Intraseasonal Variability of Surface Fluxes and Sea Surface Temperature in the Tropical Western Pacific and Indian Oceans

Abstract Sea surface temperature (SST) variability at intraseasonal time scales across the Indonesian Seas during January 1998–mid-2012 is examined. The intraseasonal variability is most energetic in the Banda and Timor Seas, with a standard deviation of 0.4°–0.5°C, representing 55%–60% of total nonseasonal SST variance. A slab ocean model demonstrates that intraseasonal air–sea heat flux variability, largely attributed to the Madden–Julian oscillation (MJO), accounts for 69%–78% intraseasonal SST variability in the Banda and Timor Seas. While the slab ocean model accurately reproduces the observed intraseasonal SST variations during the northern winter months, it underestimates the summer variability. The authors posit that this is a consequence of a more vigorous cooling effect induced by ocean processes during the summer. Two strong MJO cycles occurred in late 2007–early 2008, and their imprints were clearly evident in the SST of the Banda and Timor Seas. The passive phase of the MJO [enhanced outgoing longwave radiation (OLR) and weak zonal wind stress) projects on SST as a warming period, while the active phase (suppressed OLR and westerly wind bursts) projects on SST as a cooling phase. SST also displays significant intraseasonal variations in the Sulawesi Sea, but these differ in characteristics from those of the Banda and Timor Seas and are attributed to ocean eddies and atmospheric processes independent from the MJO.

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The tropospheric biennial oscillation defined by a biennial mode of sea surface temperature and its impact on the atmospheric circulation and precipitation in the tropical eastern Indo-western Pacific region

Climate Dynamics ◽

10.1007/s00382-016-2987-9 ◽

2016 ◽

Vol 47 (7-8) ◽

pp. 2601-2615 ◽

Cited By ~ 3

Author(s):

Jinju Kim ◽

Kwang-Yul Kim

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Atmospheric Circulation ◽

Western Pacific ◽

Sea Surface ◽

Pacific Region ◽

Western Pacific Region ◽

Tropospheric Biennial Oscillation ◽

Biennial Oscillation

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Coupled Mg/Ca and clumped isotope measurements at IODP Site U1488 confirm absence of Plio-Pleistocene sea surface temperature cooling in the Western Pacific Warm Pool

10.5194/egusphere-egu2020-16364 ◽

2020 ◽

Author(s):

Niklas Meinicke ◽

Maria Reimi ◽

Christina Ravelo ◽

Nele Meckler

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Planktonic Foraminifera ◽

Warm Pool ◽

Western Pacific ◽

Sea Surface ◽

Western Pacific Warm Pool ◽

Pacific Warm Pool ◽

The Western Pacific

The Western Pacific Warm Pool (WPWP) as a major source of heat and water vapor has a crucial influence on climate dynamics both in the tropics and globally. Yet, there is conflicting proxy evidence regarding the evolution of WPWP temperatures since the Miocene. On the one hand TEX86 data suggest a gradual cooling by ~2&#8451; (O&#8217;Brian et al., 2014, Zhang et al., 2014) from the Pliocene to today, while faunal (planktonic foraminifera) sea surface temperature estimates (Dowsett, 2007) and Mg/Ca data measured in planktonic foraminifera (Wara et al., 2005) on the other hand indicate the absence of any long-term temperature trends. It has been suggested that Mg/Ca temperatures could on these time scales be biased by long-term changes of the Mg/Ca ratio of seawater (Evans et al., 2016). To test the influence of the proposed seawater changes on Mg/Ca we combined data from two independent temperature proxies, Mg/Ca and clumped isotopes, measured on two species of planktonic foraminifera from IODP Site U1488 in the central WPWP. Our study finds good agreement between both proxies thereby verifying the validity of Mg/Ca records from the WPWP and confirming the absence of a Plio-Pleistocene cooling trend for the WPWP. This finding suggests that the persistent disagreement between foraminifer-based proxies such as Mg/Ca and biomarker data might be caused by different environmental parameters being recorded in the two archives.&#160;References:O&#8217;Brien CL, Foster GL, Mart&#237;nez-Bot&#237; MA, Abell R, Rae JWB, Pancost RD. High sea surface temperatures in tropical warm pools during the Pliocene. Nature Geoscience. 2014;7(8):606-11.Zhang YG, Pagani M, Liu Z. A 12-million-year temperature history of the tropical Pacific Ocean. Science. 2014;344(6179):84-7.Dowsett H. Faunal re-evaluation of Mid-Pliocene conditions in the western equatorial Pacific. Micropaleontology. 2007;53(6):447-56.Wara MW, Ravelo AC, Delaney ML. Permanent El Nino-like conditions during the Pliocene warm period. Science. 2005;309(5735):758-61.Evans D, Brierley C, Raymo ME, Erez J, M&#252;ller W. Planktic foraminifera shell chemistry response to seawater chemistry: Pliocene&#8211;Pleistocene seawater Mg/Ca, temperature and sea level change. Earth and Planetary Science Letters. 2016;438:139-48.

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U.S. West Coast Surface Heat Fluxes, Wind Stress, and Wind Stress Curl from a Mesoscale Model

Monthly Weather Review ◽

10.1175/mwr3025.1 ◽

2005 ◽

Vol 133 (11) ◽

pp. 3202-3216 ◽

Cited By ~ 18

Author(s):

T. Haack ◽

S. D. Burk ◽

R. M. Hodur

Keyword(s):

Relative Humidity ◽

Surface Temperature ◽

Sea Surface Temperature ◽

Wind Stress ◽

Mesoscale Model ◽

Surface Fluxes ◽

Heat Fluxes ◽

Sea Surface ◽

Wind Stress Curl ◽

Low Level

Abstract Monthly averages of numerical model fields are beneficial for depicting patterns in surface forcing such as sensible and latent heat fluxes, wind stress, and wind stress curl over data-sparse ocean regions. Grid resolutions less than 10 km provide the necessary mesoscale detail to characterize the impact of a complex coastline and coastal topography. In the present study a high-resolution mesoscale model is employed to reveal patterns in low-level winds, temperature, relative humidity, sea surface temperature as well as surface fluxes, over the eastern Pacific and along the U.S. west coast. Hourly output from successive 12-h forecasts are averaged to obtain monthly mean patterns from each season of 1999. The averages yield information on interactions between the ocean and the overlying atmosphere and on the influence of coastal terrain forcing in addition to their month-to-month variability. The spring to summer transition is characterized by a dramatic shift in near-surface winds, temperature, and relative humidity as offshore regions of large upward surface fluxes diminish and an alongshore coastal flux gradient forms. Embedded within this gradient, and the imprint of strong summertime topographic forcing, are small-scale fluctuations that vary in concert with local changes in sea surface temperature. Potential feedbacks between the low-level wind, sea surface temperature, and the wind stress curl are explored in the coastal regime and offshore waters. In all seasons, offshore extensions of colder coastal waters impose a marked influence on low-level conditions by locally enhancing stability and reducing the wind speed, while buoy measurements along the coast indicate that sea surface temperatures and wind speeds tend to be negatively correlated.

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