

Ph. D. Simon Fraser University, Burnaby, British Columbia (Physics) 1975

Hoff's 2007 CV

Atmospheric Lidar Group Homepage

The Regional East Atmospheric Lidar Mesonet (REALM) has lidar data and links for sites in the US Northeast.

Check out our Smog Blog where you can find our daily analysis of pollution in the US.

JCET Homepage
GEST Homepage

Research Interests

The lowest 20 kilometers of the atmosphere, containing the troposphere and lower stratosphere, have been strongly impacted by man's activities during the last century.  Only in the last few decades have we had optical tools by which we can measure this impact remotely, both from the ground and from space.  My research involves the use of lasers and remote sensing satellites to determine the amount of aerosols and gases which occur globally.  Lidar (or light detection and ranging) operates by firing short pulses of light into the atmosphere and detecting the backscattered radiation.  From the time-of-flight of the photons, one obtains range to the scattering object and from the amount of light which is returned one obtains its density.

My group measures both gaseous components of the atmosphere (water vapor, as well as the molecular atmosphere itself) and aerosols which are borne on the winds.  Using elastic lidar and water vapor Raman lidar, we investigate the atmosphere over Baltimore up to an altitude exceeding 10 km.  Critical to understanding the effects of aerosols on climate change is the linkage between the aerosols and the water that they absorb.  Our current research addresses the uptake of water on aerosols and the effect that has on optical extinction.

Our group includes students from the Marine Estuarine and Environmental Science Program (MEES) who operate the US Air Quality Weblog. As of December 2007, the weblog has had over 4,200,000 hits.

Aerosols are not just limited to Baltimore.  As part of a team of scientists studying global measurement techniques from space, we have participated in the Lidar In-Space Technology Experiment (LITE) and in the Cloud Aerosol LIdar for Pathfinder Spaceborne Observations (CALIPSO) mission.  This spaceborne lidar was launched in April 2006. 

For Selected Publications, see the CV above.