Editorial Type:
Article
Article Type:
Research Article

Spatial and Temporal Variability of the Three-Dimensional Flow around African Easterly Waves

Alan Brammer Department of Atmospheric and Environmental Science, University at Albany, State University of New York, Albany, New York

Search for other papers by Alan Brammer in
Current site
Google Scholar
PubMed Close
and
Chris D. Thorncroft Department of Atmospheric and Environmental Science, University at Albany, State University of New York, Albany, New York

Search for other papers by Chris D. Thorncroft in
Current site
Google Scholar
PubMed Close
Print Publication:
01 Jul 2017
DOI:
https://doi.org/10.1175/MWR-D-16-0454.1
Page(s):
2879–2895
Restricted access

Abstract

This study presents a large-scale trajectory analysis of African easterly waves (AEWs) across West Africa and the eastern Atlantic. Back trajectories were initialized at multiple pressure levels from in and around the vortex center of the AEW troughs to reveal the source regions of environmental inflow. The trajectory analysis highlights a changing influence of environmental air on AEW troughs. Over West Africa, monsoonal flow dominates with source regions of air from the southwest and east to northeast influencing the trough. As the AEW troughs leave West Africa, flow from the northwest becomes increasingly important. Cluster analysis highlighted that the contribution of trajectories from the northwest increased as the AEW troughs move westward and that this cluster also had high variability in environmental characteristics.

Correlation analysis of outgoing longwave radiation around the troughs with environmental characteristics 72 h earlier was conducted on 443 AEWs. This analysis reveals that the impact of the various source regions on convective activity within the AEW troughs is consistent with the cluster trajectory analysis. While the AEW troughs were over West Africa, convection was sensitive to midlevel equivalent potential temperature around the trough and to the northeast of the trough axis. Over the West African coast and Cape Verde basin, the correlation analysis captures the changing flow regime with sensitivity to west of the trough axis at midlevels and northwest at low levels. These results highlight that the cool and dry low-level northerly trade winds over the Canary and Cape Verde basin can be a crucial influence on AEWs as they leave West Africa.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Alan Brammer, abrammer@albany.edu

Abstract

This study presents a large-scale trajectory analysis of African easterly waves (AEWs) across West Africa and the eastern Atlantic. Back trajectories were initialized at multiple pressure levels from in and around the vortex center of the AEW troughs to reveal the source regions of environmental inflow. The trajectory analysis highlights a changing influence of environmental air on AEW troughs. Over West Africa, monsoonal flow dominates with source regions of air from the southwest and east to northeast influencing the trough. As the AEW troughs leave West Africa, flow from the northwest becomes increasingly important. Cluster analysis highlighted that the contribution of trajectories from the northwest increased as the AEW troughs move westward and that this cluster also had high variability in environmental characteristics.

Correlation analysis of outgoing longwave radiation around the troughs with environmental characteristics 72 h earlier was conducted on 443 AEWs. This analysis reveals that the impact of the various source regions on convective activity within the AEW troughs is consistent with the cluster trajectory analysis. While the AEW troughs were over West Africa, convection was sensitive to midlevel equivalent potential temperature around the trough and to the northeast of the trough axis. Over the West African coast and Cape Verde basin, the correlation analysis captures the changing flow regime with sensitivity to west of the trough axis at midlevels and northwest at low levels. These results highlight that the cool and dry low-level northerly trade winds over the Canary and Cape Verde basin can be a crucial influence on AEWs as they leave West Africa.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Alan Brammer, abrammer@albany.edu
Save
Cover Monthly Weather Review
Monthly Weather Review

  • Berry, G. J., C. D. Thorncroft, and T. Hewson, 2007: African easterly waves during 2004—Analysis using objective techniques. Mon. Wea. Rev., 135, 1251–1267, doi:10.1175/MWR3343.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Brammer, A., and C. D. Thorncroft, 2015: Variability and evolution of African easterly wave structures and their relationship with tropical cyclogenesis over the eastern Atlantic. Mon. Wea. Rev., 143, 4975–4995, doi:10.1175/MWR-D-15-0106.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Braun, S. A., 2010: Reevaluating the role of the Saharan air layer in Atlantic tropical cyclogenesis and evolution. Mon. Wea. Rev., 138, 2007–2037, doi:10.1175/2009MWR3135.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Braun, S. A., J. A. Sippel, and D. S. Nolan, 2012: The impact of dry midlevel air on hurricane intensity in idealized simulations with no mean flow. J. Atmos. Sci., 69, 236–257, doi:10.1175/JAS-D-10-05007.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Bretherton, C. S., M. E. Peters, and L. E. Back, 2004: Relationships between water vapor path and precipitation over the tropical oceans. J. Climate, 17, 1517–1528, doi:10.1175/1520-0442(2004)017<1517:RBWVPA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Brown, D., R. Brownrigg, M. Haley, and W. Huang, 2014: NCAR Command Language (version 6.3.0). UCAR/NCAR/CISL/TDD, Boulder, CO, accessed 20 March 2015, doi:10.5065/D6WD3XH5.

    • Crossref
    • Export Citation

  • Burpee, R., 1972: The origin and structure of easterly waves in the lower troposphere of North Africa. J. Atmos. Sci., 29, 77–90, doi:10.1175/1520-0469(1972)029<0077:TOASOE>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Burpee, R., 1974: Characteristics of North African easterly waves during the summers of 1968 and 1969. J. Atmos. Sci., 31, 1556–1570, doi:10.1175/1520-0469(1974)031<1556:CONAEW>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Cape, J. N., J. Methven, and L. E. Hudson, 2000: The use of trajectory cluster analysis to interpret trace gas measurements at Mace Head, Ireland. Atmos. Environ., 34, 3651–3663, doi:10.1016/S1352-2310(00)00098-4.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Carlson, T. N., 1969: Synoptic histories of three African disturbances that developed into Atlantic hurricanes. Mon. Wea. Rev., 97, 256–276, doi:10.1175/1520-0493(1969)097<0256:SHOTAD>2.3.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Carlson, T. N., and J. M. Prospero, 1972: The large-scale movement of Saharan air outbreaks over the northern equatorial Atlantic. J. Appl. Meteor., 11, 283–297, doi:10.1175/1520-0450(1972)011<0283:TLSMOS>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Chauvin, F., R. Roehrig, and J.-P. Lafore, 2010: Intraseasonal variability of the Saharan heat low and its link with midlatitudes. J. Climate, 23, 2544–2561, doi:10.1175/2010JCLI3093.1.

    • Crossref
    • 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, 553–597, doi:10.1002/qj.828.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Deshpande, R. D., M. Dave, V. Padhya, H. Kumar, and S. K. Gupta, 2015: Water vapour source identification for daily rain events at Ahmedabad in semi-arid western India: Wind trajectory analyses. Meteor. Appl., 22, 754–762, doi:10.1002/met.1515.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Diedhiou, A., S. Janicot, A. Viltard, and P. De Felice, 2001: Composite patterns of easterly disturbances over West Africa and the tropical Atlantic: A climatology from the 1979–95 NCEP/NCAR reanalyses. Climate Dyn., 18, 241–253, doi:10.1007/s003820100173.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Dorling, S. R., T. D. Davies, and C. E. Pierce, 1992: Cluster analysis: A technique for estimating the synoptic meteorological controls on air and precipitation chemistry—Method and applications. Atmos. Environ., 26, 2575–2581, doi:10.1016/0960-1686(92)90110-7.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Draxler, R. R., and G. D. Hess, 1997: Description of the HYSPLIT_4 modeling system. NOAA Tech. Memo. ERL ARL-224, NOAA/Air Resources Laboratory, Silver Spring, MD, 27 pp. [Available online at https://www.arl.noaa.gov/documents/reports/arl-224.pdf.]

  • Draxler, R. R., and G. D. Hess, 1998: An overview of the HYSPLIT_4 modeling system for trajectories, dispersion, and deposition. Aust. Meteor. Mag., 47 (4), 295–308.

    • Search Google Scholar
    • Export Citation

  • Dunion, J. P., and C. S. Velden, 2004: The impact of the Saharan air layer on Atlantic tropical cyclone activity. Bull. Amer. Meteor. Soc., 85, 353–365, doi:10.1175/BAMS-85-3-353.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Dunkerton, T., M. Montgomery, and Z. Wang, 2009: Tropical cyclogenesis in a tropical wave critical layer: Easterly waves. Atmos. Chem. Phys., 9, 5587–5646, doi:10.5194/acp-9-5587-2009.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Duvel, J.-P., 1990: Convection over tropical Africa and the Atlantic Ocean during northern summer. Part II: Modulation by easterly waves. Mon. Wea. Rev., 118, 1855–1868, doi:10.1175/1520-0493(1990)118<1855:COTAAT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Ersek, V., A. C. Mix, and P. U. Clark, 2010: Variations of δ18O in rainwater from southwestern Oregon. J. Geophys. Res., 115, D09109, doi:10.1029/2009JD013345.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Fink, A. H., and A. Reiner, 2003: Spatiotemporal variability of the relation between African easterly waves and West African squall lines in 1998 and 1999. J. Geophys. Res., 108, 4332, doi:10.1029/2002JD002816.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Fink, A. H., D. G. Vincent, P. M. Reiner, and P. Speth, 2004: Mean state and wave disturbances during phases I, II, and III of GATE based on ERA-40. Mon. Wea. Rev., 132, 1661–1683, doi:10.1175/1520-0493(2004)132<1661:MSAWDD>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Frank, N. L., 1969: The “inverted V” cloud pattern—An easterly wave? Mon. Wea. Rev., 97, 130–140, doi:10.1175/1520-0493(1969)097<0130:TVCPEW>2.3.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Fritz, C., and Z. Wang, 2013: A numerical study of the impacts of dry air on tropical cyclone formation: A development case and a nondevelopment case. J. Atmos. Sci., 70, 91–111, doi:10.1175/JAS-D-12-018.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Fuhlbrügge, S., K. Krüger, B. Quack, E. Atlas, H. Hepach, and F. Ziska, 2013: Impact of the marine atmospheric boundary layer conditions on VSLS abundances in the eastern tropical and subtropical North Atlantic Ocean. Atmos. Chem. Phys., 13, 6345–6357, doi:10.5194/acp-13-6345-2013.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Galarneau, T. J., Jr., L. F. Bosart, and R. S. Schumacher, 2010: Predecessor rain events ahead of tropical cyclones. Mon. Wea. Rev., 138, 3272–3297, doi:10.1175/2010MWR3243.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Gu, G., R. F. Adler, G. J. Huffman, and S. Curtis, 2004: African easterly waves and their association with precipitation. J. Geophys. Res., 109, D04101, doi:10.1029/2003JD003967.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Harris, J. M., and J. D. Kahl, 1990: A descriptive atmospheric transport climatology for the Mauna Loa Observatory, using clustered trajectories. J. Geophys. Res., 95, 13 651–13 667, doi:10.1029/JD095iD09p13651.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Harris, J. M., R. R. Draxler, and S. J. Oltmans, 2005: Trajectory model sensitivity to differences in input data and vertical transport method. J. Geophys. Res., 110, D14109, doi:10.1029/2004JD005750.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Huffman, G. J., and Coauthors, 2007: The TRMM Multisatellite Precipitation Analysis (TMPA): Quasi-global, multiyear, combined-sensor precipitation estimates at fine scales. J. Hydrometeor., 8, 38–55, doi:10.1175/JHM560.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Janiga, M. A., and C. D. Thorncroft, 2013: Regional differences in the kinematic and thermodynamic structure of African easterly waves. Quart. J. Roy. Meteor. Soc., 139, 1598–1614, doi:10.1002/qj.2047.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Janiga, M. A., and C. D. Thorncroft, 2016: The influence of African easterly waves on convection over tropical Africa and the east Atlantic. Mon. Wea. Rev., 144, 171–192, doi:10.1175/MWR-D-14-00419.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Karyampudi, V. M., and T. N. Carlson, 1988: Analysis and numerical simulations of the Saharan air layer and its effect on easterly wave disturbances. J. Atmos. Sci., 45, 3102–3136, doi:10.1175/1520-0469(1988)045<3102:AANSOT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Kassomenos, P., S. Vardoulakis, R. Borge, J. Lumbreras, C. Papaloukas, and S. Karakitsios, 2010: Comparison of statistical clustering techniques for the classification of modelled atmospheric trajectories. Theor. Appl. Climatol., 102, 1–12, doi:10.1007/s00704-009-0233-7.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Kiladis, G. N., C. D. Thorncroft, and N. M. J. Hall, 2006: Three-dimensional structure and dynamics of African easterly waves. Part I: Observations. J. Atmos. Sci., 63, 2212–2230, doi:10.1175/JAS3741.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Lee, H.-T., 2011: NOAA climate data record (CDR) of daily outgoing longwave radiation (OLR). NOAA/National Climatic Data Center, NOAA CDR Program, accessed 1 July 2016, doi:10.7289/V5SJ1HH2.

    • Crossref
    • Export Citation

  • Lee, H.-T., C. J. Schreck III, and K. R. Knapp, 2014: Generation of the daily OLR climate data record. Proc. EUMETSAT Meteorological Satellite Conf., Geneva, Switzerland, EUMETSAT. [Available online at http://olr.umd.edu/References/Lee_2014_Generation_of_Daily_OLR_CDR_Eumetsat_Sep2014.pdf.]

  • Lee, J. D., and Coauthors, 2010: Reactive Halogens in the Marine Boundary Layer (RHaMBLe): The tropical North Atlantic experiments. Atmos. Chem. Phys., 10, 1031–1055, doi:10.5194/acp-10-1031-2010 .

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Lélé, M. I., L. M. Leslie, and P. J. Lamb, 2015: Analysis of low-level atmospheric moisture transport associated with the West African monsoon. J. Climate, 28, 4414–4430, doi:10.1175/JCLI-D-14-00746.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • MacQueen, J., 1967: Some methods for classification and analysis of multivariate observations. Statistics, L. M. Le Cam and J. Neyman, Eds., Vol. 1, Proceedings of the Fifth Berkeley Symposium on Mathematical Statistics and Probability, University of California Press, 281–297.

  • Merrill, J. T., R. Bleck, and L. Avila, 1985: Modeling atmospheric transport to the Marshall Islands. J. Geophys. Res., 90, 12 927–12 936, doi:10.1029/JD090iD07p12927.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Moody, J. L., and J. N. Galloway, 1988: Quantifying the relationship between atmospheric transport and the chemical composition of precipitation on Bermuda. Tellus, 40B, 463–479, doi:10.3402/tellusb.v40i5.16014.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Payne, S. W., and M. M. McGarry, 1977: The relationship of satellite inferred convective activity to easterly waves over West Africa and the adjacent ocean during phase III of GATE. Mon. Wea. Rev., 105, 413–420, doi:10.1175/1520-0493(1977)105<0413:TROSIC>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Pierrehumbert, R. T., and R. Roca, 1998: Evidence for control of Atlantic subtropical humidity by large scale advection. Geophys. Res. Lett., 25, 4537–4540, doi:10.1029/1998GL900203.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Poan, D. E., R. Roehrig, F. Couvreux, and J.-P. Lafore, 2013: West African monsoon intraseasonal variability: A precipitable water perspective. J. Atmos. Sci., 70, 1035–1052, doi:10.1175/JAS-D-12-087.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Prospero, J. M., and T. N. Carlson, 1972: Vertical and areal distribution of Saharan dust over the western equatorial North Atlantic Ocean. J. Geophys. Res., 77, 5255–5265, doi:10.1029/JC077i027p05255.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Reale, O., K. M. Lau, A. Silva, and T. Matsui, 2014: Impact of assimilated and interactive aerosol on tropical cyclogenesis. Geophys. Res. Lett., 41, 3282–3288, doi:10.1002/2014GL059918.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Reed, R. J., D. C. Norquist, and E. E. Recker, 1977: The structure and properties of African wave disturbances as observed during phase III of GATE. Mon. Wea. Rev., 105, 317–333, doi:10.1175/1520-0493(1977)105<0317:TSAPOA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Riemer, M., and M. T. Montgomery, 2011: Simple kinematic models for the environmental interaction of tropical cyclones in vertical wind shear. Atmos. Chem. Phys., 11, 9395–9414, doi:10.5194/acp-11-9395-2011.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Rios-Berrios, R., R. D. Torn, and C. A. Davis, 2016: An ensemble approach to investigate tropical cyclone intensification in sheared environments. Part I: Katia (2011). J. Atmos. Sci., 73, 71–93, doi:10.1175/JAS-D-15-0052.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Roberts, A. J., J. H. Marsham, and P. Knippertz, 2015: Disagreements in low-level moisture between (re)analyses over summertime West Africa. Mon. Wea. Rev., 143, 1193–1211, doi:10.1175/MWR-D-14-00218.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Roca, R., J. P. Lafore, C. Piriou, and J.-L. Redelsperger, 2005: Extratropical dry-air intrusions into the West African monsoon midtroposphere: An important factor for the convective activity over the Sahel. J. Atmos. Sci., 62, 390–407, doi:10.1175/JAS-3366.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Saha, S., and Coauthors, 2010: The NCEP Climate Forecast System Reanalysis. Bull. Amer. Meteor. Soc., 91, 1015–1057, doi:10.1175/2010BAMS3001.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Saha, S., and Coauthors, 2014: The NCEP Climate Forecast System version 2. J. Climate, 27, 2185–2208, doi:10.1175/JCLI-D-12-00823.1.

  • Schenkel, B. A., and R. E. Hart, 2015: An analysis of the environmental moisture impacts of western North Pacific tropical cyclones. J. Climate, 28, 2600–2622, doi:10.1175/JCLI-D-14-00213.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Schwendike, J., S. C. Jones, B. Vogel, and H. Vogel, 2016: Mineral dust transport toward Hurricane Helene (2006). J. Geophys. Res. Atmos., 121, 5538–5566, doi:10.1002/2015JD024708.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Sjostrom, D. J., and J. M. Welker, 2009: The influence of air mass source on the seasonal isotopic composition of precipitation, eastern USA. J. Geochem. Explor., 102, 103–112, doi:10.1016/j.gexplo.2009.03.001.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Stein, A. F., R. R. Draxler, G. D. Rolph, B. B. Stunder, M. D. Cohen, and F. F. Ngan, 2015: NOAA’s HYSPLIT Atmospheric Transport and Dispersion Modeling System. Bull. Amer. Meteor. Soc., 96, 2059–2077, doi:10.1175/BAMS-D-14-00110.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Stohl, A., and P. Seibert, 1998: Accuracy of trajectories as determined from the conservation of meteorological tracers. Quart. J. Roy. Meteor. Soc., 124, 1465–1484, doi:10.1002/qj.49712454907.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Stohl, A., G. Wotawa, P. Seibert, and H. Kromp-Kolb, 1995: Interpolation errors in wind fields as a function of spatial and temporal resolution and their impact on different types of kinematic trajectories. J. Appl. Meteor., 34, 2149–2165, doi:10.1175/1520-0450(1995)034<2149:IEIWFA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Thompson, R. M., S. W. Payne, E. E. Recker, and R. J. Reed, 1979: Structure and properties of synoptic-scale wave disturbances in the intertropical convergence zone of the eastern Atlantic. J. Atmos. Sci., 36, 53–72, doi:10.1175/1520-0469(1979)036<0053:SAPOSS>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Thorncroft, C. D., and B. J. Hoskins, 1994: An idealized study of African easterly waves. I: A linear view. Quart. J. Roy. Meteor. Soc., 120, 953–982, doi:10.1002/qj.49712051809.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Thorncroft, C. D., H. Nguyen, C. Zhang, and P. Peyrillé, 2011: Annual cycle of the West African monsoon: Regional circulations and associated water vapour transport. Quart. J. Roy. Meteor. Soc., 137, 129–147, doi:10.1002/qj.728.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Wang, Z., and I. Hankes, 2014: Characteristics of tropical easterly wave pouches during tropical cyclone formation. Mon. Wea. Rev., 142, 626–633, doi:10.1175/MWR-D-13-00267.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Wang, Z., M. T. Montgomery, and T. Dunkerton, 2010: Genesis of Pre–Hurricane Felix (2007). Part I: The role of the easterly wave critical layer. J. Atmos. Sci., 67, 1711–1729, doi:10.1175/2009JAS3420.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Wilks, D. S., 2006: On “field significance” and the false discovery rate. J. Appl. Meteor. Climatol., 45, 1181–1189, doi:10.1175/JAM2404.1.

  • Witten, D. M., and R. Tibshirani, 2010: A framework for feature selection in clustering. J. Amer. Stat. Assoc., 105, 713–726, doi:10.1198/jasa.2010.tm09415.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 2096 1677 480
PDF Downloads 391 133 5