Scientist, Plume Modeling and Forecasting

Sunlight reflection may be the only available option, alongside dramatic emissions reductions, adaptation, and rapid scaling of carbon removal, to rapidly limit many climate impacts over the coming decades.  But we don’t know nearly enough about it to make a scientifically-informed decision about potential deployment – and we’re not on a trajectory for rapid, legitimate decision making.

Reflective is a global, non-profit research organization aiming to radically accelerate the pace of sunlight reflection research. We equip the world with the data and tools needed to make informed decisions about sunlight reflection, fast enough to matter.

What you'll do

• Reflective studies stratospheric aerosol injection (SAI) through modeling and, where the science requires it, by assessing the feasibility of small-scale outdoor experiments. Our modeling work includes AIDE-SAI, a linked set of machine-learning emulators that simulates SAI end to end, from stratospheric circulation through aerosol microphysics to radiation. Both the modeling framework and experiment feasibility assessment require better representation of plume evolution at scales our current global tools do not resolve: the global emulators only carry injected material once it has spread across a grid box, while a field study would need to forecast where a plume is and how it dilutes over days to weeks.
• As Reflective’s Scientist for Plume Modeling and Forecasting, you’ll own that scale. You’ll lead plume forecasting for balloon-based tracer campaigns run with external partners, which test forecasting methods without any aerosol release, and build Reflective’s own forecasting capability out to the 24- to 72-hour horizons a field study would require. You’ll run plume-resolving simulations from release through dispersion and turn the results into dilution rates, an effective source term, and a parameterization the global framework can use. Should a field study proceed, you’ll serve as mission scientist.

The role sits between the multi-scale team and the experiment team and reports to Reflective’s Head of Research, Marianna Linz. You’ll work daily with the OSSE Senior Scientist, who owns observing-system design and parameter estimation and runs that work from your plume simulations; the In-Situ Observing Lead and instrument specialists, who own the instruments and rely on you to tell them where to look; the experiment operations lead, who owns aircraft contracting, shipping, permitting, and in-country operations; and Reflective’s

external forecasting and modeling partners.

Responsibilities

• Lead plume forecasting for balloon-based tracer campaigns run with external partners, working within the partner’s data assimilation and forecasting process while developing in-house capabilities. These campaigns test forecasting methods and are distinct from the potential aerosol microphysics experiment.
• Develop and evaluate plume forecasting capabilities over the 24- to 72-hour horizons a potential field study would require, documenting performance limits and their implications for feasibility.
• Quantify forecast uncertainty well enough to plan against it: where the ensemble spread puts the plume, how that spread grows with lead time, and what it implies for search patterns and instrument settings.
• Translate forecast results into requirements for the observing team, including viewing geometry, altitude, timing, and expected plume extent for daytime visualization systems.
• Model detailed plume evolution to support numerical experiments that test candidate observing suites and sampling cadences at realistic density and instrument fidelity.
• Verify forecasts from each tracer campaign against what was observed and report plainly where they failed.
• Own Reflective’s plume-scale modeling: large-eddy and plume-resolving simulations of injected material from release through dispersion, covering the regime the global emulators cannot resolve.
• Turn plume-scale results into inputs the global framework can use: dilution rates, an effective source term, and a parameterization of plume-scale effects as a function of background conditions.
• Serve as the multi-scale team’s point of contact for the experiment team on plume-scale questions: what the modeling can predict today, what it can’t, and what observations could settle.
• Should a field study proceed, serve as mission scientist: real-time forecast updates, go/no-go input, and direction to pilots and instrument operators on where to sample.
• Who you are

Minimum qualifications

• PhD in atmospheric science, fluid dynamics, or a closely related field, or equivalent research experience.
• Experience running high-resolution or large-eddy simulations of dispersing material (plumes, tracers, or reacting flows) and comparing them against measurements.
• Hands-on forecasting or mission-science experience on an airborne or balloon field campaign: planning flights from ensemble forecasts and making real-time calls during them.
• Comfortable in Python and, ideally, Fortran on high-performance computing systems
• Ability to state clearly  what a model result does and does not support, and to write it down so others can act on it.
• Excellent written and verbal communication skills, especially with mixed scientific, engineering, and non-technical audiences.
• You’re creative and attached to outcomes, not process — you’re constantly looking for new paths to the destination and excited to switch gears if there’s a faster, better way to get something done.
• You are low ego, and have a proven track record for working well across disciplines and with external partners.
• You are passionate about Reflective’s mission.
• Strongly preferred
• Experience with JAX or other differentiable modeling frameworks.
• Not needed
• Stratospheric experience is helpful but not required. Most of our team learned it on the job.
• A nonprofit résumé - Reflective is technically a nonprofit, but it doesn’t feel like one — mission fit and rigor matter more than sector pedigree.
• Formal people-management experience - this role leads technical work and coordinates a team, but is not required to be anyone’s formal manager.
• We encourage anyone who is interested in this role to apply, regardless of whether you feel you meet 100% of the qualifications. The top candidates will bring their own unique perspectives, experiences, and backgrounds from a variety of industries along with many but not necessarily all the skills listed above. We offer professional learning and training opportunities to help you develop skills you may not have had the opportunity to cultivate yet.
• Location
• Our goal is to hire the right person for the role regardless of location, but we have a slight preference for candidates who can work from our Bay Area office 2-3 days/week. The role can be fully remote and we are open to candidates based anywhere in the world who can overlap with our core working hours (9am-1pm PST). We may be able to sponsor visas for US-based foreign nationals and have a moving stipend to support candidates who would like to relocate to the Bay Area.
• Regardless of location, we love seeing each other in person and believe regular co-location helps improve collaboration and team culture. As such, we plan regular team co-working weeks, typically in the Bay Area.