Overview of the Southern Andes—ANtarctic GRavity wave InitiAtive (SAANGRIA)

We will present an overview of the Southern Andes – ANtarctic GRavity wave InitiAtive (SAANGRIA), which is a comprehensive, airborne and ground-based measurement and modeling program focused on providing a new understanding of gravity wave (GW) dynamics and impacts from the troposphere through the mesosphere and lower thermosphere (MLT). This program will employ the new NSF/NCAR GV (NGV) research aircraft from a base near the southern tip of South America in a 10-week field measurement campaign from late June to early September, 2012 or 2013. The region, spanning the southern Andes, Drake Passage, and Antarctic Peninsula, is chosen since all the relevant GW sources occur strongly here, and strong stable surface and upper-level winds in winter permit GWs to propagate to very high altitudes. Indeed, satellite observations suggest this region in winter contains the largest GW amplitudes on the planet. Given large-amplitude GWs that propagate routinely into the MLT, the region offers an ideal natural laboratory for studying these important GW dynamics and effects impacting weather and climate over a much deeper atmospheric layer than previous campaigns have attempted (0-100 km altitude). Furthermore, supporting ground-based MLT instrumentation is extensively deployed in this region. The NGV will be equipped with new lidar and airglow instruments for the SAANGRIA measurement program, providing temperatures and vertical winds spanning altitudes from immediately above the NGV flight altitude (~13 km) to ~100 km. A suite of GW-focused forecasting and modeling tools will be used to guide NGV flight planning to GW events of greatest scientific significance. Those models will also drive scientific interpretation of the GW measurements, together providing answers to the key science questions posed by SAANGRIA about GW dynamics, morphology, predictability and impacts.