scholarly journals Organic aerosols in the Caribbean trade winds: A natural source?

1997 ◽  
Vol 102 (D17) ◽  
pp. 21307-21313 ◽  
Author(s):  
T. Novakov ◽  
C. E. Corrigan ◽  
J. E. Penner ◽  
C. C. Chuang ◽  
O. Rosario ◽  
...  
Keyword(s):  
Organic Aerosols ◽  
Natural Source ◽  
Trade Winds ◽  
The Caribbean

Relationship between African dust carried in the Atlantic trade winds and surges in pediatric asthma attendances in the Caribbean

2008 ◽  
Vol 52 (8) ◽  
pp. 823-832 ◽  
Author(s):  
Joseph M. Prospero ◽  
Edmund Blades ◽  
Raana Naidu ◽  
George Mathison ◽  
Haresh Thani ◽  
...  
Keyword(s):  
Pediatric Asthma ◽  
Trade Winds ◽  
African Dust ◽  
Atlantic Trade ◽  
The Caribbean

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 Polar Alkaloids from the Caribbean Marine Sponge Niphates Digitalis

2010 ◽  
Vol 5 (8) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Erik L. Regalado ◽  
Judith Mendiola ◽  
Abilio Laguna ◽  
Clara Nogueiras ◽  
Olivier P. Thomas
Keyword(s):  
Marine Sponge ◽  
Spectroscopic Data ◽  
Natural Source ◽  
Flash Chromatography ◽  
First Report ◽  
Data Analyses ◽  
Rp Hplc ◽  
The Caribbean

A method involving flash chromatography, semi-preparative phenylhexyl RP HPLC-DAD-ELSD combined with analytic polar-RP HPLC-DAD, was applied to separate and purify six highly nitrogenated bases and a bicyclic amidine alkaloid, the major components of the marine sponge Niphates digitalis. Their structures were identified as 1,8-diazabicyclo[5.4.0]undec-7-ene (1), deoxycytidine (2), phenylalanine (3), adenosine (4), deoxyguanosine (5), adenine (6) and thymidine (7) on the basis of spectroscopic data analyses. This is the first report of these compounds in a marine sponge belonging to the Niphates genus and the first evidence of the presence of 1 from a natural source.

scholarly journals Seasonal Predictions of Holopelagic Sargassum Across the Tropical Atlantic Accounting for Uncertainty in Drivers and Processes: The SARTRAC Ensemble Forecast System

2021 ◽  
Vol 8 ◽  
Author(s):  
Robert Marsh ◽  
Kwasi Appeaning Addo ◽  
Philip-Neri Jayson-Quashigah ◽  
Hazel A. Oxenford ◽  
Ava Maxam ◽  
...  
Keyword(s):  
West Africa ◽  
Early Warning ◽  
Ocean Model ◽  
Ensemble Forecast ◽  
Boreal Summer ◽  
Tropical Atlantic ◽  
Seasonal Forecasts ◽  
Forecast System ◽  
Trade Winds ◽  
The Caribbean

The holopelagic macroalgae sargassum has proliferated across the tropical Atlantic since 2011, of consequence for coastal populations from West Africa to the Caribbean with limited early warning of major beaching events. As part of an interdisciplinary project, ‘Teleconnected SARgassum risks across the Atlantic: building capacity for TRansformational Adaptation in the Caribbean and West Africa’ (SARTRAC), an ensemble forecast system, SARTRAC-EFS, is providing seasonal predictions of sargassum drift. An eddy-resolving ocean model hindcast provides the winds and currents necessary to generate ensemble members. Ensemble forecasts are then obtained for different combinations of ‘windage’, the fractional influence of winds on sargassum mats, and in situ rates of growth, mortality, and sinking. Forecasts for north and south of Jamaica are evaluated with satellite-observed distributions, associated with beaching events in specific years of heavy inundation, 2015 and 2018-20. These seasonal forecasts are evaluated, on lead times of up to 180 days. Forecasts are subject to leading modes of tropical climate variability, in particular the Atlantic Meridional Mode (AMM). More accurate forecasts for a given year are obtained with ensemble members from hindcast years with a similar spring AMM-index. This is most clearly evident during negative AMM phases in spring of 2015 and 2018, when positive sea surface temperature anomalies and anomalously weak trade winds were established across the northern tropics. On this evidence, SARTRAC-EFS is potentially useful in providing early warning of high sargassum prevalence. Extended to sargassum drift off West Africa, extensive cloud cover limits availability of the satellite data needed for full application and evaluation of SARTRAC-EFS in this region, although experimental forecasts off the coast of Ghana are found highly sensitive to the windage that is associated with strong onshore winds during boreal summer. Alongside other forecast systems, SARTRAC-EFS is providing useful early warnings of sargassum inundation at seasonal timescale.

scholarly journals Caracterización del “veranillo” en dos cuencas de la vertiente del Pacífico de Costa Rica, América Central

2015 ◽  
Vol 62 (4) ◽  
pp. 1 ◽  
Author(s):  
Eric J. Alfaro
Keyword(s):  
Costa Rica ◽  
Summer Drought ◽  
Trade Winds ◽  
Monthly Data ◽  
Tropical Regions ◽  
The Pacific ◽  
Low Level Jet ◽  
The Caribbean ◽  
Pacific Slope

<p>The Eastern Tropical Pacific region is characterized by climate features rarely observed in tropical regions, one of them is the Mid-Summer Drought (MSD), “veranillo” or “canícula” in Spanish. On the Pacific slope of Central America, the annual precipitation cycle is characterized by two rainfall maxima in June and September-October, an extended dry season from November to May, and a shorter reduced precipitation period during July–August (MSD), during July, the magnitude of the trade winds increases and this is associated also with the Caribbean Low Level Jet (CLLJ), but characterization of these features using monthly data is difficult. In this work, seven daily gauge stations records, located at two important river basins of Costa Rica, Tarcoles and Tempisque, were studied to characterize the MSD from 1937 to 2012. Among the aspects considered are the MSD Start, Timing, End, Duration, Intensity and Magnitude. The modulation and seasonal predictability of these aspects by climate variability sources as Equatorial Eastern Pacific was lately explored, showing that warmer (cooler) conditions in Niño 3.4 tend to be associated to drier (wetter) MSD events. Rev. Biol. Trop. 62 (Suppl. 4): 1-15. Epub 2014 Diciembre 01.</p><div> </div>

scholarly journals Modulation of Caribbean Precipitation by the Madden–Julian Oscillation

2011 ◽  
Vol 24 (3) ◽  
pp. 813-824 ◽  
Author(s):  
Elinor R. Martin ◽  
Courtney Schumacher
Keyword(s):  
Extreme Events ◽  
Intraseasonal Variability ◽  
Extreme Rainfall ◽  
Strong Relationship ◽  
Madden Julian Oscillation ◽  
Extreme Rainfall Events ◽  
Trade Winds ◽  
Low Level ◽  
Precipitation Anomalies ◽  
The Caribbean

Abstract Based on 12 years of daily satellite precipitation data and reanalysis winds, intraseasonal (30–90 days) variability in Caribbean precipitation is linked to phases of the Madden–Julian oscillation (MJO). Intraseasonal variability is largest during September–November (SON), but some modulation of precipitation by the MJO appears throughout all seasons. Precipitation anomalies up to 50% above (below) the annual mean are observed in phases 1 and 2 (5 and 6) of the MJO. The changes in Caribbean precipitation associated with the MJO are shown to be related to changes in the low-level (925 hPa) winds. When precipitation anomalies are above (below) average in phases 1 and 2 (5 and 6), wind anomalies act to decrease (increase) the strength of the prevailing easterly trade winds. The changes in the low-level winds are most apparent in the region of the Caribbean low-level jet (CLLJ), and divergence anomalies associated with the entrance and exit regions of the CLLJ precede the precipitation anomalies. The CLLJ itself is also shown to be subject to intraseasonal variability, and its magnitude varies with the phase of the MJO. Again, intraseasonal variability in the CLLJ associated with the MJO is observed in all seasons and shows a significant coherence with intraseasonal variability in the precipitation. Extreme rainfall events over islands in the Caribbean show a strong relationship with the MJO phase, with extreme events being most common in phases 1 and 2 of an MJO event. This relationship between the MJO and extreme events has important implications for the predictability of precipitation extremes in the Caribbean.

scholarly journals Composite Meteorological Forcing of Puerto Rican Springtime Flood Events

2009 ◽  
Vol 24 (1) ◽  
pp. 262-271 ◽  
Author(s):  
Mark R. Jury ◽  
David M. Sanchez
Keyword(s):  
Puerto Rico ◽  
Caribbean Sea ◽  
Tropical Atlantic ◽  
Flood Events ◽  
Trade Winds ◽  
Meteorological Forcing ◽  
Cloud Band ◽  
Upper Troposphere ◽  
Westerly Trough ◽  
The Caribbean

Abstract The central Antilles Islands experience short periods of heavy rainfall during the spring season (April and May) when trade winds weaken across the Caribbean Sea. Composite analysis of the top 10 flood events in the period 1979–2005 is carried out to understand the meteorological forcing. Cases are selected when mean rainfall over Puerto Rico exceeds 50 mm day−1 and emergency management reports indicate the day is a “declared weather disaster.” In the NCEP–NCAR composite analyses, pulses of moisture shift westward across the tropical Atlantic about 10 days before a flood event. Five days before the composite flood a westerly trough penetrates eastward from the Gulf of Mexico. Northward flow develops over the Caribbean Sea and a southwest-oriented cloud band extends from Colombia toward Puerto Rico. A key feature of the midtropospheric circulation field is the development of anomalous twin rotors east of Florida in the mid- to upper troposphere. The flood events coincide with a change in zonal wind shear from westerly to easterly that is brought about by slow tropical and fast subtropical wave systems.

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