Solar-powered Unmanned Marine Vehicle (UMV) developed by Institute of Atmospheric Physics (IAP) sailed to the sea after being dragged by a fish boat 50 km away from Dongshan County, Fujian Province on April 17, 2017. The UMV is used for observing marine and meterological parameters including surface air temperature, humidity, pressure, wind speed and direction, sea surface temperature and salinity.(Image by LI Jun)