Final answer:
Meteorologists rely on weather balloons to gather direct data from the upper atmosphere, as they are equipped with instruments that measure various atmospheric conditions.
Step-by-step explanation:
A meteorologist is most likely to depend on a weather balloon to collect information from the upper atmosphere. Weather balloons are equipped with instruments called radiosondes, which measure various atmospheric parameters, such as temperature, humidity, and pressure at different altitudes within the troposphere and lower stratosphere. In contrast, while weather satellites provide valuable data on a global scale, barometers, including aneroid barometers, are typically used to measure atmospheric pressure at the Earth's surface, and Doppler radar is utilized primarily to track movement and intensity of weather systems, such as storms, rather than collecting direct data from the upper layers of the atmosphere.