Archive for May, 2020

Frost Saints Days cooling since 1998 at meteoLCD

May 24, 2020


We all know since our earliest child days that in May there is a period of 5 days that often brings back severe cooling, before temperatures climb again into the summer numbers. The “Frost Saints” (or “Ice Saints”) are called “Eisheilige” in German, and are known as Mamertus, Pankratius, Servatius, Bonifatius and “die kalte Sophie” (from 11 to 15 May). The climatological cause is cold polar air streaming over a still cold nightly soil, which than often causes frost on this soil. This frost may destroy or damage young seedlings, so it always was something the peasants were afraid of.

Josef Kowatsch has an article in “Die Kalte Sonne” (English translation and comments at NoTrickszone) titled “Warum werden die Eisheiligen seit 25 Jahren immer kälter?“. Kowatsch shows that at 5 chosen German weather-stations the trend of the Frost Saints period is negative, i.e. these days are cooling. The station closest to meteoLCD is Bad Kreuznach, located 125km East of Diekirch. Here what Kowatsch has found for this station, located at practically the same altitude (184m asl versus 218m asl):

The cooling over the 25 year periods is – 0.14°C/year of -1.42 °/decade.

Now this pushed me to make the same analysis for meteoLCD, starting in 1998 (the “official” beginning of our data archive). Here is the result:

Same observation at Diekirch: since 1998 (23 years) the Ice Saints period is cooling; here the trend is -1.34 °C/decade, a quite impressive number. If one would foolishly extend this up to 2100, we would expect Ice Saints day more than 10°C cooler than today!

The plot shows that there are important variations w.r. to the linear trend line, which explains the poor R2 of 0.09. A Fourier analysis suggest 2 main underlying periods: about 2 and 10 years; the latter may be compared to the NAO (North Atlantic Oscillation) last period, which seems to be about 20 years… but this might be a coincidence.

The following graph from the excellent climate4you website shows that the heat content of the North-Atlantic changed markedly, with a cooling period following a warming:

The period of the oscillation in the green rectangle could be close to 20 years, the number discussed above for the NAO.


What remains to take home is that despite the ear-deafening shouts of the climate alarmists, the NGO’s, the politicians etc., there is some cooling going on: we are not in a situation of constant warming everywhere!

So it still might be prudent to not put all our eggs into the warming basket!

Wood burning.. real numbers for a green-hyped energy

May 3, 2020

Prof. Fritz Vahrenholt’s and Dr. Sebastian Lüning’s blog “Die kalte Sonne” has a discussion on the US movie “Burned: are trees the new coal ?” (streaming here) which shows what happens in American forests that are the source for European wood-burning installations (power stations, heating…). Since the EU made what I think the completely wrong decision to hype wood burning as “green” and “renewable”, massive quantities of wood are transported from the US East to the EU, where converted power stations like the UK Drax burn yearly wood felled from a surface of 830 km2, corresponding to 1/3 of the surface of Luxembourg (link). “Die kalte Sonne” gives a very instructive document from the Swiss Bafu (Bundes Amt für Umwelt) which shows the emissions of wood-burning installations, compared to natural gas and light oil (HEL) facilities. You may find the document here.

Concerning fine particle and dust emissions (“Staub”), just compare the numbers that I highlighted in turquoise (the unit is mg/MJ, i.e. a mass per unit of energy produced, not a mass per m3 of air!). A “normal” household heating has a power < 50kW; so comparing these, we see that wood burning has dust emissions per energy unit that are between 250 and 1000 times higher than corresponding oil or gas installations. That says it all!

PS: You may read the research paper “The Burning Question: does Forest Bioenergy Reduce Carbon Emissions” (link)

On wind, CO2 and other gases (3/3)

May 2, 2020

4. A fast recap.

This is the third and last part of my comments and observations on the influence of wind speed on near ground CO2 concentrations (mixing ratios). Let me summarize what we have seen and talked about in the first two parts:

  1. Observation shows that under low wind conditions, the daily CO2 concentration swings heavily from an early morning low to an afternoon high; the amplitude can reach values of 130 ppm.
  2.  When wind blows, and all other conditions as solar irradiance, air temperature stay more or less the same, this daily swing is dramatically dampened: the peak values can be clipped by more than 100 ppm, the minimum values remain more or less unchanged, the amplitude of the daily swing is down to about 20 ppm.
  3. A similar pattern can be observed on the NO2 concentrations, as measured for instance in the Beckerich station.
  4. Ground ozone concentrations do NOT follow this pattern of peak-clipping at all: the maxima remain more or less unchanged, but the minima are drastically higher. Air temperature plays a minor role, as shown by the next figure which shows the temperature and ozone date at meteoLCD for the 7 days ending in Saturday 02 May, afternoon:

The box A clearly shows constant O3 minima in spite of rising air temperature minima; the box B shows that the O3 maxima are lower: air temperature maxima are also lower by about 5°C (25%) whereas wind speed is much higher: the peak on the 26/04 is 1.8 m/s, and it is higher than 6 m/s  (>300%) during the B-box days! So the wind speed is possibly the main factor increasing the daily O3 minima.

5. How can we explain the different O3 pattern?

Luckily, I found a recent paper by Thomas Trick et al. published in January 2020 in “Atmospheric Chemistry and Physics”, titled: “Very high stratospheric influence observed in the free troposphere over the northern Alps – just a local phenomenon?” (link). This paper shows that incursions of stratospheric ozone are much more important than what the consensus science says. Usually it is assumed, that these incursions (known since many years) do not upper the local concentrations by much more than 10 ppb (20 ug/m3). In this paper it is shown from observations that this is not the case: the incursions can be much higher, something that activist scientists who see high ozone levels  being caused exclusively by human activity are eager to ignore. The very high O3 concentrations in the stratosphere can increase the O3 concentrations at mid-troposphere heights (and possibly lower) by quite a lot. Balloon observations and LIDAR soundings (by laser) give us a good picture of how the O3 concentration varies with altitude. The next picture (from the paper) shows the situation at Garmisch-Partenkirchen:

For us the lower part in the fuchsia colored box is important: we see that O3 concentration does vary with the time of the day, that it is highest during late afternoon (grey curve) as we know well, but most important, that the overall O3 values are more or less constant! This means that higher wind speeds do increase the mixing of air layers, but as the O3 concentration is about the same, that mixing does not cause a dilution! The low morning values during wind-poor days are the result of O3 destruction caused by NO (we may assume that NO concentrations are well correlated to NO2, the only gas of which we have observational values).

The following picture shows an extreme situation at meteoLCD, 2-Feb-2000; this was a period where our NO and NO2 sensors (by Environnement SA) were still in action. The year 2000 was a year where parts of our buildings were re-constructed, and heavy machinery as compressors and excavators were often operational at ground-level. This day they started after noon, and the extraordinary high NO levels are mainly caused by starting up the Diesel engines. The result is a near complete destruction of O3, this at a time where the O3 concentrations are normally rising:


6. In conclusion.

Once more, we have shown that near-ground CO2 concentrations are heavily influenced by wind speed; this CO2 lowering influence certainly is much more important than that of photosynthesis which works in the same direction. Ground ozone concentrations are not impacted in a similar manner, whereas those of NO2 are. So, and this may come as a surprise, the concentrations at ground level of different atmospheric gases does not respond to increasing wind speeds in the same manner!