Continuous in-situ soundings in the arctic boundary layer: A new atmospheric measurement technique using controlled meteorological balloons

Controlled Meteorological (CMET) balloons are small airborne platforms that use reversible lift-gas compression to regulate altitude. These balloons have approximately the same payload mass as standard weather balloons but can float for many days, change altitude on command, and transmit meteorological and system data in near-real time via satellite. Since 2004, more than 50 CMET balloons have been flown in nearly all of the earth's major climate zones, from the Amazon to Antarctica. This paper describes one notable flight in 2011 in which a CMET balloon performed continuous soundings in the Arctic marine boundary layer off the coast of Svalbard. It is likely that this is the first time such a feat has been accomplished by a free balloon or any other flight platform. The series 18 consecutive profiles show the time evolution of the boundary layer as it is advected northward over a 10-h period. The paper focuses on the balloon design, control algorithm, and in-flight performance. Analysis of the unique atmospheric dataset will be the subject of a subsequent publication.