There’s no real way to set a film based around grief in a tropical location. Sure, people in warm climates deal with death and sadness too, but cognitively, visually, there’s nothing quite like the cold to drive misery home. So it is in Manchester by the Sea, the delicate and powerful new film from Kenneth Lonergan. The film’s opening images are a montage of winter scenery, and of Casey Affleck’s Lee Chandler as he handles various building management duties in Quincy, Massachusetts — tossing out garbage, changing light bulbs, and shovelling snow. The snow is ever-present in Manchester by the Sea, obscuring, coating, and, in its way, marking the time. The snow sets the tone.