Sylvia Dee

Sylvia Dee wins fellowship to launch Gulf of Mexico study

– SEPTEMBER 28, 2021

National Academies back ‘bold’ research projects by early-career scientists

Sylvia Dee, an assistant professor of Earth, environmental and planetary sciences at Rice University, has won one of eight national early-career fellowships to pursue research that relates to the changing ecosystem of the Gulf of Mexico.

Sylvia Dee

Sylvia Dee

Dee was selected for the environmental protection and stewardship track of the 2021 Early-Career Research Fellowship (ECRF), announced by the Gulf Research Program (GRP) of the National Academies of Sciences, Engineering and Medicine. 

The Gulf is home to a wide variety of ecosystems including estuaries, oyster reefs, beaches and dunes, mangroves and offshore shoals and banks. Dee and her students focus their study on coral reefs, which are critically threatened in the Gulf. These fragile ecosystems continue to shift with climate change, urbanization and increased demand for food, water and energy. Predicting and anticipating these changes is essential to allocating natural resources in an equitable way while protecting the environment, according to the GHP.

The fellows will investigate specific issues related to Gulf ecosystems and produce research that helps enhance environmental protection and stewardship.

“This fellowship will be critical for supporting research in coral reef risk forecasting and mitigation,” Dee said. “Since moving to Texas, I’ve increasingly focused on local issues, and our coral reefs are critical to the ecosystem services we rely on in Houston. The grant will help us build capacity to predict, map and work with our collaborators at the Flower Garden Banks National Marine Sanctuary to protect the unique coral reefs in the Gulf of Mexico.”

The ECRF award is not attached to a specific project, which allows fellows to take on bold research they might not otherwise be able to pursue. All of the fellows are investigators, faculty members, clinician scientists or scientific team leads at colleges, universities and research institutions. Each of them will receive a $76,000 award, mentoring support and a built-in community of current and past cohorts.

“The opportunity to collaborate and interact with other early-career fellows is really exciting,” Dee said. “Our meetings provide us time to branch off into teams to identify research solutions by reaching across disciplines to work on a common problem. The mentoring component spans everything from work-life balance to networking. And in that way, the program really is designed to help us not only launch critical research, but also develop and grow as scientists and scholars.”

“Research that enhances environmental protection and stewardship requires both multidisciplinary thinking and the ability to build strong relationships with decision-makers,” said Karena Mary Mothershed, senior program manager for the GRP’s Board on Gulf Education and Engagement. “These exceptional fellows embody those qualities through their perseverance, creativity and inventiveness. One of the most unique aspects of the ECRF is that it supports people, not projects — and we’re excited to be a part of our fellows’ continued success and professional growth.”

The National Academies’ Gulf Research Program is an independent, science-based program founded in 2013 as part of legal settlements with the companies involved in the 2010 Deepwater Horizon disaster. Its goal is to enhance offshore energy system safety and protect human health and the environment by catalyzing advances in science, practice and capacity, generating long-term benefits for the Gulf of Mexico region and the nation.

PNAS: Climate models can correctly simulate the continuum of global-average temperature variability

Feng Zhu, Julien Emile-Geay, Nicholas P. McKay, Gregory J. Hakim, Deborah Khider, Toby R. Ault, Eric J. Steig, Sylvia Dee, and James W. Kirchner
Proc. Natl. Acad. Sci. USA 116 (2019) 8728-8733.

DOI: 10.1073/pnas.1809959116


Climate models are foundational to formulations of climate policy and must successfully reproduce key features of the climate system. The temporal spectrum of observed global surface temperature is one such critical benchmark. This spectrum is known to obey scaling laws connecting astronomical forcings, from orbital to annual scales. We provide evidence that the current hierarchy of climate models is capable of reproducing the increase in variance in global-mean temperature at low frequencies. We suggest that successful climate predictions at decadal-to-centennial horizons hinge critically on the accuracy of initial and boundary conditions, particularly for the deep ocean state.


Climate records exhibit scaling behavior with large exponents, resulting in larger fluctuations at longer timescales. It is unclear whether climate models are capable of simulating these fluctuations, which draws into question their ability to simulate such variability in the coming decades and centuries. Using the latest simulations and data syntheses, we find agreement for spectra derived from observations and models on timescales ranging from interannual to multimillennial. Our results confirm the existence of a scaling break between orbital and annual peaks, occurring around millennial periodicities. That both simple and comprehensive ocean–atmosphere models can reproduce these features suggests that long-range persistence is a consequence of the oceanic integration of both gradual and abrupt climate forcings. This result implies that Holocene low-frequency variability is partly a consequence of the climate system’s integrated memory of orbital forcing. We conclude that climate models appear to contain the essential physics to correctly simulate the spectral continuum of global-mean temperature; however, regional discrepancies remain unresolved. A critical element of successfully simulating suborbital climate variability involves, we hypothesize, initial conditions of the deep ocean state that are consistent with observations of the recent past.

JAS: Quantifying the Annular Mode Dynamics in an Idealized Atmosphere

Pedram Hassanzadeh and Zhiming Kuang

J. Atmos. Sci. 76 (2019) 1107-1124.

DOI: 10.1175/JAS-D-18-0268.1


The linear response function (LRF) of an idealized GCM, the dry dynamical core with Held–Suarez physics, is used to accurately compute how eddy momentum and heat fluxes change in response to the zonal wind and temperature anomalies of the annular mode at the quasi-steady limit. Using these results and knowing the parameterizations of surface friction and thermal radiation in Held–Suarez physics, the contribution of each physical process (meridional and vertical eddy fluxes, surface friction, thermal radiation, and meridional advection) to the annular mode dynamics is quantified. Examining the quasigeostrophic potential vorticity balance, it is shown that the eddy feedback is positive and increases the persistence of the annular mode by a factor of more than 2. Furthermore, how eddy fluxes change in response to only the barotropic component of the annular mode, that is, vertically averaged zonal wind (and no temperature) anomaly, is also calculated similarly. The response of eddy fluxes to the barotropic-only component of the annular mode is found to be drastically different from the response to the full (i.e., barotropic + baroclinic) annular mode anomaly. In the former, the eddy generation is significantly suppressed, leading to a negative eddy feedback that decreases the persistence of the annular mode by nearly a factor of 3. These results suggest that the baroclinic component of the annular mode anomaly, that is, the increased low-level baroclinicity, is essential for the persistence of the annular mode, consistent with the baroclinic mechanism but not the barotropic mechanism proposed in the previous studies.