The fundamental science objective of the Maldives AUAV Campaign (MAC) is to provide new insights into how aerosols and clouds regulate the planetary albedo, with particular emphasis on how anthropogenic aerosols are modifying the albedo of cloudy skies (the so-called "indirect effect"). MAC also will be able to estimate solar absorption by clouds and to measure the dependence of that absorption on the amount of absorbing aerosols. One of the fundamental challenges of observing how aerosols modulate cloud microphysics and cloud albedo is the need to observe the same cloud element simultaneously from below, above, and inside the cloud; i.e., to measure how much aerosol is being transported to the cloud from below and from above; to measure how the cloud drop number density as a function of drop radius is changing in response to the injection of aerosols; and, finally, to observe how the cloud albedo, in-cloud solar absorption, and the transmission of solar radiation through the cloud to the cloud base is responding to the change in cloud microphysical properties. The PIs will undertake such a research mission with three identical lightweight Autonomous Unmanned Aerial Vehicles (AUAVs) outfitted with miniaturized instruments for measuring aerosols, cloud microphysics, and radiation. They will conduct a pilot demonstration mission from the Maldives Islands for a period of six weeks during the dry and polluted season through February and March, 2006. Prior to the Maldives Flight Campaign, the team will be performing domestic flight tests scheduled for October 2005. The flights will operate from the Maldives, located in the heavily polluted Arabian Sea.
BROADER IMPACTS: The particular emphasis of MAC is to demonstrate that lightweight AUAVs and their miniaturized instruments are effective and inexpensive means of simultaneously sampling cloudy layers from all sides. MAC in-situ data will be used to validate NASA's A-Train constellation of satellites which perform near simultaneous measurements of aerosols, clouds, temperature, relative humidity, and radiative fluxes (the change of radiation in a layer). The potential educational and training that would result from the fieldwork and analyses phases of MAC adds an important broader impacts component to the project. Finally, MAC addresses one of the major outstanding issues in climate change science.
