Research Projects

This project will analyze molecular hydrogen (H2) in an ice core from Summit, Greenland to reconstruct atmospheric changes in H2 over the past millennium. This will be the first record of past atmospheric H2 prior to the onset of the industrial era. The results will reveal the natural variability in paleo-atmospheric H2 and how it relates to climate change. The resulting data will provide a baseline for assessing how human activities have influenced atmospheric H2 since the preindustrial era. The results of this study will inform global assessments of how the future hydrogen economy will affect atmospheric composition and climate. The project will provide training for a postdoctoral scholar and undergraduate students. 

The research involves drilling a new ice core at Summit, extracting air from the samples in the field, with subsequent analysis for H2, Ne, and CH4. Paleo-atmospheric levels of H2 will be inferred from the observed H2/Ne ratio to account for pore close-off fractionation during firn air entrapment and possible gas loss during drilling/sampling. This study will generate the first millennial scale atmospheric history of H2 and examine centennial scale variability associated with the Medieval Climate Anomaly and Little Ice Age. Climate-related variability in H2 is expected because the major loss mechanism is microbial uptake in soil, a process that is highly sensitive to hydrological conditions. The Summit paleo-atmospheric H2 record will therefore provide new constraints on our understanding of the global biogeochemical cycling of H2 and an important test for global models used to assess the climate sensitivity of future H2 emissions.

Knowledge of basal temperatures and geothermal fluxes underneath the Greenland and Antarctic ice sheets is key to modeling ice-sheet flow, to finding locations where climate records are preserved, and in general to better understand subglacial conditions that influence ice-sheet evolution. Yet such information has been difficult to acquire and there exist limited basal temperature and geothermal flux measurements from a few, isolated locations. This project will develop and test a new measurement capability that would couple unreinforced single-mode optical fiber with melt probe technology. The project aims to develop and test a capability that would greatly expand the number and distribution of temperature and flux observations from ice sheets. An immediate goal is to enhance the measurement capabilities of probes to be used by the Center for Oldest Ice Exploration (COLDEX) Science and Technology Center. 

The team will augment the capability of melt probes that are presently being built for COLDEX to deploy optical dust-loggers to depths up to 3000 m in Greenland and East Antarctica. The team will add to the Greenland commissioning probe 3000 m of single-mode optical fiber to unspool as the probe descends. Distributed Temperature Sensing at the deployment site will be realized with minimal additional surface equipment and a single additional field team member. This proof of concept will enable the option to equip the COLDEX Antarctic probes for DTS.

Summit Station in Greenland has been the research location for many National Science Foundation Office of Polar Programs (NSF-OPP) activities for over twenty years. The value of the facility is based on its location, well above the Arctic circle, high enough in elevation to be in the free troposphere, not influenced by human settlements or the moderating effects of the ocean, and the site of the Greenland Ice Sheet Project 2 (GISP2) deep ice core. Summit Station (72N, 38W, 3250 m.a.s.l.) hosts the Greenland Environmental Observatory (GEOSummit), the only NSF site with permission from the Government of Greenland and the Danish Commission for Scientific Research in Greenland to provide long-term environmental measurements. Summit Station is staffed year-round and fills an important niche in the international scientific community’s global measurement capability. The Science Coordination Office (SCO) for Summit Station represents research interests that utilize the station, providing regular feedback to the managers of the Arctic Research Support and Logistics Program (RSL) and conveying information back to the research community about NSF’s plans for the station. The SCO presents the needs and desires of the science community working on the ice sheet in interior Greenland in discussions and decision-making process between RSL and their primary logistics support contractor. NSF has stated plans to recapitalize the infrastructure at Summit Station over the next 8 years and the SCO will ensure there is communication with the research community throughout the planning and design process. The SCO concurs with NSF’s goals to make a safe and sustainable Summit Station elevated above the drifting snow and preserving the clean air and clean snow research areas. The GEOSummit website has resources for new Principal Investigators, students and educators. 

Summit Station, Greenland is the site of decades of study of the past climate through deep ice cores, and studies of atmospheric chemistry, snow processes and, more recently, the study of high-energy neutrinos from the origins of the universe. Through this effort, the SCO will ensure that plans to operate and in coming years to recapitalize the infrastructure at Summit Station will be done with the interests of the research community. The SCO meets regularly with the arctic logistics contractor science support, logistics and operations at Summit Station to remain informed about plans and communicate research interests. The SCO is invited to review documents and provide input on plans for Summit Station. SCO will continue to advocate for Summit Station site plans that accommodate an influx of astrophysical research while maintaining long standing focus on climate relevant research which needs clean air and snow conditions. This plan will also welcome and support researchers from a range of other disciplines and will include opportunities to educate students and new researchers but must keep everyone from inadvertently interfering with each other. The SCO website is a keystone of communication to the science community, with several features added over the past few years such as the web-based GIS -- recording activity in the region over the past 12 years, a virtual tour using Streetview images, a new “Working at Summit” section targeting new investigators, a comprehensive bibliography of published work near Summit, and a quarterly newsletter.

This is a project that is jointly funded by the National Science Foundation’s Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (UKRI/NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own proposals and component of the work. 

This research project continues an 11-year field experiment called the Integrated Characterization of Energy, Clouds, Atmospheric state, and Precipitation at Summit (ICECAPS) and adds measurements along Lagrangian transects (ICECAPS-MELT). The project is an international collaboration that has been operating ground-based instruments at Summit Station in Greenland since 2010, taking observations of the atmosphere to advance understanding of cloud properties, radiation and surface energy, and precipitation processes over the Greenland Ice Sheet. It is an important time to make these observations because Greenland is undergoing changes due to rapid shifts in Arctic climate. The current project continues the observations made at Summit Station and expands measurements along transects to another important region of Greenland called the percolation zone. In this zone, melt water is generated at the surface, where it can percolate down into the snow and then refreeze. This creates ice layers that can cause additional melt water to move horizontally rather than vertically. It is important to understand these processes because melting of the Greenland Ice Sheet is a significant contributor to global sea level, which is predicted to impact humans significantly over the next century. 

This new ICECAPS-MELT project complements the ICECAPS Summit observatory by building a new mobile observatory for measuring parameters of the surface mass and energy budgets of the Greenland Ice Sheet. This observatory uses a novel approach for unattended, autonomous operation by supporting instruments that require moderate power and internet bandwidth yet are quite like those operated at Summit Station. The new observatory measures surface mass and energy budget parameters, including precipitation, cloud properties, radiative and turbulent fluxes, near-surface meteorology, and subsurface temperatures and structure. To do this, the ICECAPS-MELT team deploys a precipitation radar, a cloud lidar, a microwave radiometer, a ground-penetrating radar, and an automated surface flux station, which consume approximately 500 W of power under normal conditions. The project will lead to new insights into how parameters of the surface mass and energy budgets co-vary in space and time between this new observatory and the ongoing measurements at Summit. Trajectory analyses track the changes in air parcels as they ascend the Greenland Ice Sheet and pass over the two observational sites. The mobile observatory will be deployed in successive summers at Summit Station in the dry-snow zone and at the DYE-2 station in the percolation zone. If this project is successful, a network of these observatories will be proposed for future deployment in southwestern Greenland, which will provide new insights into how atmospheric properties and processes are coupled both spatially and temporally to the ice sheet’s surface and subsurface conditions over Greenland.

This project will develop the prototype of the Radar Echo Telescope for Cosmic Rays and Neutrinos ready for installation at Taylor Dome in Antarctica. Radar echo detection is the process by which radio waves are reflected from an object in order to measure its properties, including position, direction, and spatial extent. High-energy particles interacting in a dense material like ice produce cascades of charged particles and a dense cloud of ionization, which reflects incident radio waves, allowing for remote detection of high-energy particles such as neutrinos. Such radar echoes have already been observed in a test-beam measurement. This work will establish the technical aspects of this transformative detector technology for neutrinos with energies of 10 peta-electron-volts (PeV) and beyond. Expanding access to scientific thought and activities at a young age is a key step towards expanding general scientific literacy and training future scientists from all backgrounds. The NSF-supported ASPIRE program at The Ohio State University for high school women will be extended to involve the radar detection of meteors. Students will design, construct, and use an antenna to detect a faint radio signal, inspiring curiosity and creativity. 

The first installation to be planned will be the Radar Echo Telescope (RET) for Cosmic Rays (RET-CR,) which will detect cascades from ultra-high-energy cosmic rays (UHECR) and develop the techniques for the future RET for neutrinos, RET-N. UHECR are well studied and make an ideal, in-situ ‘test beam’. The optical Cherenkov detector IceCube has detected neutrinos above 1PeV, and its upgrade will extend this to ~10 PeV. The RET targets neutrinos with energies in the 10-100 PeV range, for which there is no existing technology with greater sensitivity. Detecting a statistically significant population of 10-100 PeV neutrinos is crucial to probe the sources of UHECR and to measure neutrino-nucleon interactions at center-of-mass energies >100 TeV, both open experimental questions. This project advances the goals of the NSF Windows on the Universe Big Idea.

Ultra-high-energy neutrinos are unique astrophysical messengers as they interact only weakly with intervening matter and can therefore be used to probe high energy sources and extreme conditions throughout the universe, and to test physics at energies beyond the standard models. With support from this award, the PIs will expand the currently operating Radio Neutrino Observatory in Greenland (RNO-G) to enable observations of the highest-energy neutrinos. When combined with observations from other messengers like photons, cosmic rays, and gravitational waves, observations of neutrinos made with RNO-G can further advance our understanding of the most powerful cosmic ray accelerators and explosive events in the universe. This award will engage people from a broad range of backgrounds in multi-messenger astrophysics through this research and through dedicated student workshops and activities. This award addresses the priority areas of NSF's "Windows on the Universe" Big Idea. 

RNO-G's design is optimized to search for the radio flash generated by neutrino interactions in polar ice using modular stations that act as their own independent experiments. With the large footprint of the full array, RNO-G will have an unprecedented sensitivity and will be the first ultra-high energy neutrino observatory with a view of the Northern sky. This two-year program will continue to build the RNO-G array beyond the seven stations currently installed and operating in Greenland. The supported groups will improve the drill reliability and efficiency to more rapidly install stations in the ice. They will construct and install the instrumentation and commission the stations. They will study radio wave propagation in ice, crucial for accurate modeling of the instrument. They will operate the RNO-G stations in science data-taking mode and study the performance of the instrument.

In understanding the large-scale changes of the Greenland Ice Sheet, wide coverage is needed. While aircraft and satellites produce extensive elevation-change datasets, and regional climate models predict snowfall at high resolution, both systems require calibration and validation by on-the-ice means. Hence, there is a need for extensive on-ice elevation survey data in Greenland, typically collected using the Global Positioning System (GPS). Ground-based traverses have been highly successful in collecting such on-ice information. Similarly, on-ice static GPS stations have been installed for short-term glaciology projects. Both approaches, however, suffer significant drawbacks. The first is cost. Ground traverses are logistically complex and expensive. For traditional static stations, the high cost is associated with the hardware and the transport of large numbers of batteries due to the power required to run these stations through the dark winter. The second is limitations in spatial and temporal coverage. Traverses offer excellent spatial coverage, but temporally only a single snapshot in time over the traverse route. Conversely, static stations offer excellent temporal resolution, but operate at a fixed point and thus limited spatial resolution. 

This project will create a dense network of static on-ice GPS stations in Greenland. New GPS technology allows for a reduction in costs by leveraging the newest generation of chipsets, which offer extremely low power consumption. While currently unproven for collecting science data on ice sheets, these chipsets are now integrated in the current generation of Unmanned Aerial Vehicles (UAVs) and, when operated using Real Time Kinematic (RTK) corrections in these situations, claim centimeter-scale positioning accuracy. Over three phases, the project will 1) install a network of stations in the study area; 2) develop a standalone GNSS receiver station for deployment outside the original network; and 3) deploy a wider network of stations on the Greenland Ice Sheet. This project will also integrate research and education by supporting a graduate student who will be actively involved in all aspects of the project, and by partnering with the Women in Science Project to train a first-year female undergraduate student during a 20-week internship in each year of the project.

The Stanford Radio Glaciology Lab is developing two new ice-penetrating radar systems that will address gaps in current cryosphere radar remote sensing and may ultimately provide high impact observational tools to the glaciological and cryosphere community. The first system is an uncrewed aerial vehicle (UAV)-borne ice-penetrating radar sounder, which will provide the ability to collect data on larger spatial scales and at high frequency temporal repeats at a significantly reduced cost and with increased safety compared to crewed airborne and ground-based radar surveys. The second system is a ground-based multi-frequency integrated radar-radiometer, which leverages the frequency independence of basal material reflectivity signatures vis-a-vis the frequency dependence of basal roughness scattering signatures to enable more accurate determinations of basal material, thermal state and roughness, on ice sheets. The integrated radiometer enables combined radar-radiometer inversions for ice sheet temperature profiles with better surface to bed temperature sensitivity than either instrument alone. Both the UAV and ground-based systems utilize commercially-available software-defined radios for the backbone of the instrumentation, sharing a single codebase, which will be made open-source through this project. Testing at Summit Station during the 2023 summer season will enable researchers to demonstrate successful UAV-based radar sounding, successful multi-frequency radar surveying and to continue maturing each system to the point where they are ready for community-wide use. Data collected by these systems will be compared to the wealth of other radar data collected in the vicinity of Summit Station, as well as to data from the nearby GISP2 and GRIP ice cores. Both instruments are desired across the glaciological community for both current and proposed field experiments, but require additional testing and refinement on deep, cold ice that is unreachable outside of the Greenland or Antarctic Ice Sheets.

The Arctic and Antarctic are undergoing rapid changes in their marine, glacial, ecological, atmospheric, and social systems. Addressing the societally relevant consequences of this change, which are local and global in scope, requires a more diverse and integrative U.S. polar STEM community with leaders prepared for international and cross-cultural collaborations. Dartmouth will lead the U.S. component of two international efforts to develop inclusive polar STEM learning opportunities for high school, undergraduate, and graduate students that will help build capacity for U.S. leadership in the polar regions. The Joint Science Education Project (JSEP) includes a close collaboration with international and Indigenous partners in Greenland and Denmark, and the Joint Antarctic School Expedition (JASE) includes a partnership with Chile. The field-based JSEP program will immerse U.S. students in experiential learning in Kangerlussuaq and Summit Station, Greenland. JSEP will include a remote short course for U.S. high school students to learn about the Arctic through data-focused activities. The JASE program includes a partnership with the Chilean Antarctic Institute to co-lead a virtual symposium for students to share Arctic and Antarctic research. Applications for both programs will be encouraged from students across the U.S. and recruitment will focus on reaching students who have limited access to STEM experiences and who come from groups historically excluded from STEM fields.

The JSEP and JASE experiences will be developed around a unique intergenerational mentor-mentee model that gives U.S. high school students access to undergraduate and graduate students as near-peer mentors and opportunities for the student mentors to develop their communication and outreach skills. The effort includes an evaluation and dissemination of the inclusive models for U.S. polar STEM education and research programs that prioritize diversity, collaboration, communication, outreach, cultural sharing, and building sustained relationships with Arctic and Antarctic partners. This includes implementing new approaches for recruiting and supporting students whose opportunities for polar STEM have been limited by factors such as gender, race, ethnicity, and socio-economic and ability status. Results will inform future efforts to successfully provide education and research experiences to U.S. students interested in polar science and engineering. This project will expand an international and diverse network of students, educators, and scientists with skills for polar research, outreach, and STEM careers. JSEP and JASE will involve at least 100 U.S. high school students and up to 20 undergraduate or graduate students with a goal that many of these students come from groups historically excluded from STEM fields. Students, educators, and scientists involved with this project will gain exposure to field-based polar research and improve their skills for: science communication; cross-cultural and international collaborations; framing scholarship to meet the needs of Arctic communities; and recognizing and respecting Indigenous knowledge. The undergraduate and graduate students will receive hands-on training in interdisciplinary research and outreach, which will prepare them as STEM leaders with skills for broadening impacts of their future scholarship. The project also provides significant opportunity for science diplomacy and to strengthen relationships by engaging our Arctic and Antarctic partners in all aspects of project planning, implementation, assessment, and reporting. Assessments will allow evaluation of how the following pedagogical elements impact outcomes for U.S. students (high school, undergraduate, and graduate): field-based versus virtual, hands-on activities, interdisciplinary curriculum, Indigenous perspectives, intergenerational mentor-mentee relationships, and a multicultural setting. Results will inform future efforts to successfully provide education and research experiences to U.S. students interested in polar science and engineering.

This project supports the training of U.S. Ice Core Drilling Program (IDP) drillers on the agile Eclipse and Foro 400 drills at Summit Station, Greenland. The U.S. Ice Drilling Program (IDP) was established by the National Science Foundation (NSF) to lead integrated planning for ice coring and drilling and provision of drills and drilling services. There is a critical need for skilled drillers on agile drilling projects and training is essential. By combining this training with an in-situ science project in Greenland, efficiencies in logistics will be utilized.

Researchers at NOAA’s Earth System Research Lab (ESRL) Global Monitoring Division (GMD) conduct continuous measurements of atmospheric properties at Summit Station to better understand the Arctic climate system and contribute to the Earth monitoring mission of their worldwide observation network. GMD’s mission it to acquire, evaluate, and make available accurate, long-term records of atmospheric gases, aerosol particles, clouds, and surface radiation in a manner that allows the causes and consequences of change to be understood. 

GMD’s current measurements at Summit include: 

1. Halocarbon and other Atmospheric Trace Gases (HATS) Flasks: weekly to biweekly collection of air samples, analyzed in the U.S. (Boulder, CO) for trace gases (50+ species measured) that are important to global halocarbon chemistry, such as ozone-depleting CFCs, oxidation studies, and stratospheric ozone. These measurements have been ongoing since 2004. 

2. Global Greenhouse Gas Reference Network (GGGRN) Flasks: weekly collection of air samples, analyzed in the U.S. (Boulder, CO) for gases (30+ species measured) relevant to the global carbon cycle, including CO2 and methane. This sampling was first performed during several winters in the period 1997-2002 and has been performed year-round since 2003. 

3. In-situ Aerosol Sampling: observations of aerosol optical properties to determine aerosol radiative effects. These measurements were initiated in 2003, with the instrument suite upgraded in 2009 and 2017. 

4. Surface Ozone: observations of tropospheric ozone concentration. These measurements were taken from 2000 to 2002, and then from 2003 onward. 

5. Surface Meteorology: observations of surface meteorological properties to support science, flight operations, and general station activities. These measurements have been ongoing since summer 2005.

Cores drilled through the Antarctic ice sheet provide a remarkable window on the evolution of Earth’s climate and unique samples of the ancient atmosphere. The clear link between greenhouse gases and climate revealed by ice cores underpins much of the scientific understanding of climate change. Unfortunately, the existing data do not extend far enough back in time to reveal key features of climates warmer than today. COLDEX, the Center for Oldest Ice Exploration, will solve this problem by exploring Antarctica for sites to collect the oldest possible record of past climate recorded in the ice sheet. COLDEX will provide critical information for understanding how Earth’s near-future climate may evolve and why climate varies over geologic time. New technologies will be developed for exploration and analysis that will have a long legacy for future research. An archive of old ice will stimulate new research for the next generations of polar scientists. COLDEX programs will galvanize that next generation of polar researchers, bring new results to other scientific disciplines and the public, and help to create a more inclusive and diverse scientific community. 

Knowledge of Earth’s climate history is grounded in the geologic record. This knowledge is gained by measuring chemical, biological and physical properties of geologic materials that reflect elements of climate. Ice cores retrieved from polar ice sheets play a central role in this science and provide the best evidence for a strong link between atmospheric carbon dioxide and climate on geologic timescales. The goal of COLDEX is to extend the ice-core record of past climate to at least 1.5 million years by drilling and analyzing a continuous ice core in East Antarctica, and to much older times using discontinuous ice sections at the base and margin of the ice sheet. COLDEX will develop and deploy novel radar and melt-probe tools to rapidly explore the ice, use ice-sheet models to constrain where old ice is preserved, conduct ice coring, develop new analytical systems, and produce novel paleoclimate records from locations across East Antarctica. The search for Earth’s oldest ice also provides a compelling narrative for disseminating information about past and future climate change and polar science to students, teachers, the media, policy makers and the public. COLDEX will engage and incorporate these groups through targeted professional development workshops, undergraduate research experiences, a comprehensive communication program, annual scientific meetings, scholarships, and broad collaboration nationally and internationally. COLDEX will provide a focal point for efforts to increase diversity in polar science by providing field, laboratory, mentoring and networking experiences for students and early career scientists from groups underrepresented in STEM, and by continuous engagement of the entire COLDEX community in developing a more inclusive scientific culture.