Why does wind energy become less efficient when used at larger scales? Basic physics explains this effect, starting with a very limited ability of the atmosphere to generate wind energy from radiation, as described in my new review just published.

Wind energy plays an important role in the transition to a carbon-neutral, sustainable energy system and is rapidly expanding. So it is a good time to ask how much wind energy there actually is, whether we get close to the limits anytime soon, and why the efficiency of wind energy must decline when used at larger scales. These are basic science questions: How, and why, does the atmosphere actually generate motion, how much does it generate, and how much of it can at most be used? These questions I address in a review paper just published in which I show that it does not take much physics to answer these.

Continue reading “Why does wind energy become less efficient when used at larger scales? Basic physics explains this effect, starting with a very limited ability of the atmosphere to generate wind energy from radiation, as described in my new review just published.”

AGU Fall Meeting 2020: A brief summary of our contributions and takeways

Corona has impeded everything in 2020 including researchers’ involvement in scientific conferences. However, innovation and the internet made it possible to contribute to large and much anticipated conferences like the AGU Fall Meeting ‘20. Thus, 2 of our PhD researchers, Annu Panwar and Jonathan Minz, presented their scientific results, keeping the spirit of science communication alive, despite tough times.

Continue reading “AGU Fall Meeting 2020: A brief summary of our contributions and takeways”

Which factors make forests cooler: Evaporation or their high aerodynamic conductance? Our paper just published in HESS suggests that it is the latter.

Trees and plants moderate the Earth’s surface temperature. Generally, the cooling effect of vegetation is mainly attributed to the process of evapotranspiration. In our paper just published in HESS, we used observations to unravel the importance of evaporative cooling for short vegetation and forest in shaping diurnal variations in temperatures and found that, actually, it is not only evaporation that keeps the forests cool.

Continue reading “Which factors make forests cooler: Evaporation or their high aerodynamic conductance? Our paper just published in HESS suggests that it is the latter.”

If you think surface and air temperature are basically the same thing, think again. Or read our new paper.

In meteorology, air temperature measurements are typically taken 2m above the surface.  It is a routine measurement at weather stations, and this temperature is the basis for analyzing trends, such as global warming.  The temperature of the surface is not so often measured, but it can be inferred by satellites from how much radiation is being emitted by the surface.  Being only 2m apart, one may think that the temperatures basically reflect more or less the same, given their close proximity. We actually found out that this is not the case: surface temperature responds much more strongly to a lack of water than air temperature.  This finding was just published in our article in the journal Geophysical Research Letters. Continue reading “If you think surface and air temperature are basically the same thing, think again. Or read our new paper.”