Editorial Type:
Article
Article Type:
Research Article

The Santa Cruz Eddy. Part I: Observations and Statistics

Cristina L. Archer Stanford University, Stanford, California

Search for other papers by Cristina L. Archer in
Current site
Google Scholar
PubMed Close
,
Mark Z. Jacobson Stanford University, Stanford, California

Search for other papers by Mark Z. Jacobson in
Current site
Google Scholar
PubMed Close
, and
Francis L. Ludwig Stanford University, Stanford, California

Search for other papers by Francis L. Ludwig in
Current site
Google Scholar
PubMed Close
Print Publication:
01 Apr 2005
DOI:
https://doi.org/10.1175/MWR2885.1
Page(s):
767–782
Restricted access

We are aware of a technical issue preventing figures and tables from showing in some newly published articles in the full-text HTML view.
While we are resolving the problem, please use the online PDF version of these articles to view figures and tables.

Abstract

A shallow cyclonic circulation that occurs in the summertime over the Monterey Bay (California) is investigated. Since it is often centered offshore from the city of Santa Cruz and has never been studied in detail before, it is named the Santa Cruz eddy (SCE) in this study. Its horizontal size is 10–40 km, and its vertical extent is 100–500 m. The SCE is important for local weather because it causes surface winds along the Santa Cruz coast to blow from the east instead of from the northwest, the latter being the climatological summer pattern for this area. As a consequence of the eddy, cool and moist air is advected from the south and southeast into the Santa Cruz area, bringing both relief from the heat and fog to the city.

The SCE is unique in its high frequency of occurrence. Most vortices along the western American coast form only during unusual weather events, whereas the SCE forms 78%–79% of the days during the summer. The SCE frequency was determined after analyzing two years of data with empirical orthogonal functions (EOFs) from a limited observational network and satellite imagery. An explanation of the formation mechanism of the SCE will be provided in Part II of this study.

Corresponding author address: Cristina L. Archer, Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305. Email: lozej@stanford.edu

Abstract

A shallow cyclonic circulation that occurs in the summertime over the Monterey Bay (California) is investigated. Since it is often centered offshore from the city of Santa Cruz and has never been studied in detail before, it is named the Santa Cruz eddy (SCE) in this study. Its horizontal size is 10–40 km, and its vertical extent is 100–500 m. The SCE is important for local weather because it causes surface winds along the Santa Cruz coast to blow from the east instead of from the northwest, the latter being the climatological summer pattern for this area. As a consequence of the eddy, cool and moist air is advected from the south and southeast into the Santa Cruz area, bringing both relief from the heat and fog to the city.

The SCE is unique in its high frequency of occurrence. Most vortices along the western American coast form only during unusual weather events, whereas the SCE forms 78%–79% of the days during the summer. The SCE frequency was determined after analyzing two years of data with empirical orthogonal functions (EOFs) from a limited observational network and satellite imagery. An explanation of the formation mechanism of the SCE will be provided in Part II of this study.

Corresponding author address: Cristina L. Archer, Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305. Email: lozej@stanford.edu

Save
Cover Monthly Weather Review
Monthly Weather Review

  • Abbs, D. J., 1986: Sea-breeze interactions along a concave coastline in southern Australia: Observations and numerical modeling study. Mon. Wea. Rev., 114 , 831–848.

    • Search Google Scholar
    • Export Citation

  • Alpert, T., M. Tzidulko, and D. Iziksohn, 1999: A shallow, short-lived meso-β cyclone over the Gulf of Antalya, eastern Mediterranean. Tellus, 51A , 249–262.

    • Search Google Scholar
    • Export Citation

  • Archer, C. L., 2004: The Santa Cruz Eddy and U.S. wind power. Ph.D. thesis, Stanford University, 190 pp.

  • Archer, C. L., and M. Z. Jacobson, 2005: The Santa Cruz Eddy. Part II: Mechanisms of formation. Mon. Wea. Rev., in press.

  • Bosart, L. F., 1983: Analysis of a California Catalina event. Mon. Wea. Rev., 111 , 1619–1633.

  • Clark, J. H., 1994: The role of Kelvin waves in evolution of the Catalina eddy. Mon. Wea. Rev., 122 , 838–850.

  • Clark, J. H., and S. R. Dembek, 1991: The Catalina eddy event of July 1987: A coastally trapped mesoscale response to synoptic forcing. Mon. Wea. Rev., 119 , 1714–1735.

    • Search Google Scholar
    • Export Citation

  • Crook, N. A., T. L. Clark, and M. W. Moncrieff, 1990: The Denver cyclone. Part I: Generation in low Froude number flow. J. Atmos. Sci., 47 , 2725–2742.

    • Search Google Scholar
    • Export Citation

  • Crook, N. A., T. L. Clark, and M. W. Moncrieff, 1991: The Denver cyclone. Part II: Interaction with the convective boundary layer. J. Atmos. Sci., 48 , 2109–2126.

    • Search Google Scholar
    • Export Citation

  • Davis, C., S. Low-Nam, and C. F. Mass, 2000: Dynamics of a Catalina eddy revealed by numerical simulation. Mon. Wea. Rev., 128 , 2885–2904.

    • Search Google Scholar
    • Export Citation

  • Dorman, C. E., 1985: Evidence of Kelvin waves in California’s marine layer and related eddy generation. Mon. Wea. Rev., 113 , 827–839.

    • Search Google Scholar
    • Export Citation

  • Dorman, C. E., and C. D. Winant, 2000: The structure and variability of the marine atmosphere around the Santa Barbara channel. Mon. Wea. Rev., 128 , 261–282.

    • Search Google Scholar
    • Export Citation

  • Eddington, L. W., J. J. O’Brien, and D. W. Stuart, 1992: Numerical simulation of topographically forced mesoscale variability in a well-mixed marine layer. Mon. Wea. Rev., 120 , 2881–2896.

    • Search Google Scholar
    • Export Citation

  • Hardy, D. M., 1977: Empirical eigenvector analysis of vector observations. Geophys. Res. Lett., 4 , 319–320.

  • Holton, J. R., 1992: An Introduction to Dynamic Meteorology. Academic Press, 511 pp.

  • Hucshke, R. E., 1959: Glossary of Meteorology. Amer. Meteor. Soc., 638 pp.

  • Kaihatu, J. M., R. A. Handler, G. O. Marmorino, and L. K. Shay, 1998: Empirical orthogonal function analysis of ocean surface currents using complex and real-vector methods. J. Atmos. Oceanic Technol., 15 , 927–941.

    • Search Google Scholar
    • Export Citation

  • Kessler, R. C., and S. G. Douglas, 1991: Numerical simulation of topographically forced mesoscale variability in a well-mixed marine layer. J. Appl. Meteor., 30 , 633–651.

    • Search Google Scholar
    • Export Citation

  • Laing, A. K., and S. J. Reid, 1999: Evidence of mesoscale lows off the west coast of New Zealand. Wea. Forecasting, 14 , 369–383.

  • Lin, Y. L., and I. C. Jao, 1995: A numerical study of flow circulations in the Central Valley of California and formation mechanisms of the Fresno Eddy. Mon. Wea. Rev., 123 , 3227–3239.

    • Search Google Scholar
    • Export Citation

  • Lorenz, E. N., 1956: Empirical orthogonal functions and statistical weather prediction. Science Rep. 1, Statistical Forecasting Project, Dept. of Meteorology, Massachusetts Institute of Technology, 49 pp.

  • Ludwig, F. L., and G. Byrd, 1980: A very efficient method for deriving mass consistent flow fields from wind observations in rough terrain. Atmos. Environ., 14 , 585–587.

    • Search Google Scholar
    • Export Citation

  • Ludwig, F. L., and R. L. Street, 1995: Modification of multiresolution feature analysis for application to three-dimensional atmospheric wind fields. J. Atmos. Sci., 52 , 139–157.

    • Search Google Scholar
    • Export Citation

  • Lumley, J. L., 1981: Coherent structures in turbulence. Transition and Turbulence, R. E. Meyer, Ed., Academic Press, 215–242.

  • Mahrt, L., 1991: Eddy asymmetry in the sheared heated boundary layer. J. Atmos. Sci., 48 , 472–492.

  • Manning, K. W., and H. Frank, 1988: Eigenstructure of eddy microfronts. Tellus, 40A , 107–119.

  • Mass, C. F., and M. D. Albright, 1989: Origin of the Catalina eddy. Mon. Wea. Rev., 117 , 2405–2436.

  • Seaman, N. L., and D. R. Stauffer, 1994: The Fresno eddy: Numerical investigation of a mesoscale wind feature of the San Joaquin Valley using the Penn State/NCAR MM5. Preprints, Sixth Conf. on Mesoscale Processes, Portland, OR, Amer. Meteor. Soc., 572–575.

  • Sirovich, L., 1988: Analysis of turbulent flows by means of empirical orthogonal functions. Center for Fluid Mechanics Rep. 90–212, Brown University, Providence, RI, 40 pp.

  • Skamarock, W. C., R. Rotunno, and J. B. Klemp, 2002: Catalina eddies and coastally trapped disturbances. J. Atmos. Sci., 59 , 2270–2278.

    • Search Google Scholar
    • Export Citation

  • Thompson, W. T., S. D. Burk, and J. Rosenthal, 1997: An investigation of the Catalina eddy. Mon. Wea. Rev., 125 , 1135–1146.

  • Ueyoshi, K., and J. O. Roads, 1993: Simulation and prediction of the Catalina eddy. Mon. Wea. Rev., 121 , 2975–3000.

  • Ulrickson, B. L., J. S. Hoffmaster, J. Robinson, and D. Vimont, 1995: A numerical modeling study of the Catalina eddy. Mon. Wea. Rev., 123 , 1364–1373.

    • Search Google Scholar
    • Export Citation

  • Wakimoto, R. M., 1987: The Catalina eddy and its effects on air pollution over southern California. Mon. Wea. Rev., 115 , 837–855.

  • Wilczak, J. M., and T. W. Christian, 1990: Case study of an orographically induced, mesoscale vortex (Denver Cyclone). Mon. Wea. Rev., 118 , 837–855.

    • Search Google Scholar
    • Export Citation

  • Wilczak, J. M., W. F. Dabberdt, and R. A. Kropfli, 1991: Observations and numerical-model simulations of the atmospheric boundary layer in the Santa Barbara coastal region. J. Appl. Meteor., 30 , 652–673.

    • Search Google Scholar
    • Export Citation

  • Wilczak, J. M., and J. W. Glendening, 1988: Observations and mixed-layer modeling of a terrain-induced mesoscale gyre: The Denver Cyclone. Mon. Wea. Rev., 116 , 1599–1622.

    • Search Google Scholar
    • Export Citation

  • Wilczak, J. M., W. D. Neff, D. Ruffieux, and J. Schmidt, 1994: Atmospheric and oceanic mesoscale flows in the Monterey Bay, California region. Preprints, Second Int. Conf. on Air–Sea Interaction and on Meteorology and Oceanography of the Coastal Zone, Lisbon, Portugal, Amer. Meteor. Soc., 196–197.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 941 667 157
PDF Downloads 289 143 6