Connor DiMarco
PhD Candidate in Climate and Space Sciences and Engineering
University of Michigan
Hi! I'm a PhD candidate in Climate and Space Sciences and Engineering at the University of Michigan, working with Tuija Pulkkinen. I got through an aerospace engineering background and a series of undergraduate research positions at NASA Goddard Space Flight Center. I am currently a Center for Space and Earth Science Graduate Research Fellow at Los Alamos National Laboratory, where I collaborate with staff scientists on magnetospheric research.
My dissertation asks why Earth's magnetosphere cycles through energy storage and release on a remarkably consistent two-to-four-hour timescale, regardless of what the solar wind is doing. I approach this through sawtooth events: quasi-periodic energetic particle injections at geostationary orbit that repeat with a regularity nobody has fully explained. The work spans the full pipeline from upstream solar wind data products to observational statistics to global MHD simulations.
Research Interests
- Magnetospheric dynamics and substorm/sawtooth periodicity
- Solar wind data fusion and upstream monitoring
- Global MHD simulation of geomagnetic storms
- Radiation belt boundary diagnostics
- Space weather forecasting infrastructure
Research
Statistical and Temporal Characteristics of Sawtooth Events Published
A comprehensive statistical study of magnetospheric sawtooth events during solar cycle 24 (2008–2016). We compile an 81-event catalog from geostationary energetic particle detectors and characterize their solar-cycle distribution, intertooth periodicity, and multi-point injection and dipolarization signatures. Results show near-simultaneous particle injections across all magnetic local time sectors, while magnetic field dipolarization is confined to the midnight region. This rules out global magnetospheric instability as the driver and points instead to nightside tail reconnection with enhanced convection.
Comparative Dynamics of Substorms and Sawtooth Events In Review
A side-by-side comparison of magnetospheric substorms and sawtooth events using multi-point observations from THEMIS, RBSP, and geostationary satellites. Despite distinct solar wind driving conditions, both phenomena exhibit similar magnetic field dipolarization signatures at 8–10 RE. Sawtooth events occur during sustained southward IMF and elevated proton densities; both show a roughly three-hour periodicity, but periodicity alone does not create the sawtooth mode. The results indicate that sawtooth events represent a storm-time mode of repetitive substorm activity driven by sustained energy input.
Merged Interplanetary Data from L1: MIDL In Review
We present MIDL, a solar wind data product that merges observations from ACE, DSCOVR, and Wind via a three-stage pipeline: per-satellite filtering and despiking, multi-satellite quality screening with agreement-first source selection, and propagation to the bow shock nose using both ballistic and 1D MHD methods. MIDL achieves near-complete temporal coverage (>95%) with strong agreement against OMNI (Pearson r = 0.99 for Vx, 0.96 for density, 0.86 for Bz). The product is publicly available through a web interface and Python package.
Intrinsic Magnetospheric Periodicity Persists in Global MHD In Preparation
Using SWMF Geospace simulations driven by observed solar wind for 122 storm periods (2010–2019), we investigate whether the intrinsic periodicity of the magnetospheric loading-unloading cycle is reproduced in global MHD. Simulations reproduce a 2–4 hour loading-unloading periodicity with a spectral peak near 144 minutes, consistent with observations, but fail to reproduce sawtooth event morphology with global particle injections. This suggests that the periodicity is a fundamental property of the coupled system, while the injection mechanism requires physics beyond ideal MHD.
Software & Projects
MIDL
csem.engin.umich.edu/MIDLAn end-to-end data product and web application that fuses 21 years of solar wind observations from ACE, DSCOVR, Wind, and IMP-8 into a single minute-resolution merged dataset. The pipeline performs per-satellite quality screening, multi-source consensus selection, and bow shock propagation using both ballistic and 1D MHD methods. MIDL raises usable plasma-data coverage from roughly 70% to over 95% and eliminates propagation artifacts present in legacy products. The web interface provides interactive plotting, custom time-range downloads, and full source provenance for every data point.
SWORD
csem.engin.umich.edu/SWORDWebsite for the Space Weather Operational Readiness Development center, a multi-institutional NASA center of excellence bridging research-grade physics and operational forecasting for the geospace environment. SWORD brings together groups from CU Boulder, the University of Michigan, the Earth System Modeling Framework, the University of Alaska Fairbanks, and the University of Iowa.
Sawtooth Event Catalog
A manually compiled catalog of 81 magnetospheric sawtooth events spanning solar cycle 24 (2008–2016), built from visual inspection of geostationary energetic particle data at Los Alamos National Laboratory. Each event record includes injection times, tooth boundaries, solar wind conditions, and multi-satellite coverage metadata. Combined with an earlier solar cycle 23 catalog, it provides nearly two decades of sawtooth observations and underpins the statistical analyses in two of my publications.
CV
Education
Ph.D., Climate and Space Sciences and Engineering
Expected Aug 2026M.S., Space Sciences and Engineering
2024B.S.E., Aerospace Engineering
2022Experience
Doctoral Researcher
2022 – Present- Led 4-year thesis program synthesizing multi-satellite observations, global ground-magnetometer networks, and global magnetohydrodynamic storm simulations to investigate periodic geomagnetic storm dynamics.
- Authored 4 first-author publications advancing understanding of the roughly 3-hour loading-unloading cycle that governs energy transfer through Earth's magnetosphere.
- Served as Graduate Student Instructor for SPACE 574: Introduction to Space Physics, a graduate-level course; led instruction, developed problem sets, and advised students on course material.
- Designed MIDL, an end-to-end product fusing 21 years of observations from three NASA/NOAA spacecraft; raised usable plasma-data coverage from 70% to >95% and eliminated propagation artifacts in the legacy dataset feeding NOAA's operational space-weather model.
Graduate Research Collaborator
2023 – Present- Won competitive research grant from the LANL Center for Space and Earth Science to partner with LANL staff scientists on ongoing magnetospheric research.
- Secured access to proprietary LANL satellite datasets and integrated them with public archives, enabling comparative analyses cited across two first-author publications.
Publications
- C. C. DiMarco, T. I. Pulkkinen, M. G. Henderson. “Statistical and Temporal Characteristics of Sawtooth Events.” Annales Geophysicae, 2025.
- C. C. DiMarco, T. I. Pulkkinen, R. L. McPherron, M. G. Henderson, J. W. Gjerloev. “Comparative Dynamics of Substorms and Sawtooth Events.” JGR: Space Physics, in review.
- C. C. DiMarco, T. I. Pulkkinen, J. W. Gjerloev. “Intrinsic Magnetospheric Periodicity Persists in Global MHD.” Geophysical Research Letters, in preparation.
- C. C. DiMarco, G. Tóth, T. I. Pulkkinen. “Merged Interplanetary Data from L1: MIDL.” Space Weather, submitted.
Skills
Technical: Python, MATLAB, SQL, Spark; statistical modeling, time-series analysis, large-scale data pipelines; embedded prototyping (I2C/SPI, microcontrollers, PCB, CATIA, 3D printing, laser cutting).