While there’s a study that enlists the kinds of powers more commonly given to women, it doesn’t take ethnicity into account especially which ethnicity’s more likely to have these abilities and skills at all. It’s even goes without saying that while there are well-intentioned attempts at introducing multiethnic and multicultural superhero teams, for some characters they’re beholden to stereotypes. Characters like Siryn and Shamrock play into stereotypes about Irish people being red-haired and in the case of the former, drunk.
I’m not saying that there aren’t any red-haired Irish people, but the Irish people I personally know (online to be certain) aren’t big on drinking and I can’t name any red-haired Irish celebrity. Blond maybe, especially if you’re Ronan Keating and Mairead Ni Mhaonaigh. But I can’t name a single red-haired Irish celebrity, which again tells you how these characters play into stereotypes about Irish people made worse by that they’re not written by Irish people.
In the case with two Norwegian superheroes in DC Comics, both Glacier and Ice have ice powers and the latter was created to replace the former (in a way, by mistake). Even not all Scandinavian heroes in DC Comics necessarily have ice powers, it does play into stereotypes about Scandinavians being frigid. Not that there aren’t any glaciers in Norway at all and part of it is in the Arctic Circle. But for some reason, there’s not a single Argentinian character with ice powers.
Argentina’s very close to Antarctica so it gets really cold down south and it’s a missed opportunity when it comes to creating an Argentinian superhero with ice powers, likewise since Iceland has a lot of volcanoes it should make sense to create an Icelandic superhero with volcanic powers. It’s these quirks of geography that can and should inspire writers to create characters based on those, but due to ethnic stereotypes this may never come to be.
The biggest risk of say a Norwegian superhero as written by a non-Norwegian is that there’s a chance of playing into stereotypes, even if it happens accidentally, but it does tell you about how they see a certain ethnicity as. If you want to know what a Norwegian superhero would be like, if they were conceived by a Norwegian here are two examples. The other one’s even black, which’s something neither DC and Marvel have done outside of the latter’s version of Thor.
Likewise, a Brazilian superhero by a Brazilian writer would more accurately depict Brazilian culture. I think no matter how well-intentioned the writer this, if the writer doesn’t share the character’s ethnicity and nationality there’s a chance of playing into stereotypes even if it happens accidentally but still.