• Asefi-Najafabady, S., and S. Saatchi, 2013: Response of African humid tropical forests to recent rainfall anomalies. Philos. Trans. Roy. Soc. London, 368B, 20120306, doi:10.1098/rstb.2012.0306.

    • Search Google Scholar
    • Export Citation
  • Badgley, G., J. B. Fisher, C. Jiménez, K. P. Tu, and R. Vinukollu, 2015: On uncertainty in global terrestrial evapotranspiration estimates from choice of input forcing datasets. J. Hydrometeor., 16, 14491455, doi:10.1175/JHM-D-14-0040.1.

    • Search Google Scholar
    • Export Citation
  • Baldocchi, D., and Coauthors, 2001: Fluxnet: A new tool to study the temporal and spatial variability of ecosystem-scale carbon dioxide, water vapor and energy flux densities. Bull. Amer. Meteor. Soc., 82, 24152434, doi:10.1175/1520-0477(2001)082<2415:FANTTS>2.3.CO;2.

    • Search Google Scholar
    • Export Citation
  • Balsamo, G., and Coauthors, 2012: ERA-Interim/Land: A global land-surface reanalysis based on ERA-Interim meteorological forcing. ERA Rep. Series 13, 27 pp.

  • Balsamo, G., and Coauthors, 2015: ERA-Interim/Land: A global land surface reanalysis data set. Hydrol. Earth Syst. Sci., 19, 389407, doi:10.5194/hess-19-389-2015.

    • Search Google Scholar
    • Export Citation
  • Bosilovich, M. G., and S. D. Schubert, 2002: Water vapor tracers as diagnostics of the regional hydrologic cycle. J. Hydrometeor., 3, 149165, doi:10.1175/1525-7541(2002)003<0149:WVTADO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Bosilovich, M. G., F. R. Robertson, and J. Chen, 2011: Global energy and water budgets in MERRA. J. Climate, 24, 57215739, doi:10.1175/2011JCLI4175.1.

    • Search Google Scholar
    • Export Citation
  • Bosilovich, M. G., J. D. Chern, D. Mocko, F. R. Robertson, and A. M. da Silva, 2015: Evaluating observation influence on regional water budgets in reanalyses. J. Climate, 28, 36313649, doi:10.1175/JCLI-D-14-00623.1.

    • Search Google Scholar
    • Export Citation
  • Bretherton, C. S., and D. S. Battisti, 2000: An interpretation of the results from atmospheric general circulation models forced by the time history of the observed sea surface temperature distribution. Geophys. Res. Lett., 27, 767770, doi:10.1029/1999GL010910.

    • Search Google Scholar
    • Export Citation
  • Camberlin, P., S. Janicot, and I. Poccard, 2001: Seasonality and atmospheric dynamics of the teleconnection between African rainfall and tropical sea‐surface temperature: Atlantic vs. ENSO. Int. J. Climatol., 21, 9731005, doi:10.1002/joc.673.

    • Search Google Scholar
    • Export Citation
  • Canadell, J. G., P. Ciais, K. Gurney, C. Le Quéré, S. Piao, M. R. Raupach, and C. L. Sabine, 2011: An international effort to quantify regional carbon fluxes. Eos, Trans. Amer. Geophys. Union, 92, 8182, doi:10.1029/2011EO100001.

    • Search Google Scholar
    • Export Citation
  • Chen, M., W. Shi, P. Xie, V. B. S. Silva, V. E. Kousky, R. W. Higgins, and J. E. Janowiak, 2008: Assessing objective techniques for gauge-based analyses of global daily precipitation. J. Geophys. Res. Atmos., 113, D04110, doi:10.1029/2007JD009132.

    • Search Google Scholar
    • Export Citation
  • Chou, C., and J. D. Neelin, 2004: Mechanisms of global warming impacts on regional tropical precipitation. J. Climate, 17, 26882701, doi:10.1175/1520-0442(2004)017<2688:MOGWIO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Compo, G. P., and Coauthors, 2011: The Twentieth Century Reanalysis Project. Quart. J. Roy. Meteor. Soc., 137, 128, doi:10.1002/qj.776.

    • Search Google Scholar
    • Export Citation
  • Dai, A., 2011: Characteristics and trends in various forms of the Palmer drought severity index during 1900–2008. J. Geophys. Res., 116, D12115, doi:10.1029/2010JD015541.

    • Search Google Scholar
    • Export Citation
  • Dai, A., 2013: The influence of the inter-decadal Pacific oscillation on US precipitation during 1923–2010. Climate Dyn., 41, 633646, doi:10.1007/s00382-012-1446-5.

    • Search Google Scholar
    • Export Citation
  • Dai, A., 2016: Historical and future changes in streamflow and continental runoff: A review. Terrestrial Water Cycle and Climate Change: Natural and Human-Induced Impacts, Geophys. Monogr., Vol. 221, Amer. Geophys. Union, 17–37.

  • Dai, A., and T. M. L. Wigley, 2000: Global patterns of ENSO-induced precipitation. Geophys. Res. Lett., 27, 12831286, doi:10.1029/1999GL011140.

    • Search Google Scholar
    • Export Citation
  • Dai, A., and T. Zhao, 2016: Uncertainties in historical changes and future projections of drought. Part I: Estimates of historical drought changes. Climatic Change, doi:10.1007/s10584-016-1705-2, in press.

    • Search Google Scholar
    • Export Citation
  • Dai, A., T. Qian, K. E. Trenberth, and J. D. Milliman, 2009: Changes in continental freshwater discharge from 1948 to 2004. J. Climate, 22, 27732792, doi:10.1175/2008JCLI2592.1.

    • Search Google Scholar
    • Export Citation
  • Dee, D. P., and S. Uppala, 2009: Variational bias correction of satellite radiance data in the ERA-Interim reanalysis. Quart. J. Roy. Meteor. Soc., 135, 18301841, doi:10.1002/qj.493.

    • Search Google Scholar
    • Export Citation
  • Dee, D. P., and Coauthors, 2011: The ERA-Interim reanalysis: Configuration and performance of the data assimilation system. Quart. J. Roy. Meteor. Soc., 137, 553597, doi:10.1002/qj.828.

    • Search Google Scholar
    • Export Citation
  • Dirmeyer, P. A., A. J. Dolman, and N. Sato, 1999: The Global Soil Wetness Project: A pilot project for global land surface modeling and validation. Bull. Amer. Meteor. Soc., 80, 851878, doi:10.1175/1520-0477(1999)080<0851:TPPOTG>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Dirmeyer, P. A., X. Gao, M. Zhao, Z. Guo, T. Oki, and N. Hanasaki, 2006: GSWP-2: Multimodel analysis and implications for our perception of the land surface. Bull. Amer. Meteor. Soc., 87, 13811397, doi:10.1175/BAMS-87-10-1381.

    • Search Google Scholar
    • Export Citation
  • Ebita, A., and Coauthors, 2011: The Japanese 55-year Reanalysis “JRA-55”: An interim report. SOLA, 7, 149152, doi:10.2151/sola.2011-038.

    • Search Google Scholar
    • Export Citation
  • Eltahir, E. A. B., and R. L. Bras, 1994: Precipitation recycling in the Amazon basin. Quart. J. Roy. Meteor. Soc., 120, 861880, doi:10.1002/qj.49712051806.

    • Search Google Scholar
    • Export Citation
  • Enfield, D. B., A. M. Mestas‐Nuñez, and P. J. Trimble, 2001: The Atlantic multidecadal oscillation and its relation to rainfall and river flows in the continental U.S. Geophys. Res. Lett., 28, 20772080, doi:10.1029/2000GL012745.

    • Search Google Scholar
    • Export Citation
  • Folland, C. K., T. N. Palmer, and D. E. Parker, 1986: Sahel rainfall and worldwide sea temperatures, 1901–85. Nature, 320, 602607, doi:10.1038/320602a0.

    • Search Google Scholar
    • Export Citation
  • Folland, C. K., A. W. Colman, D. P. Rowell, and M. K. Davey, 2001: Predictability of northeast Brazil rainfall and real-time forecast skill, 1987–98. J. Climate, 14, 19371958, doi:10.1175/1520-0442(2001)014<1937:PONBRA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Giannini, A., R. Saravanan, and P. Chang, 2003: Oceanic forcing of Sahel rainfall on interannual to interdecadal time scales. Science, 302, 10271030, doi:10.1126/science.1089357.

    • Search Google Scholar
    • Export Citation
  • Gloor, M., and Coauthors, 2013: Intensification of the Amazon hydrological cycle over the last two decades. Geophys. Res. Lett., 40, 17291733, doi:10.1002/grl.50377.

    • Search Google Scholar
    • Export Citation
  • Gobron, N., B. Pinty, F. Mélin, M. Taberner, M. M. Verstraete, M. Robustelli, and J.-L. Widlowski, 2007: Evaluation of the MERIS/ENVISAT FAPAR product. Adv. Space Res., 39, 105115, doi:10.1016/j.asr.2006.02.048.

    • Search Google Scholar
    • Export Citation
  • Greve, P., B. Orlowsky, B. Mueller, J. Sheffield, M. Reichstein, and S. I. Seneviratne, 2014: Global assessment of trends in wetting and drying over land. Nat. Geosci., 7, 716721, doi:10.1038/ngeo2247.

    • Search Google Scholar
    • Export Citation
  • Grimm, A. M., 2003: The El Niño impact on the summer monsoon in Brazil: Regional processes versus remote influences. J. Climate, 16, 263280, doi:10.1175/1520-0442(2003)016<0263:TENIOT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Gu, G., R. F. Adler, G. J. Huffman, and S. Curtis, 2007: Tropical rainfall variability on interannual-to-interdecadal and longer time scales derived from the GPCP monthly product. J. Climate, 20, 40334046, doi:10.1175/JCLI4227.1.

    • Search Google Scholar
    • Export Citation
  • Haddeland, I., and Coauthors, 2011: Multimodel estimate of the global terrestrial water balance: Setup and first results. J. Hydrometeor., 12, 869884, doi:10.1175/2011JHM1324.1.

    • Search Google Scholar
    • Export Citation
  • Harding, R., and Coauthors, 2011: WATCH: Current knowledge of the terrestrial global water cycle. J. Hydrometeor., 12, 11491156, doi:10.1175/JHM-D-11-024.1.

    • Search Google Scholar
    • Export Citation
  • Hastenrath, S., and L. Greischar, 1993: Circulation mechanisms related to northeast Brazil rainfall anomalies. J. Geophys. Res., 98, 50935102, doi:10.1029/92JD02646.

    • Search Google Scholar
    • Export Citation
  • Hendon, H. H., 2003: Indonesian rainfall variability: Impacts of ENSO and local air–sea interaction. J. Climate, 16, 17751790, doi:10.1175/1520-0442(2003)016<1775:IRVIOE>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Jiménez, C., and Coauthors, 2011: Global intercomparison of 12 land surface heat flux estimates. J. Geophys. Res., 116, D02102, doi:10.1029/2010JD014545.

    • Search Google Scholar
    • Export Citation
  • Jung, M., M. Reichstein, and A. Bondeau, 2009: Towards global empirical upscaling of FLUXNET eddy covariance observations: Validation of a model tree ensemble approach using a biosphere model. Biogeosciences, 6, 52715304, doi:10.5194/bg-6-2001-2009.

    • Search Google Scholar
    • Export Citation
  • Jung, M., and Coauthors, 2010: Recent decline in the global land evapotranspiration trend due to limited moisture supply. Nature, 467, 951954, doi:10.1038/nature09396.

    • Search Google Scholar
    • Export Citation
  • Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77, 437471, doi:10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Kato, H., M. Rodell, F. Beyrich, H. Cleugh, E. van Gorsel, H. Liu, and T. P. Meyers, 2007: Sensitivity of land surface simulations to model physics, land characteristics, and forcings, at four CEOP sites. J. Meteor. Soc. Japan, 85, 187204.

    • Search Google Scholar
    • Export Citation
  • Kleist, D. T., D. F. Parrish, J. C. Derber, R. Treadon, W.-S. Wu, and S. Lord, 2009: Introduction of the GSI into the NCEP Global Data Assimilation System. Wea. Forecasting, 24, 16911705, doi:10.1175/2009WAF2222201.1.

    • Search Google Scholar
    • Export Citation
  • Kobayashi, S., and Coauthors, 2015: The JRA-55 Reanalysis: General specifications and basic characteristics. J. Meteor. Soc. Japan, 93, 548, doi:10.2151/jmsj.2015-001.

    • Search Google Scholar
    • Export Citation
  • Koster, R. D., M. J. Suarez, A. Ducharne, M. Stieglitz, and P. Kumar, 2000: A catchment-based approach to modeling land surface processes in a general circulation model: 1. Model structure. J. Geophys. Res., 105, 24 80924 822, doi:10.1029/2000JD900327.

    • Search Google Scholar
    • Export Citation
  • Koster, R. D., and Coauthors, 2010: The contribution of land surface initialization to sub-seasonal forecast skill: First results from the GLACE-2 Project. Geophys. Res. Lett., 37, L02402, doi:10.1029/2009GL041677.

    • Search Google Scholar
    • Export Citation
  • Koster, R. D., and Coauthors, 2011: The second phase of the global land-atmosphere coupling experiment: Soil moisture contributions to sub-seasonal forecast skill. J. Hydrometeor., 12, 805822, doi:10.1175/2011JHM1365.1.

    • Search Google Scholar
    • Export Citation
  • Krinner, G., and Coauthors, 2005: A dynamic global vegetation model for studies of the coupled atmosphere-biosphere system. Global Biogeochem. Cycles, 19, GB1015, doi:10.1029/2003GB002199.

    • Search Google Scholar
    • Export Citation
  • Lawrence, D. M., and Coauthors, 2011: Parameterization improvements and functional and structural advances in version 4 of the Community Land Model. J. Adv. Model. Earth Syst., 3, M03001, doi:10.1029/2011MS000045.

    • Search Google Scholar
    • Export Citation
  • L’Ecuyer, T. S., and Coauthors, 2015: The observed state of the energy budget in the early twenty-first century. J. Climate, 28, 83198346, doi:10.1175/JCLI-D-14-00556.1.

    • Search Google Scholar
    • Export Citation
  • Lipton, A. E., and Coauthors, 2015: Sources of discrepancies between satellite‐derived and land surface model estimates of latent heat fluxes. J. Geophys. Res. Atmos., 120, 23252341, doi:10.1002/2014JD022641.

    • Search Google Scholar
    • Export Citation
  • Lorenz, C., and H. Kunstmann, 2012: The hydrological cycle in three state-of-the-art reanalyses: Intercomparison and performance analysis. J. Hydrometeor., 13, 13971420, doi:10.1175/JHM-D-11-088.1.

    • Search Google Scholar
    • Export Citation
  • Lyon, B., and D. G. DeWitt, 2012: A recent and abrupt decline in the East African long rains. Geophys. Res. Lett., 39, L02702, doi:10.1029/2011GL050337.

    • Search Google Scholar
    • Export Citation
  • Lyon, B., A. G. Barnston, and D. G. DeWitt, 2014: Tropical Pacific forcing of a 1998–1999 climate shift: Observational analysis and climate model results for the boreal spring season. Climate Dyn., 43, 893909, doi:10.1007/s00382-013-1891-9.

    • Search Google Scholar
    • Export Citation
  • Malhi, Y., and J. Wright, 2004: Spatial patterns and recent trends in the climate of tropical rainforest regions. Philos. Trans. Roy. Soc. London., 359B, 311329, doi:10.1098/rstb.2003.1433.

    • Search Google Scholar
    • Export Citation
  • Marengo, J. A., 2004: Interdecadal variability and trends of rainfall across the Amazon basin. Theor. Appl. Climatol., 78, 7996, doi:10.1007/s00704-004-0045-8.

    • Search Google Scholar
    • Export Citation
  • Miyakoda, K., G. D. Hembree, R. F. Strickler, and I. Shulman, 1972: Cumulative results of extended forecast experiments: I. Model performance for winter cases. Mon. Wea. Rev., 100, 836855, doi:10.1175/1520-0493(1972)100<0836:CROEFE>2.3.CO;2.

    • Search Google Scholar
    • Export Citation
  • Molod, A., L. Takacs, M. Suarez, and J. Bacmeister, 2015: Development of the GEOS-5 atmospheric general circulation model: Evolution from MERRA to MERRA2. Geosci. Model Dev., 8, 13391356, doi:10.5194/gmd-8-1339-2015.

    • Search Google Scholar
    • Export Citation
  • Mueller, B., and Coauthors, 2013: Benchmark products for land evapotranspiration: LandFlux-EVAL multi-dataset synthesis. Hydrol. Earth Syst. Sci., 17, 37073720, doi:10.5194/hess-17-3707-2013.

    • Search Google Scholar
    • Export Citation
  • New, M., M. Todd, M. Hulme, and P. Jones, 2001: Precipitation measurements and trends in the twentieth century. Int. J. Climatol., 21, 18891922, doi:10.1002/joc.680.

    • Search Google Scholar
    • Export Citation
  • Ngo-Duc, T., J. Polcher, and K. Laval, 2005: A 53-year forcing data set for land surface models. J. Geophys. Res., 110, D06116, doi:10.1029/2004JD005434.

    • Search Google Scholar
    • Export Citation
  • Oleson, K. W., and Coauthors, 2010: Technical description of version 4.0 of the Community Land Model (CLM). NCAR Tech. Note NCAR/TN-478+STR, 257 pp.

  • Onogi, K., and Coauthors, 2007: The JRA-25 Reanalysis. J. Meteor. Soc. Japan, 85, 369432, doi:10.2151/jmsj.85.369.

  • Pan, M., A. K. Sahoo, T. J. Troy, R. K. Vinukollu, J. Sheffield, and E. F. Wood, 2012: Multisource estimation of long-term terrestrial water budget for major global river basins. J. Climate, 25, 31913206, doi:10.1175/JCLI-D-11-00300.1.

    • Search Google Scholar
    • Export Citation
  • Poli, P., H. Hersbach, P. Berrisford, D. P. Dee, A. Simmons, and P. Laloyaux, 2015: ERA-20C deterministic. ERA Rep. Series 20, 48 pp. [Available online at http://www.ecmwf.int/sites/default/files/elibrary/2015/11700-era-20c-deterministic.pdf.]

  • Power, S., T. Casey, C. Folland, A. Colman, and V. Mehta, 1999: Inter-decadal modulation of the impact of ENSO on Australia. Climate Dyn., 15, 319324, doi:10.1007/s003820050284.

    • Search Google Scholar
    • Export Citation
  • Reager, J. T., A. S. Gardner, J. S. Famiglietti, D. N. Weiss, A. Eicker, and M. H. Lo, 2016: A decade of sea level rise slowed by climate-driven hydrology. Science, 351, 699703, doi:10.1126/science.aad8386.

    • Search Google Scholar
    • Export Citation
  • Reichle, R. H., and Q. Liu, 2014: Observation-corrected precipitation estimates in GEOS-5. NASA Tech. Rep. NASA/TM-2014-104606, 24 pp. [Available online at http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150000725.pdf.]

  • Reichle, R. H., R. D. Koster, G. J. M. De Lannoy, B. A. Forman, Q. Liu, S. P. P. Mahanama, and A. Toure, 2011: Assessment and enhancement of MERRA land surface hydrology estimates. J. Climate, 24, 63226338, doi:10.1175/JCLI-D-10-05033.1.

    • Search Google Scholar
    • Export Citation
  • Richman, M. B., 1986: Rotation of principal components. J. Climatol., 6, 293335, doi:10.1002/joc.3370060305.

  • Rienecker, M., and Coauthors, 2011: MERRA: NASA’s Modern-Era Retrospective Analysis for Research and Applications. J. Climate, 24, 36243648, doi:10.1175/JCLI-D-11-00015.1.

    • Search Google Scholar
    • Export Citation
  • Robertson, F. R., M. G. Bosilovich, J. Chen, and T. L. Miller, 2011: The effect of satellite observing system changes on MERRA water and energy fluxes. J. Climate, 24, 51975217, doi:10.1175/2011JCLI4227.1.

    • Search Google Scholar
    • Export Citation
  • Robertson, F. R., M. G. Bosilovich, J. B. Roberts, R. H. Reichle, R. Adler, L. Ricciardulli, W. Berg, and G. J. Huffman, 2014: Consistency of estimated global water cycle variations over the satellite era. J. Climate, 27, 61356154, doi:10.1175/JCLI-D-13-00384.1.

    • Search Google Scholar
    • Export Citation
  • Rodell, P., and Coauthors, 2004: The Global Land Data Assimilation System. Bull. Amer. Meteor. Soc., 85, 381394, doi:10.1175/BAMS-85-3-381.

    • Search Google Scholar
    • Export Citation
  • Rodell, P., E. B. McWilliams, J. S. Famiglietti, H. K. Beaudoing, and J. Nigro, 2011: Estimating evapotranspiration using an observation based terrestrial water budget. Hydrol. Processes, 25, 40824092, doi:10.1002/hyp.8369.

    • Search Google Scholar
    • Export Citation
  • Rodell, P., and Coauthors, 2015: The observed state of the water cycle in the early twenty-first century. J. Climate, 28, 82898318, doi:10.1175/JCLI-D-14-00555.1.

    • Search Google Scholar
    • Export Citation
  • Ropelewski, C. F., and M. S. Halpert, 1987: Global and regional scale precipitation patterns associated with the El Niño/Southern Oscillation. Mon. Wea. Rev., 115, 16061626, doi:10.1175/1520-0493(1987)115<1606:GARSPP>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Saha, S., and Coauthors, 2010: The NCEP Climate Forecast System Reanalysis. Bull. Amer. Meteor. Soc., 91, 10151057, doi:10.1175/2010BAMS3001.1.

    • Search Google Scholar
    • Export Citation
  • Schlosser, C., and X. Gao, 2009: Assessing evapotranspiration estimates from the Global Soil Wetness Project phase 2 (GSWP‐2). MIT Joint Program on the Science and Policy of Global Change Tech. Rep. 179, 35 pp.

  • Schubert, S., and Y. Chang, 1996: An objective method for inferring sources of model error. Mon. Wea. Rev., 124, 325340, doi:10.1175/1520-0493(1996)124<0325:AOMFIS>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Sheffield, J., G. Goteti, and E. F. Wood, 2006: Development of a 50-yr high-resolution global dataset of meteorological forcings for land surface modeling. J. Climate, 19, 30883111, doi:10.1175/JCLI3790.1.

    • Search Google Scholar
    • Export Citation
  • Sheffield, J., E. F. Wood, and M. L. Roderick, 2012: Little change in global drought over the past 60 years. Nature, 491, 435438, doi:10.1038/nature11575.

    • Search Google Scholar
    • Export Citation
  • Simmons, A. J., K. M. Willett, P. D. Jones, P. W. Thorne, and D. P. Dee, 2010: Low-frequency variations in surface atmospheric humidity, temperature, and precipitation: Inferences from reanalyses and monthly gridded observational data sets. J. Geophys. Res., 115, D01110, doi:10.1029/2009JD012442.

    • Search Google Scholar
    • Export Citation
  • Sitch, S., and Coauthors, 2013: Trends and drivers of the regional-scale sources and sinks of carbon dioxide over the past two decades. Biogeosciences, 12, 653679, doi:10.5194/bgd-10-20113-2013.

    • Search Google Scholar
    • Export Citation
  • Sutton, R. T., and D. L. Hodson, 2005: Atlantic Ocean forcing of North American and European summer climate. Science, 309, 115118, doi:10.1126/science.1109496.

    • Search Google Scholar
    • Export Citation
  • Takacs, L. L., M. J. Suárez, and R. Todling, 2015: Maintaining atmospheric mass and water balance in reanalyses. Quart. J. Roy. Meteor. Soc., 142, 15651573, doi:10.1002/qj.2763.

    • Search Google Scholar
    • Export Citation
  • Tapley, B. D., S. Bettadpur, J. C. Ries, P. F. Thompson, and M. M. Watkins, 2004: GRACE measurements of mass variability in the Earth system. Science, 305, 503505, doi:10.1126/science.1099192.

    • Search Google Scholar
    • Export Citation
  • Ting, M., Y. Kushnir, R. Seager, and C. Li, 2011: Robust features of Atlantic multi-decadal variability and its climate impacts. Geophys. Res. Lett., 38, L17705, doi:10.1029/2011GL048712.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., 1999: Atmospheric moisture recycling: Role of advection and local evaporation. J. Climate, 12, 13681381, doi:10.1175/1520-0442(1999)012<1368:AMRROA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., and C. J. Guillemot, 1998: Evaluation of the atmospheric moisture and hydrological cycle in the NCEP/NCAR reanalyses. Climate Dyn., 14, 213231, doi:10.1007/s003820050219.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., and J. T. Fasullo, 2013: Regional energy and water cycles: Transports from ocean to land. J. Climate, 26, 78377851, doi:10.1175/JCLI-D-13-00008.1.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., J. T. Fasullo, and J. Mackaro, 2011: Atmospheric moisture transports from ocean to land and global energy flows in reanalyses. J. Climate, 24, 49074924, doi:10.1175/2011JCLI4171.1.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., A. Dai, G. van der Schrier, P. D. Jones, J. Barichivich, K. R. Briffa, and J. Sheffield, 2014: Global warming and changes in drought. Nat. Climate Change, 4, 1722, doi:10.1038/nclimate2067.

    • Search Google Scholar
    • Export Citation
  • Uppala, S. M., and Coauthors, 2005: The ERA-40 Re-Analysis. Quart. J. Roy. Meteor. Soc., 131, 29613012, doi:10.1256/qj.04.176.

  • Van Dijk, A. I. J. M., L. J. Renzullo, Y. Wada, and P. Tregoning, 2014: A global water cycle reanalysis (2003–2012) merging satellite gravimetry and altimetry observations with a hydrological multi-model ensemble. Hydrol. Earth Syst. Sci., 18, 29552973, doi:10.5194/hess-18-2955-2014.

    • Search Google Scholar
    • Export Citation
  • Wang, B., J. Liu, H. J. Kim, P. J. Webster, and S. Y. Yim, 2012: Recent change of the global monsoon precipitation (1979–2008). Climate Dyn., 39, 11231135, doi:10.1007/s00382-011-1266-z.

    • Search Google Scholar
    • Export Citation
  • Wang, W., P. Xie, S.-H. Yoo, Y. Xue, A. Kumar, and X. Wu, 2010: An assessment of the surface climate in the NCEP Climate Forecast System Reanalysis. Climate Dyn., 37, 16011620, doi:10.1007/s00382-010-0935-7.

    • Search Google Scholar
    • Export Citation
  • Washington, R., R. James, H. Pearce, W. M. Pokam, and W. Moufouma-Okia, 2013: Congo Basin rainfall climatology: Can we believe the climate models? Philos. Trans. Roy. Soc. London, 368B, 20120296, doi:10.1098/rstb.2012.0296.

    • Search Google Scholar
    • Export Citation
  • Weedon, G. P., and Coauthors, 2011: Creation of the WATCH forcing data and its use to assess global and regional reference crop evaporation over land during the twentieth century. J. Hydrometeor., 12, 823848, doi:10.1175/2011JHM1369.1.

    • Search Google Scholar
    • Export Citation
  • Weedon, G. P., S. Gomes, G. Balsamo, M. J. Best, N. Bellouin, and P. Viterbo, 2012: README file for the “WFDEI” dataset (version: 18th September 2013). WATCH Water and Global Change. [Available online at http://www.eu-watch.org/gfx_content/documents/README-WFDEI%20(v2016).pdf.]

  • Wisser, D., B. M. Fekete, C. J. Vörösmarty, and A. H. Schumann, 2010: Reconstructing 20th century global hydrography: A contribution to the Global Terrestrial Network-Hydrology (GTN-H). Hydrol. Earth Syst. Sci., 14, 124, doi:10.5194/hess-14-1-2010.

    • Search Google Scholar
    • Export Citation
  • Zaitchik, B. F., M. Rodell, and F. Olivera, 2010: Evaluation of the Global Land Data Assimilation System using global river discharge data and a source to sink routing scheme. Water Resour. Res., 46, W06507, doi:10.1029/2009WR007811.

    • Search Google Scholar
    • Export Citation
  • Zhang, Y., J. M. Wallace, and D. S. Battisti, 1997: ENSO-like interdecadal variability: 1900–93. J. Climate, 10, 10041020, doi:10.1175/1520-0442(1997)010<1004:ELIV>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 220 165 30
PDF Downloads 113 63 3

Reconciling Land–Ocean Moisture Transport Variability in Reanalyses with P − ET in Observationally Driven Land Surface Models

View More View Less
  • 1 Earth Science Office, NASA Marshall Space Flight Center, Huntsville, Alabama
  • | 2 Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
  • | 3 Earth Science Office, NASA Marshall Space Flight Center, Huntsville, Alabama
© Get Permissions Rent on DeepDyve
Restricted access

Abstract

Vertically integrated atmospheric moisture transport from ocean to land [vertically integrated atmospheric moisture flux convergence (VMFC)] is a dynamic component of the global climate system but remains problematic in atmospheric reanalyses, with current estimates having significant multidecadal global trends differing even in sign. Continual evolution of the global observing system, particularly stepwise improvements in satellite observations, has introduced discrete changes in the ability of data assimilation to correct systematic model biases, manifesting as nonphysical variability. Land surface models (LSMs) forced with observed precipitation P and near-surface meteorology and radiation provide estimates of evapotranspiration (ET). Since variability of atmospheric moisture storage is small on interannual and longer time scales, VMFC = P − ET is a good approximation and LSMs can provide an alternative estimate. However, heterogeneous density of rain gauge coverage, especially the sparse coverage over tropical continents, remains a serious concern.

Rotated principal component analysis (RPCA) with prefiltering of VMFC to isolate the artificial variability is used to investigate artifacts in five reanalysis systems. This procedure, although ad hoc, enables useful VMFC corrections over global land. The P − ET estimates from seven different LSMs are evaluated and subsequently used to confirm the efficacy of the RPCA-based adjustments. Global VMFC trends over the period 1979–2012 ranging from 0.07 to −0.03 mm day−1 decade−1 are reduced by the adjustments to 0.016 mm day−1 decade−1, much closer to the LSM P − ET estimate (0.007 mm day−1 decade−1). Neither is significant at the 90% level. ENSO-related modulation of VMFC and P − ET remains the largest global interannual signal, with mean LSM and adjusted reanalysis time series correlating at 0.86.

Corresponding author address: Franklin R. Robertson, NASA Marshall Space Flight Center, 320 Sparkman Dr., Huntsville, AL 35805. E-mail: pete.robertson@nasa.gov

Abstract

Vertically integrated atmospheric moisture transport from ocean to land [vertically integrated atmospheric moisture flux convergence (VMFC)] is a dynamic component of the global climate system but remains problematic in atmospheric reanalyses, with current estimates having significant multidecadal global trends differing even in sign. Continual evolution of the global observing system, particularly stepwise improvements in satellite observations, has introduced discrete changes in the ability of data assimilation to correct systematic model biases, manifesting as nonphysical variability. Land surface models (LSMs) forced with observed precipitation P and near-surface meteorology and radiation provide estimates of evapotranspiration (ET). Since variability of atmospheric moisture storage is small on interannual and longer time scales, VMFC = P − ET is a good approximation and LSMs can provide an alternative estimate. However, heterogeneous density of rain gauge coverage, especially the sparse coverage over tropical continents, remains a serious concern.

Rotated principal component analysis (RPCA) with prefiltering of VMFC to isolate the artificial variability is used to investigate artifacts in five reanalysis systems. This procedure, although ad hoc, enables useful VMFC corrections over global land. The P − ET estimates from seven different LSMs are evaluated and subsequently used to confirm the efficacy of the RPCA-based adjustments. Global VMFC trends over the period 1979–2012 ranging from 0.07 to −0.03 mm day−1 decade−1 are reduced by the adjustments to 0.016 mm day−1 decade−1, much closer to the LSM P − ET estimate (0.007 mm day−1 decade−1). Neither is significant at the 90% level. ENSO-related modulation of VMFC and P − ET remains the largest global interannual signal, with mean LSM and adjusted reanalysis time series correlating at 0.86.

Corresponding author address: Franklin R. Robertson, NASA Marshall Space Flight Center, 320 Sparkman Dr., Huntsville, AL 35805. E-mail: pete.robertson@nasa.gov
Save