by Gwyneth Matthews (@GwynRMatthews), February 2024

In 1998 there were only about 10 female professors of mathematics in the UK (UCU, 2007; Series, 2021), including Nancy Nichols (University of Reading) who was appointed in 1995. Nichols has made significant contributions to numerical analysis, systems control, and data assimilation. In 2014, she was elected as a Fellow of the Society for Industrial and Applied Mathematics (SIAM) in recognition of her work. As a mentor, Nichols guided 42 PhD students and championed diversity in STEM, earning a nomination for the UKRC WISE Award for Lifetime Achievement. Some of Nichols’ recent collaborative work won the Times Higher Education’s Research Project of the Year for STEM award, for optimizing flight paths between European and USA destinations.

Eugenia Kalnay was the first female PhD recipient and faculty member in the Department of Meteorology at the Massachusetts Institute of Technology (MIT). Kalnay later became the Director of the Environmental Modeling Center at the National Centers for Environmental Prediction (NCEP). Kalnay oversaw transformative changes, including the implementation of the operational 3D-Var data assimilation system, and the operationalisation of the first ensemble weather forecast.

Around the same period in 1997, Florence Rabier implemented the first operational 4D-Var data assimilation system at the European Centre for Medium-range Weather Forecasts (ECMWF). Over the next decade, Rabier led the observation section of Meteo-France, coordinating international field campaigns and integrating new satellite observations. Today, Rabier serves as the Director General of ECMWF, influencing the direction of weather and climate research.

International Day of Women and Girls in Science (11th February)

The theme this year is Women and Girls in Science Leadership, a New Era for Sustainability.’ In the realm of data assimilation, numerous women occupy leadership positions, driving innovation in theoretical techniques, operational applications, and the integration of non-traditional and Earth observation data to enhance modelled data.

Sarah Dance (University of Reading, NCEO), co-director of DARC, was appointed as the Director of the NCEO Data Assimilation division, overseeing the development and delivery of the data assimilation scientific strategy within NCEO. Lili Lei (Nanjing University) plays a significant role in developing various data assimilation techniques, including many used in weather and climate research. Rossella Arcucci (Imperial College London), an elected member of the WMO, leads the Data Learning (Data Assimilation and Machine Learning) Group. Tijana Janic (Katholische Universität Eichstätt-Ingolstadt) serves on the board of the DFG Collaborative Research Center, “Waves, Clouds, Weather.” Saroja Polavarapu (Environment and Climate Change Canada) served on and led various WCRP and WWRP working groups. Xuguang Wang (University of Oklahoma) leads the university’s Multiscale Data Assimilation and Predictability (MAP) lab, contributing to operational numerical weather prediction systems. Femke Vossepoel (Delft University of Technology) is a member of the management team of the Delft Safety and Security Institute, advising the government of The Netherlands on ground motion risk and induced seismicity. Chiara Piccolo (UK Met Office) is the head of satellite applications and manages the NWP SAF, a European collaboration. Nancy Baker (Naval Research Laboratory) heads the data assimilation section and serves as the associate director for the Navy at the Joint Center for Satellite Data Assimilation.

Women in Research

Despite the remarkable contributions from women (both those mentioned above and countless more), they remain a minority in data assimilation. Of the past four International Symposium on Data Assimilation events, the scientific committee comprised, at most, 28% women. This reflects the broader trend where women accounted for only 33.3% of all researchers globally from 2015 to 2018 (Bello et al., 2021). Women face challenges in research including:

  • Applying for and being awarded smaller grants (UKRI, 2021; UKRI, 2022).
  • Lack of representation in cutting-edge fields (e.g., 1 in 5 professionals (22%) in artificial intelligence are women; WEF, 2018).
  • Underrepresentation in high-profile journals, often being passed over for promotion (Bello et al., 2021).

Progress is evident at the bachelor’s, master’s, and PhD levels, as many countries are close to reaching parity in science at these levels (Bello et al., 2021; Huyer, 2015). However, there is still a persistent gender gap at A-level, with low percentages of women studying mathematics and further mathematics, 37.7% and 28.1%, respectively (WISE, 2023).

Not just for a day

International Days often face criticism for being fleeting spotlights on persistent issues, but they serve as important reminders to celebrate achievements and reflect on the road ahead. The stories of these remarkable women in data assimilation exemplify the progress made but also underscore the challenges that persist, and the need for commitment and collective effort to dismantle the glass ceiling still experienced by many across scientific disciplines (Bello et al., 2021). As 10-year-old Anya Daneez Khan (2019) said:

“The reason we celebrate this Day is to make sure it becomes not a story about exceptional women but a norm that girls belong and succeed in science and technology.”

Networks for women in science


Bello, A.; Blowers, T.; Schneegans, S. and T. Straza (2021) To be smart, the digital revolution will need to be inclusive. In UNESCO Science Report: the Race Against Time for Smarter Development. Schneegans, S.; Straza, T. and J. Lewis (eds). UNESCO Publishing: Paris

Huyer, Sophie (2015) Is the gender gap narrowing in science and engineering? In: UNESCO Science Report: Towards 2030. S. Schneegans and D. Eröcal (eds). ISBN: 978-92-3-100129-1. UNESCO Publishing: Paris, pp. 84–103.

Series, C (2021). The LMS Committee For Women and Mathematics – A History 1995-2021. (Accessed: 2 February 2024).

UCU (2007). Higher education employment data Academic staff. (Accessed: 2 February 2024).

UKRI (2022). UKRI diversity data for funding applicants and awardees 2020 to 2021 update: main report.  (Accessed: 30 January 2024).

UKRI (2021). Diversity results for UKRI funding data 2014-15 to 2019-20.  (Accessed: 30 January 2024).

WEF (2018). The Global Gender Gap Report 2018. World Economic Forum: Geneva.  (Accessed: 30 January 2024).

WISE (2023). A Level Results 2023.  (Accessed: 30 January 2024).