Contrasting North–South changes in Amazon wet-day and dry-day frequency and related atmospheric features (1981–2017)

Simple item page
dc.contributor.authorEspinoza, Jhan Carlo
dc.contributor.authorRonchail, Josyane
dc.contributor.authorMarengo, José Antonio
dc.contributor.authorSegura Cajachagua, Hans Mikhail
dc.coverage.spatialAmazonía
dc.date.accessioned2019-04-15T09:49:40Z
dc.date.available2019-04-15T09:49:40Z
dc.date.issued2019
dc.description.abstractThis study provides an updated analysis of the evolution of seasonal rainfall intensity in the Amazon basin, considering the 1981–2017 period and based on HOP (interpolated HYBAM observed precipitation) and CHIRPS (The Climate Hazards Group Infrared Precipitation with Stations) rainfall data sets. Dry and wet day frequencies as well as extreme percentiles are used in this analysis, producing the same results. Dry-day frequency (DDF) significantly increases in the Southern Amazon (p<0.01), particularly during September–November (SON) in the Bolivian Amazon, central Peruvian Amazon and far southern Brazilian Amazon. Consistently, total rainfall in the southern Amazon during SON also shows a significant diminution (p<0.05), estimated at 18%. The increase in SON DDF in the southern Amazon is related to a warming of the northern tropical Atlantic Ocean and a weakening of water vapour flux from the tropical Atlantic Ocean. The increase in DDF in the southern Amazon is related to enhanced wind subsidence (ascendance) over the 10°S–20°S (5°S–5°N) region and to a deficit (excess) of specific humidity at 1000–300 hPa south of 10°S (north of the 5°S), which suggest a reduction of deep convection over southern Amazonia. Subsidence over the southern Amazon shows a significant trend (p<0.01), which can explain the significant increase in DDF. Wet-day frequency (WDF) significantly increases in the northern Amazon, particularly during the March–May (MAM) period (p<0.01), producing an estimated rainfall increase during MAM of 17% (p<0.01) between 1981 and 2017. Significant changes in both WDF and rainfall in northern Amazon have been detected in 1998 (p<0.01). After 1998, the increase in MAM WDF and rainfall is explained by enhanced moisture flux from the tropical North Atlantic Ocean and an increase in deep convection over the northern and northwestern Amazon. These evolutions in DDF and WDF and in the tropical atmosphere occur simultaneously with an increase in sea surface temperature in the northern Atlantic Ocean, particularly after the mid-1990s. These results provide new insight into rainfall variability and climatic features related to increasing dry season length in southern Amazonia. Severe recent droughts may be associated with the increase in DDF in the South. In addition, the increase in MAM rainfall intensity in northern Amazon after 1998 may be associated with several historical floods that occurred after this date.es_ES
dc.description.peer-reviewPor pareses_ES
dc.formatapplication/pdfes_ES
dc.identifier.citationEspinoza, J. C., Ronchail, J., Marengo, J. A., & Segura, H. (2019). Contrasting North–South changes in Amazon wet-day and dry-day frequency and related atmospheric features (1981–2017).==$Climate Dynamics, 52,$==5413-5430. https://doi.org/10.1007/s00382-018-4462-2es_ES
dc.identifier.doihttps://doi.org/10.1007/s00382-018-4462-2es_ES
dc.identifier.govdocindex-oti2018
dc.identifier.journalClimate Dynamicses_ES
dc.identifier.urihttp://hdl.handle.net/20.500.12816/4456
dc.language.isoenges_ES
dc.publisherSpringeres_ES
dc.relation.ispartofurn:issn:0930-7575
dc.rightsinfo:eu-repo/semantics/restrictedAccesses_ES
dc.subjectSouthern Amazones_ES
dc.subjectTropical North Atlantic Ocean (TNA)es_ES
dc.subjectBolivian Amazones_ES
dc.subjectClimate Hazards Group InfraRed Precipitationes_ES
dc.subjectEnhanced Moisture Fluxes_ES
dc.subject.ocdehttp://purl.org/pe-repo/ocde/ford#1.05.00es_ES
dc.subject.ocdehttp://purl.org/pe-repo/ocde/ford#1.05.09es_ES
dc.subject.ocdehttp://purl.org/pe-repo/ocde/ford#1.05.10es_ES
dc.titleContrasting North–South changes in Amazon wet-day and dry-day frequency and related atmospheric features (1981–2017)es_ES
dc.typeinfo:eu-repo/semantics/articlees_ES

Files

License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download

Collections

Arbitrados