Using a large NOAA Storm Prediction Center database covering United States and Canadian tornadoes, our group analyses the traits and tendencies of tornadic activity across North America. With recent improvements in tornadic data collection, there is a surplus of topics to thoroughly explore. Some of our work includes investigating relationships between two parameters such as CAPE (convective available potential energy), and CIN (convective inhibition) or precipitable water and temperature. Furthermore, we created histograms with Gaussian curves and probability plots for the most critical parameters for tornadic development to better understand the distribution of data and how much it deviates from a centered mean. Currently, we are in the process of creating filled contours to visualize the geographic distribution of parameters across the United States. Our goal is to create a more nuanced tornado climatology. In doing so, we hope to further understand tornadoes and their tendencies with hopes of making our interactions with these events much safer.

Plants have evolved to represent a diversity of species, characterized by functional traits that dictate their performance in response to changing environments. One such leaf functional trait that relates to plant ecological strategy and is strongly correlated with photosynthetic rates, is minor leaf vein density (LVD). Our study will assess how ecological strategies within plant communities shifted in response to Earth’s most recent major global warming event, the Middle Miocene Climatic Optimum (MMCO) from 17-14 Ma, where rises in both global temperature and atmospheric CO₂ levels occurred. We hypothesize that global warming led to longer growing seasons and ecological strategies that prioritized persistence over productivity became dominant, and more favorable climates increased the diversity of ecological strategies present within the community. We will be traveling to various museums to photograph fossils that have all their minor veins preserved, collected from sites representing before, during, and after the MMCO in the Pacific Northwest region. Our goal will be to include several species per site, and photograph their fossil leaves under a stereo microscope. From there we will measure LVD using the program ImageJ using standard protocols. Once we have that data, we will calculate measures of the community-level distribution of this trait (mean, variance, kurtosis), and then compare those values between sites, and thus across the MMCO. In support of our hypothesis, we predict to see a lower mean and kurtosis, and higher variance of LVD values in MMCO plant communities, relative to those existing before or after the warming event. Overall this research is important to not only understanding how plant communities responded in ancient times to rising temperature but how plant communities could potentially respond to the rising temperatures in the future.

Trait-based plant ecology can serve as a means to better understand shifts in ecological strategies within plant communities, and how that affects greater ecosystem processes, such as productivity, before, during, and after a period of major climate change. Apart from modern anthropogenic activity regarding greenhouse gases, the most recent major global warming event was the Middle Miocene Climatic Optimum (MMCO). 17 14 million years ago, this event was a short aberration to a long-term cooling trend that lasted over the last 53 million years, with global temperature averages during the MMCO estimated to be about 8°C warmer than preindustrial averages. Through statistical analysis of leaf functional trait measurements such as leaf area, leaf perimeter, tooth count, and petiole width, we seek to help document an example of how global warming affected vegetation in Earth’s past by comparing changes in leaf traits across the MMCO to modern leaves. While studying Miocene fossil leaves, we are creating a modern leaf database to better interpret trait trends analyzed from samples. This is building off of a previous study’s global dataset to create a model that can be used as an analog for categorizing fossil plant assemblages into different vegetation types using functional trait distributions, as well as assist in trait trend interpretation. At this point in time, we have analyzed enough modern samples to be prepared to interpret trait trends preserved in MMCO leaf fossils. Our objective during the 2021-2022 school year will be to collect enough MMCO trait trend data to make stronger predictions about how modern plant communities will be affected by climate change.

Soil pedogenic carbonates are precipitates of carbonate minerals, majorly calcite, that accumulate in soils in arid, temperate, and subtropical areas. They retain clues to their environment in their isotopic signature that make them important for paleoclimate reconstructions across subtropical to subpolar regions. However, we lack an exact understanding of pedogenic carbonate accumulation in subtropical and monsoonal regions, where heavy rainfall encourages leaching in the soil profile, yet soil carbonates are still observed. A clearer understanding of the process by which carbonates accumulate in the subtropics will aid the interpretation of isotopic data from past warmer and wetter periods. To better understand their formation in these soils, I used HYDRUS-1D, a numerical model that simulates soil processes, to track calcite accumulation over a five-year period under conditions resembling the environment of Myanmar, which today lies in the monsoonal domain. I tested various scenarios of rainfall, vegetation, soil type, and temperature to determine the control of these environmental factors on the depth, timing, and amount of calcite accumulation. Results show that as precipitation increases, the major effect on accumulation results from varying rainfall distribution and rooting depth. Most carbonate precipitation occurs during the dry season in winter and spring, indicating a clear seasonal bias in their isotopic record. This seasonal bias – commonly ignored in paleoenvironmental studies – should be considered in future work.