A recent question here on SE:WB reminded me of a short story I wrote a long time ago, and has inspired me to revisit the idea.
The premise: A race of massive alien creatures travel from planet to planet, solar system to solar system, via large wormholes embedded in planetary atmospheres (reason being that atmospheres "stabilize" the wormholes, where they would otherwise destabilize and collapse). The wormholes leak the atmospheres of the many connected worlds, leading to homogenized planets over great timescales, "mongrel planets."
In my story, the aliens emerge in our Solar System. First in the outer planets, they work their way through the Solar System, weaving a network of wormholes. Eventually, a wormhole connecting Jupiter and Earth is established. One throat travels through Jupiter's atmosphere at around the 250 kPa mark, and the other travels through the Pacific Ocean and other adjoining oceans, nearest the sea floor where the pressure is greatest.
The wormhole has an effective throat diameter of around 100 meters. It expels Jupiter's atmosphere only (no need to account for any other planetary atmospheres): 88-92% hydrogen, 8-12% helium, and trace amounts of other chemicals such as methane, water vapor, ammonia, carbon, ethane, hydrogen sulfide, sulfur, and so on, proportional in quantity to their abundance in Jupiter at the wormhole's altitude.
My question is this: what are the immediate (hours, days) and long term (weeks, months, years) effects of the Jupiter aperture on Earth? I'm specifically interested in the immediate effect on Earth's climate (and what people nearby the event might witness), as well as how Earth's condition might evolve over those weeks and months.