Meteo @ WUR

The fluid dynamics of snowmelt

An important fraction of snowmelt is driven by the wind. Determining the melt rate is challenging in a landscape that is partially covered by snow patches that remain at the melting temperature, while surrounding land warms up as an effect of incoming solar solar radiation. In a new study, which

SLOCS

Lockdown contribution to spring 2020 record clear skies in western Europe

Spring 2020 was exceptionally sunny for western Europe. Did the reduced air traffic and industrial activity due to lockdowns play a role?

Publications

The anomalous moisture sources of the Rhine during the dry summers of 2003 and 2018

Were you in western Europe during the summer of 2018? Then you probably remember the long lasting drought and high temperatures, resulting in reduced crop yields, forest fires, overheated power plants, and most striking excess death. Now dr. Imme Benedict (congratulations!) investigated the lack of moisture transport towards the Rhine

SLOCS

Speeding up radiative transfer solvers with machine learning

Machine learning provides great opportunities for accelerating the representation of physical processes in weather and climate models. Radiative transfer solvers, which deal with the transport of solar and thermal radiation, are often the most costly parametrization in models. Speeding them up is one of the main ambitions of SLOCS [https:

Clouds

Details of the surface wind matter in tropical convection

Tropical clouds play an important role in the energy balance of the earth. Clouds reflect solar radiation into space, but also absorb heat that is emitted from the surface of the earth. Clouds therefore play an important role in setting the global atmospheric temperature. In turn, the atmospheric temperature determines

Hydrology

Mississippi’s moisture sources in present and future climate

In our new study (led by PhD student Imme Benedict [https://www.researchgate.net/profile/Imme_Benedict]), we have assessed the water budget of the Mississippi River Basin under present and future climate conditions. Our main aim was to find out where the precipitation originates from, and in particular whether

Weather

Mega-heatwave amplification due to upstream drought

In a new publication led by Dominik Schumacher [https://www.ugent.be/bw/environment/en/research/lhwm/staff/dominik_schumacher.htm] of Ghent University (DRY-2-DRY [http://www.dry2dry.org] project funded by ERC), we have quantified the impact of upstream drought on mega-heatwaves. With the help of satellite observations and

Evaporation

Better hydrological cycle with high-resolution global models?

To study the global hydrological cycle and its response to a changing climate, we rely on global climate models (GCMs) and global hydrological models (GHMs). In a new paper in HESS [https://doi.org/10.5194/hess-23-1779-2019], we have evaluated the benefits of increasing the resolution of a GCM and

Publications

Surface warming leads to more clouds over temperate forest

In a new paper [https://rmets.onlinelibrary.wiley.com/doi/10.1002/qj.3441] in Quarterly Journal of Royal Meteorological Society, we present a potential mechanism to explain the observed enhanced cloud formation over Western European forests [https://chiel.ghost.io/2017/01/20/clouds/], such as in Les Landes,

Solar energy

Project on solar energy and electricity grid management granted

Our project Every ray counts has been granted in the Industrial Doctorates [https://www.nwo.nl/actueel/nieuws/2018/07/zestien-industrial-doctorates-aan-de-slag-in-bedrijfsleven.html] call from NWO [https://www.nwo.nl]. In this project, our group at Wageningen University and Research [https://www.wur.nl/en/Research-Results/Chair-groups/Environmental-Sciences/Meteorology-and-Air-Quality-Group.htm] and

Clouds

Three new papers on land-atmosphere interactions

We have published three new papers on land-atmosphere interactions, and the soil moisture-precipitation feedback. The first paper Land-Atmosphere Interactions: The LoCo Perspective [https://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-17-0001.1] is published in BAMS, the American Meteorological Society's flagship journal. The paper presents an overview of

Weather

Global moisture transport in ERA5

The new ECMWF ERA5 [https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5] data shows the global moisture transport at an unprecedented detail level. For my atmospheric dynamics class, I have downloaded a year of data at the 850 hPa level (just above the boundary layer) and composed a movie.

MicroHH

MicroHH reference paper published

The reference paper of MicroHH [https://chiel.ghost.io/microhh/] is accepted as a full contribution to Geoscientific Model Development [https://www.geosci-model-dev.net/10/3145/2017/]. This paper describes the final result of several years of model development: MicroHH 1.0. The short summary on the GMD [http://www.

Coding

The beauty of containers in C++11

Containers for storing data are one of many great features of the C++ Standard Library [https://en.wikipedia.org/wiki/C%2B%2B_Standard_Library]. Despite their advantages, to initialize them, and to loop over them was not always easy. Fortunately, the C++11 [https://en.wikipedia.org/wiki/C%

Publications

Clouds can enhance photosynthesis and evapotranspiration

Clouds reflect incoming solar radiation back into space, but also increase the amount of diffuse radiation that reaches the land surface. Our new study [http://journals.ametsoc.org/doi/10.1175/JHM-D-16-0279.1] (lead author Xabier Pedruzo-Bagazgoitia) shows that thin clouds are beneficial for CO2 assimilation and evapotranspiration, due to

Publications

MicroHH discussion paper online

The reference paper of MicroHH [https://chiel.ghost.io/microhh/] is available as a discussion paper on the website of Geoscientific Model Development [http://www.geosci-model-dev-discuss.net/gmd-2017-41/#discussion]. This paper describes the final result of several years of model development: MicroHH 1.0. The short summary on the GMD

Coding

How (not) to copy a NumPy array

The Python code below has puzzled me for a while. It shows the initialization of NumPy array a and three examples of copy assignment stored in b, c, and d. import numpy as np a = np.arange(3,5) #a = [3, 4] b = a c = a[:] d = a.copy() print(

Publications

More clouds over Western European forests

Our new article [http://www.nature.com/articles/ncomms14065] in Nature Communications (lead author Ryan Teuling) presents observational proof of enhanced cloud formation over Western European forests. The related press release of Wageningen University can be found here (in Dutch) [https://www.wur.nl/nl/nieuws/Bossen-bevorderen-wolkenvorming.htm]. The sketch