Bits, blog posts, and links on thermodynamics and Earth system science from Axel Kleidon's research group at the Max-Planck-Institute for Biogeochemistry in Jena, Germany
We were back in India, spending a week at the IIT Roorkee to teach a short course on the Second Law in the Earth System Science, giving talks and having discussions at IIT Gandhinagar, IIT Bombay, IISER Pune and IITM. Find out more on what we did and discussed, look at a few photos, and some related papers in this blogpost.
Entropy has intrigued me for a long time – it usually comes up at the very end of asking “why” questions. It is such a fundamental concept in physics, but then – why does nobody talk about it in Earth system science? My review paper just published in Earth System Dynamics explains why entropy is so essential to understand the dynamics of the Earth system: because it limits how much work can be done, and work is at the very core of what we call dynamics.
Continue reading “New paper: Working at the limit – how entropy, work and limits shape Earth system functioning. Here is a simple, but long summary of the key points.”
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”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.”My former postdoc, Maik Renner, just got his paper published in the Journal of Hydrometeorology, in which he evaluated the performance of common land surface models at the diurnal time scale using FluxNet observations. The evaluation was based on a simple concept that we developed in my group: that solar radiation is the main driver of the diurnal variation of variables that characterize the land-atmosphere system. This sounds trivial. Of course solar radiation is the dominant driver, so what novel insights can be gained from this view? Continue reading “Solar radiation is the main cause for diurnal variations on land. Looking at this slightly differently than how it is normally done helps to better understand observations and evaluate models of the land surface”
Earthsystem.org 