Sum of stations != ALL stations for Obs/Mods Trends.

[heikoklein]

Describe the bug

In the results shown here: https://aeroval-test.met.no/danielh/pages/evaluation/?project=EC-Report-final-fix&frequency=yearly&experiment=Trends_2015-2022&parameter=concCecpm10&observation=EBAS-m&tsType=weekly&model=EMEP-Standard&season=All&statistic=obs%2Fmod_median_trend&tab=heatmap&region=Norway#

In the upper right plot, ALL has 7 Stations (upper right corner), while on the map (upper left) are only 6, as are in the upper right corner when one sums over Germany (1), Spain (1), France (1) and Norway (3).

This happens for all *Trends plots, while normal NMB show ALL = 7, but besides the 6 other countries above also Sweden with an additional Station. For some reason, the Swedish station is dropped for the Trends, but not in ALL.

The data was generated by : 2025-07-08 0.31.dev0

Screenshots

[heikoklein]

Reported originally by @svetlanat

[dulte]

Seems to be due to the fact that trends are Null in the map files for yearly for this station. Since the other statistics are non-Null, there is an entry in the file, thus aeroval counts that station as existing when making the bar plot. I think aeroval remove the markers from the map is the value is Null, thus we get a differing number of station on the map and in the bar plot. So either aeroval has to subtract any stations with Null, or use a special marker for Null stations