Brines (salty aqueous solutions) are prominent across diverse planetary bodies. Their presence has been reconstructed from precipitates on the surface of Mars, observed in the gas plumes erupting from Enceladus, and inferred from meteoritic samples. My work seeks to characterize the kinetic and thermodynamic phase transitions of these brines. Salt solutions can be supercooled below temperatures where thermodynamics predict crystallization of salt or ice. While a supercooled liquid is outside thermodynamic equilibrium, it can exist in a metastable state. Supercooling and glass formation are important for assessing habitability and biosignature preservation potential but are not well characterized for many brines relevant to planetary science. To understand the possibility for supercooled liquids and glasses on Mars and other cold bodies, I conduct experiments and create models for supercooling and vitrification features. Our recent work has shown that liquid water can be stabile as a perchlorate brine during the spring and summer at a high latitude location on Mars, while during the winter, the supercooled brine may transition and persist in a glassy state. Vitrification is a cryopreservation strategy potentially important for astrobiology that enables living cells to reach cryogenic temperatures without the harmful crystallization of ice. Liquid water exists in a disordered state inside living organisms. During vitrification, it is advantageous to maintain the natural disorder of water molecules so the system being preserved is minimally disturbed. On Earth, freeze avoidance by supercooling and vitrification are survival mechanisms employed by polar species in extreme environments. Life forms on Mars or other icy worlds could utilize a similar survival mechanism, either by producing their own organic cryoprotectants or in supercooled or glassy brine solutions. Vitrified brines may be important in the context of astrobiological targets for the future exploration missions of icy worlds, such as Mars, Enceladus, Europa, Ganymede, Callisto, and Titan.

1. Effect of Concentration, Cooling, and Warming Rates on Glass Transition Temperatures for NaClO4, Ca(ClO4)2, and Mg(ClO4)2 Brines with Relevance to Mars and Other Cold Bodies. Ardith D. Bravenec and David C. Catling, ACS Earth and Space Chemistry 2023 7 (7), 1433-1445. DOI: 10.1021/acsearthspacechem.3c00090

Glass forming ability of different materials in slow cooling (e.g., Mars) or fast cooling (e.g., plumes from Enceladus) environments.

Sea ice is an inherent part of our climate system that responds rapidly to climate change. It is commonly conceptualized as a collection of many strongly interacting floes (sea ice fragments). However, climate models treat sea ice as a continuum, as resolving the complexity of floe-scale mechanical and thermodynamical processes is challenging. We created a conceptually new sea ice model (SubZero) that can explicitly simulate the life cycle of individual sea ice floes, including collisions, fractures, ridging and rafting, welding, and growth. The unique SubZero capabilities may improve the realism of sea ice modeling.

CITATIONS:

Example of two floes in contact leading to various possible outcomes, including welding, ridging/rafting, and fractures. The floe interaction forces are computed based on the geometry of the overlapping area. Collision forces define the homogenized floe stress tensor used in the fracture parameterization that splits the floe into several pieces. Welding occurs if a thermodynamic criterion is satisfied and leads to the merger of two floes into one. The ridging/rafting parameterization determines if the overlap area between the floes will be absorbed into increasing the thickness of one of the two floes in contact.

Hauke Schulz is working with Prof. Robert Wood (UW Atmospheric Sciences) and Dr. Dongxiao Zhang (CICOES/NOAA PMEL) to better understand the atmospheric and oceanic processes leading to the organization of shallow convection in the trades. Dr. Schulz and his colleagues have recently discovered the importance of the meso-scale organization of shallow clouds for the net cloud-radiative effect and their ability to cool the atmosphere. The formation mechanism of these cloud formations remains, however, an open question. Dr. Schulz will use autonomous saildrones to particularly capture the processes at the air-sea interface to study the importance of small-scale processes like cold pools for the formation of meso-scale cloud structures. Paired with satellite observations and large-eddy simulations these measurements will shed light on how shallow clouds organize in the current climate, but also addresses the question on how the clustering of clouds will react and feedback in a future climate.

Citations:

Schulz, H., Eastman, R., & Stevens, B. (2021). Characterization and Evolution of Organized Shallow Convection in the Downstream North Atlantic Trades. Journal of Geophysical Research: Atmospheres, 126(17), e2021JD034575. https://doi.org/10.1029/2021JD034575

Schulz, H., & Stevens, B. (in review). On the representation of shallow convection in the trades by large-domain, hecto-meter, large-eddy simulations. https://doi.org/10.31223/X5H651

Bony, S., Schulz, H., Vial, J., & Stevens, B. (2020). Sugar, Gravel, Fish, and Flowers: Dependence of Mesoscale Patterns of Trade-Wind Clouds on Environmental Conditions. Geophysical Research Letters, 47(7), e2019GL085988. https://doi.org/10.1029/2019GL085988

Comparison of variability of trade-wind convection in observations (left) and large-eddy simulations (right) reveals current agreement and challenges that still need to be tackled.

Coastal communities in Alaska rely heavily on fisheries to support their food security. Climate change is currently impacting those fisheries in unprecedented ways. My research focuses on exploring ways that government agencies and organizations can better support food security and sovereignty in these communities in the face of these changes.

Parks, Melissa. 2022. The Influence of Nonhuman Assemblage Interactions on Small Farmers’ Perceptions of Weather in Oregon: A Social Network Analysis. Human Ecology 50: 1103– 1114. https://doi.org/10.1007/s10745-022-00372-y

Parks, Melissa, Gabrielle Roesch-McNally and Amy Garrett. 2021. Bridging Scientific and Experiential Knowledges in Collaborative Climate Adaptation Research: A Case Study of Dry Farmers in Oregon. Journal of Agriculture, Food Systems and Community Development 10(3):187-203. https://doi.org/10.5304/jafscd.2021.103.015

Social-ecological systems in Alaskan fisheries

I am a Physical Oceanographer, working with Drs. Wei Cheng and Albert J. Hermann (CICOES, also affiliated with NOAA PMEL) and Dr. Phyllis Stabeno (NOAA PMEL) on implementation and refinement of a regional Modular Ocean Model version 6 (MOM6) for the Northeast Pacific domain (MOM6-NEP), spanning from Baja California to the Chukchi Sea. MOM6-NEP incorporates ocean biogeochemical, sea ice, and tidal dynamics. The goal of the research is to perform multi-decadal simulations using MOM6-NEP under historical atmospheric and oceanic forcing conditions, evaluate the results against in-situ and satellite observations, identify model biases, and develop methods to reduce those biases. This work will support the NOAA cross-line office Climate, Ecosystems, and Fisheries Initiative (CEFI) to assist NOAA Fisheries management.

1. Seelanki, V., Nigam, T., & Pant, V. (2022). Unravelling the roles of Indian Ocean Dipole and El-Niño on winter primary productivity over the Arabian Sea. Deep-Sea Research. Part I, Oceanographic Research Papers, 103913, 103913. https://doi.org/10.1016/j.dsr.2022.103913

2. Seelanki, V., Nigam, T., & Pant, V. (2022). Inconsistent response of biophysical characteristics in the western Bay of Bengal associated with positive Indian Ocean Dipole. Oceanologia. https://doi.org/10.1016/j.oceano.2022.04.003

3. Seelanki, V., & Pant, V. (2021). An Evaluation of the Impact of Pandemic Driven Lockdown on the Phytoplankton Biomass Over the North Indian Ocean Using Observations and Model. Frontiers in Marine Science, 8. https://doi.org/10.3389/fmars.2021.722401

4. Seelanki, V., Nigam, T., & Pant, V. (2021). Upper-ocean physical and biological features associated with Hudhud cyclone: A bio-physical modelling study. Journal of Marine Systems, 215, 103499. https://doi.org/10.1016/j.jmarsys.2020.103499

5. Seelanki, V., & Pant, V. (2021). Diversity in the Simulation of Chlorophyll Concentration by CMIP5 Earth System Models over the Indian Ocean. Marine Geodesy, 44(6), 505–530. https://doi.org/10.1080/01490419.2021.1909193

6. Seelanki, V., Sreenivas, P., & Prasad, K. V. S. R. (2018). Impact of Aquarius Sea-Surface Salinity Assimilation in Improving the Ocean Analysis Over Indian Ocean. Marine Geodesy, 41(2), 144–158. https://doi.org/10.1080/01490419.2017.1422817s

MOM6 model domain (left) and The comparison of PAPA mooring (right upper) and model simulated (right below) upper-ocean profiles of Temperature, Salinity and Brunt vaisala frequency

I am an Afro-Latina American with Belizean and Caribbean heritage, who has observed that the Global South suffers from a lack of research infrastructure to confront anthropogenic impacts on ecosystems. As a Washington Research Foundation Postdoctoral Fellow based at the Padilla-Gamiño Lab at the UW School of Aquatic and Fishery Sciences, I draw on my background as performing artist and environmental filmmaker to weave my expertise in eco-physiology and science communication in engaging community stakeholders in climate solutions development in Placencia, Belize. My inclusive science and storytelling work will honor cultural perspectives on environmental challenges while engaging stakeholders in scientific discovery.

Clare, X. S., Kui, L., & Hofmann, G. E. (2022). Larval Thermal Tolerance of Kellet’s Whelk (Kelletia kelletii) as a Window into the Resilience of a Wild Shellfishery to Marine Heatwaves. Journal of Shellfish Research, 41(2), 283-290.