Climate: Germany is heading for the next drought

There is a world famous image by the Venetian painter Bernardo Bellotto, called Canaletto, which shows the silhouette of the city of Dresden: you can see in it the Hofkirche, which is under construction, the castle, the Frauenkirche, but especially the Elbe, which lazily flows under the Augustusbrücke. .

The river has gotten pretty narrow right now, as images from a nearby webcam show. On the Neustädter side, a broad, dry, drooping strip protrudes from the Elbe. The level was only 95 centimeters on Tuesday. That’s not even half the 2.1-meter seasonal average. According to current forecasts, the water level in Dresden could drop to 87 centimeters or less in the coming days.

“We urgently need a warm rain from the country”

It is a symbolic image: it has not rained much in many parts of the country for a long time. For the Dresden airport weather station, for example, this means that in April only 1.5 liters per square meter fell so far. That is exactly four percent of the long-term average. Throughout Germany, a lack of rain is causing problems for farmers and gardeners. “Our soils, regardless of whether they are arable or grassland, have superficially dried. We urgently need a warm rain,” complains the head of the farmers’ association, Joachim Rukwied, in the “Bild”.

Watering your crops may be an option for some gardeners to ensure the survival and growth of their plants. But this is only an option for very few farmers. On the one hand, the corresponding systems have to be available for this, on the other hand, the thing is simply too expensive. If you grow potatoes, fruits, and vegetables, you might consider spraying in the dry season, but for grain or rapeseed it wouldn’t be worth it due to low market prices.

The year 2020 has been too hot and too dry recently: the months of January to March in Europe were the warmest first quarter in 100 years, according to the German Weather Service, half a degree warmer than the previous record year of 1990. Considered only Germany’s temperatures remain the third highest average since 1881.

And then there was the lack of rain: “We have had little rain in large parts of Germany since mid-March,” says DWD meteorologist Andreas Friedrich. In April, only about five percent of the usual amount of rain had fallen across the country. Because there was also strong wind, especially light and sandy soils and the upper 20 centimeters of the subsoil had dried up.

At least the winter was relatively humid

Warmth, dryness, wind: In many places, this is the third consecutive spring with little rain. The risk of forest fires is already extremely high in some parts of the country. The corresponding danger index of the German Meteorological Service considers, among other things, air temperature, humidity, wind speed and rain. Especially in Brandenburg and Saxony-Anhalt, the value is currently five. There is nothing worse.

After all, there are at least some differences from last year: in many places, the dams are even more crowded than around 2019. And at least from a depth of about 60 centimeters, forecasters say, the ground looks a bit better. “We are lucky that the winter was wetter than normal this year, especially in February,” said DWD meteorologist Friedrich. This gave him a better starting point compared to last year. “With the exception of some regions in Saxony-Anhalt, Saxony and Thuringia, the situation in the deeper layers of the soil is still relaxed,” Friedrich said.

Decreased flight movements have nothing to do with lack of rain.

A question that comes up again and again these days, especially on social media: Is it possible that the current lack of rain also has to do with the small number of jets flying in the sky over Germany in times of the crisis of the crown? After all, fewer wakes form in the sky than usual.

The current Eurocontrol figures show how massive the decline in flight movements is. For example, there were only 883 flights in German airspace on Sunday, 89 percent less than the same day the year before, even though it was Easter.

But meteorologist Friedrich rules out: There is no connection between the number of planes and the missing clouds. In addition, air masses at cruising altitude are currently so dry that trails will not form in the long term.

An omega in heaven

Instead, lack of rain is to blame for an atmospheric constellation that also prevailed during the hot summer of 2018. Climate experts call it omegalage. This means that a high pressure area that rotates clockwise determines the climate in Europe. On its east and west sides, two low pressure areas rotate counterclockwise again.

Climate systems intertwine like the gears of a gearbox, and are fixed together so that the high and low pressure areas do not move as usual. Therefore, rain is permanently channeled around continental Europe, but also around the British Isles. The course of the flow is reminiscent of the Greek letter Omega, hence the name.

According to some climate researchers, changes in the area of ​​the so-called jet stream could be to blame for the stability of this climate situation. This strong wind at a height of around ten kilometers blows from west to east in the northern hemisphere, sometimes up to 500 kilometers per hour.

The jet stream usually flutters through the atmosphere like a ribbon. However, as a result of climate change, individual waves in this wind band could stop more often in one place rather than continue traveling around the earth. In such cases, there would be less variety in the climate, extreme situations (droughts in some places, floods in other places) would occur more frequently. Some studies suggest this, but the question is not entirely clear.

“Dry bone until at least Friday”

If the current climate situation continues, a severe drought threatens. For the next few days, meteorologists definitely have no hope of rain at first. “It will be completely dry until at least Friday,” says DWD employee Friedrich. But what’s next? Forecasts of rain over longer timescales are “incredibly uncertain,” says meteorologist Florian Pappenberger of the European Center for Medium-Term Weather Forecasting (ECMWM) in Reading, UK.