Can we infer rainfall sensitivity to global warming using observations of precipitation and temperature? Not quite, until you correct for the cooling effects of clouds.

Rainfall events are expected to become heavier as the hydrologic cycle intensifies with global warming. To determine this strengthening, many studies use observed precipitation events and test how these change with observed temperatures. These so-called scaling rates differ from what is expected from theory, showing a decline above temperatures of around 23° – 25°C. This breakdown in scaling makes it difficult to interpret the precipitation response to global warming and its cause further remains unclear. It also raises the question of whether a high-temperature threshold limits the increase in the intensity of precipitation events with temperature. We resolve this in our latest paper by showing that the break in scaling primarily occurs due to radiative effect of clouds on surface temperatures that leads to a covariation between the two variables.

Continue reading “Can we infer rainfall sensitivity to global warming using observations of precipitation and temperature? Not quite, until you correct for the cooling effects of clouds.”
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Short course on „Thermodynamics and Optimality in the Earth system“ – live in Florence and accessible online. If you ever wanted to know why the second law is so important, come and join!

How does the second law of thermodynamics apply to the Earth system and why is it so important? As it turns out, it dominantly shapes natural Earth system functioning, from the climate system to hydrologic cycling, the biosphere, and renewable energy resources, yielding simple, emergent functioning as a consequence of systems operating at their thermodynamic limits. This short course provides the basics to understand why entropy is so important and how it shapes Earth system functioning.

Continue reading “Short course on „Thermodynamics and Optimality in the Earth system“ – live in Florence and accessible online. If you ever wanted to know why the second law is so important, come and join!”

How much does evaporation affect temperature variations during the day?  That’s what we looked at in a paper just published online in the Journal of Climate.  @annuPanwar_sci @ametsoc @MPI_BGC

Over land, there is a marked variation in surface and air temperature during day and night, with the amplitude described by the diurnal temperature range.  What are the main factors that determine its magnitude across regions and how much is it shaped by evaporation?  This is what Annu Panwar looked at in her last part of her PhD using FluxNet observations and the ERA 5 reanalysis products, with the results just published online in the Journal of Climate. What this analysis shows is that energy balances go a long way to explain the main influences and that evaporation does not have quite such a strong effect as one may think.

Continue reading “How much does evaporation affect temperature variations during the day?  That’s what we looked at in a paper just published online in the Journal of Climate.  @annuPanwar_sci @ametsoc @MPI_BGC”

We’ll be at #EGU22, showing how radiation and maximum power shape temperatures, their extremes, the atmospheric circulation and the wind energy resource. @akleidon @s_ghausi @yinglin_tian

Corona is still around, also in Vienna, but the EGU General Assembly will nevertheless happen again, in a hybrid form. We are thrilled to be there physically, giving our 6 minute short talks on our work, and look forward to seeing and talking to you there!

Continue reading “We’ll be at #EGU22, showing how radiation and maximum power shape temperatures, their extremes, the atmospheric circulation and the wind energy resource. @akleidon @s_ghausi @yinglin_tian”

“Thermodynamics and Optimality of the Biosphere” – online lecture, today, Friday, March 25, at 17:00 Jena time (CET) or 10:00 in Mexico. Interested? You can join too, if you like, here’s the link and background material.

Thermodynamics, entropy and life — does this sound intriguing but also confusing to you? As part of the virtual Spring School on Physics and Mathematics applied to Ecology, organized by Oliver Lopez Corona, I give a lecture where I will cover how thermodynamics applies to the biosphere and the planetary environment, and how it connects to concepts such as the Gaia hypothesis or planetary boundaries. Hopefully, after the lecture, it is clearer to you what entropy is, how it applies to the Earth system, its biosphere, and their interactions. And why it is so important! If you are interested to learn more, this blogpost provides some links to literature mentioned in the lecture.

Continue reading ““Thermodynamics and Optimality of the Biosphere” – online lecture, today, Friday, March 25, at 17:00 Jena time (CET) or 10:00 in Mexico. Interested? You can join too, if you like, here’s the link and background material.”

Interested in how the Earth system works?  I have a #PostDoc opening available in my group, applying thermodynamics, max. power, and optimality to Earth system science. @MPI_BGC

The position is in my research group, which focuses on how the Earth functions as a whole system, the role of life within it, and what a sustainable human future might look like. We take a unique Earth system approach that focuses on thermodynamics, energy conversions, and limits/optimality such as maximum power.

We are seeking a motivated and interested person to help us further develop this approach, evaluate it using observational data, and/or compare it to climate model results. More details are provided in the formal job announcement, which you can find here. More background information in this post.

Continue reading “Interested in how the Earth system works?  I have a #PostDoc opening available in my group, applying thermodynamics, max. power, and optimality to Earth system science. @MPI_BGC”

Last week our group member @annuPanwar_sci successfully defended her PhD thesis on diurnal temperature variations and how they are affected by evaporation and vegetation. Very well done, and congratulations, Annu! @mpibgc

Evaporation cools, right? What may sound so obvious was the topic of Annu’s PhD thesis: to look into observations and find the effects of evaporation in how surface and near-surface air temperatures vary throughout the day. The results are not quite as obvious, and we learned a lot. Here is a brief summary of her thesis, with its contents spread over three papers. Very nice work!

Continue reading “Last week our group member @annuPanwar_sci successfully defended her PhD thesis on diurnal temperature variations and how they are affected by evaporation and vegetation. Very well done, and congratulations, Annu! @mpibgc”

Can we solve the freshwater problem by taking moisture out of the atmosphere with dehumidifiers? When we look at how the hydrologic cycle does its work, we get a straight and clear answer: no, we don’t solve the problem!

In Germany, the construction of Tesla’s Gigafactory near Berlin draws its attention, including its substantial need for freshwater. Despite its many lakes, the area around Berlin is among the driest in Germany. The atmosphere contains water vapor, and it seems like a tempting source for freshwater, just sitting there to be harvested by some form of technology. This is what a company claims to do (and quite a few others elsewhere as well). But can this promise hold up?

Continue reading “Can we solve the freshwater problem by taking moisture out of the atmosphere with dehumidifiers? When we look at how the hydrologic cycle does its work, we get a straight and clear answer: no, we don’t solve the problem!”

“Kraftwerk Erde: Wie der belebte Planet Energie umwandelt” – Vortrag bei #FasziAstroOnline, heute Abend, 13.01.2022, 19 Uhr, live auf youtube.  Mehr Infos im Blog. @MPI_BGC @HdAstro

Die Erde arbeitet wie ein Kraftwerk, indem sie Sonnenenergie in andere Formen umwandelt, die die Winde der Atmosphäre, den Wasserkreislauf, und auch das Leben und die Menschheit auf der Erde erhalten.  Diese Umwandlungen folgen den Gesetzen der Thermodynamik, die sowohl die Richtung als auch die Grenzen setzt.  Aber Erdsystemprozesse beeinflussen sich auch gegenseitig, sodass man einen Blick auf das Gesamtsystem braucht.  In diesem Vortrag zeige ich, dass man allein durch diesen grundlegenden physikalischen Ansatz schon erstaunlich viel vom Erdsystem verstehen kann – über die fundamentalen Rolle von Energie und Entropie, wie Leben den Planeten verändert, aber auch zu angewandten Themen wie dem Klimawandel und warum die Photovoltaik die Technologie ist, die bei weitem den größten Beitrag zur Energiewende liefern wird.

Continue reading ““Kraftwerk Erde: Wie der belebte Planet Energie umwandelt” – Vortrag bei #FasziAstroOnline, heute Abend, 13.01.2022, 19 Uhr, live auf youtube.  Mehr Infos im Blog. @MPI_BGC @HdAstro”

“Was leistet die Erde und was trägt die Menschheit dazu bei? Nachhaltigkeit aus thermodynamischer Sicht.” zoom-Vortrag, öffentlich, Montag, 13.12.2021, 18:00, tinyurl.com/HM-ForFuture

Im Rahmen der Ringvorlesung “Lectures for Future”, zusammen veranstaltet von der Hochschule München und der LMU, hält Axel Kleidon einen Vortrag zu unserem thermodynamischen Erdsystemansatz und was man daraus für Nachhaltigkeit lernen kann. Der Vortrag ist öffentlich und kann über diesen Zoom Link gesehen werden.

Continue reading ““Was leistet die Erde und was trägt die Menschheit dazu bei? Nachhaltigkeit aus thermodynamischer Sicht.” zoom-Vortrag, öffentlich, Montag, 13.12.2021, 18:00, tinyurl.com/HM-ForFuture”