The U.S. contribution to
Climate Variability and Predictability
Eastern Pacific Investigation of Climate Processes on the Coupled Ocean-Atmosphere System
EPIC is a five year experiment designed to to improve understanding of the inter-tropical convergence zone (ITCZ), its interactions witht he cold tongue of water that extends along the equator, and the physics of the stratus cloud deck that forms over the cool waters off South America. EPIC Scientific Objectives include: (1) To observe and understand the ocean-atmosphere processes responsible for the structure and evolution of the large-scale atmospheric heating gradients in the equatorial and northeastern Pacific portions of the cold-tongue/ITCZ complex. (2) To observe and understand the dynamical, radiative and microphysical properties of the extensive boundary layer cloud decks in the southeasterly tradewind and cross-equatorial flow regime and their interactions with the ocean below. |
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EPIC
Activities
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An EPIC 2005 Workshop entitled: Workshop on the Application of EPIC2001 Data for Improving and Testing Coupled Atmosphere-Ocean Models took place 11-13 May 2005 at the University of Washington
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EPIC is currently in a modeling/analysis post field phase
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EPIC2001 was a 2-month intensive process study, embedded in 4-years of enhanced monitoring, built on the ENSO observing system. The field program was divided into two pieces: (1) a study of the ITCZ, the cross-equatorial inflow, and ocean mixing processes north of the equator, and (2) measurements in the stratocumulus region south of the equator.
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EPIC 2001 was embedded in longer term enhanced monitoring (3-4 years), built on the ENSO observing system, and began in 1999.
Accomplishments
- Enhanced monitoring along 95W and 110W.
- Scanning radar studies have provided unprecedented observations of east Pacific ITCZ convection.
- EPIC has provided benchmark data sets for evaluating model and numerical weather products and satellite fields.
- EPIC is leading to new parameterizations and improved general circulation models of the eastern tropical Pacific.
- A powerpoint presentation of EPIC highlights can be downloaded here. (7.6MB PDF)
EPIC Web Links
- http://www.physics.nmt.edu/~raymond/epic2001/epic2001.html
- EPIC Aircraft Mission data (http://merlin.nmt.edu/projects/epic2001/)
- http://www.etl.noaa.gov/programs/2001/epic/
- TAO/EPIC Project: http://www.pmel.noaa.gov/tao/epic/
- WHOI Stratus Mooring Page (http://uop.whoi.edu/projects/Stratus.stratus.html)
- U.S. CLIVAR Pan American Workshop 2003 (http://www.usclivar.org/MTG_PanAmerican_0903.html)
- EPIC Workshop 2002 (http://www.pmel.noaa.gov/tao/epic/epicmtg02.html)
EPIC Publications
2006
Maike Ahlgrimm and David A. Randall. 2006: Diagnosing Monthly Mean Boundary Layer Properties from Reanalysis Data Using a Bulk Boundary Layer Model. Journal of the Atmospheric Sciences: Vol. 63, No. 3, pp. 998–1012.
Jorge A. Amador, Eric J. Alfaro, Omar G. Lizano and Victor O. Magaña, 2006: Atmospheric forcing of the eastern tropical Pacific: Progress In Oceanography, Volume 69, Issues 2-4, May-June 2006, Pages 101-142
Wesley Berg, Tristan L'Ecuyer and Christian Kummerow. 2006: Rainfall Climate Regimes: The Relationship of Regional TRMM Rainfall Biases to the Environment. Journal of Applied Meteorology and Climatology: Vol. 45, No. 3, pp. 434–454.
Jasmine Cetrone and Robert A. Houze Jr.. 2006: Characteristics of Tropical Convection over the Ocean near Kwajalein. Monthly Weather Review: Vol. 134, No. 3, pp. 834–853.
Charles Cornish, Chris Bretherton, and Donald Percival, 2006: Maximal Overlap Wavelet Statistical Analysis With Application to Atmospheric Turbulence. Boundary Layer Meteorology, 119(2), pp. 339-374.
Meghan F. Cronin, CW Fairall, and MJ McPhaden, 2006: An assessment
of buoy derived and NWP surface heat fluxes in the tropical Pacific.
J. Geophys. Res./, 111, C06038,
doi:10.1029/2005JC003324
Meghan F. Cronin, Nicholas A. Bond, Christopher W. Fairall and Robert A. Weller. 2006: Surface Cloud Forcing in the East Pacific Stratus Deck/Cold Tongue/ITCZ Complex*. Journal of Climate: Vol. 19, No. 3, pp. 392–409.
Fairall, C. W., J. E. Hare, T. Uttal, D. Hazen, Meghan Cronin, Nicholas A. Bond, and Dana Veron, 2006: A seven-cruise sample of clouds, radiation, and surface forcing in the Equatorial Eastern Pacific. J. Clim., submitted.
M.F. Lavín, P.C. Fiedler, J.A. Amador, L.T. Ballance, J. Färber-Lorda and A.M. Mestas-Nuñez, 2006: A review of eastern tropical Pacific oceanography: Progress In Oceanography, Volume 69, Issues 2-4, May-June 2006, Pages 391-398
L. Gustavo Pereira and Steven A. Rutledge. 2006: Diurnal Cycle of Shallow and Deep Convection for a Tropical Land and an Ocean Environment and Its Relationship to Synoptic Wind Regimes, Monthly Weather Review, Volume 134, Issue 10 pp. 2688–2701
+(PACS/NSF)David J. Raymond, Christopher S. Bretherton and John Molinari. 2006: Dynamics of the Intertropical Convergence Zone of the East Pacific. Journal of the Atmospheric Sciences: Vol. 63, No. 2, pp. 582–597.
R. M. Samelson, E. D. Skyllingstad, D. B. Chelton, S. K. Esbensen, L. W. O'Neill and N. Thum. 2006: On the Coupling of Wind Stress and Sea Surface Temperature. Journal of Climate: Vol. 19, No. 8, pp. 1557–1566.
Robert Wood and Christopher S. Bretherton. 2006: On the Relationship between Stratiform Low Cloud Cover and Lower-Tropospheric Stability, Journal of Climate, Volume 19, Issue 24 pp. 6425–6432
Zhou M., X. Zeng, M. Brunke, Z. Zhang, C. Fairall (2006), An analysis of statistical characteristics of stratus and stratocumulus over eastern Pacific, Geophys. Res. Lett., 33, L02807, doi:10.1029/2005GL024796.
Zuidema, P., B. Mapes, J. Lin, and C. W. Fairall, 2005: A new look at - Tropical Middle-Troposphere Clouds. J. Atmos. Sci., to appear.
Zuidema, P., B. Mapes, J. Lin, and C. W. Fairall, 2005: Cloud vertical structure in the Eastern Tropical Pacific. J. Clim., to appear.
Zuidema, P., B. Mapes, J. Lin, and C. W. Fairall, 2005 : The role of middle-tropospheric dry air intrusions in the Eastern Tropical Pacific. J. Clim., submitted.
2005
Larissa E. Back and Christopher S. Bretherton. 2005: The Relationship between Wind Speed and Precipitation in the Pacific ITCZ. Journal of Climate: Vol. 18, No. 20, pp. 4317–4328.
Dennis J. Boccippio, Walter A. Petersen and Daniel J. Cecil. 2005: The Tropical Convective Spectrum. Part I: Archetypal Vertical Structures. Journal of Climate: Vol. 18, No. 14, pp. 2744–2769.
Peter Caldwell, Christopher S. Bretherton and Robert Wood. 2005: Mixed-Layer Budget Analysis of the Diurnal Cycle of Entrainment in Southeast Pacific Stratocumulus. Journal of the Atmospheric Sciences: Vol. 62, No. 10, pp. 3775–3791.
Kimberly K. Comstock, Christopher S. Bretherton and Sandra E. Yuter. 2005: Mesoscale Variability and Drizzle in Southeast Pacific Stratocumulus. Journal of the Atmospheric Sciences: Vol. 62, No. 10, pp. 3792–3807.
de Szoeke, Simon P., Christopher S. Bretherton, Nicholas A. Bond, Meghan F. Cronin and Bruce M. Morley, 2005: EPIC 95°W Observations of the Eastern Pacific Atmospheric Boundary Layer from the Cold Tongue to the ITCZ. Journal of Atmos. Sci., 62(2) pages 426–442.
Simon P. de Szoeke and Christopher S. Bretherton. 2005: Variability in the Southerly Flow into the Eastern Pacific ITCZ*. Journal of the Atmospheric Sciences: Vol. 62, No. 12, pp. 4400–4411.
David B. Enfield and Sang-ki Lee. 2005: The Heat Balance of the Western Hemisphere Warm Pool. Journal of Climate: Vol. 18, No. 14, pp. 2662–2681.
Zeljka Fuchs and David J. Raymond. 2005: Large-Scale Modes in a Rotating Atmosphere with Radiative–Convective Instability and WISHE. Journal of the Atmospheric Sciences: Vol. 62, No. 11, pp. 4084–4094.
Jiang, C.-L., M. F. Cronin, K. A. Kelly, and L. Thompson (2005). Evaluation of a hybrid satellite and NWP based turbulent heat flux product using TAO buoys. J. Geophys. Res., 110, C09007, doi:10.1029/2004JC002824.
Brian E. Mapes and Jialin Lin. 2005: Doppler Radar Observations of Mesoscale Wind Divergence in Regions of Tropical Convection. Monthly Weather Review: Vol. 133, No. 7, pp. 1808–1824.
Eric D. Maloney and Steven K. Esbensen. 2005: A Modeling Study of Summertime East Pacific Wind-Induced Ocean–Atmosphere Exchange in the Intraseasonal Oscillation. Journal of Climate: Vol. 18, No. 4, pp. 568–584.
Brian Medeiros, Alex Hall and Bjorn Stevens. 2005: What Controls the Mean Depth of the PBL?. Journal of Climate: Vol. 18, No. 16, pp. 3157–3172.
Larry W. O’Neill, Dudley B. Chelton, Steven K. Esbensen and Frank J. Wentz. 2005: High-Resolution Satellite Measurements of the Atmospheric Boundary Layer Response to SST Variations along the Agulhas Return Current. Journal of Climate: Vol. 18, No. 14, pp. 2706–2723.
Hollis E. Pyatt, Bruce A. Albrecht, Chris Fairall, J. E. Hare, Nicholas Bond, Patrick Minnis and J. Kirk Ayers. 2005: Evolution of Marine Atmospheric Boundary Layer Structure across the Cold Tongue–ITCZ Complex. Journal of Climate: Vol. 18, No. 5, pp. 737–753.
R. Justin Small, Shang-Ping Xie, Yuqing Wang, Steven K. Esbensen and Dean Vickers. 2005: Numerical Simulation of Boundary Layer Structure and Cross-Equatorial Flow in the Eastern Pacific*. Journal of the Atmospheric Sciences: Vol. 62, No. 6, pp. 1812–1830.
Haiming Xu, Shang-Ping Xie and Yuqing Wang. 2005: Subseasonal Variability of the Southeast Pacific Stratus Cloud Deck*. Journal of Climate: Vol. 18, No. 1, pp. 131–142.
Yuqing Wang, Shang-Ping Xie, Bin Wang and Haiming Xu. 2005: Large-Scale Atmospheric Forcing by Southeast Pacific Boundary Layer Clouds: A Regional Model Study*. Journal of Climate: Vol. 18, No. 7, pp. 934–951.
Gary A. Wick, J. Carter Ohlmann, Christopher W. Fairall and Andrew T. Jessup. 2005: Improved Oceanic Cool-Skin Corrections Using a Refined Solar Penetration Model. Journal of Physical Oceanography: Vol. 35, No. 11, pp. 1986–1996.
Wijesekera, H. W., D. L. Rudnick, C. A. Paulson, S. D. Pierce, S. Pegau, J. Mickett, and M. C. Gregg, 2005: Upper ocean heat and freshwater budgets in the eastern Pacific warm pool. J. Geophys Res., 110 (C8): Art. No. C08004 AUG 11
Xie SP, Xu HM, Kessler WS, et al.:, 2005: Air-sea interaction over the eastern Pacific warm pool: Gap winds, thermocline dome, and atmospheric convection , J. Clim. 18 (1): 5-20.
Xu HM, Xie SP, Wang YQ, et al., 2005 : Effects of Central American mountains on the eastern Pacific winter ITCZ and moisture transport , J. Clim. 18 (18): 3856-3873.
Yunyan Zhang; Bjorn Stevens; Michael Ghil, 2005: On the diurnal cycle and susceptibility to aerosol concentration in a stratocumulus-topped mixed layer. Quarterly Journal of the Royal Meteorological Society (Royal Meteorological Society), 131(608), 567-1583
Zuidema, P., C. W. Fairall, E. Westwater, and D. Hazen, 2005: Ship-based liquid water path estimates in marine stratus. J. Geophys. Res., 110 (D20): Art. No. D20206 OCT 26.
2004
Bielli, Soline and Dennis L. Hartmann, 2004: On Wind, Convection, and SST Variations in the Northeastern Tropical Pacific Associated with the Madden–Julian Oscillation. J. Clim., 17, 4080–4088.
Bretherton, Christopher S., T. Uttal, C.W. Fairall, S.E. Yuter, R.A. Weller, D. Baumgardner, K. Comstock, R. Wood, and G.B. Raga, July 2004: “The EPIC 2001 Strocumulus Study”, Bulletin of the American Meteorological Society, Vol. 85, No. 7, pp967-977.
Bretherton C.S., Peters M.E., Back L.E., 2004: Relationships between water vapor path and precipitation over the tropical oceans. J. Clim., 17 (7): 1517-1528
Robert Cifelli, Lawrence Carey, Walter A. Petersen and Steven A. Rutledge. 2004: An Ensemble Study of Wet Season Convection in Southwest Amazonia: Kinematics and Implications for Diabatic Heating. Journal of Climate: Vol. 17, No. 24, pp. 4692–4707.
Kimberly K. Comstock; Robert Wood; Sandra E. Yuter; Christopher S. Bretherton, 2004: Reflectivity and rain rate in and below drizzling stratocumulus. Quarterly Journal of the Royal Meteorological Society (Royal Meteorological Society), 130(603), 2891-2918
S. P. de Szoeke and C. S. Bretherton. 2004: Quasi-Lagrangian Large Eddy Simulations of Cross-Equatorial Flow in the East Pacific Atmospheric Boundary Layer. Journal of the Atmospheric Sciences: Vol. 61, No. 15, pp. 1837–1858.
René D. Garreaud and Ricardo Muñoz. 2004: The Diurnal Cycle in Circulation and Cloudiness over the Subtropical Southeast Pacific: A Modeling Study. Journal of Climate: Vol. 17, No. 8, pp. 1699–1710.
Jimnez, J. C., D. Baumgardner, G. B. Raga, 2004: Aerosol particles in the Mexican east Pacific part I: processing and vertical redistribution by clouds. Atmo. Chem. Phys. Disc., 4, 7795-7818. SRef-ID: 1680-7375/acpd/2004-4-7795.
Kollias P., C. W. Fairall, P. Zuidema, J. Tomlinson, G. A. Wick (2004), Observations of marine stratocumulus in SE Pacific during the PACS 2003 cruise, Geophys. Res. Lett., 31, L22110, doi:10.1029/2004GL020751.
Sergey Y. Matrosov, Taneil Uttal and Duane A. Hazen. 2004: Evaluation of Radar Reflectivity–Based Estimates of Water Content in Stratiform Marine Clouds. Journal of Applied Meteorology: Vol. 43, No. 3, pp. 405–419.
Michael McGauley, Chidong Zhang and Nicholas A. Bond. 2004: Large-Scale Characteristics of the Atmospheric Boundary Layer in the Eastern Pacific Cold Tongue–ITCZ Region*. Journal of Climate: Vol. 17, No. 20, pp. 3907–3920.
Nesbitt, S. W., R. Cifelli, S. A. Rutledge, and D. J. Boccippio, D. J. Cecil, and E. J. Zipser, 2004: The Horizontal Structure of Precipitating Systems in the Tropics According to TRMM. The 2nd TRMM International Science Conference, 6-10 Spetember, 2004, Nara, Japan.
Sungsu Park, Conway B. Leovy and Margaret A. Rozendaal. 2004: A New Heuristic Lagrangian Marine Boundary Layer Cloud Model. Journal of the Atmospheric Sciences: Vol. 61, No. 24, pp. 3002–3024.
Raymond, David J., Steven K. Esbensen, Clayton Paulson, Michael Gregg, Christopher S. Bretherton, Walter A. Petersen, Robert Cifelli, Lynn K. Shay, Carter Ohlmann and Paquita Zuidema, 2004: EPIC2001 and the Coupled Ocean–Atmosphere System of the Tropical East Pacific. Bull. Am. Met. Soc., 85, 1341–1354.
Yolande L. Serra and Michael J. McPhaden. 2004: In Situ Observations of Diurnal Variability in Rainfall over the Tropical Pacific and Atlantic Oceans*. Journal of Climate: Vol. 17, No. 18, pp. 3496–3509.
Adam H. Sobel, Sandra E. Yuter, Christopher S. Bretherton and George N. Kiladis. 2004: Large-Scale Meteorology and Deep Convection during TRMM KWAJEX*. Monthly Weather Review: Vol. 132, No. 2, pp. 422–444.
Stevens, B., G. Vali, K. Comstock, R. Wood, M. C. van Zanten, P. H. Austin, C. S. Bretherton, and D. H. Lenschow, 2004: Pockets of open cells (POCs) and drizzle in marine stratocumulus. Bull. Amer. Meteor. Soc., 86 (1): 51+
Xu, Haiming, Yuqing Wang and S.-P. Xie, "Effects of the Andes on Eastern Pacific Climate: A Regional Atmospheric Model Study". Journal of Climate, Vol. 17, No. 3, pp. 589-602.
Yuqing Wang, Haiming Xu and Shang-Ping Xie. 2004: Regional Model Simulations of Marine Boundary Layer Clouds over the Southeast Pacific off South America. Part I: Control Experiment*. Monthly Weather Review: Vol. 132, No. 1, pp. 274-296.
Yuqing Wang, Haiming Xu and Shang-Ping Xie. 2004: Regional Model Simulations of Marine Boundary Layer Clouds over the Southeast Pacific off South America. Part II: Sensitivity Experiments*. Monthly Weather Review: Vol. 132, No. 11, pp. 2650–2668.
Robert Wood and Christopher S. Bretherton. 2004: Boundary Layer Depth, Entrainment, and Decoupling in the Cloud-Capped Subtropical and Tropical Marine Boundary Layer. Journal of Climate: Vol. 17, No. 18, pp. 3576–3588.
Xubin Zeng, Michael A. Brunke, Mingyu Zhou, Chris Fairall, Nicholas A. Bond and Donald H. Lenschow. 2004: Marine Atmospheric Boundary Layer Height over the Eastern Pacific: Data Analysis and Model Evaluation. Journal of Climate: Vol. 17, No. 21, pp. 4159–4170.
Chidong Zhang, Michael McGauley and Nicholas A. Bond. 2004: Shallow Meridional Circulation in the Tropical Eastern Pacific*. Journal of Climate: Vol. 17, No. 1, pp. 133–139.
2003
Meghan F. Cronin, Shang-Ping Xie and Hiroshi Hashizume. 2003: Barometric Pressure Variations Associated with Eastern Pacific Tropical Instability Waves*. Journal of Climate: Vol. 16, No. 18, pp. 3050–3057.
Eric. D. Maloney and Steven K. Esbensen. 2003: The Amplification of East Pacific Madden–Julian Oscillation Convection and Wind Anomalies during June–November. Journal of Climate: Vol. 16, No. 21, pp. 3482–3497.
Nesbitt, S. W., R. Cifelli, and S.A. Rutledge, 2003: EPIC and Other Recent Field Campaign Radar Data Collected in the Context of the TRMM PR Climatology. EPIC 2001 Workshop, 15-16 September, 2003, Boulder, CO.
J. Carter Ohlmann. 2003: Ocean Radiant Heating in Climate Models. Journal of Climate: Vol. 16, No. 9, pp. 1337–1351.
Walter A. Petersen, Robert Cifelli, Dennis J. Boccippio, Steven A. Rutledge and Chris Fairall. 2003: Convection and Easterly Wave Structures Observed in the Eastern Pacific Warm Pool during EPIC-2001. Journal of the Atmospheric Sciences: Vol. 60, No. 15, pp. 1754–1773.
Raymond, David J., G. B. Raga, Christopher S. Bretherton, John Molinari, Carlos López-Carrillo and Željka Fuchs, 2003: Convective Forcing in the Intertropical Convergence Zone of the Eastern Pacific. J. Atmos. Sci., 60, 2064–2082.
Rodríguez-Rubio, Efraín; Schneider, Wolfgang; Abarca del Río, Rodrigo, 2003: On the seasonal circulation within the Panama Bight derived from satellite observations of wind, altimetry and sea surface temperature. Geophys. Res. Lett. 30 No. 7. 10.1029/2002GL016794.
Schneider, Wolfgang; Fuenzalida, Rosalino; Rodríguez-Rubio, Efraín; Garcés, José; Bravo, Luis. Characteristics and Formation of Eastern South Pacific Intermediate Water. Geophys. Res. Lett., 30 (11): Art. No. 1581.
Small, R. Justin, Shang-Ping Xie and Yuqing Wang, 2003: Numerical Simulation of Atmospheric Response to Pacific Tropical Instability Waves. J. Clim., 16, 3723–3741.
Sun, De-Zheng, John Fasullo, Tao Zhang and Andrew Roubicek, "On the Radiative and Dynamical Feedbacks over the Equatorial Pacific Cold Tongue". Journal of Climate, Vol. 16, No. 14, pp. 2425-2532.
Shouping Wang, Qing Wang and Graham Feingold. 2003: Turbulence, Condensation, and Liquid Water Transport in Numerically Simulated Nonprecipitating Stratocumulus Clouds. Journal of the Atmospheric Sciences: Vol. 60, No. 2, pp. 262–278.
Chidong Zhang; Brian E. Mapes; Brian J. Soden, 2003: Bimodality in tropical water vapour. Quarterly Journal of the Royal Meteorological Society (Royal Meteorological Society), 129(594), 2847-2866
2002
Cronin, M. F., N. Bond, and C. Fairall. Seasonal and year-to-year variations
in the cold-tongue / ITCZ complex. U. S. CLIVAR Variations, 1(1),
7-9, 2002.
Cronin, M. F., N. Bond, C. W. Fairall, J. E. Hare, M. J. McPhaden, and R. A. Weller, 2002: Enhanced oceanic and atmospheric monitoring for the Eastern Pacific Investigation of Climate Processes (EPIC) experiment. EOS, Transactions of AGU, 83, 205-211
Thum, Nicolai, Steven K. Esbensen, Dudley B. Chelton and Michael J. McPhaden. 2002: Air–Sea Heat Exchange along the Northern Sea Surface Temperature Front in the Eastern Tropical Pacific. J. Clim., 15, 3361–3378.