Ministério da Ciência e TecnologiaMinistério da Ciência e TecnologiaInstituto Nacional de Pesquisas EspaciaisInstituto Nacional de Pesquisas Espaciais

Centro de Previsão de Tempo e Estudos ClimáticosCentro de Previsão de Tempo e Estudos Climáticos

El Niño-Tropical El Niño-Tropical Cyclones/Hurricanes and Cyclones/Hurricanes and

Extreme weatherExtreme weather

Trends in tropical Cyclones and Hurricanes

Frequency and Strength of Hurricanes over the North Atlantic

During the last century an increase in frequency and strength of tropical storms could not be proven.

Number of hurricanes and tropical stroms in the North Atlantic basin Source: Climate Assessment 1998, BAMS, 1999.

Strength ( Vmax 2 / 105) of hurricanes and tropical stroms in the

North Atlantic. Source: Climate Assessment 1999, BAMS, 2000.

                                                                               

           

Atlantic accumulated hurricane energy August to October in different ENSO events, 1950-2001.

                                                                                          

Tracks Density of Atlantic Hurricanes August to October, 1950-2001 for El Niño years (top pannel) and La Niña years (bottom pannel).

                            Tracks of tropical cyclones in the South Pacific in two contrasting years.

Top: 1975/76 season, cold phase of ENSO (La Niña).

Bottom: 1976/77 season, warm phase of ENSO (El Niño).

                                                                                            

              Comparison of hurricane tracks for wet versus dry years based on Gulf of Guinea rainfall. (A) The 10 wettest years and all hurricanes; (B) 10 driest years and all hurricanes; (C) 10 wettest years and tropical-only hurricanes; (D) 10 driest years and tropical-only hurricanes. Number of hurricanes for each category are shown in the upper-right corner of each panel (from Hess et al. 1995).

                                                                                               

     Location of meteorological and oceanographic parameters used in the Atlantic seasonal forecasts by Gray et al.101 See text for details.

                                                                     

Annual number of tropical storms in the Northwest Pacific Basin from 1959-1994. Two second-order polynomials are fit to the time series shown in the dashed (1959-1994) and dash-dotted (1972-1994) lines.

                                                                                 

         Annual number of tropical and subtropical storms over the Atlantic basin for the period of reliable record. The best fit linear trend is superimposed on the time series. (Figure adapted from Landsea et al. 1996).

                                                                                          

Annual number of intense hurricanes in the Atlantic basin for the period of reliable record. Data from 1944-1969 have been revised downward to reflect the overestimation of intensities during these years. See Landsea (1993) for details. (Figure adapted from Landsea et al. 1996).

                                                                                

          Annual number of intense hurricanes that have made landfall along the US East Coast, which has been subdivided into the Florida peninsula (black) and the Upper Atlantic (from Georgia to New England in blue) for the period of reliable records. Figure updated from Landsea (1993).

Extreme rainfall events:Venezuela

December 1999

Mar

Car

ibe N

Caracas DF

Cerro El Avila

3-D Projection of Caracas andCoastal line of Venezuela

La Guaira

Maiquetia

Region affected by intense rainfall, landslides, and floods

N

PLUMAS DE SEDIMENTACIÓN LITORAL

CONOIDES DE DEYECCIÓN REACTIVADOS, SEDIMENTACIÓN E INUNDACIÓN VIOLENTA

CAUCES Y TORRENTES DE MONTAÑA POR DONDE TRANSITARON LAS AVALANCHAS

ÁREAS CON DESLIZAMIENTOS, EROSIÓN INTENSA, ALUDES

CARACAS

LA GUAIRAMAIQUETÍA

EL ÁVILA

LOS EFECTOS DE LA GEODINÁMICA EXTERNA, LOS EFECTOS DE LA GEODINÁMICA EXTERNA, COSTA CENTRAL DE VENEZUELA, DICIEMBRE, 1999COSTA CENTRAL DE VENEZUELA, DICIEMBRE, 1999(Mapa esquemático basado en información periodística -prensa, televisión- e información facilitada por R. Sancio y D. Salcedo)

Other extreme rainfall events in Venezuela

Another intense rainfal episode:February 1951

Mapa Sinóptico 17/02/51 (CNMH)

Rainfall estimated by satellite in Venezuela 15-17 December 1999

Forecast of rainfall (accumulated 24 hours) for 15 December –Global and regional models

MGC CPTEC/COLA T126

(100 km)

Modelo regional Eta/ (24 horas) Modelo regional Eta/ (60 horas)

MGC CPTEC/COLA T062 (200 km)

El Niño-regional impacts and variability

Fact:

Once developed, El Niño and La Niña "events" are known to shift seasonal temperature and precipitation patterns in many different regions of the world.  In several parts of the tropics, and some areas outside of the tropics, these seasonal shifts are fairly consistent from one El Niño and La Niña event to the next.  It is important to remember, however, that no two El Niño or La Niña events are identical and that the seasonal shifts in temperature and precipitation patterns associated with them can vary from one event to the next.   Thus, when an El Niño or La Niña  develops, it does not guarantee that regions which are typically affected by them will be affected, only  that there is enhanced probability that this will be the case.

Defficient rain

Abundant rain

Rainfall anomalies During El Niño andLa Niña

           

SECTORS AFFECTED BY EL NIÑO 1997-98IN MESOAMERICA

AgricultureForestryFishery

Natural Disasters(drought)

AgricultureForestryFishery

Natural disasters(drought)

Health

AgricultureForestry

Natural Disasters(droughts and floods)

AgricultureForestry

Natural disasters(drought)

AgriculturaGeneración de Energía

Desastres Naturales(sequías)

AgricultureHealth

CommunicationsElectricity generation

¿ How muchc did El Niño 1997-98 cost in Mexico?

In other countries:In other countries:(millions of dollars)(millions of dollars)

Bolivia 527Bolivia 527Colombia Colombia 564 564EcuadorEcuador 2882 2882PerúPerú 3498 3498VenezuelaVenezuela 72 72Costa Rica 82 Costa Rica 82 Argentina 2500Argentina 2500Source: CEPAL, CAFSource: CEPAL, CAF

Fuente: Magaña et. al. 1999Fuente: Magaña et. al. 1999

Summers during El Niño featured severe droughts in most of Mexico

Summers during La Niña, back toNormal or aboe normal rain

El Niño

La Niña

Rains in NW Mexico show littleAssociation with EL Nino (lowerPredictability).

Summers of El Niño Drought in large part of Mexico

% Superficiesiniestrada

Rainfall anomalies duringSummer of El Niño

Impacts in the agriculture in 1997

Rainfall summer of 1982Very wetVery wet, , wetwet, , normalnormal, , drydry, , very dryvery dry

Rainfall Summer of 1997Very wetVery wet, , wetwet, , normalnormal, , drydry, , very dryvery dry

Rainfall in Summer 1986Very wetVery wet, , wetwet, , normalnormal, , drydry, , very dryvery dry

Rainfall in summer 1991 Very wetVery wet, , wetwet, , normalnormal, , drydry, , very dryvery dry

Forecast for summer 2002

JunioJunio

JulioJulio

AgostoAgosto

SeptiembreSeptiembre

Very wetVery wet, , wetwet, , normalnormal, , drydry, , very dryvery dry

Impacto en clima/hidrológia

Sub región o país Referencia

Sequías severas en años recientes

México Magaña et al. (1999)

Sequías severas Nordeste de Brasil Hastenrath y Heller (1977), Hastenrath and Greischar (1883), Nobre y Shukla (1996), Silva Dias y Marengo (1999)

Disminución de precipitación

América Central;-Cuenca del Pacífico

Magaña et al. (1999)

Aumento de precipitación América Central;-Cuenca del Atlántico

Magaña et al. (1999), Carvajal et al. (1999)

Disminción de precipitación y descargas de ríos

Colombia Poveda y Mesa (1997)

Aumento de precipitación y descargas de ríos

Noroeste de Peru-Ecuador

Cornejo et al. (1986), Marengo et al. (1998a), SENAMHI (1999), Peñaherrera (1999)

Disminución e precipitación, sequias y aumento de riesgo de incendios forestales

Norte de Amazonia Marengo (1992), Aceituno (1988), Richey et al. (1999), Nepstad et al. (1999), Meggers et al. (1994)

Aumento de precipitación (Nov-Ene)

Región de Pampas Argentinas

Tanco y Berri (1996), Barros et al. (1996), Nagrin et al. (1998)

Aumento de precipitación (Nov-Ene)

Uruguay Bidegain y Cafera (1989), Pisciotano et al. (1994)

Aumento de descargas Chile y centro oeste de Argentina

(Compganucci (2000), Compagnucci y Vargas (1998)

Sequías Altiplano Peru-Bolivia Aceituno (1988), SENAMHI (1998-99)

Impacto en clima/hidrológia

Sub región o país Referencia

Precipitaciones abudantes e inundaciones

Colombia Carvajal et al. 1999

Disminución de precipitación, sequias

Uruguay Bidegain y Cafera (1989), Pisciotano et al. (1994)

Sequias severas Sur de Brasil Grimm et al. (1996, 2000)

Disminución de precipitación (Oct-Dic)

Pampas Argentinas Tanco y Berri (1996), Barros et al. (1996), Magrin net al. (1998)

Disminción de precipitación y descargas de ríos

Colombia Poveda y Mesa (1997)

Incremento de precipitacion y descargas

Nordeste de Brasil, Norte de Amazonia de Peru y Brasil

Marengo (1992), Aceituno (1988), Meggers et al. (1884), Marengo et al. (1998b), Trebejo y Diaz (1998)

Disminución de precipitación

Chile y Centro oeste de Argentina

Compagnucci 20000)

Tendencias a sequias Norte de Peru Marengo et al. (1998a), Aceituno (1988)

Climate Trends

Patterns of Global Temperature Change

°C Temperature anomalies from the period 1961-1990

                                                        

Climate Trends and extreme events

Observed (20th century) linear trends in total seasonal precipitation and frequency of heavy precipitation events for various region. From Easterling et al., BAMS, 81, 2000, 417-425.

Climate Change and human health

                                     

Distribution of Aedes aegypti (shaded areas) in the Americas in 1970, at the end of the mosquito eradication program, and in 1995.