Staff profile

since 07/2024 — Associate Professor, Earth Sciences, Durham University

12/2020 - 06/2024 — Assistant Professor, Earth Sciences, Durham University

06/2020 - 11/2020 — Oberassistent (Senior Research Assistant), ETZ Zurich

05/2018 - 05/2020 — Postdoctoral Fellow, ETH Zurich

06/2017 - 04/2018 — Postdoctoral Researcher, University of Tuebingen

10/2013 - 05/2017 — PhD student, University of Tuebingen

• Catchment hydrology
• Groundwater-surface water interactions
• Hydrology
• Rivers & streams
• Stable water isotopes
• Tracers of flowpaths
• Water quality

Chapter in book

• Knapp, J. (2023). Using diel solute signals to assess ecohydrological processing in lotic systems. In S. Krause, D. M. Hannah, & N. B. Grimm (Eds.), Ecohydrological Interfaces. Wiley

Journal Article

• Knapp, J. L. A., Napitupulu, T., von Freyberg, J., Rücker, A., Studer, B., Zappa, M., & Kirchner, J. W. (2024). Multi-year time series of daily solute and isotope measurements from three Swiss pre-Alpine catchments. Scientific Data, 11(1), 393. https://doi.org/10.1038/s41597-024-03192-5
• Li, L., Knapp, J. L. A., Lintern, A., Ng, G. C., Perdrial, J., Sullivan, P. L., & Zhi, W. (2024). River water quality shaped by land–river connectivity in a changing climate. Nature Climate Change, 14(3), 225-237. https://doi.org/10.1038/s41558-023-01923-x
• Knapp, J. L. A., & Kelleher, C. (2023). The heat is on: Predicting urban stream temperature responses to summer storms. Hydrological Processes, 37(11), Article e15033. https://doi.org/10.1002/hyp.15033
• Knapp, J. L., Li, L., & Musolff, A. (2022). Hydrologic connectivity and source heterogeneity control concentration–discharge relationships. Hydrological Processes, 36(9), Article e14683. https://doi.org/10.1002/hyp.14683
• Krause, S., Abbott, B. W., Baranov, V., Bernal, S., Blaen, P., Datry, T., …Zarnetzke, J. P. (2022). Organizational Principles of Hyporheic Exchange Flow and Biogeochemical Cycling in River Networks Across Scales. Water Resources Research, 58(3), Article e2021WR029771. https://doi.org/10.1029/2021wr029771
• Popp, A. L., Manning, C. C., & Knapp, J. L. (2021). Rapid Advances in Mobile Mass Spectrometry Enhance Tracer Hydrology and Water Management. Water Resources Research, 57(6), Article e2021WR029890. https://doi.org/10.1029/2021wr029890
• Li, L., Sullivan, P. L., Benettin, P., Cirpka, O. A., Bishop, K., Brantley, S. L., …Kirchner, J. W. (2021). Toward catchment hydro‐biogeochemical theories. Wiley Interdisciplinary Reviews: Water, https://doi.org/10.1002/wat2.1495
• Comer-Warner, S., Knapp, J. L., Blaen, P., Klaar, M., Shelley, F., Zarnetske, J., …Krause, S. (2020). The method controls the story - Sampling method impacts on the detection of pore-water nitrogen concentrations in streambeds. Science of the Total Environment, 709, https://doi.org/10.1016/j.scitotenv.2019.136075
• Kirchner, J. W., & Knapp, J. L. (2020). Technical note: Calculation scripts for ensemble hydrograph separation. Hydrology and Earth System Sciences, 24(11), https://doi.org/10.5194/hess-24-5539-2020
• von Freyberg, J., Knapp, J. L., Rücker, A., Studer, B., & Kirchner, J. W. (2020). Technical note: Evaluation of a low-cost evaporation protection method for portable water samplers. Hydrology and Earth System Sciences, 24(12), 5821-5834. https://doi.org/10.5194/hess-24-5821-2020
• Knapp, J. L., von Freyberg, J., Studer, B., Kiewiet, L., & Kirchner, J. W. (2020). Concentration–discharge relationships vary among hydrological events, reflecting differences in event characteristics. Hydrology and Earth System Sciences, 24(5), 2561-2576. https://doi.org/10.5194/hess-24-2561-2020
• Gootman, K. S., González‐Pinzón, R., Knapp, J. L., Garayburu‐Caruso, V., & Cable, J. E. (2020). Spatiotemporal Variability in Transport and Reactive Processes Across a First‐ to Fifth‐Order Fluvial Network. Water Resources Research, 56(5), https://doi.org/10.1029/2019wr026303
• Knapp, J. L., & Kelleher, C. (2020). A Perspective on the Future of Transient Storage Modeling: Let's Stop Chasing Our Tails. Water Resources Research, 56(3), https://doi.org/10.1029/2019wr026257
• Ward, A. S., Zarnetske, J. P., Baranov, V., Blaen, P. J., Brekenfeld, N., Chu, R., …Wondzell, S. M. (2019). Co-located contemporaneous mapping of morphological, hydrological, chemical, and biological conditions in a 5th-order mountain stream network, Oregon, USA. Earth System Science Data, 11(4), https://doi.org/10.5194/essd-11-1567-2019
• Ward, A. S., Wondzell, S. M., Schmadel, N. M., Herzog, S., Zarnetske, J. P., Baranov, V., …Wisnoski, N. I. (2019). Spatial and temporal variation in river corridor exchange across a 5th-order mountain stream network. Hydrology and Earth System Sciences, 23(12), https://doi.org/10.5194/hess-23-5199-2019
• Knapp, J. L., Neal, C., Schlumpf, A., Neal, M., & Kirchner, J. W. (2019). New water fractions and transit time distributions at Plynlimon, Wales, estimated from stable water isotopes in precipitation and streamflow. Hydrology and Earth System Sciences, 23(10), https://doi.org/10.5194/hess-23-4367-2019
• Kelleher, C., Ward, A., Knapp, J., Blaen, P., Kurz, M., Drummond, J., …Krause, S. (2019). Exploring Tracer Information and Model Framework Trade‐Offs to Improve Estimation of Stream Transient Storage Processes. Water Resources Research, 55(4), https://doi.org/10.1029/2018wr023585
• Ward, A. S., Kurz, M. J., Schmadel, N. M., Knapp, J. L., Blaen, P. J., Harman, C. J., …Zarnetske, J. P. (2019). Solute Transport and Transformation in an Intermittent, Headwater Mountain Stream with Diurnal Discharge Fluctuations. Water, 11(11), Article 2208. https://doi.org/10.3390/w11112208
• Knapp, J. L., Osenbrück, K., Brennwald, M. S., & Cirpka, O. A. (2019). In-situ mass spectrometry improves the estimation of stream reaeration from gas-tracer tests. Science of the Total Environment, 655, https://doi.org/10.1016/j.scitotenv.2018.11.300
• Guillet, G., Knapp, J. L., Merel, S., Cirpka, O. A., Grathwohl, P., Zwiener, C., & Schwientek, M. (2019). Fate of wastewater contaminants in rivers: Using conservative-tracer based transfer functions to assess reactive transport. Science of the Total Environment, 656, https://doi.org/10.1016/j.scitotenv.2018.11.379
• Knapp, J. L., & Cirpka, O. A. (2018). A Critical Assessment of Relating Resazurin–Resorufin Experiments to Reach‐Scale Metabolism in Lowland Streams. Journal of Geophysical Research: Biogeosciences, 123(12), https://doi.org/10.1029/2018jg004797
• Blaen, P., Kurz, M., Drummond, J., Knapp, J., Mendoza-Lera, C., Schmadel, N., …Krause, S. (2018). Woody debris is related to reach-scale hotspots of lowland stream ecosystem respiration under baseflow conditions. Ecohydrology, 11(5), https://doi.org/10.1002/eco.1952
• Knapp, J. L., González-Pinzón, R., & Haggerty, R. (2018). The Resazurin-Resorufin System: Insights From a Decade of “Smart” Tracer Development for Hydrologic Applications. Water Resources Research, 54(9), https://doi.org/10.1029/2018wr023103
• Knapp, J. L., González‐Pinzón, R., Drummond, J. D., Larsen, L. G., Cirpka, O. A., & Harvey, J. W. (2017). Tracer‐based characterization of hyporheic exchange and benthic biolayers in streams. Water Resources Research, 53(2), https://doi.org/10.1002/2016wr019393
• Knapp, J. L., & Cirpka, O. A. (2017). Determination of hyporheic travel time distributions and other parameters from concurrent conservative and reactive tracer tests by local‐in‐global optimization. Water Resources Research, 53(6), https://doi.org/10.1002/2017wr020734
• Schmadel, N. M., Ward, A. S., Kurz, M. J., Fleckenstein, J. H., Zarnetske, J. P., Hannah, D. M., …Krause, S. (2016). Stream solute tracer timescales changing with discharge and reach length confound process interpretation. Water Resources Research, 52(4), https://doi.org/10.1002/2015wr018062
• Knapp, J. L., Osenbrück, K., & Cirpka, O. A. (2015). Impact of non-idealities in gas-tracer tests on the estimation of reaeration, respiration, and photosynthesis rates in streams. Water Research, 83, https://doi.org/10.1016/j.watres.2015.06.032