Pacific Ocean: mean surface geostrophic circulation with the current systems described in this text. Mean surface height (cm) relative to a zero global mean height, based on surface drifters, satellite altimetry, and hydrographic data. (NGCUC = New Guinea Coastal Undercurrent and SECC = South Equatorial Countercurrent). Data from Niiler, Maximenko, and McWilliams (2003).

Annual mean winds. (a) Wind stress (N/m²) (vectors) and wind-stress curl (x10⁻⁷ N/m³) (color), multiplied by −1 in the Southern Hemisphere. (b) Sverdrup transport (Sv), where blue is clockwise and yellow-red is counterclockwise circulation. Data from NCEP reanalysis (Kalnay et al.,1996).

Annual mean winds. (a) Wind stress (N/m²) (vectors) and wind-stress curl (x10⁻⁷ N/m³) (color), multiplied by −1 in the Southern Hemisphere. (b) Sverdrup transport (Sv), where blue is clockwise and yellow-red is counterclockwise circulation. Data from NCEP reanalysis (Kalnay et al.,1996).

The subtropical-subarctic transition along 150°W in the central North Pacific (May–June, 1984). SAFZ and STFZ: subarctic and subtropical frontal zones. (a) Potential temperature (°C), (b) salinity, (c) nitrate (μmol/kg), and (d) nitrate versus potential density. After Roden (1991). Data from WOCE Pacific Ocean Atlas; Talley (2007).

Subpolar gyre regimes. Only the major features are described in the text. Source: From Favorite, Dodimead, and Nasu (1976).

Oyashio. Acceleration potential anomaly (similar to geopotential anomaly) on the isopycnal σ _θ = 26.52 kg/m³ (150 cl/ton) referenced to 1500 dbar in September 1990. Source: From Kono and Kawasaki (1997).

(a) The Oyashio, Kuroshio, and Mixed Water Region east of Japan. (b) The southernmost latitude of the first Oyashio intrusion east of Honshu. Source: From Sekine (1999).

(a) Ocean color from the SeaWIFS satellite, showing an anticyclonic Haida Eddy in the Alaska Current on June 13, 2002. Source: From NASA Visible Earth (2008). (b) Tracks of Sitka and Haida Eddies in 1995 and 1998 (top right) and in remaining years between 1993 and 2001 (bottom right). Source: From Crawford (2002).

(a) Ocean color from the SeaWIFS satellite, showing an anticyclonic Haida Eddy in the Alaska Current on June 13, 2002. Source: From NASA Visible Earth (2008). (b) Tracks of Sitka and Haida Eddies in 1995 and 1998 (top right) and in remaining years between 1993 and 2001 (bottom right). Source: From Crawford (2002).

Mean steric height at (a) 150 m and (b) 500 m relative to 2000 m; contour intervals are 0.04 and 0.02 m, respectively. Source: From Ridgway and Dunn (2003).

Mean steric height at (a) 150 m and (b) 500 m relative to 2000 m; contour intervals are 0.04 and 0.02 m, respectively. Source: From Ridgway and Dunn (2003).

Sea level (m). (a) Total sea level, and (b) RMS sea level anomalies, from satellite altimetry. The 3000 m isobath is shown (purple). Source: From Mata, Wijffels, Church, and Tomczak (2006).

Sea level (m). (a) Total sea level, and (b) RMS sea level anomalies, from satellite altimetry. The 3000 m isobath is shown (purple). Source: From Mata, Wijffels, Church, and Tomczak (2006).

Surface chlorophyll concentration in austral winter (June, July, August) and summer (December, January, February), derived from SeaWiFS satellite observations. Source: From Mackas, Strub, Thomas, and Montecino (2006).

Eastern South Pacific zonal vertical sections at 33°S: (a) temperature with meridional current directions, (b) salinity, (c) dissolved oxygen, and (d) phosphate.

RMS variability in surface height (cm) from satellite altimetry, high-passed with half power at 180 days to depict the mesoscale eddy energy. ©American Meteorological Society. Reprinted with permission. Source: From Qiu, Scott, and Chen (2008).

Mean flow at 900 m depth in the tropical and South Pacific based on subsurface float observations. (a) Velocity (cm/sec). (b) Geostrophic streamfunction (1000 m²/s). ©American Meteorological Society. Reprinted with permission. Source: From Davis (2005).

Mean flow at 900 m depth in the tropical and South Pacific based on subsurface float observations. (a) Velocity (cm/sec). (b) Geostrophic streamfunction (1000 m²/s). ©American Meteorological Society. Reprinted with permission. Source: From Davis (2005).

Pacific abyssal circulation schematics. Low latitude North Pacific. Source: From Kawabe, Yanagimoto, and Kitagawa (2006).

Northward transports (Sv) across zonal sections in isopycnal layers, integrated upwards from zero at the bottom. Section latitudes are indicated in parentheses. Ekman transport is not included. Gray indicates the uncertainty. Source: From Ganachaud (2003).

Climatological wind stress (N/m²) (vectors) and wind stress curl (N/m³, multiplied by −1 in Southern Hemisphere; contours, shading is negative): (a) February and (b) August. Monthly mean wind data are from the NCEP reanalysis (Kalnay et al., 1996). (c) Sverdrup transport (Sv) in the tropical Pacific Ocean, calculated from Hellerman-Rosenstein (1983) wind stress. Positive (negative) values yield clockwise (counterclockwise) circulation. ©American Meteorological Society. Reprinted with permission. Source: From Qu and Lindstrom (2002).

Climatological wind stress (N/m²) (vectors) and wind stress curl (N/m³, multiplied by −1 in Southern Hemisphere; contours, shading is negative): (a) February and (b) August. Monthly mean wind data are from the NCEP reanalysis (Kalnay et al., 1996). (c) Sverdrup transport (Sv) in the tropical Pacific Ocean, calculated from Hellerman-Rosenstein (1983) wind stress. Positive (negative) values yield clockwise (counterclockwise) circulation. ©American Meteorological Society. Reprinted with permission. Source: From Qu and Lindstrom (2002).

Dynamic height (dyn cm) along the equator; transport (Sv) of the Equatorial Undercurrent is shown in the inset. ©American Meteorological Society. Reprinted with permission. Source: From Leetmaa and Spain (1981).

Chlorophyll composite images from SeaWiFS (January 1998 during El Niño and July 1998 during transition to La Niña). Red = highest chlorophyll contents, dark purple = lowest chlorophyll. Source: From SeaWiFS Project (2009).

Currents in the western tropical Pacific. NEC = North Equatorial Current; NECC = North Equatorial Countercurrent; SEC = South Equatorial Current; EUC = Equatorial Undercurrent; NSCC and SSCC = North and South Subsurface Countercurrent; MC = Mindanao Current; MUC = Mindanao Undercurrent; ME = Mindanao Eddy; HE = Halmahera Eddy; NGCC = New Guinea Coastal Current; NGCUC = New Guinea Coastal Undercurrent; GBRUC = Great Barrier Reef Undercurrent; EAC = East Australian Current; LC = Leeuwin Current; AAIW = Antarctic Intermediate Water. Source: From Lukas, Yamagata, and McCreary (1996); after Fine et al. (1994).

Tropical sea surface temperature from the Tropical Rainfall Mapping Mission (TRMM) Microwave Imager (TMI) for ten-day intervals from June 1 to August 30, 1998. Source: From Remote Sensing Systems (2004).

Winds and SST along the equator in the Pacific. Climatological zonal wind speed in (a) February and (b) August. Source: From TAO Project Office (2009b). (c) Monthly zonal wind speed (m/s) and SST (°C). Positive wind is towards the east. Source: From TAO Project Office (2009a).

Winds and SST along the equator in the Pacific. Climatological zonal wind speed in (a) February and (b) August. Source: From TAO Project Office (2009b). (c) Monthly zonal wind speed (m/s) and SST (°C). Positive wind is towards the east. Source: From TAO Project Office (2009a).

(a) February mean winds (vectors) from COADS and February mean SST. The large arrows emphasize the gaps through the American cordillera. From north to south: Tehuantepec, Papagayo, and Panama. Source: From Kessler (2009). (b) SST in the Gulf of Tehuantepec, January 22, 1996. Source: From Zamudio et al. (2006).

(a) February mean winds (vectors) from COADS and February mean SST. The large arrows emphasize the gaps through the American cordillera. From north to south: Tehuantepec, Papagayo, and Panama. Source: From Kessler (2009). (b) SST in the Gulf of Tehuantepec, January 22, 1996. Source: From Zamudio et al. (2006).

(a) Southern Oscillation Index (SOI) time series from 1876 to 2008 (annual average). Data from Australian Government Bureau of Meteorology (2009). (b) "Oceanic Nino Index" based on SST in the region 5°N–5°S, 170°W–120°W, as in Figure 10.28b. Red and blue in both panels correspond to El Niño and La Niña, respectively. (c) SST reconstructions from the region 5°N–5°S, 150°W– 90°W. Source: From IPCC (2001). (d) Correlation of monthly sea level pressure anomalies with the ENSO Nino3.4 index, averaged from 1948 to 2007. The Nino3.4 index is positive during the El Niño phase, so the signs shown are representative of this phase. Data and graphical interface from NOAA ESRL (2009b).

(a) Southern Oscillation Index (SOI) time series from 1876 to 2008 (annual average). Data from Australian Government Bureau of Meteorology (2009). (b) "Oceanic Nino Index" based on SST in the region 5°N–5°S, 170°W–120°W, as in Figure 10.28b. Red and blue in both panels correspond to El Niño and La Niña, respectively. (c) SST reconstructions from the region 5°N–5°S, 150°W– 90°W. Source: From IPCC (2001). (d) Correlation of monthly sea level pressure anomalies with the ENSO Nino3.4 index, averaged from 1948 to 2007. The Nino3.4 index is positive during the El Niño phase, so the signs shown are representative of this phase. Data and graphical interface from NOAA ESRL (2009b).

(a) Southern Oscillation Index (SOI) time series from 1876 to 2008 (annual average). Data from Australian Government Bureau of Meteorology (2009). (b) "Oceanic Nino Index" based on SST in the region 5°N–5°S, 170°W–120°W, as in Figure 10.28b. Red and blue in both panels correspond to El Niño and La Niña, respectively. (c) SST reconstructions from the region 5°N–5°S, 150°W– 90°W. Source: From IPCC (2001). (d) Correlation of monthly sea level pressure anomalies with the ENSO Nino3.4 index, averaged from 1948 to 2007. The Nino3.4 index is positive during the El Niño phase, so the signs shown are representative of this phase. Data and graphical interface from NOAA ESRL (2009b).

Global precipitation anomalies for Northern Hemisphere summer (left) and winter (right) during El Niño. Source: From NOAA PMEL (2009d).

Anomalies of United States winter (JFM) (a) temperature (°C) and (b) precipitation (mm) during composite El Niño events from 1950 to 2008. Source: From NWS Internet Services Team (2008).

Subtropical Mode Water. (a) Vertical profile through North Pacific Subtropical Mode Water, at 29° 5'N, 158° 33'E. Source: From Hanawa and Talley (2001). (b) North Pacific: thickness of the 17–18 °C layer. Source: From Masuzawa (1969). (c) South Pacific: thickness of the 15–17 °C layer. ©American Meteorological Society. Reprinted with permission. Source: From Roemmich and Cornuelle (1992).

(c) South Pacific: thickness of the 15–17 °C layer. ©American Meteorological Society. Reprinted with permission. Source: From Roemmich and Cornuelle (1992).

Salinity at the NPIW salinity minimum. Outer dark contour is the edge of the salinity minimum. ©American Meteorological Society. Reprinted with permission. Source: From Talley (1993).

(a) Salinity, (b) oxygen (μmol/kg), and (c) silicate (μmol/kg) along 165°W. Neutral densities 28.00 and 28.10 kg/m³ are superimposed. Station locations are shown in inset in (c). Source: From WOCE Pacific Ocean Atlas, Talley (2007).

(a) Salinity, (b) oxygen (μmol/kg), and (c) silicate (μmol/kg) along 165°W. Neutral densities 28.00 and 28.10 kg/m³ are superimposed. Station locations are shown in inset in (c). Source: From WOCE Pacific Ocean Atlas, Talley (2007).

(a) Salinity, (b) silicate (μmol/kg), (c) Δ¹⁴C (/mille), and (d) δ³He (%) at neutral density 28.01 kg/m³ (σ₂ ~ 36.96 kg/m³), characterizing PDW/UCDW at mid-depth. The depth of the surface is approximately 2600—2800 m north of the Antarctic Circumpolar Current. Source: From WOCE Pacific Ocean Atlas, Talley (2007).

(a) Salinity, (b) silicate (μmol/kg), and (c) depth (m) at neutral density 28.10 kg/m³ (σ₄ ~ 45.88 kg/m³), characteristic of LCDW. (d) Potential temperature at 4000 m. Source: From WOCE Pacific Ocean Atlas, Talley (2007).