Cloud and Thermodynamic Observations During the First Year of the GOAmazon Campaign

Tuesday, 16 December 2014
David Troyan, Michael P Jensen, Scott E Giangrande, Karen L Johnson and Tami Toto, Brookhaven National Laboratory, Upton, NY, United States
The Green Ocean Amazon (GOAmazon) field campaign is a two-year mission (January 2014 through December 2015) designed to increase our understanding of aerosol-cloud interactions near a tropical megacity. Part of this study involves learning more about the lifecycle and associated properties of the clouds found in Brazil’s Amazon Basin. The ARM Mobile Facility (AMF) has been deployed near Manacapuru which lies downwind of the city of Manaus. In this region, the pristine air conditions over the Amazon regularly interacts with the pollution plume extending from Manaus. Observations from the AMF instrumentation are used to analyze the relationship between clouds and the thermodynamic environment in this rarely observed region. Pertinent AMF instruments for determining cloud properties include the 95—GHz W-band ARM Cloud Radar (WACR), micropulse lidar, and Vaisala ceilometer. Observations from these instruments are merged to determine cloud boundaries, and time-height fields of quality-controlled radar moments and linear depolarization ratios. Profiles of cloud frequency and occurrence for the first year’s deployment are examined in the context of the dry and wet seasons and through seasonal transitions. Additional context for cloud statistics are provided using sounding observations of convective indices including convective available potential energy, convective inhibition, and planetary boundary layer height.