You just mentioned cloud formation If I am correct the formation of clouds is a process that climate models still have problems to describe correctly What is the current status here

Clouds generally form, because air cools as it rises. When the air gets colder, at some point the saturation humidity is reached, water condensates and clouds are formed. Cloud formation depends on the vertical motion field in the atmosphere. But the vertical motion field is much weaker than the horizontal motion field. The reason for that is that the vertical motion field is determined by slight imbalances in the horizontal motion field. The average wind speed at 5 km height is maybe about 15-20 meters per second. And we can measure this with an accuracy of a couple of meters per second. But to determine the up-and downward motion, we must have a description of the wind which is more accurate than the current observations. So it is really the model dynamics that determine where we have these ups and downs in the motion field. And that determines where the clouds form. Furthermore, when the clouds form, they have all kinds of shapes. The effect on radiation is very sensitive on whether clouds contain water drops or ice crystals. And this point is really the big challenge today—and very difficult: To describe properly where we have water clouds and where we have ice clouds. We know from basic thermodynamics, that ice particles start to form at temperatures below 0°C. Around temperatures of -15° C, we have a maximal efficiency in the conversion from water to ice. And as we get to temperatures of -40° C to -50° C, everything is ice. But in between, there is a mixture of water and ice. It is very tricky to describe this properly. Surely, this is one of the big questions in climate research today. The parametrization of this process is one of the major uncertainties in determining the cloud feedbacks and sensitivity of climate models to changes in radiative forcing or changes in CO2 concentrations.

Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

Get My Free Ebook

Post a comment