• Alexander, M. A., , and J. D. Scott, 1997: Surface flux variability over the North Pacific and North Atlantic Oceans. J. Climate, 10, 29632978, doi:10.1175/1520-0442(1997)010<2963:SFVOTN>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Barsugli, J. J., , and D. S. Battisti, 1998: The basic effects of atmosphere–ocean thermal coupling on midlatitude variability. J. Atmos. Sci., 55, 477493, doi:10.1175/1520-0469(1998)055<0477:TBEOAO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Bhat, G. S., 2001: Near surface atmospheric characteristics over the north Bay of Bengal during the Indian summer monsoon. Geophys. Res. Lett., 28, 987990, doi:10.1029/2000GL012455.

    • Search Google Scholar
    • Export Citation
  • Bhat, G. S., , and H. J. S. Fernando, 2016: Remotely driven anomalous sea–air heat flux over the north Indian Ocean during the summer monsoon season. Oceanography, 29 (2), 232241, doi:10.5670/oceanog.2016.55.

    • Search Google Scholar
    • Export Citation
  • Bhat, G. S., and et al. , 2001: BOBMEX: The Bay of Bengal Monsoon Experiment. Bull. Amer. Meteor. Soc., 82, 22172243, doi:10.1175/1520-0477(2001)082<2217:BTBOBM>2.3.CO;2.

    • Search Google Scholar
    • Export Citation
  • De Boyer Montégut, C., , J. Vialard, , S. S. C. Shenoi, , D. Shankar, , F. Durand, , C. Ethé, , and G. Madec, 2007: Simulated seasonal and interannual variability of the mixed layer heat budget in the northern Indian Ocean. J. Climate, 20, 32493268, doi:10.1175/JCLI4148.1.

    • Search Google Scholar
    • Export Citation
  • DiNezio, P. N., , A. C. Clement, , G. A. Vecchi, , B. J. Soden, , B. P. Kirtman, , and S.-K. Lee, 2009: Climate response of the equatorial Pacific to global warming. J. Climate, 22, 48734892, doi:10.1175/2009JCLI2982.1.

    • Search Google Scholar
    • Export Citation
  • Fairall, C. W., , E. F. Bradley, , D. P. Rogers, , J. B. Edson, , and G. S. Young, 1996: Bulk parameterization of air–sea fluxes for Tropical Ocean-Global Atmosphere Coupled-Ocean Atmosphere Response Experiment. J. Geophys. Res., 101, 37473764, doi:10.1029/95JC03205.

    • Search Google Scholar
    • Export Citation
  • Fairall, C. W., , E. F. Bradley, , J. E. Hare, , A. A. Grachev, , and J. B. Edson, 2003: Bulk parameterization of air–sea fluxes: Updates and verification for the COARE algorithm. J. Climate, 16, 571591, doi:10.1175/1520-0442(2003)016<0571:BPOASF>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Frankignoul, C., , and K. Hasselmann, 1977: Stochastic climate models, Part II: Application to sea-surface temperature anomalies and thermocline variability. Tellus, 29A, 289305, doi:10.1111/j.2153-3490.1977.tb00740.x.

    • Search Google Scholar
    • Export Citation
  • Gao, S., , L. S. Chiu, , and C.-L. Shie, 2013: Trends and variations of ocean surface latent heat flux: Results from GSSTF2c data set. Geophys. Res. Lett., 40, 380385, doi:10.1029/2012GL054620.

    • Search Google Scholar
    • Export Citation
  • Kalnay, E., and et al. , 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
  • Levitus, S., , J. I. Antonov, , T. P. Boyer, , and C. Stephens, 2000: Warming of the World Ocean. Science, 287, 22252229, doi:10.1126/science.287.5461.2225.

    • Search Google Scholar
    • Export Citation
  • Liu, W. T., 1988: Moisture and latent heat flux variabilities in the tropical Pacific derived from satellite data. J. Geophys. Res., 93, 67496760, doi:10.1029/JC093iC06p06749.

    • Search Google Scholar
    • Export Citation
  • Muller-Karger, F. E., and et al. , 2015: Natural variability of surface oceanographic conditions in the offshore Gulf of Mexico. Prog. Oceanogr., 134, 5476, doi:10.1016/j.pocean.2014.12.007.

    • Search Google Scholar
    • Export Citation
  • Neelin, J. D., , and I. M. Held, 1987: Modeling tropical convergence based on the moist static energy budget. Mon. Wea. Rev., 115, 312, doi:10.1175/1520-0493(1987)115<0003:MTCBOT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Nisha, P. G., , P. M. Muraleedharan, , M. G. Keerthi, , P. V. Sathe, , and M. Ravichandran, 2012: Does sea level pressure modulate the dynamic and thermodynamic forcing in the tropical Indian Ocean? Int. J. Remote Sens., 33, 19912002, doi:10.1080/01431161.2011.604653.

    • Search Google Scholar
    • Export Citation
  • Ramanathan, V., , and W. Collins, 1992: Thermostat and global warming. Nature, 357, 649, doi:10.1038/357649a0.

  • Schott, F. A., , S.-P. Xie, , and J. P. McCreary Jr., 2009: Indian Ocean circulation and climate variability. Rev. Geophys., 47, RG1002, doi:10.1029/2007RG000245.

    • Search Google Scholar
    • Export Citation
  • Seager, R., , R. Murtugudde, , A. Clement, , and C. Herweijer, 2003: Why is there an evaporation minimum at the equator? J. Climate, 16, 37933802, doi:10.1175/1520-0442(2003)016<3793:WITAEM>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Sengupta, D., , S. R. Parampil, , G. S. Bhat, , V. S. N. Murty, , V. R. Babu, , T. Sudhakar, , K. Premkumar, , and Y. Pradhan, 2008: Warm pool thermodynamics from the Arabian Sea Monsoon Experiment (ARMEX). J. Geophys. Res., 113, C10008, doi:10.1029/2007JC004623.

    • Search Google Scholar
    • Export Citation
  • Sobel, A. H., 2003: On the coexistence of an evaporation minimum and precipitation maximum in the warm pool. J. Climate, 16, 10031009, doi:10.1175/1520-0442(2003)016<1003:OTCOAE>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Sui, C.-H., , K.-M. Lau, , and A. K. Betts, 1991: An equilibrium model for the coupled ocean–atmosphere boundary layer in the tropics. J. Geophys. Res., 96, 31513163, doi:10.1029/90JC01776.

    • Search Google Scholar
    • Export Citation
  • Taylor, C. M., , R. J. Ellis, , D. J. Parker, , R. R. Burton, , and C. D. Thorncroft, 2003: Linking boundary-layer variability with convection: A case-study from JET2000. Quart. J. Roy. Meteor. Soc., 129, 22332253, doi:10.1256/qj.02.134.

    • Search Google Scholar
    • Export Citation
  • Wallace, J. M., 1992: Effect of deep convection on the regulation of tropical sea surface temperature. Nature, 357, 230231, doi:10.1038/357230a0.

    • Search Google Scholar
    • Export Citation
  • Wu, R., , B. P. Kirtman, , and K. Pegion, 2006: Local air–sea relationship in observations and model simulations. J. Climate, 19, 49144932, doi:10.1175/JCLI3904.1.

    • Search Google Scholar
    • Export Citation
  • Wu, R., , B. P. Kirtman, , and K. Pegion, 2007: Surface latent heat flux and its relationship with sea surface temperature in the National Centers for Environmental Prediction Climate Forecast System simulations and retrospective forecasts. Geophys. Res. Lett., 34, L17712, doi:10.1029/2007GL030751.

    • Search Google Scholar
    • Export Citation
  • Xie, S.-P., , and S. G. H. Philander, 1994: A coupled ocean–atmosphere model of relevance to the ITCZ in the eastern Pacific. Tellus, 46A, 340350, doi:10.1034/j.1600-0870.1994.t01-1-00001.x.

    • Search Google Scholar
    • Export Citation
  • Yu, L., , X. Jin, , and R. A. Weller, 2007: Annual, seasonal, and interannual variability of air–sea heat fluxes in the Indian Ocean. J. Climate, 20, 31903209, doi:10.1175/JCLI4163.1.

    • Search Google Scholar
    • Export Citation
  • Zhang, G. J., , and M. J. McPhaden, 1995: The relationship between sea surface temperature and latent heat flux in the equatorial Pacific. J. Climate, 8, 589605, doi:10.1175/1520-0442(1995)008<0589:TRBSST>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Zhang, G. J., , V. Ramanathan, , and M. J. McPhaden, 1995: Convection–evaporation feedback in the equatorial Pacific. J. Climate, 8, 30403051, doi:10.1175/1520-0442(1995)008<3040:CEFITE>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
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Latent Heat Flux Sensitivity to Sea Surface Temperature: Regional Perspectives

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  • 1 ESSO Indian National Centre for Ocean Information Services, Hyderabad, India
  • | 2 NOAA/Pacific Marine Environmental Laboratory, Seattle, Washington
  • | 3 ESSO Indian National Centre for Ocean Information Services, Hyderabad, India
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Abstract

A global analysis of latent heat flux (LHF) sensitivity to sea surface temperature (SST) is performed, with focus on the tropics and the north Indian Ocean (NIO). Sensitivity of LHF state variables (surface wind speed Ws and vertical humidity gradients Δq) to SST give rise to mutually interacting dynamical (Ws driven) and thermodynamical (Δq driven) coupled feedbacks. Generally, LHF sensitivity to SST is pronounced over tropics where SST increase causes Wsq) changes, resulting in a maximum decrease (increase) of LHF by ~15 W m−2 (°C)−1. But the Bay of Bengal (BoB) and north Arabian Sea (NAS) remain an exception that is opposite to the global feedback relationship. This uniqueness is attributed to strong seasonality in monsoon Ws and Δq variations, which brings in warm (cold) continental air mass into the BoB and NAS during summer (winter), producing a large seasonal cycle in air–sea temperature difference ΔT (and hence in Δq). In other tropical oceans, surface air is mostly of marine origin and blows from colder to warmer waters, resulting in a constant ΔT ~ 1°C throughout the year, and hence a constant Δq. Thus, unlike other basins, when the BoB and NAS are warming, air temperature warms faster than SST. The resultant decrease in ΔT and Δq contributes to decrease the LHF with increased SST, contrary to other basins. This analysis suggests that, in the NIO, LHF variability is largely controlled by thermodynamic processes, which peak during the monsoon period. These observed LHF sensitivities are then used to speculate how the surface energetics and coupled feedbacks may change in a warmer world.

Indian National Centre for Ocean Information Services Contribution Number 265 and Pacific Marine Environmental Laboratory Contribution Number 4463.

Corresponding author address: B. Praveen Kumar, Modelling and Ocean Observations Group, Indian National Centre for Ocean Information Services, Ocean Valley, Pragathi Nagar, Nizampet, Hyderabad, Telangana 500090, India. E-mail: praveen.b@incois.gov.in

Abstract

A global analysis of latent heat flux (LHF) sensitivity to sea surface temperature (SST) is performed, with focus on the tropics and the north Indian Ocean (NIO). Sensitivity of LHF state variables (surface wind speed Ws and vertical humidity gradients Δq) to SST give rise to mutually interacting dynamical (Ws driven) and thermodynamical (Δq driven) coupled feedbacks. Generally, LHF sensitivity to SST is pronounced over tropics where SST increase causes Wsq) changes, resulting in a maximum decrease (increase) of LHF by ~15 W m−2 (°C)−1. But the Bay of Bengal (BoB) and north Arabian Sea (NAS) remain an exception that is opposite to the global feedback relationship. This uniqueness is attributed to strong seasonality in monsoon Ws and Δq variations, which brings in warm (cold) continental air mass into the BoB and NAS during summer (winter), producing a large seasonal cycle in air–sea temperature difference ΔT (and hence in Δq). In other tropical oceans, surface air is mostly of marine origin and blows from colder to warmer waters, resulting in a constant ΔT ~ 1°C throughout the year, and hence a constant Δq. Thus, unlike other basins, when the BoB and NAS are warming, air temperature warms faster than SST. The resultant decrease in ΔT and Δq contributes to decrease the LHF with increased SST, contrary to other basins. This analysis suggests that, in the NIO, LHF variability is largely controlled by thermodynamic processes, which peak during the monsoon period. These observed LHF sensitivities are then used to speculate how the surface energetics and coupled feedbacks may change in a warmer world.

Indian National Centre for Ocean Information Services Contribution Number 265 and Pacific Marine Environmental Laboratory Contribution Number 4463.

Corresponding author address: B. Praveen Kumar, Modelling and Ocean Observations Group, Indian National Centre for Ocean Information Services, Ocean Valley, Pragathi Nagar, Nizampet, Hyderabad, Telangana 500090, India. E-mail: praveen.b@incois.gov.in
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