The simulation of peak and delayed ENSO teleconnections
There is much evidence that El Niño and La Niña lead to significant atmospheric seasonal predictability across much of the globe. However, despite successful predictions of tropical Pacific SSTs, atmospheric seasonal forecasts have had limited success. This study investigates model errors in the Had...
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ftunivreading:oai:centaur.reading.ac.uk:5197 2024-09-15T17:36:29+00:00 The simulation of peak and delayed ENSO teleconnections Spencer, Hilary Slingo, J. M. 2003-06 https://centaur.reading.ac.uk/5197/ unknown American Meteorological Society Spencer, H. <https://centaur.reading.ac.uk/view/creators/90000848.html> orcid:0000-0003-4553-7082 and Slingo, J. M. <https://centaur.reading.ac.uk/view/creators/90000425.html> (2003) The simulation of peak and delayed ENSO teleconnections. Journal of Climate, 16 (11). pp. 1757-1774. ISSN 0894-8755 doi: https://doi.org/10.1175/1520-0442(2003)016<1757:TSOPAD>2.0.CO;2 <https://doi.org/10.1175/1520-0442(2003)016<1757:TSOPAD>2.0.CO;2> 551 Geology hydrology meteorology Article PeerReviewed 2003 ftunivreading https://doi.org/10.1175/1520-0442(2003)016<1757:TSOPAD>2.0.CO;2 2024-06-25T14:39:27Z There is much evidence that El Niño and La Niña lead to significant atmospheric seasonal predictability across much of the globe. However, despite successful predictions of tropical Pacific SSTs, atmospheric seasonal forecasts have had limited success. This study investigates model errors in the Hadley Centre Atmospheric Model version 3 (HadAM3) by analyzing composites of similar El Niño and La Niña events at their peak in December–January–February (DJF) and through their decay in March–April–May (MAM). The large-scale, tropical ENSO teleconnections are modeled accurately by HadAM3 during DJF but the strongest extratropical teleconnection, that in the North Pacific during winter, is modeled inaccurately. The Aleutian low is frequently observed to shift eastward during El Niño but the modeled response always consists of a deepening of the low without a shift. This is traced to small errors in the sensitivity of precipitation to SST in the tropical Pacific, which does not display enough variability so that the precipitation is always too high over the warmest SSTs. This error is reduced when vertical resolution is increased from 19 to 30 levels but enhanced horizontal resolution does not improve the simulation further. In MAM, following the peak of an El Niño or La Niña, atmospheric anomalies are observed to decay rapidly. The modeled ENSO response in DJF persists into MAM, making the extratropical anomalies in MAM too strong. This inaccuracy is again likely to be due to the high modeled sensitivity of tropical Pacific precipitation to SST, which is not significantly improved with enhanced vertical or horizontal resolution in MAM. Article in Journal/Newspaper aleutian low CentAUR: Central Archive at the University of Reading |
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CentAUR: Central Archive at the University of Reading |
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ftunivreading |
language |
unknown |
topic |
551 Geology hydrology meteorology |
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551 Geology hydrology meteorology Spencer, Hilary Slingo, J. M. The simulation of peak and delayed ENSO teleconnections |
topic_facet |
551 Geology hydrology meteorology |
description |
There is much evidence that El Niño and La Niña lead to significant atmospheric seasonal predictability across much of the globe. However, despite successful predictions of tropical Pacific SSTs, atmospheric seasonal forecasts have had limited success. This study investigates model errors in the Hadley Centre Atmospheric Model version 3 (HadAM3) by analyzing composites of similar El Niño and La Niña events at their peak in December–January–February (DJF) and through their decay in March–April–May (MAM). The large-scale, tropical ENSO teleconnections are modeled accurately by HadAM3 during DJF but the strongest extratropical teleconnection, that in the North Pacific during winter, is modeled inaccurately. The Aleutian low is frequently observed to shift eastward during El Niño but the modeled response always consists of a deepening of the low without a shift. This is traced to small errors in the sensitivity of precipitation to SST in the tropical Pacific, which does not display enough variability so that the precipitation is always too high over the warmest SSTs. This error is reduced when vertical resolution is increased from 19 to 30 levels but enhanced horizontal resolution does not improve the simulation further. In MAM, following the peak of an El Niño or La Niña, atmospheric anomalies are observed to decay rapidly. The modeled ENSO response in DJF persists into MAM, making the extratropical anomalies in MAM too strong. This inaccuracy is again likely to be due to the high modeled sensitivity of tropical Pacific precipitation to SST, which is not significantly improved with enhanced vertical or horizontal resolution in MAM. |
format |
Article in Journal/Newspaper |
author |
Spencer, Hilary Slingo, J. M. |
author_facet |
Spencer, Hilary Slingo, J. M. |
author_sort |
Spencer, Hilary |
title |
The simulation of peak and delayed ENSO teleconnections |
title_short |
The simulation of peak and delayed ENSO teleconnections |
title_full |
The simulation of peak and delayed ENSO teleconnections |
title_fullStr |
The simulation of peak and delayed ENSO teleconnections |
title_full_unstemmed |
The simulation of peak and delayed ENSO teleconnections |
title_sort |
simulation of peak and delayed enso teleconnections |
publisher |
American Meteorological Society |
publishDate |
2003 |
url |
https://centaur.reading.ac.uk/5197/ |
genre |
aleutian low |
genre_facet |
aleutian low |
op_relation |
Spencer, H. <https://centaur.reading.ac.uk/view/creators/90000848.html> orcid:0000-0003-4553-7082 and Slingo, J. M. <https://centaur.reading.ac.uk/view/creators/90000425.html> (2003) The simulation of peak and delayed ENSO teleconnections. Journal of Climate, 16 (11). pp. 1757-1774. ISSN 0894-8755 doi: https://doi.org/10.1175/1520-0442(2003)016<1757:TSOPAD>2.0.CO;2 <https://doi.org/10.1175/1520-0442(2003)016<1757:TSOPAD>2.0.CO;2> |
op_doi |
https://doi.org/10.1175/1520-0442(2003)016<1757:TSOPAD>2.0.CO;2 |
_version_ |
1810489884872278016 |