Impact of Central and Eastern Atlantic Niño on SST and precipitation patterns in reanalysis and Earth System Models
Cruz-Perez, A., Li, H.. (2025). Impact of Central and Eastern Atlantic Niño on SST and precipitation patterns in reanalysis and Earth System Models. , doi:https://doi.org/10.5065/4ebw-0v18
| Title | Impact of Central and Eastern Atlantic Niño on SST and precipitation patterns in reanalysis and Earth System Models |
|---|---|
| Genre | Manuscript |
| Author(s) | Allan Cruz-Perez, Hui Li |
| Abstract | Differentiating between the two recently identified types of Atlantic Niño (AN) – Central (CAN) and Eastern (EAN) Atlantic Niño – which have distinct patterns and impact on the tropics, is essential to understand the sources of biases in Earth System Models related to the AN. Earth System Models exhibit sea surface temperature (SST) and precipitation biases over the tropical Atlantic and Eastern Pacific, which may be related to the timing and intensity of the AN. In this study, we use empirical orthogonal function (EOF)-based indices to differentiate CAN and EAN interactions with the Pacific during boreal summer (JJA) and fall (SON). We use linear regressions of precipitation, SSTs, and vertical and zonal winds against the Central (CANI) and Eastern (EANI) Atlantic Niño indices. The results from reanalysis are compared with the Community Earth System Model version 2.1 (CESM2.1) Large Ensemble (LENS2) and the Energy Exascale Earth System Model version 2 Large Ensemble (E3SMv2-LE). A 21-year rolling window variance was calculated on each index to compare the difference in evolution of the AN between datasets. Initial results demonstrate the connection between CAN and EAN to the La Niña phase of El Niño Southern Oscillation (ENSO) with colder SST regressions during the SON season and drier precipitation conditions across the equatorial Pacific. In contrast, CESM2.1 ensemble means show warmer SSTs south of the equatorial Pacific with minimal significant precipitation regressions, highlighting a biased relationship between the Atlantic and Pacific. Further studies of the AN and ENSO interaction are essential for correcting biases across the tropics in Earth System Models. |
| Publication Title | |
| Publication Date | Aug 1, 2025 |
| Publisher's Version of Record | https://doi.org/10.5065/4ebw-0v18 |
| OpenSky Citable URL | https://n2t.net/ark:/85065/d7p55sz1 |
| OpenSky Listing | View on OpenSky |
| CGD Affiliations | ESP |