Science in the Sky: Ella Gilbert
24 December 2017 – Rothera
Wow, time has really flown by. We’ve finished this season’s MASIN flying campaign and the rest of the team are leaving to head back to the UK.
Meanwhile, I’m staying at Rothera for another ten days to help with meteorological (met) observations, which are vital for the aircraft operations, global weather forecasting and long-term atmospheric monitoring. This involves making hourly observations of the weather – or at least the parts the pilots are interested in, like cloud heights, visibility and contrast, as well as three-hourly ‘synop’ observations, and releasing weather balloons, or sondes.
Synops are made all over the world, and contain detailed information about the weather at each location that can be fed into global weather prediction models. Sondes measure profiles of the atmosphere from the surface up to around 25 km altitude. They are especially useful to do in Antarctica because there are very few places on the continent where measurements of the atmosphere can be made. That means the balloons we release at Rothera can help improve the weather forecast across the world, which is pretty cool. Synops and sondes are also important for long-term monitoring of the global climate, and have helped reveal recent atmospheric trends in Antarctica.
Up until now though, I’ve been flying with MASIN as part of the ORCHESTRA project. We’ve done just over 50 hours of flights measuring the exchange of heat and of gases like carbon dioxide, methane and water vapour between the surface of the ocean and the atmosphere. To do this, we’ve been flying in the boundary layer, the layer of the atmosphere nearest the surface.
This exchange, or flux, happens differently over open water and sea ice, so we’ve been flying over both of these. We’ve also been coordinating with scientists on board the JCR to measure these properties in regions where the ocean sucks up lots of heat and energy.
We flew from the Chilean base, Marsh, over sea gliders deployed north of the Antarctic Peninsula by the RRS James Clark Ross (read more about the glider deployments here). These gliders are located near ocean fronts, which mark the boundaries between water with different characteristics, much like weather fronts. They are measuring the same things from the water that we are measuring in the air, which means we can get a more complete picture of how greenhouse gases and heat are transferred from the atmosphere into the ocean, and how they are stored at depth. Understanding this will help us improve our knowledge of how much heat the Southern Ocean can store, and therefore improve our predictions of future climate change.