Where German Easter fires burn on Saturday evening, Dutch Easter fires burn on Easter Sunday. So this Easter Monday morning it’s time to look at the second spike of PM10 pollution in the air. The smell in the garden is as strong as yesterday.

The sensor grid shows a much more muted picture this morning. First the same sensors as I looked at yesterday.

Ter Apel (on the German border, have their own fire on Sunday evening, had an extreme reading after the German fires), shows twice the norm. Still a high outlier, but it pales in comparison to the 5 times the norm reading a day earlier. The peak also dissipates more quickly.

Upwind from us, in the Flevo polders, it is a similar picture, a less distinct peak than yesterday but still well above twice the norm.

And near us in Utrecht the readings are actually about the same as yesterday. That matches with my perception that the smell around our house is about the same as yesterday. It also implies that though yesterdays fires were much closer, they were perhaps less in numbers (some were cancelled due to drought) or intensity, or they weren’t actually as neatly upwind from us as the German fires and passed to the south of us.

The latter seems to be borne out by readings from some of the other sensors.
First Eibergen, on the border between the Twente and Achterhoek regions, an area with lots of Easter fires.

Eibergen shows a higher peak due to the Sunday fires than the day before, yet both peaks are in the same range at 2 to 2.5 times the norm.

South and east of the region we see similar patterns.
In Nijmegen more southern, the peak is higher than the day before, because they were not downwind of many German fires.

On the Veluwe, which is more eastern and closer to us, the peak is again lower than the day before yet still distinct.

Overall the pollution of Sunday’s fires is less visible across the Netherlands. Where Saturday’s fires made sensors go into the red from the north-eastern border, southwesterly across the country to Amsterdam, for Sunday’s fires such a clear corridor doesn’t show.

It’s only morning on Easter Sunday, but apparently in Germany, over 160 kilometers away, Easter fires have been burning on Saturday evening. This morning we woke up to a distinct smell of burning outside (and not just of the wood burning type of smell, also plastics). Dutch Easter fires usually burn on Easter Sunday, not the evening before. So we looked up if there had been a nearby fire, but no, it’s Easter fires from far away.

The national air quality sensor grid documents the spike in airborne particles clearly.
First a sensor near where E’s parents live, on the border with Germany.

A clear PM10 spike starts on Saturday evening, and keeps going throughout the night. It tops out at well over 200 microgram per cubic meter of air at 6 am this morning, or over 5 times the annual average norm deemed acceptable.

The second graph below is on a busy road in Utrecht, about 20 mins from here, and 180 kilometers from the previous sensor. The spike starts during the night, when the wind has finally blown the smoke here, and is at just over 80 microgram per cubic meter of air at 8 am, or double the annual average norm deemed acceptable.

This likely isn’t the peak value yet, as a sensor reading upwind from us shows readings still rising at 9 am:

On a map the sensor points show how the smoke is coming from the north east. The red dot at the top right is Ter Apel, the first sensor reading shown above, the other red points moving west and south have their peaks later or are still showing a rise in PM10 values.

The German website luftdaten.info also shows nicely how the smoke from the north eastern part of Germany, between Oldenburg and the border with the Netherlands is moving across the Netherlands.

The wind isn’t going to change much, so tomorrow the smell will likely be worse, as by then all the Easter fires from Twente will have burnt as well, adding their emissions to the mix.