@article {23934,
	title = {ENSO surface longwave radiation forcing over the tropical Pacific},
	volume = {7},
	year = {2007},
	month = {2007/04/1},
	pages = {2013 - 2026},
	abstract = {We have studied the spatial and temporal variation of the surface longwave radiation (downwelling and net) over a 21-year period in the tropical and subtropical Pacific Ocean (40 S-40 N, 90 E-75 W). The fluxes were computed using a deterministic model for atmospheric radiation transfer, along with satellite data from the ISCCP-D2 database and reanalysis data from NCEP/NCAR (acronyms explained in main text), for the key atmospheric and surface input parameters. An excellent correlation was found between the downwelling longwave radiation (DLR) anomaly and the Ni\&amp;ntilde;o-3.4 index time-series, over the Ni\&amp;ntilde;o-3.4 region located in the central Pacific. A high anti-correlation was also found over the western Pacific (15-0 S, 105-130 E). There is convincing evidence that the time series of the mean downwelling longwave radiation anomaly in the western Pacific precedes that in the Ni\&amp;ntilde;o-3.4 region by 3-4 months. Thus, the downwelling longwave radiation anomaly is a complementary index to the SST anomaly for the study of ENSO events and can be used to asses whether or not El Ni\&amp;ntilde;o or La Ni\&amp;ntilde;a conditions prevail. Over the Ni\&amp;ntilde;o-3.4 region, the mean DLR anomaly values range from +20 Wm<SUP>-2</SUP> during El Ni\&amp;ntilde;o episodes to -20 Wm<SUP>-2</SUP> during La Ni\&amp;ntilde;a events, while over the western Pacific (15-0 S, 105-130 E) these values range from -15 Wm<SUP>-2</SUP> to +10 Wm<SUP>-2</SUP>, respectively. The long- term average (1984-2004) distribution of the net downwelling longwave radiation at the surface over the tropical and subtropical Pacific for the three month period November-December-January shows a net thermal cooling of the ocean surface. When El Ni\&amp;ntilde;o conditions prevail, the thermal radiative cooling in the central and south-eastern tropical Pacific becomes weaker by 10 Wm<SUP>-2</SUP> south of the equator in the central Pacific (7-0 S, 160-120 W) for the three-month period of NDJ, because the DLR increase is larger than the increase in surface thermal emission. In contrast, the thermal radiative cooling over Indonesia is enhanced by 10 Wm<SUP>-2</SUP> during the early (August-September-October) El Ni\&amp;ntilde;o phase.},
	isbn = {1680-73671680-73161680-7324       Atmospheric Chemistry and Physics},
	url = {https://ui.adsabs.harvard.edu/abs/2007ACP.....7.2013P},
	author = {Pavlakis, K. G. and Hatzidimitriou, D. and Drakakis, E. and Matsoukas, C. and Fotiadi, A. and Hatzianastassiou, N. and Vardavas, I.}
}
