Analysis of long-term and real-time aerosol optical properties near the New England coast: preparation for the Two-Column Aerosol Project (TCAP) field campaign
Authors
Duli Chand — Pacific Northwest National Laboratory
Carl M. Berkowitz — Pacific Northwest National Laboratory
Larry Berg — Pacific Northwest National Laboratory
Elaine Chapman — Pacific Northwest National Laboratory
Evgueni Kassianov — Pacific Northwest National Laboratory
Category
Field Campaigns
Description
One of the key objectives of the U.S. Department of Energy’s Two-Column Aerosol Project (TCAP) is to provide observations with which to evaluate the uncertainty in model simulations of aerosol optical depth (AOD) and their relation to estimates of aerosol radiative forcing, and hence, to climate. The objectives are met by having detailed ground-based aerosol measurements via deployment of the ARM Mobile Facility (AMF) and the Mobile Aerosol Observing System (MAOS) at Cape Cod, Massachusetts, for a 12-month period starting in the summer of 2012. These measurements will be supported by two scheduled aircraft campaigns using the ARM Aerial Facility’s (AAF) G-1 aircraft and NASA’s B-200 aircraft in July 2012 and again in February 2013. Each campaign will include sampling within two atmospheric columns using the two aircraft; one column will be located directly over, or very close to the AMF located on Cape Cod, while the second will be over a relatively remote maritime location. The pre-campaign study presented here is designed to help select the optimal location of the second, remote maritime atmospheric column using the mean and standard deviation of previously observed AODs from surface and space. The optimal site for the maritime location will have a high degree of variability so that the observations made here will stress model capabilities to capture both the temporal and spatial changes to AOD.
In this study, we present regional climatological values of (1) AOD from the Moderate Resolution Imaging Spectrometer (MODIS) on Terra and Aqua satellite platforms; (2) the vertical distribution of aerosol layers from the Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite; and (3) the long-term aerosol optical properties from the Aerosol Robotic Network (AERONET) surface sunphotometer at Martha’s Vineyard, Massachusetts. Seasonal and geographical variations in these quantities are analyzed and tentative explanations sought based on historical records of regional meteorology and emissions. In addition to the climatology of aerosol optical properties, we also discuss the potential use of near real-time MODIS satellite images and simulations from the Navy Aerosol Analysis and Prediction System (NAAPS) in planning and implementation of the TCAP field campaign.