Blog: southern ocean climate models - 13 March
Twice a day at 1pm and 8.30 pm Sean Hartery, NIWA, and Peter Kuma, University of Canterbury, head for the Fantail at the very back of the ship to release their weather balloons.
They have two types of balloons: the larger balloon with a radiosonde attachment, which we have mentioned in an earlier blog, can reach 20 km high, and a smaller balloon called a windsonde that can usually get to about 6 km up. The sondes take measurements of air temperature, pressure, and relative humidity in the atmosphere.
Along with the radiosondes that are being released daily, Peter Kuma, University of Canterbury, has installed several instruments around the bridge of the R/V Tangaroa to take recordings from the atmosphere in the Ross Sea that will help him to answer questions about cloud formation and their simulation in climate models in the Southern Ocean. Peter explains what some of these bits of equipment do and how they will help his PhD research:
Way up on the gantry high above the bridge of the Tangaroa a Ceilometer, which is a type of Lidar or laser radar, sends pulses of infrared radiation into the atmosphere and this bounces back off cloud droplets and ice crystals in the clouds. If clouds are thick then we can only see the cloud base, if they are thin then we can see right through them. This graph is an output from the Ceilometer and shows that the cloud base is at about 1km in this case. The bottom axis of the graph shows time, the side axis shows altitude.