Impact of the Atlantic Warm Pool on precipitation and temperature in Florida during North Atlantic cold spells

Abstract

Recurrent phases of increased pine at Lake Tulane, Florida have previously been related to strong stadials terminated by so-called Heinrich events. The climatic significance of these pine phases has been interpreted in different ways. Using a pollen-climate inference model, we quantified the climate changes and consistently found that mean summer precipitation (P JJA ) increased (0.5-0.9 mm/day) and mean November temperature increased (2.0-3.0°C) during pine phases coeval with Heinrich events and the Younger Dryas. Marine sea surface temperature records indicate that potential sources for these moisture and heat anomalies are in the Gulf of Mexico and the western tropical Atlantic. We explain this low latitude warming by an increased Loop Current facilitated by persistence of the Atlantic Warm Pool during summer. This hypothesis is supported by a climate model sensitivity analysis. A positive heat anomaly in the Gulf of Mexico and equatorial Atlantic best approximates the polleninferred climate reconstructions from Lake Tulane during the (stadials around) Heinrich events and the Younger Dryas.

Moisture contribution of the Atlantic Warm Pool to precipitation: a Lagrangian analysis

“…For instance, reconstructed paleoclimatic data indicate that the persistence of the AWP during summer is responsible for increased precipitation and temperature detected in Florida during Heinrich events (Donders et al, 2011). Boer et al (2011) suggest that the AWP may have played a key role in the glacial climate, by acting as a gatekeeper to regulate atmospheric moisture transport from the Atlantic across the Central American isthmus toward the Pacific.…”

Middle Holocene humidity increase in Florida: climate or sea-level?

“…Surrounded by warm surface currents, Florida climate responds sensitively to both Northern Hemisphere cold events (Grimm et al, 2006) and movements of the Intertropical Convergence Zone (ITCZ) (Poore et al, 2003;Van Soelen et al, 2012). As a result, it is a key area to detect changes in low-latitude heat buildup due to slowdowns in the Atlantic meridional overturning circulation (AMOC) (Donders et al, 2011). The northern, central and southern portions of the Florida peninsula are differentially regulated by sea-surface temperatures and circulation patterns in the Atlantic and Gulf of Mexico (Enfield et al, 2001).…”

“…Alternatively, a dominantly climatological forcing would likely have been a regionally divergent. For the southernmost transect sites, Lake Tulane (LT) (Grimm et al, 1993(Grimm et al, , 2006 and Lake Annie (LA) (Watts, 1975), quantitative reconstructions are already available (Donders et al, 2011). The same transfer function is used to obtain estimates from additional localities (Fig.…”

“…I apply a recently developed transfer model (Donders et al, 2011) to provide a quantitative reinterpretation of previously published pollen records from Florida and examine a north-tosouth gradient of precipitation in Florida during the Holocene. Updated chronologies of the sites, based on recalibrated radiocarbon ages and new age-depth modelling, provide an improved regional comparison.…”

Feral swine damage to globally imperiled wetland plant communities in a significant biodiversity hotspot in Florida

“…The El Niño Southern Oscillation (ENSO) cycle accentuates or diminishes the effects of seasonal precipitation in the region (Slocum et al 2010;Slocum and Orzell 2013). During the La Niña phase of ENSO, reduced precipitation creates severe drought during the dry season (Brenner 1991;Beckage et al 2003), whereas during the El Niño phase, dry season precipitation increases (Donders et al 2005(Donders et al , 2011Slocum and Orzell 2013). Intra-annual variation in the wet/dry seasonal climates and variations in the ENSO cycle influence hydrology and affect the hydro-period within seasonal wetlands, pine savannas, and grasslands.…”