scholarly journals Role of moisture transport for Central American precipitation

2016 ◽  
Author(s):  
Ana María Durán-Quesada ◽  
Luis Gimeno ◽  
Jorge Amador
Keyword(s):  
Central America ◽  
Moisture Transport ◽  
Rainy Season ◽  
Large Scale ◽  
Southern Oscillation ◽  
Caribbean Sea ◽  
Central American ◽  
Moisture Supply ◽  
The Caribbean ◽  
Precipitation Trends

Abstract. A climatology of moisture sources linked with Central American precipitation was computed based upon Lagrangian trajectories for the analysis period 1980–2013. The response of the annual cycle of precipitation in terms of moisture supply from the sources was analysed. Regional precipitation patterns are mostly driven by moisture transport from the Caribbean Sea (CS). Moisture supply from the Eastern Tropical Pacific (ETPac) and Northern South America (NSA) exhibits a strong seasonal pattern but weaker compared to CS. The regional distribution of rainfall is largely influenced by a local signal associated with surface fluxes during the first part of the rainy season, whereas large scale dynamics forces rainfall during the second part of the rainy season. The Caribbean Low Level Jet (CLLJ) and the Chocó Jet (CJ) are the main conveyors of regional moisture, being key to define the seasonality of large scale forced rainfall. Therefore, interannual variability of rainfall is highly dependent of the regional LLJs to the atmospheric variability modes. The El Niño-Southern Oscillation (ENSO) was found to be the dominant mode affecting moisture supply for Central American precipitation via the modulation of regional phenomena. Evaporative sources show opposite anomaly patterns during warm and cold ENSO phases, as a result of the strengthening and weakening, respectively, of the CLLJ during the summer months. Trends in both moisture supply and precipitation over the last three decades were computed, results suggest that precipitation trends are not homogeneous for Central America. Trends in moisture supply from the sources identified show a marked north-south seesaw, with an increasing supply from the Caribbean Sea to northern Central America. Long term trends in moisture supply are larger for the transition months (March and October). This might have important implications given that any changes in the conditions seen during the transition to the rainy season may induce stronger precipitation trends.

scholarly journals Role of moisture transport for Central American precipitation

2017 ◽  
Vol 8 (1) ◽  
pp. 147-161 ◽  
Author(s):  
Ana María Durán-Quesada ◽  
Luis Gimeno ◽  
Jorge Amador
Keyword(s):  
Central America ◽  
Moisture Transport ◽  
Rainy Season ◽  
Large Scale ◽  
Southern Oscillation ◽  
Regional Distribution ◽  
Central American ◽  
Moisture Supply ◽  
The Caribbean ◽  
Precipitation Trends

Abstract. A climatology of moisture sources linked with Central American precipitation was computed based upon Lagrangian trajectories for the analysis period 1980–2013. The response of the annual cycle of precipitation in terms of moisture supply from the sources was analysed. Regional precipitation patterns are mostly driven by moisture transport from the Caribbean Sea (CS). Moisture supply from the eastern tropical Pacific (ETPac) and northern South America (NSA) exhibits a strong seasonal pattern but weaker compared to CS. The regional distribution of rainfall is largely influenced by a local signal associated with surface fluxes during the first part of the rainy season, whereas large-scale dynamics forces rainfall during the second part of the rainy season. The Caribbean Low Level Jet (CLLJ) and the Chocó Jet (CJ) are the main conveyors of regional moisture, being key to define the seasonality of large-scale forced rainfall. Therefore, interannual variability of rainfall is highly dependent of the regional LLJs to the atmospheric variability modes. The El Niño–Southern Oscillation (ENSO) was found to be the dominant mode affecting moisture supply for Central American precipitation via the modulation of regional phenomena. Evaporative sources show opposite anomaly patterns during warm and cold ENSO phases, as a result of the strengthening and weakening, respectively, of the CLLJ during the summer months. Trends in both moisture supply and precipitation over the last three decades were computed, results suggest that precipitation trends are not homogeneous for Central America. Trends in moisture supply from the sources identified show a marked north–south seesaw, with an increasing supply from the CS Sea to northern Central America. Long-term trends in moisture supply are larger for the transition months (March and October). This might have important implications given that any changes in the conditions seen during the transition to the rainy season may induce stronger precipitation trends.

scholarly journals A Transbasin Mode of Interannual Variability of the Central American Gap Winds: Seasonality and Large-Scale Forcing

2017 ◽  
Vol 30 (20) ◽  
pp. 8223-8235
Author(s):  
Jun-Chao Yang ◽  
Xiaopei Lin ◽  
Shang-Ping Xie
Keyword(s):  
Central America ◽  
Large Scale ◽  
Southern Oscillation ◽  
Function Analysis ◽  
Walker Circulation ◽  
Central American ◽  
Boreal Summer ◽  
Wind Variability ◽  
The Pacific ◽  
Gap Winds

Abstract A transbasin mode (TBM) is identified as the leading mode of interannual surface wind variability over the Intra-Americas Seas across Central America based on empirical orthogonal function analysis. The TBM is associated with variability in Central American gap winds, most closely with the Papagayo jet but with considerable signals over the Gulfs of Tehuantepec and Panama. Although El Niño–Southern Oscillation (ENSO) is the main large-scale forcing, the TBM features a distinct seasonality due to sea level pressure (SLP) adjustments across the Pacific and Atlantic. During July–September, ENSO causes meridional SLP gradient anomalies across Central America, intensifying anomalous geostrophic winds funneling through Papagayo to form the TBM. During wintertime, ENSO peaks but imparts little anomalous SLP gradient across Central America with a weak projection on the TBM because of the competing effects of the Pacific–North American teleconnection and tropospheric Kelvin waves. Besides ENSO, tropical Atlantic sea surface temperature anomalies make a weak contribution to the TBM in boreal summer by strengthening the cross-basin gradient. ENSO and the Atlantic forcing constitute a cross-basin seesaw pattern in SLP, manifested as an anomalous Walker circulation across the tropical Americas. The TBM appears to be part of the low-level branch of the anomalous Walker circulation, which modulates Central American wind jets by orographic effect. This study highlights the seasonality of gap wind variability, and calls for further research into its influence on regional climate.

A morphological and molecular revision of lizards of the genus Marisora Hedges & Conn (Squamata: Mabuyidae) from Central America and Mexico, with descriptions of four new species

Zootaxa ◽  
2020 ◽  
Vol 4763 (3) ◽  
pp. 301-353
Author(s):  
JAMES R. MCCRANIE ◽  
AMY J. MATTHEWS ◽  
S. BLAIR HEDGES
Keyword(s):  
New Species ◽  
South America ◽  
Central America ◽  
Caribbean Sea ◽  
Molecular Data ◽  
Central American ◽  
The Caribbean ◽  
Northern South America ◽  
Genetic Distinctiveness ◽  
Morphological And Molecular Data

The skink genus Marisora ranges from Mexico to northern South America and occurs on some islands in the Caribbean Sea. We conducted a revision of the genus Marisora from Mexico and Central America, using new morphological and molecular data, and find support for the five previously described species (Marisora alliacea, M.aurulae, M. brachypoda, M. magnacornae, and M. roatanae) and describe four new species: Marisora lineola sp. nov., M. aquilonaria sp. nov., M. syntoma sp. nov., and M. urtica sp. nov. We show that two species previously known only from Central American islands, M. magnacornae and M. roatanae, also occur on the adjacent mainland and that two species recently placed in Alinea belong to this evolutionary clade: Marisora berengerae n. comb. and Marisora pergravis n. comb. Together with M. falconensis and M. unimarginata, these 13 species of Marisora arose mostly in the Pliocene and are largely allopatric but are sympatric and nearly sympatric at several locations in Central America where they maintain their morphological and genetic distinctiveness. 

Identification of Tropical Cyclones’ Critical Positions Associated with Extreme Precipitation Events in Central America

2021 ◽  
Author(s):  
Hugo G. Hidalgo ◽  
Eric J. Alfaro ◽  
Franklin Hernández-Castro ◽  
Paula M. Pérez-Briceño
Keyword(s):  
Central America ◽  
Tropical Cyclones ◽  
Critical Path ◽  
Central American ◽  
Pacific Basin ◽  
Extreme Precipitation Events ◽  
The Pacific ◽  
The Caribbean ◽  
Indirect Impacts ◽  
Precipitation Events

<p>Tropical cyclones are one of the most important causes of disasters in Central America. Using historical (1970–2010) tracks of cyclones in the Caribbean and Pacific basin, we identify critical path locations where these low-pressure systems cause the highest number of floods in a set of 88 precipitation stations in the region. Results show that tropical cyclones from the Caribbean and Pacific basin produce a large number of indirect impacts on the Pacific slope of the Central American isthmus. Although the direct impact of a tropical cyclone usually results in devastation in the affected region, the indirect effects are more common and sometimes equally severe. In fact, the storm does not need to be an intense hurricane to cause considerable impacts and damage. The location of even a lower intensity storm in critical positions of the oceanic basin can result in destructive indirect impacts in Central America. The identification of critical positions can be used for emergency agencies in the region to issue alerts of possible flooding and catastrophic events.</p>

The African Presence in Central American History

2020 ◽  
Author(s):  
Robinson Herrera
Keyword(s):  
Central America ◽  
Cultural Landscape ◽  
18Th Century ◽  
African Descent ◽  
Central American ◽  
Cultural Traditions ◽  
Spanish Conquest ◽  
African Slaves ◽  
The Caribbean ◽  
Sub Saharan

Far from monolithic, the seven Central American countries—Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama—each have unique cultural traditions and historical trajectories. Their different geographies, while not deterministic in any facile manner, influenced their development in ways that continue to shape their national characteristics. The cataclysmic 16th-century Spanish Conquest introduced new peoples and cultural traditions to the region. African slaves, primarily from the sub-Saharan region, accompanied the first Spanish ventures, and, later, as the colonies consolidated and grew, peoples of African descent, both enslaved and free, became a part of the area’s economic and cultural landscape. Starting in the late 18th century, African peoples from the Caribbean—whether forcefully exiled or as a result of searching for economic opportunities—traveled to Central America. Despite a contemporary collective historical amnesia that imagines Africans isolated in specific regions, namely the Caribbean coast, peoples of African descent can be found throughout the Central American nations. Rather than addressing each country, a thematic approach that focuses on the Spanish Conquest, slavery, emancipation, the ethnogenesis of African connected cultures, the historical erasure of Africans, and the contributions of peoples of African descent helps to understand the complex ways that peoples of African descent have impacted the history of modern Central America. For far from isolated to small populations along the Caribbean, the African presence can be discerned throughout the region, even in places often perceived as entirely devoid of its influence.

scholarly journals The Surface Circulation of the Caribbean Sea and the Gulf of Mexico as Inferred from Satellite Altimetry

2009 ◽  
Vol 39 (3) ◽  
pp. 640-657 ◽  
Author(s):  
Aida Alvera-Azcárate ◽  
Alexander Barth ◽  
Robert H. Weisberg
Keyword(s):  
Gulf Of Mexico ◽  
Time Scales ◽  
Satellite Altimetry ◽  
Southern Oscillation ◽  
Caribbean Sea ◽  
Vertical Shear ◽  
Loop Current ◽  
Surface Circulation ◽  
The Caribbean ◽  
Anticyclonic Eddies

Abstract The surface circulation of the Caribbean Sea and Gulf of Mexico is studied using 13 years of satellite altimetry data. Variability in the Caribbean Sea is evident over several time scales. At the annual scale, sea surface height (SSH) varies mainly by a seasonal steric effect. Interannually, a longer cycle affects the SSH slope across the current and hence the intensity of the Caribbean Current. This cycle is found to be related to changes in the wind intensity, the wind stress curl, and El Niño–Southern Oscillation. At shorter time scales, eddies and meanders are observed in the Caribbean Current, and their propagation speed is explained by baroclinic instabilities under the combined effect of vertical shear and the β effect. Then the Loop Current (LC) is considered, focusing on the anticyclonic eddies shed by it and the intrusion of the LC into the Gulf of Mexico through time. Twelve of the 21 anticyclonic eddies observed to detach from the LC are shed from July to September, suggesting a seasonality in the timing of these events. Also, a relation is found between the intrusion of the LC into the Gulf of Mexico and the size of the eddies shed from it: larger intrusions trigger smaller eddies. A series of extreme LC intrusions into the Gulf of Mexico, when the LC is observed as far as 92°W, are described. The analyses herein suggest that the frequency of such events has increased in recent years, with only one event occurring in 1993 versus three from 2002 to 2006. Transport through the Straits of Florida appears to decrease during these extreme intrusions.

scholarly journals Impact of the Atlantic Warm Pool on the Summer Climate of the Western Hemisphere

2007 ◽  
Vol 20 (20) ◽  
pp. 5021-5040 ◽  
Author(s):  
Chunzai Wang ◽  
Sang-ki Lee ◽  
David B. Enfield
Keyword(s):  
North Atlantic ◽  
Moisture Transport ◽  
Caribbean Sea ◽  
Warm Pool ◽  
Western Hemisphere ◽  
Trade Winds ◽  
The North ◽  
Atlantic Warm Pool ◽  
Tropical North Atlantic ◽  
The Caribbean

Abstract The Atlantic warm pool (AWP) is a large body of warm water that comprises the Gulf of Mexico, the Caribbean Sea, and the western tropical North Atlantic. Located to its northeastern side is the North Atlantic subtropical high (NASH), which produces the tropical easterly trade winds. The easterly trade winds carry moisture from the tropical North Atlantic into the Caribbean Sea, where the flow intensifies, forming the Caribbean low-level jet (CLLJ). The CLLJ then splits into two branches: one turning northward and connecting with the Great Plains low-level jet (GPLLJ), and the other continuing westward across Central America into the eastern North Pacific. The easterly CLLJ and its westward moisture transport are maximized in the summer and winter, whereas they are minimized in the fall and spring. This semiannual feature results from the semiannual variation of sea level pressure in the Caribbean region owing to the westward extension and eastward retreat of the NASH. The NCAR Community Atmospheric Model and observational data are used to investigate the impact of the climatological annual mean AWP on the summer climate of the Western Hemisphere. Two groups of the model ensemble runs with and without the AWP are performed and compared. The model results show that the effect of the AWP is to weaken the summertime NASH, especially at its southwestern edge. The AWP also strengthens the summertime continental low over the North American monsoon region. In response to these pressure changes, the CLLJ and its moisture transport are weakened, but its semiannual feature does not disappear. The weakening of the easterly CLLJ increases (decreases) moisture convergence to its upstream (downstream) and thus enhances (suppresses) rainfall in the Caribbean Sea (in the far eastern Pacific west of Central America). Model runs show that the AWP’s effect is to always weaken the southerly GPLLJ. However, the AWP strengthens the GPLLJ’s northward moisture transport in the summer because the AWP-induced increase of specific humidity overcomes the weakening of southerly wind, and vice versa in the fall. Finally, the AWP reduces the tropospheric vertical wind shear in the main development region that favors hurricane formation and development during August–October.

scholarly journals The easternmost tropical Pacific. Part II: Seasonal and intraseasonal modes of atmospheric variability

2016 ◽  
Vol 64 (1) ◽  
pp. 23 ◽  
Author(s):  
Jorge A. Amador ◽  
A. M. Durán-Quesada ◽  
E. R. Rivera ◽  
G. Mora ◽  
F. Sáenz ◽  
...  
Keyword(s):  
Climate Variability ◽  
Moisture Transport ◽  
Southern Oscillation ◽  
Tropical Pacific ◽  
Transport Processes ◽  
Seasonal Migration ◽  
World Heritage Site ◽  
Summer Drought ◽  
Low Level ◽  
The Caribbean

<p>This is Part II of a two-part review about climate and climate variability focused on the Eastern Tropical Pacific (ETP) and the Caribbean Sea (CS). Both parts are aimed at providing oceanographers, marine biologists, and other ocean scientists, a guiding base for ocean-atmosphere interaction processes affecting the CS, the ETP, and the waters of Isla del Coco. Isla del Coco National Park is a Costa Rican World Heritage site. Part I analyzed the mean fields for both basins and a larger region covering 25º S - 35º N, 20º W - 130º W. Here we focus on a smaller area (65º W - 95º W, 0º - 20º N), as a complement to Part 1. Incoming solar radiation and surface energy fluxes reveal the complex nature of the ETP and CS for convective activity and precipitation on seasonal and intraseasonal time scales. Both regions are relevant as sources of evaporation and the associated moisture transport processes. The American Monsoon System influences the climate and climate variability of the ETP and CS, however, the precise way systems affect regional precipitation and transport of moisture, within the Intra Americas Sea (IAS) are not clear. Although the Caribbean Low-Level Jet (CLLJ) is known to act as a conveyor belt for moisture transport, intraseasonal and seasonal modes of the CLLJ and their interactions with other IAS systems, have to be further investigated. Trans-isthmic jets, exert a variable seasonal wind stress force over the ocean surface co-generating regions of great marine productivity. Isolated convection, the seasonal migration of the Intertropical Convergence Zone, the hurricane season, the Mid-Summer Drought, the seasonal and intraseasonal behavior of low-level jets and their interactions with transients, and the southward incursion of cold fronts contribute to regional seasonal precipitation. Many large-scale systems, such as El Niño-Southern Oscillation, the Atlantic Multidecadal Oscillation and the Madden-Julian Oscillation (MJO, also influence the variability of precipitation by modulating regional features associated with convection and precipitation. Monthly tropical storm (TS) activity in the CS and ETP basins is restricted to the period May-November, with very few cases in December. The CS presents TS peak activity during August, as well as for the number of hurricanes and major hurricanes, in contrast to the ETP that shows the same features during September.</p><div> </div>

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