Backyard science: isotope hydrology style

A few days ago, someone asked me whether I’d done any Citizen Science projects with my 4 year old daughter. I said “no”, but then spouted off a couple of projects I was looking forward to starting in the next few years, including CoCoRAHs and Project Budburst. After the conversation ended, I spent a few moments berating myself for failing to have introduced my child to Citizen Science projects before age 4, but then I realized I was being an idiot. Not only is my daughter exposed to a wealth of scientific experiences – museum visits, mixing things together in the kitchen, throwing sticks into streams, hiking and camping in national parks, watching nature documentaries, helping Cookie Monster test hypotheses – but she’s also been helping me with my scientific research for over two years. (Actually, earlier than that – her first field expedition was at 2 months.)

One of my research interests is in understanding the sources of water in streams and the flowpaths and timescales water takes to get there. The isotopes of hydrogen and oxygen in the water molecule give me important information about these sources, flowpaths, and timescales. But in order to know what’s going on in the stream, I must also understand the input signal, i.e., precipitation. I need to know how the isotopic composition of precipitation varies between storms and seasonally in my field area – which is largely in and around Charlotte, North Carolina. No one else is measuring precipitation isotopes in this region, so I need to. And what better place than my backyard.

Precipitation collection apparatus, iteration 1, January 2009

In January 2009, I set up a simple collection apparatus on the edge of my back deck. Basic elements of it included my recently disused Christmas tree-stand, a funnel, and an abandoned bisphenol-A containing Nalgene bottle. This set up certainly made it convenient to retrieve the samples as soon as it stopped raining, but it had a couple of drawbacks. I was worried about interference from the house, the funnel tended to tip at an odd angle, and in a few gusty winds, the whole thing blew off the deck railing.

Precipitation collection apparatus, iteration 2, February - August 2009

By February 2009, with an undergraduate student committed to analyzing the data for an independent study, I had somewhat upgraded my collection technique. I moved the collection site to the top of my daughter’s monkey bars, because that was the farthest from any roofline or tall tree in the backyard. I started using tape to secure the funnel to the (shorter) collection bottle and make sure it was pointedstraight up.

And, for a while, I had a tipping bucket rain gage installed a few feet away. That rain gage position represents a compromise between ability to stretch the short download cord to a relatively secure position from which to connect it to a laptop (i.e., the “tree house” rather than the ladder to the monkey bars) and potential interference from the tree house roof. Unfortunately, the rain gage never did work properly and a few months later it was removed from the play set.

The swing set set-up had a few drawbacks though. My backyard has low permeability clay-rich soils (i.e., extremely poor drainage) and it collects standing water after heavy rain storms, and I’d always forget about that before dashing outside to collect a sample in barefeet or sandals. Also, the ladder was rather perilous to climb up because it got quite slippery when wet and covered in mud (from that poorly drained backyard). There was a particularly memorable evening when I needed to retrieve a sample just as a heavy downpour became a heavy snowstorm at 0 degrees C.

Eventually, after careful consideration, I moved my sampling location again. Now, when I collect precipitation samples, I do it at the very end of my driveway, a few feet away from my mailbox. That’s as far away from any roofs or trees as I can get on my property, there’s no ladder to climb, and the pavement is never slippery or muddy. The only problem here is that I need to deploy the collection apparatus (i.e., tree stand, bottle, and funnel) only when there’s an anticipated rain event, so my daughter has experienced a couple of occasions where we’ve raced home from school, driving with one eye on the darkening sky, and set up the collection apparatus as the first heavy rain drops begin to fall.

My child loves to help me collect water samples. “Mommy, do you need to collect a water sample?” is a reasonably frequent refrain in my house. And it’s not just precipitation. Since I work in urban watersheds, I’ve also gotten interested in isotopes in municipal drinking and wastewater. My daughter loves to collect samples from our kitchen faucet, and she’s very adept at getting vials full to the brim and tightly sealed. She’s also been to the wastewater treatment plant with me to collect treated effluent, and we had lots of good conversations around our trip to “the poopy and pee-pee factory.”

So, yes, my daughter has experienced citizen science. While she hasn’t entered data into an online form and we didn’t find the project in a list on the internet, my four year old has had first-hand experience with the process of collecting good-quality scientific data. The next step: getting her to run the lab analyses. Muahahahahaha.

Liquid water isotope analyzer, my lab, UNC Charlotte