Today in New York, it rained. I know it rained because I could hear the intermittent, staccato of taps on the air conditioner, despite the fact that my work-at-home “desk” (our converted dining room table) faces a wall with pictures Scotch-taped to it.
In normal times, the tapping would probably pass unnoticed and honestly would likely annoy me. It would be easy to mistake for the family of pigeons that has decided to roost near our window. Yet in the era of quarantine and shelter-in-place – the age of Zoom, and stalking Amazon for a delivery slot, and avoiding the news like I’m social distancing from The New York Times app – the rain sounds different. It is the sound of the weather – it represents one of the last ways in which the outside world and its rhythms find their way into our small Manhattan apartment.
Since my wife and I started seriously self-isolating due to the coronavirus almost two months ago, I have found myself more and more enamored with rainy days. In some sense, these days offer a small return to something like normalcy. On rainy days, we would be less inclined to go out even in pre-coronavirus times. It seems a bit easier, psychologically, to stay inside while it rains. I hear less news of people crowding into parks and putting themselves and others at risk. I feel cozy, rather than trapped or cooped up. It also feels like the city outside is cleansed by the rain, washing its hands (wash your hands!) while singing happy birthday twice. I don’t think, as a scientist, the rain really makes it much cleaner in a way relevant to the pandemic, but the romantic in me cannot shake the association with a healing outpouring from the skies.
I am an atmospheric scientist: I think a lot about the rain as a professional matter. Since I work on the tropics especially, questions about where and why it rains are fundamental and foundational in my subfield. Yet an under-appreciated aspect of rain (to many non-scientists or non-specialists) which is quite well understood is that it releases heat. As the water goes from a frantic gaseous state to a more calm, cool, and collected liquid, it emits heat into the surrounding atmosphere, like a tiny, liquid toaster. This heating goes largely unnoticed in people’s everyday lives (certainly no one on the ground really thinks about storm clouds above their head as heaters) but it is, in fact, a crucial aspect of the Earth system.
A somewhat miraculous consequence of this heating (with some good approximations and the law of conservation of energy) is that from it, one can infer how much it should rain on Earth, on average. This calculation can be done given only information about the energy coming from the sun, and a few facts about the molecular properties of water and the composition and structure of the atmosphere. The number, for those of you who like to know such things, is about 3 millimeters per day: approximately a stack of three pennies.
It is important to note, this calculation can say nothing about where the rain falls, or when it falls, or how it is distributed. It is an average over the whole Earth on long timescales. It is a global equilibrium statement, not something that has to hold locally. But in this regard, it represents one of the ways that atmospheric science has changed the way I have come to think about the world.
These types of laws and principles don’t care about borders or nationalities. Instead, they require us to think about everywhere, all at once. The rain tells us that, even if we cannot say how things are in one place, or at one time, if we zoom out enough we can hope to understand something larger and fundamental. We can find meaning and truth on the scale of the whole planet.
I think about this now when it rains in New York. How odd it is, and how profound, that the rain here is contributing in a minuscule way to a deep balance that spans the entire globe, the length and breadth of which recently seems ever more out of reach. We are all – if you’ll pardon the pun – in the same bucket, and must understand that we are connected through the Earth system in ways that no policy or executive order can circumvent.
In an era of rising nationalism, and during a time when we all must isolate individually, this global mindset is particularly useful, even to those who have no professional reason to think about rain. We are never not connected: for better or for worse, whether we like it or not. New York’s pains and triumphs, and mine, and yours, must belong to all of us. When it rains in New York, it rains a bit on all of us.
Sometimes it helps to zoom out. And other times, it’s nice just to listen to the rain.