The depth of HKU’s representation extends beyond sheer numbers. Forty-nine HKU scholars are ranked within the top 100 worldwide for their single-year research impact, and another 49 have achieved global top 100 recognition for their career-long influence. Placement within the top 100 of any broad disciplinary field is an exceptional outcome in a ranking that draws on the entire global population of active researchers, and the fact that HKU places nearly a hundred scholars in that bracket across the two impact measures signals concentrations of world-leading expertise across multiple departments and faculties.

Several individual HKU researchers achieved strikingly high positions in their respective fields. In the single recent-year rankings, Professor Bing Zhang, a Global STEM Scholar and Chair of Astrophysics in the Department of Physics within the Faculty of Science, is ranked fourth globally in Astronomy and Astrophysics. Professor Guochun Zhao, Mok Sau-King Professor and Chair of Earth Sciences in the Department of Earth and Planetary Sciences, Faculty of Science, is ranked sixth globally in Geochemistry and Geophysics. Professor Peng Gong, Vice-President and Pro-Vice-Chancellor for Academic Development and Chair of Global Sustainability, who holds appointments in the Department of Geography in the Faculty of Social Sciences and the Department of Earth Sciences in the Faculty of Science, is ranked ninth globally in Geological and Geomatics Engineering.

The career-long impact rankings tell a similar story of enduring scholarly distinction. Professor Guochun Zhao is ranked sixth overall in his field when cumulative career influence is measured, confirming that his recent-year prominence rests on decades of sustained contribution to the earth sciences. Other leading career-long performers include Professor Hongjie Dai, Sapientia Eminence Professor and Chair of Chemistry in the Department of Chemistry, Faculty of Science, ranked ninth in Nanoscience and Nanotechnology, and Professor Fan Sheung Tat, Emeritus Professor and Honorary Clinical Professor in the Department of Surgery within the School of Clinical Medicine of the Li Ka Shing Faculty of Medicine, ranked tenth in Surgery. A top-ten career-long position in any field places a researcher among the most-cited contributors that discipline has produced over the modern era of indexed publishing.

Stanford’s list of the Top 2% Scientists is compiled into two distinct categories: one based on career-long impact and the other on recent research influence. The ranking is designed to recognise both lifelong scholarly achievement and current research excellence, an architecture that deliberately separates durable reputations from short-term surges in attention. This dual structure matters for interpretation. A researcher can appear in the single-year list because of one highly cited paper, a major review article, or a timely dataset that the community immediately adopts, whereas career-long placement reflects the accumulated weight of an entire body of work. Researchers who appear prominently in both lists, as several of the HKU scholars named by the university do, are those whose recent output continues to command citations at the same extraordinary level that defined their earlier careers.

Although the university announcement summarises the outcomes, the underlying methodology of the Stanford ranking is worth understanding, because it explains why placement in the top two percent is statistically remarkable. The list, produced by a team at Stanford University working with Elsevier citation data, evaluates scientists using a composite indicator that combines information on citations, an author’s h-index, a co-author-adjusted hm-index, citations of papers in which the author appears in different authorship positions, and measures of solo, first, and last authorship. Composite scoring of this kind is intended to dampen some of the distortions that arise when any single metric is used alone, such as the inflation of citation counts through massive multi-author collaborations or through self-citation networks. By integrating multiple facets of scholarly influence into one score, the ranking attempts to approximate the overall significance of an individual researcher’s contribution to their field.

Field-specific normalisation is another technical foundation of the ranking, and it is central to why cross-field comparisons are meaningful. Citation practices differ enormously between disciplines: a high-energy physics paper with thousands of authors and a clinical surgery paper with a small author group operate under entirely different citation regimes, and comparing their raw citation counts would be misleading. The Stanford list therefore standardises each researcher’s citation profile against others in the same subfield, allowing a fourth-ranked astrophysicist and a ninth-ranked nanotechnologist to be judged against the distribution of their own discipline rather than against a global average dominated by high-citation fields. The classification into 22 major fields and 174 subfields gives the ranking its fine granularity, and it is at this subfield level that the HKU positions described by the university, from astronomy to geochemistry to surgery, are determined.

The distribution of HKU’s recognised scholars across physics, earth sciences, geography and sustainability, chemistry, nanoscience, and clinical medicine illustrates the breadth that composite, field-normalised rankings are designed to capture. The presence of researchers such as Professor Peng Gong, whose appointments span geography and earth sciences and whose work is ranked in Geological and Geomatics Engineering, reflects the increasingly interdisciplinary character of top-tier research, where remote sensing, environmental monitoring, and geospatial engineering converge. Similarly, the strong showing in earth sciences, with Professor Zhao ranked in the global top ten in both single-year and career-long measures, points to a department whose publications have become standard reference points for the international geoscience community over a sustained period.

Institutionally, the results carry weight beyond prestige. Rankings of this type are consulted by governments, funding agencies, prospective graduate students, and international partners as one input, among many, for assessing research strength, and a concentration of top-two-percent researchers at a single university is often read as evidence of an environment that attracts and retains leading talent. HKU’s stated position as the local university with the highest number of recognised scholars is likely to feature in its competitive positioning for research funding and global partnerships. At the same time, citation-based rankings carry well-understood limitations: they measure influence as registered by the citation record rather than the intrinsic quality or societal impact of research, and they can under-represent fields where outputs are books, datasets, software, or clinical practice guidelines rather than heavily cited journal articles. The Stanford team acknowledges these caveats, positioning the list as a publicly available database for research evaluation rather than a definitive judgement of scholarly merit.

What the 2026 edition nonetheless documents is a measurable, data-driven snapshot of where scholarly influence is concentrated, and in this snapshot the University of Hong Kong stands out regionally. Nearly six hundred recognised researchers, roughly one hundred placements in the global top 100 across the two impact measures, and multiple subfield top-ten positions in both recent and career-long rankings together form a picture of an institution whose research is not only prolific but consistently among the most consulted work in its disciplines. For the individual scholars named, from an astrophysicist ranked fourth in the world to a surgeon ranked tenth for career-long influence, the recognition formalises what citation databases have been quietly recording for years: that their papers are the ones their colleagues around the world read, cite, and build upon. The full Stanford database remains freely accessible to researchers, allowing independent verification of the figures the university has announced and enabling scholars and institutions alike to track how the geography of global research influence continues to evolve.

Subject of Research: Stanford University's 2026 Top 2% Scientists ranking and the University of Hong Kong's scholarly representation

Article Title: HKU receives recognition with nearly 600 scholars named in Stanford’s 2026 Top 2% Scientists List

Article References: HKU receives recognition with nearly 600 scholars named in Stanford’s 2026 Top 2% Scientists List. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: HKU, Stanford University, Top 2% Scientists, citation metrics, career-long impact, single-year impact, h-index, bibliometrics, Astronomy and Astrophysics, Geochemistry and Geophysics, Nanoscience and Nanotechnology, research rankings