US-BFS tower<\/a> continuously tracks the daily exchange of carbon dioxide, water vapor and energy between the Field Station\u2019s native coastal sage scrub ecosystem and the surrounding Los Angeles atmosphere. The tower offers rare, year-round insights into how a drought-adapted, urban ecosystem \u201cbreathes\u201d across seasons, including heat waves and dry spells.<\/p>\n\n\n\nThe tower is part of AmeriFlux, a network of sites that measure ecosystem CO\u2082, water, energy fluxes and other climate-related data in North, Central and South America. The network connects research on field sites, all of which represent major climate and ecological biomes. Prior to the US-BFS\u2019s establishment, there were no active monitoring sites of this kind in all of Los Angeles County. This gap meant scientists lacked continuous, reliable data on whether native coastal sage scrub in an urban setting function as a carbon sink or if it can transform to becoming a carbon source under extreme heat and drought. Researchers say determining the answer is critical for improving climate models and understanding how much carbon the Earth\u2019s surface can realistically remove from the atmosphere. <\/p>\n\n\n\n
The tower measures three main categories of data: ecosystem fluxes, which capture how much carbon dioxide, water vapor and heat move between plants, soil and air; basic meteorology, including wind, temperature, humidity, sunlight and soil moisture; and local air-quality indicators such as particulate matter and gases like ozone. Together, these measurements allow students and collaborators to link ecosystem behavior directly to changing environmental conditions.<\/p>\n\n\n\n
US-BFS is distinctive as it is the only of its kind in Los Angeles County as well as for the leading role students played in building and maintaining it.<\/p>\n\n\n\n
\u201cThis is all a story of student accomplishments,\u201d said Professor of Climate and Chemistry Sarah Kavassalis. \u201cThey turned instruments into a community resource.\u201d<\/p>\n\n\n\n
During the 2023\u20132024 academic year, Helen Chen \u201924 designed the entire site as part of her undergraduate chemistry thesis, where she determined where the tower should be placed and how the instruments should be arranged. Before heading into the field, Chen and Sorin Jayaweera \u201927 tested and validated the full system in the lab to ensure it could collect reliable data.<\/p>\n\n\n\n
In summer 2024, Chen led a team of students (Mia Mirabelli \u201926, Anna Figge \u201927 and Matthew Simpson \u201927), which installed the tower at the Field Station and connected the tower online. <\/p>\n\n\n\n
After Chen graduated, Simpson took over as the project\u2019s lead and wrote the site\u2019s data-processing code from scratch, producing the first publishable US-BFS dataset. This dataset was a milestone that made the measurements accessible to the wider scientific community.<\/p>\n\n\n\n
\u201cMost of my research involves processing the data from the flux tower,\u201d said Simpson. \u201cUnderstanding whether our local ecosystem is a carbon source or sink could better inform scientific modelers and policymakers when they calculate our carbon budget. Having accurate, ground-based measurements is important to verify climate models and satellite data products.\u201d<\/p>\n\n\n\n
In summer 2025, Simpson led another student team, including Figge, Stephanie Fulcar \u201925, Kennetta Roebuck \u201926 and Tzaara Jauhar \u201927, to relocate the tower within the Field Station to an even more optimal location. The team adapted their processing tools to make them more user-friendly for outside researchers.<\/p>\n\n\n\n
\u201cI have learned so much about atmospheric chemistry, especially the eddy covariance method, which is the technique we use to measure fluxes and surface-level atmospheric dynamics,\u201d said Simpson. \u201cThere has also been a lot that\u2019s gone wrong along the way. The tower\u2019s generator was stolen one winter, and we had to move the tower during the summer of 2025 to get better measurements. This taught me that scientific research is a very nonlinear process. It is reassuring to see that research can still produce interesting and impactful results despite the difficulties that researchers often face.\u201d<\/p>\n\n\n\n
The result is a site that functions as both a research platform and a community resource for researchers. Because the data is archived and shared through the AmeriFlux network, the US-BFS\u2019s data is now part of a global system of ecosystem monitoring stations that supports climate and environmental science worldwide.<\/p>\n\n\n\n
US-BFS was designed to serve as a long-term monitoring site. The team is building a multiyear record capable of capturing climate variability and extreme conditions, while actively maintaining and continuously updating the public dataset. New multiyear research funding from a grant by the Seaver Foundation will also support the expansion of complementary measurements at the site.<\/p>\n\n\n\n
Interest in the data is already growing. Researchers at The Claremont Colleges are developing projects that build on the tower\u2019s footprint, including studies of plant water stress and soil greenhouse-gas fluxes. US-BFS was also selected as a participating site in a soil hydrology project led by Indiana University, Bloomington, and faculty from other higher education institutions have reached out about potential collaborations.<\/p>\n\n\n\n
The project\u2019s hands-on research of interdisciplinary learning and societal impact of science and engineering was a key focus. Students involved in US-BFS bring together chemistry, atmospheric science, ecology, engineering and data science, designing field instrumentation, writing and validating code and interpreting how carbon, water, and energy move through a vulnerable native ecosystem. AmeriFlux\u2019s sharing and archiving system also allows students to learn best practices in open data science while contributing a community resource used well beyond campus. <\/p>\n\n\n\n
The experience is already shaping students\u2019 academic paths. Two project alumni took paths in graduate studies involving atmospheric chemistry, carrying their field and data-science training into the next stage of their research careers. For Simpson, the project is preparing him for his pursuit of a career as a university professor, which he anticipates will include substantial scientific research.<\/p>\n\n\n\n
\u201cIt\u2019s been exciting to be positioned in an understudied environment so I can investigate the instrumental and data processing mechanisms that are often less emphasized in other research groups,\u201d said Simpson. \u201cI was part of the team that first set up the tower in the summer of 2024, so it has been satisfying to see how far we have come with the project since then.\u201d<\/p>\n\n\n\n
The establishment of the US-BFS tower also opens doors to future grants and partnerships through the AmeriFlux network. The network provides shared tools and scientific visibility that connect researchers working across climate, ecology, biology and Earth systems science.<\/p>\n\n\n\n
The tower functions as a major contribution to scientific research. The US-BFS transformed a patch of native landscape into a living, \u201cbreathing\u201d laboratory, resulting in a worldwide effort to understand a changing planet.<\/p>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
A student-built monitoring tower known as US-BFS is helping Harvey Mudd College students answer some of Southern California\u2019s most pressing […]<\/p>\n","protected":false},"author":372,"featured_media":15030,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[4,6,967,26,30,382],"class_list":["post-15029","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-biology","category-chemistry","category-general-feed","category-research","category-students","category-sustainability"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/posts\/15029","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/users\/372"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/comments?post=15029"}],"version-history":[{"count":5,"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/posts\/15029\/revisions"}],"predecessor-version":[{"id":15074,"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/posts\/15029\/revisions\/15074"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/media\/15030"}],"wp:attachment":[{"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/media?parent=15029"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hmc.edu\/about\/wp-json\/wp\/v2\/categories?post=15029"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}