Distinguished Research Professor
UW Center for Limnology
Carbon cycling: Lakes play important roles in carbon cycling at the watershed, regional, and even global scales. The balance between carbon sequestration and storage versus mineralization in lakes depends on how ecosystem boundaries are drawn, the nature of the lake and the load, and the time scale of interest. My research in carbon cycling focuses on how ecosystem processes alter these balances across different space and time scales in different ways among lakes of the world. Carbon cycling theme pervades work in a number of funded research projects in which I’m the lead PI or a co-PI, including the North Temperate Lakes LTER, a Wisconsin Focus on Energy project, and a collaborative project funded by Mellon foundation on regional carbon cycling modeling in Wisconsin.
Ecosystem variability: My general interest in ecological scaling issues underlies recent work in cross-scale analyses of lake data sets. Ecological data are inherently messy and tend to show pattern at multiple scales — a phenomenon especially evident in data from sensor networks. Understanding controls over that variability presents analytical challenges that benefit from signal processing tools, such as wavelet transforms, spectral analysis, and other system identification approaches. The payoff has been a clearer picture of, e.g., how dissolved oxygen in lakes is controlled by internal waves at short time scales, metabolism at days to weeks, and long-term weather oscillations at decades. Such approaches also show promise for developing scaling laws governing, e.g., phytoplankton dynamics.
Microbes, algae, and even fish: Although some of my past work has emphasized fish bioenergetics and fish identification through software and modeling tools, I’ve recently downsized in organisms. The control over microbial (bacteria and phytoplankton) dynamics in real ecosystems remains a mystery under many conditions. Through partnerships with microbial ecologists and physical limnologists at the University of Wisconsin and in the Global Lake Ecological Observatory Network (GLEON), we are using high-tech sensor network measurements, coupled physical-chemical-biological models, and signal processing to study the vagaries of microbial dynamics. Studies of algal blooms, for example, are central to much of the research happening on Lake Mendota in Madison, Wisconsin.
CDI: New knowledge from the Global Lake Ecological Observatory Network (GLEON)
GLEON: Advancing lake ecology by building an international community to exploit innovations in sensor network technology (GLEON)
Mendota Research Group (MeRG)
North Temperate Lakes Long Term Ecological Research Program (NTL LTER)
NYC Department of Environmental Protection, Climate Change and Reservoir Modeling
Lakebase (Luke Winslow)
Gil, Y., F. Michel, V. Ratnakar, M. Hauder, C. Duffy, and P.C. Hanson. 2015. A task-centered framework for computationally-grounded science collaborations.
Gil, Yl, F. Michel, V. Ratnakar, J.S. Read, M. Hauder, C. Duffy, P.C. Hanson, and H. Dugan. 2015. Supporting Open Collaboration in Science Through Explicit and Linked Semantic Description of Processes. In: Gandon F, Sabou M, Sack H, D’Amato C, Cudré-Mauroux P, Zimmermann A, editors. The Semantic Web: Latest Advances and New Domains; 12th European Semantic Web Conference, ESWC 2015, Portoroz, Slovenia, May 31 – June 4, 2015, Proceedings. New York: Springer. p 830.
Read, E.K., V. Patil, S.K. Oliver, A.L. Hetherington, J. Brentrup, J. Zwart, K. Winters, J. Corman, E. Nodine, R.I. Woolway, H. Dugan, A. Jaimes, A. Santoso, G.S. Hong, L.A. Winslow, P.C. Hanson, K.C. Weathers. 2015. The importance of lake-specific characteristics for water quality across the continental United States. Ecological Applications, 25: 943-955
Winslow, L.A., J.S. Read, P.C. Hanson, and E.H. Stanley. 1015. Does lake size matter? Combining morphology and process modelling to examine the contribution of lake classes to population-scale processes Inland Waters. 5:7-14.
Winslow, L.A., J. Read, G. Hansen, P.C. Hanson. 2015. Small lakes show muted climate change signal in deep-water temperatures. Geophysical Research Letters 42:355-361.
Crawford, J.T., N.R. Lottig, E.H. Stanley, J.F. Walker, P.C. Hanson, J. Findlay, and R.G. Stiegl. 2014. CO2 and CH4 emissions from streams in a lake-rich landscape: Patterns, controls and regional significance. Global Biogeochemical Cycles, 28, doi:10.1002/2013GB004661.
Hamilton, D.P., C.C Carey, L. Arvola, P. Arzberger, C. Brewer, J.J. Cole, E. Gaiser, P.C. Hanson et al. 2014. A Global Lake Ecological Observatory Network (GLEON) for synthesising high-frequency sensor data for validation of deterministic ecological models. Inland Waters. 5: 49-56.
Hanson, P.C., M. Pace, J.J. Cole, and S.R. Carpenter. 2014. Integrating Landscape Carbon Cycling: Research Needs for Resolving Organic Carbon Budgets of Lakes. Ecosystems. DOI: 10.1007/s10021-014-9826-9
Watras, C.J., K.A. Morrison, J.T. Crawford, C.P. McDonald, S.K. Oliver and P.C. Hanson. 2014. Diel cycles in the fluorescence of dissolved organic matter in dystrophic Wisconsin seepage lakes: Implications for carbon turnover. Limnol. Oceanogr. 60(1)
Read, J.S., L.A. Winslow, G.A. Hansen, J. Van den Hoek, P.C. Hanson, L.C. Bruce, and C.D. Markfort. 2014. Simulating 2,368 temperate lakes reveals weak coherence in stratification phenology. Ecological Modelling 291: 142-150
Rigosi, A. P.C. Hanson, D. Hamilton, M. Hipsey, J. Bois, J.D. Brookes. In press. Determining the probability of cyanobacterial blooms: the application of Bayesian networks in multiple lake systems. Ecological Applications
Read, E.K., M. Ivancic, P.C. Hanson, B. Cade-Menun, and K.D. McMahon. 2014. Phosphorus speciation in a eutrophic lake by 31P NMR spectroscopy. Water research 62: 229-240
Rose, K.C., L.A. Winslow, J.S. Read, E.K. Read, C.T. Solomon, R. Adrian, and P.C. Hanson. In press. Understanding variability in ecosystem metabolism estimates: the important role of physics. Limnol. Oceanogr. Methods.
Watras, C. J., K.A. Morrison, J. Mather, P. Milewski, and P.C. Hanson. 2014. Correcting CDOM fluorescence measurements for temperature effects under field conditions in freshwaters. Limnol. Oceanogr. Methods 12: 23–24.
Davies, N., D. Field, L. Amaral-Zettler…, P.C. Hanson et al. 2014. The founding charter of the Genomic Observatories Network. GigaScience, 3:2. www.gigasciencejournal.com/content/3/1/2
Cheruvelil, K.S., P.A. Soranno, K.C. Weathers, P.C. Hanson, S. Goring. 2014. Creating and maintaining high-performing collaborative research teams: the importance of diversity and socio-cognitive skills. Frontiers in Ecology and the Environment.
Hanson, P.C., I. Buffam, J. Rusak, E.H. Stanley, C. Watras. 2014. Quantifying organic carbon loads to lakes using a simple equilibrium model. Limnol. Oceanograph. 59:167-181
Winslow, L.A., J.S. Read, P.C. Hanson, E.H. Stanley. 2014. The distribution of lake aquatic-terrestrial interface in the contiguous United States. Freshwater Biology. 59: 213-223, doi:10.1111/fwb.12258
Watras, C.J., M. Morrow, K.M. Morrison, S. Scannell, S. Yaziciaglu, P.C. Hanson, J.S. Read, and Y-H Hu. 2013. Wetland observatories: monitoring the impact of weather and climate on hydrochemical dynamics with wireless sensor networks (WSNs). Environ Monitor and Assess. 10.1007/s10661-013-3424-8
Solomon, C.T., D.A. Bruesewitz, D.C. Richardson, D.C. Rose, M.C. Van de Bogert, P.C.Hanson et al. 2013. Ecosystem respiration: drivers of daily variability and background respiration in lakes around the globe. Limnol. Oceanogr. 58: 849-866.
Gil, Y., V. Ratnakar, and P.C. Hanson. 2013. Organic Data Publishing: A Novel Approach to Scientific Data Sharing. 2nd International Workshop on Linked Science 2012—Tackling Big Data (LISC2012). Boston, MA.
Van de Bogert, M.C., D.L. Bade, S.R. Carpenter, J.J. Cole, M.L. Pace, P.C. Hanson, O.C. Langman. 2012. Spatial heterogeneity strongly affects estimates of ecosystem metabolism in two north temperate lakes. Limnol. Oceanogr. 57:1689-1700.
Kara, E.L., P.C. Hanson, Y.H. Hu, L.A. Winslow, and K.D. McMahon. 2012. A decade of seasonal dynamics and co-occurrences within freshwater bacterioplankton communities from eutrophic Lake Mendota, Wisconsin, USA. ISME J. doi:10.1038/ismej.2012.118
Read, J.S., D.P. Hamilton, A.R. Desai, K.C. Rose, S. MacIntyre, J.D. Lenters, R.L. Smyth, P.C. Hanson, J.J. Cole, P.A. Staehr, J.A. Rusak, D.C. Pierson, J.D. Brookes, A. Laas, and C. Wu. 2012. Lake-size dependency of wind shear and convection as controls on gas exchange. Geophysical Research Letters, 39, doi:10.1029/2012GL051886.
Kara, E.L., P.C. Hanson, D.P. Hamilton, M. Hipsey, K.D. McMahon, J. Read, L. Winslow, J. Dedrick, K. Rose, C.C. Carey, S. Bertilsson, D. Motta Marques, L. Beversdorf, T. Miller, C. Wu, Y.F. Hsieh, E. Gaiser, and T.K. Kratz. 2012. Time-scale dependence in numerical simulations: Assessment of physical, chemical, and biological predictions in a stratified lake at temporal scales of hours to months. Environmental Modelling & Software. 35:104-121, doi: 10.1016/j.envsoft.2012.02.014.
Davies, N., D. Field, et al. 2012. Sequencing data: A genomic network to monitor Earth. Nature 481: 145 doi:10.1038/481145a.
Carey, C.C., P.C. Hanson, D.A. Bruesewitz, et al. 2012. Organized Oral Session 43. Novel Applications of High-Frequency Sensor Data in Aquatic Ecosystems: Discoveries from GLEON, the Global Lake Ecological Observatory Network. Bulletin of the Ecological Society of America 93:100–105. [doi:http://dx.doi.org/10.1890/0012-9623-93.1.100]
Lottig, N.R., E.H. Stanley, P.C. Hanson, and T.K. Kratz. 2011. Comparison of regional stream and lake chemistry: Differences, similarities, and potential drivers. Limnology and Oceanography 56:1551-1562, doi:10.4319/lo.2011.56.5.1551
Porter, J.H., P.C. Hanson, C.C. Lin. 2011. Staying afloat in the sensor data deluge. TREE 1484:1-9.
Trolle, D., D.P. Hamilton, M.R. Hipsey, K. Bolding, J. Bruggemen, W.M. Mooij, J.H. Janse, A. Nielsen, E. Jeppesen, J.A. Elliot, V. Makler-Pick, T. Petzoldt, K. Rinke, M.R. Flindt, G.B. Arhonditsis, G. Gal, R. Bjerring, K. Tominaga, J. Hoen, A.S. Downing, D. M. Marques, C.R. Fragoso, M. Sondergaard, P.C. Hanson. 2011. A community-based framework for aquatic ecosystem models. Hydrobiologia. DOI 10.1007/s10750-011-0957-0.
Hanson, P.C., D.P. Hamilton, E.H. Stanley, N. Preston, O.C. Langman, E.L. Kara. 2011. Fate of Allochthonous Dissolved Organic Carbon in Lakes: A Quantitative Approach. Plos One. 6:E21884. http://dx.plos.org/10.1371/journal.pone.0021884.
Watras, C.J., P.C. Hanson, T.L. Stacey, K.M. Morrison, J. Mather, Y.H. Hu, and P. Milewski. 2011. A temperature compensation method for CDOM fluorescence sensors in freshwater. Limnol. Oceanogr. Methods. 9: 296-301. DOI: 10.4319/lom.2011.9.296
Tsai, J.W., T.K. Kratz, P.C. Hanson, N. Kimura, W.C. Liu, F.P. Lin, H.M. Chou, J.T. Wu, and C.Y. Chiu. 2011. Metabolic changes and the resistance and resilience of a subtropical heterotrophic lake to typhoon disturbance. Can. J. Fish. Aquat. Sci. 68: 768-780.
Staehr, P.A., D. Bade, M. Van de Bogert, G. Koch, C. Williamson, P.C. Hanson, J. Cole, and T.K. Kratz. 2010. Lake metabolism and the diel oxygen technique: State of the science. Limnol. Oceanogr. Methods. 8: 268-644.
Buffam, I., M.G. Turner, A.R. Desai, P.C. Hanson, J.A. Rusak, N.R. Lottig, and S.R. Carpenter. 2010. Integrating aquatic and terrestrial components to construct a complete carbon budget for a north temperate lake district. Global Change Biology. doi:10.1111/j.1365-2486.2010.02313.x
Langman, O.C., P.C. Hanson, S.R. Carpenter, K. Chiu, and Y.H. Hu. 2010. Control of dissolved oxygen in northern temperate lakes over scales ranging from minutes to days. Aquatic Biology (9): 193–202, 2010doi: 10.3354/ab00249
Buffam, I., S.R. Carpenter, W. Yeck, P.C. Hanson, and M.G. Turner. 2010. Filling holes in regional carbon budgets: predicting peat depth in a north-temperate lake district. Journal of Geophysical Research (115), G01005, doi:10.1029/2009JG001034.