Climate Dynamics

, Volume 29, Issue 4, pp 411–422 | Cite as

Variability of the Caribbean Low-Level Jet and its relations to climate

Article

Abstract

A maximum of easterly zonal wind at 925 hPa in the Caribbean region is called the Caribbean Low-Level Jet (CLLJ). Observations show that the easterly CLLJ varies semi-annually, with two maxima in the summer and winter and two minima in the fall and spring. Associated with the summertime strong CLLJ are a maximum of sea level pressure (SLP), a relative minimum of rainfall (the mid-summer drought), and a minimum of tropical cyclogenesis in July in the Caribbean Sea. It is found that both the meridional gradients of sea surface temperature (SST) and SLP show a semi-annual feature, consistent with the semi-annual variation of the CLLJ. The CLLJ anomalies vary with the Caribbean SLP anomalies that are connected to the variation of the North Atlantic Subtropical High (NASH). In association with the cold (warm) Caribbean SST anomalies, the atmosphere shows the high (low) SLP anomalies near the Caribbean region that are consistent with the anomalously strong (weak) easterly CLLJ. The CLLJ is also remotely related to the SST anomalies in the Pacific and Atlantic, reflecting that these SST variations affect the NASH. During the winter, warm (cold) SST anomalies in the tropical Pacific correspond to a weak (strong) easterly CLLJ. However, this relationship is reversed during the summer. This is because the effects of ENSO on the NASH are opposite during the winter and summer. The CLLJ varies in phase with the North Atlantic Oscillation (NAO) since a strong (weak) NASH is associated with a strengthening (weakening) of both the CLLJ and the NAO. The CLLJ is positively correlated with the 925-hPa meridional wind anomalies from the ocean to the United States via the Gulf of Mexico. Thus, the CLLJ and the meridional wind carry moisture from the ocean to the central United States, usually resulting in an opposite (or dipole) rainfall pattern in the tropical North Atlantic Ocean and Atlantic warm pool versus the central United States.

Keywords

Tropical Cyclone Wind Anomaly North Atlantic Subtropical High Atlantic Warm Pool North Pacific Subtropical High 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgments

I thank Mr Jay Harris for downloading the data used in this study. Dr Sang-ki Lee assists with Fig. 1 and calculates the significance test of the semi-annual feature of the CLLJ. Comments by Dr German Poveda, an anonymous reviewer, and the Editor (Dr Edwin Schneider) are appreciated. This work was supported by a grant from National Oceanic and Atmospheric Administration (NOAA) Climate Program Office and by the base funding of NOAA Atlantic Oceanographic and Meteorological Laboratory. The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the funding agency.

References

  1. Adler RF, et al (2003) The version-2 global precipitation climatology project (GPCP) monthly precipitation analysis (1979-present). J Hydrometeorol 4:1147–1167CrossRefGoogle Scholar
  2. Amador JA (1998) A climatic feature of the tropical Americas: The trade wind easterly jet. Top Meteor Oceanogr 5(2):1–13Google Scholar
  3. Amador JA, Magana V (1999) Dynamics of the low level jet over the Caribbean Sea. Preprints, the 23rd conference on hurricanes and tropical meteorology, American Meteorological Society, Dallas, pp 868–869Google Scholar
  4. Bosilovich MG, Schubert SD (2002) Water vapor tracers as diagnostics of the regional hydrologic cycle. J Hydrometeorol 3:149–165CrossRefGoogle Scholar
  5. Brubaker KL, Dirmeyer PA, Sudradjat A, Levy B, Bernal F (2001) A 36-yr climatological description of the evaporative sources of warm season precipitation in the Mississippi river basin. J Hydrometeorol 2:537–557CrossRefGoogle Scholar
  6. Emery WJ, Thomson RE (1997) Data analysis methods in physical oceanography. Elsevier, Amsterdam, p 638Google Scholar
  7. Enfield DB, Mayer DA (1997) Tropical Atlantic sea surface temperature variability and its relation to El Niño-Southern Oscillation. J Geophys Res 102:929–945CrossRefGoogle Scholar
  8. Gill AE (1980) Some simple solutions for heat-induced tropical circulation. Q J R Meteorol Soc 106:447–462CrossRefGoogle Scholar
  9. Gray WM (1984) Atlantic seasonal hurricanes frequency. Part II: forecasting its variability. M Weather Rev 112:1669–1683CrossRefGoogle Scholar
  10. Hu Q, Feng S (2001) Climate role of the southerly flow from the Gulf of Mexico in interannual variations in summer rainfall in the Central United States. J Clim 14:3156–3170CrossRefGoogle Scholar
  11. Hurrel JM (1995) Decadal trends in the North Atlantic Oscillation: regional temperature and precipitation. Science 269:676–679CrossRefGoogle Scholar
  12. Inoue M, Handoh IC, Bigg GR (2002) Bimodal distribution of tropical cyclogenesis in the Caribbean: characteristics and environmental factors. J Clim 15:2897–2905CrossRefGoogle Scholar
  13. Kalnay E, et al (1996) The NCEP/NCAR 40-year reanalysis project. Bull Am Meteorol Soc 77:437–471CrossRefGoogle Scholar
  14. Lindzen RS, Nigam S (1987) On the role of sea surface temperature gradients in forcing low-level winds and convergence in the Tropics. J Atmos Sci 44:2418–2436CrossRefGoogle Scholar
  15. Magaña V, Amador JA, Medina S (1999) The midsummer drought over Mexico and central America. J. Clim 12:1577–1588CrossRefGoogle Scholar
  16. Mapes BE, Liu P, Buenning N (2005) Indian monsoon onset and the Americas midsummer drought: out-of-equilibrium response to smooth seasonal forcing. J Clim 18:1109–1115CrossRefGoogle Scholar
  17. Mestas-Nunez AM, Zhang C, Enfield DB (2005) Uncertainties in estimating moisture fluxes over the Intra-Americas Sea. J Hydrometeorol 6:696–709CrossRefGoogle Scholar
  18. Mo KC, Higgins RW (1996) Large-scale atmospheric water vapor transport as evaluated from the NCEP/NCAR and the NASA/DOA reanalyses. J Clim 9:1531–1545CrossRefGoogle Scholar
  19. Mo KC, Chelliah M, Carrera ML, Higgins RW, Ebisuzaki W (2005) Atmospheric moisture transport over the United States and Mexico as evaluated in the NCEP regional reanalysis. J Hydrometeorol 6:710–728CrossRefGoogle Scholar
  20. Poveda G, Mesa OJ (1999) The low level westerly jet (Choco jet) and two other jets in Colombia: climatology and variability during ENSO phases (in Spanish). Rev Academia Colomb Cienc 23(89):517–528Google Scholar
  21. Poveda G, Waylen PR, Pulwarty RS (2006) Annual and interannual variability of the present climate in northern South America and southern Mesoamerica. Palaeogeogr Palaeoclimatol Palaeoecol 234:3–27CrossRefGoogle Scholar
  22. Rasmusson EM (1967) Atmospheric water vapor transport and the water balance of North America: part I. Characteristics of the water vapor flux field. M Weather Rev 95:403–426CrossRefGoogle Scholar
  23. Shay LK, Goni GJ, Black PG (2000) Effects of a warm oceanic feature on Hurricane Opal. M Wea Rev 128:1366–1383CrossRefGoogle Scholar
  24. Smith TM, Reynolds RW (2004) Improved extended reconstruction of SST (1854–1997). J Clim 17:2466–2477CrossRefGoogle Scholar
  25. Wang C, Enfield DB (2001) The tropical Western Hemisphere warm pool. Geophys Res Lett 28:1635–1638CrossRefGoogle Scholar
  26. Wang C, Enfield DB (2003) A further study of the tropical Western Hemisphere warm pool. J Clim 16:1476–1493Google Scholar
  27. Wang C, Lee SK (2007) Atlantic warm pool, Caribbean low-level jet and their potential impact on Atlantic hurricanes. Geophys Res Lett 34:L02703. doi:10.1029/2006GL028579Google Scholar
  28. Wang C, Enfield DB, Lee SK, Landsea CW (2006) Influences of the Atlantic warm pool on Western Hemisphere summer rainfall and Atlantic hurricanes. J Clim 19:3011–3028CrossRefGoogle Scholar
  29. Wang C, Lee SK, Enfield DB (2007) Impact of the Atlantic warm pool on the summer climate of the Western Hemisphere. J Clim 20 (in press)Google Scholar
  30. Xie P, Arkin PA (1997) Global precipitation: a 17-year monthly analysis based on gauge observations, satellite estimates, and numerical model outputs. Bull Am Meteorol Soc 78:2539–2558CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Physical Oceanography DivisionNOAA Atlantic Oceanographic and Meteorological LaboratoryMiamiUSA

Personalised recommendations