MATLAB Recipes for Earth Sciences
Martin H. Trauth, University of Potsdam, Germany
The Volkswagen Foundation is funding our 5th summer school on “Trends, Rhythms and Events in the Earth’s Climate System – Past, Present and Future” in 2021. After summer schools in Africa and Europe, this one will be taught entirely online. Continue reading “Summer School on “Trends, Rhythms and Events in the Earth’s Climate System – Past, Present and Future””
On 25 September 2020 the University of Potsdam will open virtual lecture halls for 8–11 year old children in order to inspire them for the world of science. During the event I will teach a lecture on “Knochenjob in Ostafrika – unterwegs auf den Spuren der ersten Menschen” during the Children’s University Potsdam.
In two weeks scientists from the Chew Bahir project will meet in the Virtual Space to discuss the latest results of the 290 m long ICDP cores from S Ethiopia. Continue reading “Sixth Chew Bahir Drilling Project Workshop in the Virtual Space”
Reading meteorological parameters through a weather station connected to the Internet has gained great popularity. Here’s an example of how to set up a weather station, connect it to ThingSpeak and display the time series. We use the inexpensive and very popular Smart Weather Station from Netatmo in this experiment. Continue reading “ThingSpeak IoT Weather Station”
Computing the evolutionary spectrum of a short piano piece helps to recognize that music is the result of a complex interplay of temporal and spectral changes of sound. The MATLAB Audio Toolbox has numerous useful functions for spectrally analyzing music. Continue reading “Analyzing Music in the Time and Frequency Domain using MATLAB”
Color is an uncertain characteristic for the determination of minerals. Many minerals occur in a variety of different colors. Examples are quartz with its color variants amethyst, rose quartz or smoky quartz or feldspar with color variants like amazonite. However, if the minerals in a rock are reliably determined, their different coloring can be used to quantify them. In this example we use a simple RGB photo taken with a smartphone to determine the amounts of quartz, plagioclase, alkali feldspar and dark minerals such as biotite and hornblende in granite. To facilitate the differentiation of minerals, we use a principal component analysis (PCA), which is also used to unmix and classify spectral images such as satellite images (Trauth, 2020).
In paleoclimate time series amplitude of spectral peaks usually varies with time. Evolutionary power spectral analysis such as the FFT-based spectrogram and wavelet power spectral analysis helps. These methods, however, require interpolation of the time series to a grid of evenly-spaced times. Instead we can use the Lomb-Scargle Method for unevenly-spaced spectral analysis, computed for a sliding window, to map changes of the cyclicities through time.
Continue reading “Evolutionary Lomb-Scargle Power Spectral Analysis with MATLAB”
