Bio


Alexandra Konings is a hydrologist interested in how ecosystems and the carbon cycle respond to variations in water availability at large scales. Research questions in the Konings lab span a range of ecosystem properties, but many of them surround the role of vegetation water content in predicting plant health and its associated fluxes and growth. She holds SB and PhD degrees from MIT (working with Dara Entekhabi), and a M.S. from Duke University (working with Gaby Katul). She joined the Department of Earth System Science as an assistant professor in 2016 after two short postdoctoral stints at Columbia University (working with Pierre Gentine) and the NASA Jet Propulsion Laboratory (working with Dave Schimel, Sassan Saatchi, and others).

Academic Appointments


Administrative Appointments


  • Faculty Affiliate, Stanford Woods Institute for the Environment (2016 - Present)
  • Assistant Professor, Stanford Department of Earth System Science (2016 - Present)
  • Visiting Postdoc, NASA Jet Propulsion Laboratory (2016 - 2016)
  • Visiting Postdoc, Columbia University (2015 - 2016)
  • NASA Earth and Space Science Fellow, Massachusetts Institute of Technology (2012 - 2015)
  • NSF Graduate Research Fellow, Massachusetts Institute of Technology (2011 - 2011)
  • NSF Graduate Research Fellow, Duke University (2009 - 2011)

Honors & Awards


  • New (Early Career) Investigator Award, NASA (2018-2021)
  • Group Achievement Award: AirMOSS Implementation Team, NASA (2016)
  • Best Doctoral Thesis Award, MIT Department of Civil and Environmental Engineering (2015-2016)
  • Earth and Space Science Fellowship, NASA (2012-2015)
  • Graduate Research Fellowship, National Science Foundation (2009-2012)
  • James B. Duke Fellowship, Duke University (2009-2011)

Boards, Advisory Committees, Professional Organizations


  • Member, Jasper Ridge Biological Preserve Faculty Advisory Committee (2017 - Present)
  • Member, AGU Hydrology Technical Committee on Remote Sensing (2016 - Present)
  • Member, IEEE Geoscience and Remote Sensing Society (2010 - Present)
  • Member, American Geophysical Union (2008 - Present)

Professional Education


  • Ph.D., Massachusetts Institute of Technology, Hydrology (2015)
  • M.S., Duke University, Environmental Science (2011)
  • S.B., Massachusetts Institute of Technology, Environmental Engineering Science (2009)

2018-19 Courses


Stanford Advisees


All Publications


  • Global-scale assessment and combination of SMAP with ASCAT (active) and AMSR2 (passive) soil moisture products REMOTE SENSING OF ENVIRONMENT Kim, H., Parinussa, R., Konings, A. G., Wagner, W., Cosh, M. H., Lakshmi, V., Zohaib, M. 2018; 204: 260-275
  • Characterization of vegetation and soil scattering mechanisms across different biomes using P-band SAR polarimetry REMOTE SENSING OF ENVIRONMENT Alemohammad, S., Konings, A. G., Jagdhuber, T., Moghaddam, M., Entekhabi, D. 2018: 107-117
  • Hydraulic diversity of forests regulates ecosystem resilience during drought NATURE Anderegg, W. R., Konings, A. G., Trugman, A. T., Yu, K., Bowling, D. R., Gabbitas, R., Karp, D. S., Pacala, S., Sperry, J. S., Sulman, B. N., Zenes, N. 2018; 561: 538-541
  • Tall Amazonian forests are less sensitive to precipitation variability NATURE GEOSCIENCE Giardina, F., Konings, A. G., Kennedy, D., Alemohammad, S., Oliviera, R. S., Uriarte, M., Gentine, P. 2018: 405-409
  • L-band vegetation optical depth seasonal metrics for crop yield assessment REMOTE SENSING OF ENVIRONMENT Chapparo, D., Piles, M., Vall-llossera, M., Camps, A., Konings, A. G., Entekhabi, D. 2018
  • Active microwave observations of diurnal and seasonal variations of canopy water content across the humid African tropical forests GEOPHYSICAL RESEARCH LETTERS Konings, A. G., Yu, Y., Xu, L., Yang, Y., Schimel, D., Saatchi, S. 2017; 44: 2290-2299

    View details for DOI 10.1002/2016GL072388

  • Water, Energy, and Carbon with Artificial Neural Networks (WECANN): a statistically based estimate of global surface turbulent fluxes and gross primary productivity using solar-induced fluorescence BIOGEOSCIENCES Alemohammad, S., Fang, B., Konings, A. G., Aires, F., Green, J. K., Kolassa, J., Miralles, D., Prigent, C., Gentine, P. 2017; 14: 4101-4124

    Abstract

    A new global estimate of surface turbulent fluxes, latent heat flux (LE) and sensible heat flux (H), and gross primary production (GPP) is developed using a machine learning approach informed by novel remotely sensed Solar-Induced Fluorescence (SIF) and other radiative and meteorological variables. This is the first study to jointly retrieve LE, H and GPP using SIF observations. The approach uses an artificial neural network (ANN) with a target dataset generated from three independent data sources, weighted based on triple collocation (TC) algorithm. The new retrieval, named Water, Energy, and Carbon with Artificial Neural Networks (WECANN), provides estimates of LE, H and GPP from 2007 to 2015 at 1° × 1° spatial resolution and on monthly time resolution. The quality of ANN training is assessed using the target data, and the WECANN retrievals are evaluated using eddy covariance tower estimates from FLUXNET network across various climates and conditions. When compared to eddy covariance estimates, WECANN typically outperforms other products, particularly for sensible and latent heat fluxes. Analysing WECANN retrievals across three extreme drought and heatwave events demonstrates the capability of the retrievals in capturing the extent of these events. Uncertainty estimates of the retrievals are analysed and the inter-annual variability in average global and regional fluxes show the impact of distinct climatic events - such as the 2015 El Niño - on surface turbulent fluxes and GPP.

    View details for DOI 10.5194/bg-14-4101-2017

    View details for PubMedCentralID PMC5744880

  • Relationship between vegetation microwave optical depth and cross-polarized backscatter from multi-year Aquarius observations. IEEE JOURNAL OF SELECTED TOPICS IN EARTH OBSERVATIONS AND REMOTE SENSING Rotzer, K., Montzka, C., Entekhabi, D., Konings, A. G., McColl, K. A., Piles, M., Vereecken, H. 2017
  • Estimating global ecosystem iso/anisohydry using active and passive microwave satellite data JOURNAL OF GEOPHYSICAL RESEARCH - BIOGEOSCIENCES Li, Y., Guan, K., Gentine, P., Konings, A. G., Meinzer, F. C., Kimball, J. S., Xu, X., Anderegg, W. R., McDowell, N. G., Martinez-Vilalta, J., Long, D. G., Good, S. P. 2017; 122

    View details for DOI 10.1002/2017JG003958

  • Interacting effects of leaf water potential and biomass on vegetation optical depth JOURNAL OF GEOPHYSICAL RESEARCH - BIOGEOSCIENCES Momen, M., Wood, J. D., Novick, K. A., Pangle, R., Pockman, W. T., McDowell, N. G., Konings, A. G. 2017; 122

    View details for DOI 10.1002/2017JG004145

  • Regionally strong feedbacks between the atmosphere and terrestrial biosphere NATURE GEOSCIENCE Green, J., Konings, A. G., Alemohammad, S., Berry, J., Entekhabi, D., Kolassa, J., Lee, J., Gentine, P. 2017; 10: 410–414

    View details for DOI 10.1038/ngeo2957

  • The global distribution and dynamics of surface soil moisture NATURE GEOSCIENCE McColl, K. A., Alemohammad, S., Akbar, R., Konings, A., Yueh, S., Entekhabi, D. 2017; 10: 100-104

    View details for DOI 10.1038/ngeo2868

  • Global variations in ecosystem scale isohydricity GLOBAL CHANGE BIOLOGY Konings, A. G., Gentine, P. 2017; 23 (2): 891-905

    View details for DOI 10.1111/gcb.13389

  • L-band vegetation optical depth and scattering albedo estimation from SMAP REMOTE SENSING OF ENVIRONMENT Konings, A. G., Piles, M., Das, N., Entekhabi, D. 2017; 198: 460-470
  • Sensitivity of grassland productivity to aridity controlled by stomatal and xylem regulation NATURE GEOSCIENCE Konings, A. G., Williams, A., Gentine, P. 2017; 10: 284-288

    View details for DOI 10.1038/ngeo2903

  • Triple collocation for binary and categorical variables: Application to validating landscape freeze/thaw retrievals REMOTE SENSING OF ENVIRONMENT McColl, K. A., Roy, A., Derksen, C., Konings, A. G., Alemohammed, S. H., Entekhabi, D. 2016; 176: 31-42
  • Vegetation optical depth and scattering albedo retrieval using time series of dual-polarized L-band radiometer observations REMOTE SENSING OF ENVIRONMENT Konings, A. G., Piles, M., Roetzer, K., McColl, K. A., Chan, S. K., Entekhabi, D. 2016; 172: 178-189
  • L-Band Radar Soil Moisture Retrieval Without Ancillary Information IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING Bruscantini, C. A., Konings, A. G., Narvekar, P. S., McColl, K. A., Entekhabi, D., Grings, F. M., Karszenbaum, H. 2015; 8 (12): 5526-5540
  • How Many Parameters Can Be Maximally Estimated From a Set of Measurements? IEEE GEOSCIENCE AND REMOTE SENSING LETTERS Konings, A. G., McColl, K. A., Piles, M., Entekhabi, D. 2015; 12 (5): 1081-1085
  • Characterization of precipitation product errors across the United States using multiplicative triple collocation HYDROLOGY AND EARTH SYSTEM SCIENCES Alemohammad, S. H., McColl, K. A., Konings, A. G., Entekhabi, D., Stoffelen, A. 2015; 19 (8): 3489-3503
  • The Effect of Variable Soil Moisture Profiles on P-Band Backscatter IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING Konings, A. G., Entekhabi, D., Moghaddam, M., Saatchi, S. S. 2014; 52 (10): 6315-6325
  • Extended triple collocation: Estimating errors and correlation coefficients with respect to an unknown target GEOPHYSICAL RESEARCH LETTERS McColl, K. A., Vogelzang, J., Konings, A. G., Entekhabi, D., Piles, M., Stoffelen, A. 2014; 41 (17): 6229-6236
  • Thermodynamics of an idealized hydrologic cycle WATER RESOURCES RESEARCH Konings, A. G., Feng, X., Molini, A., Manzoni, S., Vico, G., Porporato, A. 2012; 48
  • A phenomenological model for the flow resistance over submerged vegetation WATER RESOURCES RESEARCH Konings, A. G., Katul, G. G., Thompson, S. E. 2012; 48
  • Mean Velocity Profile in a Sheared and Thermally Stratified Atmospheric Boundary Layer PHYSICAL REVIEW LETTERS Katul, G. G., Konings, A. G., Porporato, A. 2011; 107 (26)

    Abstract

    A stability correction function φ(m)(ζ) that accounts for distortions to the logarithmic mean velocity profile (MVP) in the lower atmosphere caused by thermal stratification was proposed by Monin and Obukhov in the 1950s using dimensional analysis. Its universal character was established from many field experiments. However, theories that describe the canonical shape of φ(m)(ζ) are still lacking. A previous link between the spectrum of turbulence and the MVP is expanded here to include the effects of thermal stratification on the turbulent kinetic energy dissipation rate and eddy-size anisotropy. The resulting theory provides a novel explanation for the power-law exponents and coefficients already reported for φ(m)(ζ) from numerous field experiments.

    View details for DOI 10.1103/PhysRevLett.107.268502

    View details for Web of Science ID 000298609000019

    View details for PubMedID 22243189

  • Drought sensitivity of patterned vegetation determined by rainfall-land surface feedbacks JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES Konings, A. G., Dekker, S. C., Rietkerk, M., Katul, G. G. 2011; 116
  • Unsteady overland flow on flat surfaces induced by spatial permeability contrasts ADVANCES IN WATER RESOURCES Thompson, S., Katul, G., Konings, A., Ridolfi, L. 2011; 34 (8): 1049-1058
  • Comparative hydrology across AmeriFlux sites: The variable roles of climate, vegetation, and groundwater WATER RESOURCES RESEARCH Thompson, S. E., Harman, C. J., Konings, A. G., Sivapalan, M., Neal, A., Troch, P. A. 2011; 47
  • Effect of Radiative Transfer Uncertainty on L-Band Radiometric Soil Moisture Retrieval IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING Konings, A. G., Entekhabi, D., Chan, S. K., Njoku, E. G. 2011; 49 (7): 2686-2698
  • The rainfall-no rainfall transition in a coupled land-convective atmosphere system GEOPHYSICAL RESEARCH LETTERS Konings, A. G., Katul, G. G., Porporato, A. 2010; 37
  • Conditioning Stochastic Rainfall Replicates on Remote Sensing Data IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING Wojcik, R., McLaughlin, D., Konings, A. G., Entekhabi, D. 2009; 47 (8): 2436-2449