Will Cantrell
Department of Physics
Michigan Tech

A complete list of my publications is accessible via my Google Scholar profile, here.

Below I have listed a few of my publications with some thoughts on them, beyond what's in the paper itself.


Droplet growth or evaporation does not buffer the variability in supersaturation in clean clouds, J. Atmos. Sci., doi.org/10.1175/JAS-D-23-0104.1, 2024.
This paper started as Jesse's MS project.

Molecular simulations reveal that heterogeneous ice nucleation occurs at higher temperatures in water under capillary tension, Atmos. Phys. Chem., doi.org/10.5194/acp-23-10625-2023, 2023.
We spent quite a long time trying to find a way to isolate the effects of negative pressure due to negative curvature. Eventually, the I-beam configuration that we use in this paper was the one that worked. 

Dependence of aerosol-droplet partitioning on turbulence in a laboratory cloud, J. Geophys. Res., doi.org/10.1029/2020JD033799, 2021.
I told Shawon and Prasanth that the key idea in this paper probably wasn't going to work. The pool of salty water at the bottom of the chamber enables decoupling the temperature gradient in the chamber and the mean saturation ratio. I didn't think that they would be able to get enough coverage at the bottom of the chamber, but Shawon, Prasanth, and Greg found a way to do it. We wrote this paper during the pandemic. In some ways, this paper helped me decompress. I would spend the day dealing with administrative stuff, then get up onto the platform bed in my home office with the laptop propped on a pillow in front of me, and immerse myself in CCN, turbulence, integral radii... 

High supersaturation in the wake of falling hydrometeors: Implications for cloud invigoration and ice nucleation, Geophys. Res. Lett., doi::10.1029/2020GL088055, 2020
Prasanth (the lead author) had done some work at his home institution, looking at wakes of sulfur hexafloride drops. That work was published in PRL. His advisor suggested that he might extend the work in the cloud chamber and arranged for him to spend a month with us, trying to do just that. We got some preliminary data and were encouraged enough with our initial submission (which was rejected) that we went back to the lab for more data. 

Aerosol indirect effect from turbulence-induced broadening of cloud-droplet size distributions, Proc. Nat. Academy. Sci., doi:10.1073/pnas.1612686113, 2016.
This was the first paper to come out of the Cloud Chamber. It started fron the first proof of concept experiments that we were doing, then developed into a major research effort once we saw that we could make headway on the results using stochastic condensation.

Contact freezing of water by salts, J. Phys. Chem. Lett., 6, 3490–3495, 2015.
This paper started as one of those just-try-it-and-see-what-happens moments. We took the top off the cold stage we were using to do contact freezing experiments and dropped salt on the cold drop, just to see what happens. We got some freezing events, which was very interesting, so we designed a more careful experiment. I thought I knew what was going on until we tried an exothermic salt and the droplets still froze.

Characterization of dust particles’ 3D shape and roughness with nanometer resolution. Aerosol Sci. Technol., 49, 229-238, 2015.
This was Xinxin's Masters project. Looking at real dust particles with an atomic force microscope was no trivial task, but we managed to do it. Dust is remarkably smooth on that scale. And most dust is more like a pancake than a sphere.

Heat of Freezing for Supercooled Water: Measurements at Atmospheric Pressure. J. Phys. Chem. A, 115, 5729-5734, 2011.
This started as an undergraduate research project, when Alexandria returned from a year studying in Australia. Tony picked it up when she left. Writing this paper was the product of many long, intense discussion between me and Alex on thermodynamics, solids, irreversibility... It was fun though. The review process for this paper, on the other hand, was not fun.

Entropic aspects of supercooled droplet freezing, J. Atmos. Sci., 65, 2961-2971, 2008.
This paper started as a homework problem when I was teaching undergraduate Thermodynamics and Statistical Mechanics. Alex and I walked home together pretty frequently then (he lives two streets up the hill from me) and we were talking about calculating entropy from heat capacity as a function of temperature. We started wondering if maybe there's something like a law of corresponding states. We never made that work, but we did get sidetracked into latent heat and entropy.
 
Detection of spatial correlations among aerosol particles. Aerosol Sci. Technol., 37, 476-485, 2003.
This was my first paper to come out of work done at Michigan Tech. Mike Larsen had been working with Alex Kostinski on correlations among cloud droplets. We started wondering if that extended to aerosol particles. We took some data with a CLiMET particle counter that I had borrowed from Glenn Shaw (my graduate advisor) and showed that it does.

Nucleated deliquescence of salt. J. Chem. Phys., 116, 2116-2120, 2002.
This paper also started as an undergraduate research project. George Ewing (my postdoctoral advisor) and I were talking about thin films of water on solid surfaces, when he asked, "I wonder how thick the film of water just before deliquescence is." Thinking it would be straightforward, we asked Charles to take it on as research project. It wasn't as straightforward as it first seemed. The film remained stubbornly thin. I told Charles that he had to be very careful not to let the relative humidity in the sample cell exceed 75%, because the salt (NaCl) would deliquesce. Finally, I told him to deliquesce the salt no matter what. I remember checking in with him several times and thinking the system must be broken, because he was up over 80% RH, and the film of water on the surface was still only a few layers thick. It deliquesced that first time at just over 90% relative humidity. It took me a while to wrap my head around nucleation as the reason for that. Usually, efflorescence is considered as the phase transition that must be nucleated. But if the surface that's deliquescing is nearly defect free (like the one we were using), that transition has to be nucleated too.

Cloud properties inferred from bimodal aerosol number distributions. J. Geophys. Res., 104, 27615-27624, 1999.
I remember reading papers by Hoppel and Frick and thinking, "We have a bunch of distributions that have a minimum like what they describe. If we assume a composition, we can get a maximum supersaturation out of that." Glenn (my advisor) was on sabbatical at the time, so I ran my idea by another faculty member in the department. He told me that the instruments were unreliable and that supersaturations in the atmosphere never got above above 0.1% anyway. (Some of my analysis showed 0.5% and higher.) His dismissive attitude really got under my skin. So I dug into the literature and found a paper describing a method to measure (not infer) supersaturation and that measured values in fogs could be 0.5%. (The paper is Gerber, JAS, 1991) I continued with my analysis. When I showed it to Glenn, he was really excited by it. Then... I went to the library one day and started perusing the latest issue of JGR. There was "Deducing droplet concentration and supersaturation in marine boundary layer clouds from surface aerosol measurements" by Hoppel, Frick, and Fitzgerald. I'd been scooped! (I had gotten the idea from reading their papers, after all.) I wrote up my results anyway (we had quite a bit of data), and this paper was the result.

Evidence for sulfuric acid coated particles in the Arctic air mass. Geophys. Res. Lett., 24, 3005-3008, 1997.
This was my first paper. Dave and I had set up the experiment at Poker Flat, and this was a set of data that looked interesting.