Dominant Role of Subtropical Pacific Warming in Extreme Eastern Pacific Hurricane Seasons: 2015 and the Future

2017 ◽  
Vol 30 (1) ◽  
pp. 243-264 ◽  
Author(s):  
Hiroyuki Murakami ◽  
Gabriel A. Vecchi ◽  
Thomas L. Delworth ◽  
Andrew T. Wittenberg ◽  
Seth Underwood ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
El Niño ◽  
El Nino ◽  
Dominant Role ◽  
Boreal Summer ◽  
Central Pacific ◽  
Central Pacific Ocean ◽  
The Pacific ◽  
Hurricane Season ◽  
Resolution Model

The 2015 hurricane season in the eastern and central Pacific Ocean (EPO and CPO), particularly around Hawaii, was extremely active, including a record number of tropical cyclones (TCs) and the first instance of three simultaneous category-4 hurricanes in the EPO and CPO. A strong El Niño developed during the 2015 boreal summer season and was attributed by some to be the cause of the extreme number of TCs. However, according to a suite of targeted high-resolution model experiments, the extreme 2015 EPO and CPO hurricane season was not primarily induced by the 2015 El Niño tropical Pacific warming, but by warming in the subtropical Pacific Ocean. This warming is not typical of El Niño, but rather of the Pacific meridional mode (PMM) superimposed on long-term anthropogenic warming. Although the likelihood of such an extreme year depends on the phase of natural variability, the coupled GCM projects an increase in the frequency of such extremely active TC years over the next few decades for EPO, CPO, and Hawaii as a result of enhanced subtropical Pacific warming from anthropogenic greenhouse gas forcing.

scholarly journals Changes in Spread and Predictability Associated with ENSO in an Ensemble Coupled GCM

2006 ◽  
Vol 19 (17) ◽  
pp. 4378-4396 ◽  
Author(s):  
Renguang Wu ◽  
Ben P. Kirtman
Keyword(s):  
Surface Pressure ◽  
El Niño ◽  
El Nino ◽  
Tropical Pacific ◽  
La Niña ◽  
Boreal Summer ◽  
Boreal Winter ◽  
Central Pacific ◽  
La Nina ◽  
Signal Change

Abstract The present study documents the influence of El Niño and La Niña events on the spread and predictability of rainfall, surface pressure, and 500-hPa geopotential height, and contrasts the relative contribution of signal and noise changes to the predictability change based on a long-term integration of an interactive ensemble coupled general circulation model. It is found that the pattern of the El Niño–Southern Oscillation (ENSO)-induced noise change for rainfall follows closely that of the corresponding signal change in most of the tropical regions. The noise for tropical Pacific surface pressure is larger (smaller) in regions of lower (higher) mean pressure. The ENSO-induced noise change for 500-hPa height displays smaller spatial scales compared to and has no systematic relationship with the signal change. The predictability for tropical rainfall and surface pressure displays obvious contrasts between the summer and winter over the Bay of Bengal, the western North Pacific, and the tropical southwestern Indian Ocean. The predictability for tropical 500-hPa height is higher in boreal summer than in boreal winter. In the equatorial central Pacific, the predictability for rainfall is much higher in La Niña years than in El Niño years. This occurs because of a larger percent reduction in the amplitude of noise compared to the percent decrease in the magnitude of signal from El Niño to La Niña years. A consistent change is seen in the predictability for surface pressure near the date line. In the western North and South Pacific, the predictability for boreal winter rainfall is higher in El Niño years than in La Niña years. This is mainly due to a stronger signal in El Niño years compared to La Niña years. The predictability for 500-hPa height increases over most of the Tropics in El Niño years. Over western tropical Pacific–Australia and East Asia, the predictability for boreal winter surface pressure and 500-hPa height is higher in El Niño years than in La Niña years. The predictability change for 500-hPa height is primarily due to the signal change.

Annual, Interannual, and Intraseasonal Variability of Tropical Tropopause Transition Layer Cirrus

2010 ◽  
Vol 67 (10) ◽  
pp. 3097-3112 ◽  
Author(s):  
Katrina S. Virts ◽  
John M. Wallace
Keyword(s):  
Annual Cycle ◽  
El Niño ◽  
Transition Layer ◽  
El Nino ◽  
Southern Oscillation ◽  
Cirrus Clouds ◽  
Boreal Winter ◽  
Central Pacific ◽  
Tropical Tropopause ◽  
The Pacific

Abstract Cloud fields based on the first three years of data from the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission are used to investigate the relationship between cirrus within the tropical tropopause transition layer (TTL) and the Madden–Julian oscillation (MJO), the annual cycle, and El Niño–Southern Oscillation (ENSO). The TTL cirrus signature observed in association with the MJO resembles convectively induced, mixed Kelvin–Rossby wave solutions above the Pacific warm pool region. This signature is centered to the east of the peak convection and propagates eastward more rapidly than the convection; it exhibits a pronounced eastward tilt with height, suggestive of downward phase propagation and upward energy dispersion. A cirrus maximum is observed over equatorial Africa and South America when the enhanced MJO-related convection enters the western Pacific. Tropical-mean TTL cirrus is modulated by the MJO, with more than twice as much TTL cirrus fractional coverage equatorward of 10° latitude when the enhanced convection enters the Pacific than a few weeks earlier, when the convection is over the Indian Ocean. The annual cycle in cirrus clouds around the base of the TTL is equatorially asymmetric, with more cirrus observed in the summer hemisphere. Higher in the TTL, the annual cycle in cirrus clouds is more equatorially symmetric, with a maximum in the boreal winter throughout most of the tropics. The ENSO signature in TTL cirrus is marked by a zonal shift of the peak cloudiness toward the central Pacific during El Niño and toward the Maritime Continent during La Niña.

El Nino Chaos: Overlapping of Resonances Between the Seasonal Cycle and the Pacific Ocean-Atmosphere Oscillator

Science ◽  
1994 ◽  
Vol 264 (5155) ◽  
pp. 72-74 ◽  
Author(s):  
E. Tziperman ◽  
L. Stone ◽  
M. A. Cane ◽  
H. Jarosh
Keyword(s):  
Pacific Ocean ◽  
El Niño ◽  
Seasonal Cycle ◽  
El Nino ◽  
The Pacific ◽  
Ocean Atmosphere ◽  
The Pacific Ocean

scholarly journals Ship- and island-based soundings from the 2016 El Niño Rapid Response (ENRR) field campaign

2018 ◽  
Author(s):  
Leslie M. Hartten ◽  
Christopher J. Cox ◽  
Paul E. Johnston ◽  
Daniel E. Wolfe ◽  
Scott Abbott ◽  
...  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Rapid Response ◽  
Public Access ◽  
Central Pacific ◽  
Quasi Biennial Oscillation ◽  
East Central ◽  
Field Campaign ◽  
Central Pacific Ocean ◽  
Christmas Island

Abstract. As the 2015/2016 El Niño was gathering strength in late 2015, scientists at the Earth System Research Laboratory's Physical Sciences Division proposed and led the implementation of NOAA's El Niño Rapid Response (ENRR) Field Campaign. ENRR observations included wind and thermodynamic profiles of the atmosphere over the near-equatorial east-central Pacific Ocean, many of which were collected from two field sites and transmitted in near-real time for inclusion in global forecasting models. From 26 January to 28 March 2016, twice-daily rawinsonde observations were made from Kiritimati (pronounced Christmas) Island (2.0°N, 157.4°E; call sign CXENRR). From 16 February to 16 March 2016, three to eight radiosondes were launched each day from the NOAA Ship Ronald H. Brown (allocated call sign WTEC) as it travelled southeast from Hawaii to service Tropical Atmosphere Ocean (TAO) buoys along longitudes 140°W and 125°W and then north to San Diego, California. Both the rapid and the remote nature of these deployments created particular difficulties in collecting and disseminating the soundings; these are described together with the methods used to reprocess the data after the field campaign finished. The reprocessed and lightly quality-controlled data have been put into an easy-to-read text format, qualifying them to be termed Level 2 soundings. They are archived and freely available for public access at NOAA's National Centers for Environmental Information (NCEI) in the form of two separate data sets: one consisting of 125 soundings from Kiritimati Island (doi:10.7289/V55Q4T5K), the other of 193 soundings from the NOAA Ship Ronald H. Brown (doi:10.7289/V5X63K15). Of the Kiritimati soundings, 94 % reached the tropopause and 88 % reached 40 hPa, while 89 % of the ship's soundings reached the tropopause and 87 % reached 40 hPa. The soundings captured the repeated advance and retreat of the ITCZ at Kiritimati, a variety of marine tropospheric environments encountered by the ship, and lower-stratospheric features of the 2015–2016 QBO (quasi-biennial oscillation), all providing a rich view of the local atmosphere's response to the east-central Pacific's extremely warm waters during the 2015/16 El Niño.

scholarly journals The relationship between intraseasonal tropical variability and ENSO and its modulation at seasonal to decadal timescales

2011 ◽  
Vol 3 (2) ◽  
Author(s):  
Daria Gushchina ◽  
Boris Dewitte
Keyword(s):  
El Niño ◽  
General Circulation ◽  
Rossby Waves ◽  
El Nino ◽  
General Circulation Models ◽  
Wave Radiation ◽  
Boreal Summer ◽  
Central Pacific ◽  
Tropical Variability ◽  
Intraseasonal Tropical Variability

AbstractThe intraseasonal tropical variability (ITV) patterns in the tropical troposphere are documented using double space-time Fourier analysis. Madden and Julian oscillations (MJO) as well as equatorial coupled waves (Kelvin and Rossby) are investigated based on the NCEP/NCAR Reanalysis data for the 1977–2006 period and the outputs of an intermediate ocean-atmosphere coupled model named LODCA-OTCM. A strong seasonal dependence of the ITV/ENSO relationship is evidenced. The leading relationship for equatorial Rossby waves (with the correlation of the same order than for the MJO) is documented; namely, it is shown that intensification of Rossby waves in the central Pacific during boreal summer precedes by half a year the peak of El Niño. The fact that MJO activity in spring-summer is associated to the strength of subsequent El Niño is confirmed. It is shown that LODCA-QTCM is capable of simulating the convectively coupled equatorial waves in outgoing long wave radiation and zonal wind at 850 hPa fields with skill comparable to other Coupled General Circulation Models. The ITV/ENSO relationship is modulated at low frequency. In particular the periods of low ENSO amplitude are associated with weaker MJO activity and a cancellation of MJO at the ENSO development phase. In opposition, during the decaying phase, MJO signal is strong. The periods of strong ENSO activity are associated with a marked coupling between MJO, Kelvin and equatorially Rossby waves and ENSO; the precursor signal of MJO (Rossby waves) in the western (central) Pacific is obvious. The results provide material for the observed change in ENSO characteristics in recent years and question whether the characteristics of the ITV/ENSO relationship may be sensitive to the observed warming in the central tropical Pacific.

scholarly journals Meridional Extent and Interannual Variability of the Pacific Ocean Tropical–Subtropical Warm Water Exchange

2005 ◽  
Vol 35 (3) ◽  
pp. 323-335 ◽  
Author(s):  
Christopher S. Meinen
Keyword(s):  
Pacific Ocean ◽  
El Niño ◽  
El Nino ◽  
Warm Water ◽  
Height Anomaly ◽  
The South ◽  
El Niño Event ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The Tropics

Abstract Altimetric observations of sea surface height anomaly (SSHA) from the TOPEX/Poseidon and ERS satellites, hydrography, and the ECMWF and Florida State University wind products are used to track warm water (≥20°C) as it is exchanged between the equatorial Pacific Ocean and the higher latitudes during 1993–2003. The large El Niño event of 1997–98 resulted in a significant discharge of warm water toward the higher latitudes within the interior of the Pacific Ocean. The exchange of anomalous warm water volume with the Northern Hemisphere appears to be blocked under the intertropical convergence zone, consistent with most current ideas on the time-mean tropical–subtropical exchange. Little of the warm water discharged northward across 5° and 8°N during the 1997–98 El Niño event could be traced as far as 10°N. To the south, however, these anomalous volumes of warm water were visible at least as far as 20°S, primarily in the longitudes around 130°–160°W. In both hemispheres most of the warm water appeared to flow westward before returning to the Tropics during the recharge phase of the El Niño–La Niña cycle. The buildup of warm water in the Tropics before the 1997–98 El Niño is shown to be fed primarily by warm water drawn from the region in the western Pacific within 5°S–15°N. The exchange cycle between the equatorial band and the higher latitudes north of the equator leads the cycle in the south by 6–8 months. These results are found in all three datasets used herein, hydrography, altimetric observations of SSHA, and Sverdrup transports calculated from multiple wind products, which demonstrates the robustness of the results.

Recreational billfish catches and gamefishing facilities of Pacific Island nations in the Western and Central Pacific Ocean

2003 ◽  
Vol 54 (4) ◽  
pp. 463 ◽  
Author(s):  
Wade Whitelaw
Keyword(s):  
Pacific Ocean ◽  
Purse Seine ◽  
Pacific Island ◽  
Central Pacific ◽  
Central Pacific Ocean ◽  
Tax Relief ◽  
The Pacific ◽  
Pacific Island Nations ◽  
Subsistence Fishing ◽  
Pacific Community

Gamefishing is a developing industry for many of the Pacific Island nations, with a number of countries encouraging the industry with tax relief and tourism promotion. This paper was prepared to provide a preliminary appraisal of gamefish facilities and recreational billfish catches of Pacific Island countries in the Western and Central Pacific Ocean. The level of development of gamefishing varies among Pacific Island nations, with fishers of some countries only carrying out subsistence fishing (including billfish), whereas others have a well-developed gamefishing infrastructure. The gamefish facilities of each country are described, including charter operations, number of private vessels and berthing facilities. Estimates of recreationally caught billfish are also provided for each Pacific Island nation. These estimates have been facilitated by the development of a gamefish catch and effort database by the Secretariat of the Pacific Community. Presently, an estimated 1050 metric tonnes of marlin are caught by gamefishing in the Western and Central Pacific Ocean, which compares with an estimate of around 18 000 metric tonnes caught by commercial longline and purse seine vessels.

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