Research Interests: Current research involves investigation of Arctic clouds and aerosol characteristics using radar, radiometers, and lidar. Observed cloud properties include water contents, phase, vertical distribution and optical properties which are considered to be important in determining how clouds will impact atmospheric radiation budgets, and how energy will be exchanged between the surface and the atmosphere. A primary objective is to collect long-time records of clouds to directly measure how they change over different seasons, and from year to year. These data sets will be important in determining the processes and mechanisms force climate change so we can answer not only "how" but "why" our environment is changing. An important component of this activity is to compare these surface data sets to satellite observations of cloud properties and to develop improved representation of Arctic clouds in climate models.

Current Activities: Since 2004 an active program has been pursued of installing atmospheric observing instrumentation in Alert and Eureka Canada including radiometers for measuring atmospheric surface radiation balances/fluxes and cloud radars, radars and interferometers for measuring properties of clouds and aerosols in the lower atmosphere. These intensive measurements are designed to be directly comparable to measurements taken in Barrow, Alaska so that atmospheric proesses in two important and distinct Arctic regions can be compared. Preliminary planning is in progress to establish an atmospheric observatory site in Tiksi, Russia.