Diurnal Patterns of Rainfall in Northwestern South America. Part III: Diurnal Gravity Waves and Nocturnal Convection Offshore

Mapes, Brian E.; Warner, Thomas T.; Xu, Min

doi:10.1175/1520-0493(2003)131<0830:dporin>2.0.co;2

Cited by 253 publications

(332 citation statements)

References 33 publications

Supporting

Mentioning

279

Contrasting

Unclassified

Order By: Relevance

“…If a typical Sumatran topographic height of 1000 m is added to the heating profiles, they then closely match the gravity wave structures over the ocean. A similar result was found for the diurnal cycle of heating and offshore gravity waves off South America (Mapes et al, 2003).…”

Section: Objective Analysis Of Gravity Wave Modessupporting

confidence: 85%

See 1 more Smart Citation

The diurnal cycle of precipitation over the Maritime Continent in a high‐resolution atmospheric model

Love

Matthews

Lister

2011

Quart J Royal Meteoro Soc

177

200

View full text Add to dashboard Cite

Climate models can exhibit systematic errors in their mean precipitation over the Maritime Continent of the Indonesian archipelago at the heart of the tropical warm pool. These can often be traced back to an erroneous simulation of the diurnal cycle, and can lead to errors in global climate, through planetary wave propagation. Here, we examine the simulation of the diurnal cycle over the Maritime Continent in a series of high-resolution integrations of the UK Met Office atmospheric model, with horizontal resolutions of 40 and 12 km (where the convection is parametrised) and 4 km (where the convection is explicitly resolved), as part of the Cascade project. In these models, the vertical heating profile over the islands changes from a convective profile with a mid-tropospheric maximum in the early afternoon to a more stratiform profile with upper-tropospheric heating and mid-tropospheric cooling later. The convective heating profile forces a first internal mode gravity wave that propagates rapidly offshore; the deep warm anomalies behind its downwelling wavefront suppress convection offshore during early afternoon. The stratiform heating profile forces a gravity wave with a higher-order vertical mode that propagates slowly offshore later in the afternoon. This mode has a negative, destabilising temperature anomaly in the mid-troposphere. Together with the convergence zone between the wave fronts of the two modes, favourable conditions are created for offshore convection. In the 4 km explicit convection model, the offshore convection responds strongly to this gravity wave forcing, in agreement with observations, supporting a gravity wave-convection paradigm for the diurnal cycle over the Maritime Continent. However, the convective response in the lower-resolution models is much less coherent, leading to errors in the diurnal cycle and mean precipitation.

show abstract

Section: Objective Analysis Of Gravity Wave Modessupporting

confidence: 85%

“…Yang and Slingo, 2001;Mapes et al, 2003). These interactions are now examined first in the 40 km model.…”

Section: Diurnal Heating Over Land and Offshore Gravity Wave Propagationmentioning

confidence: 99%

The diurnal cycle of precipitation over the Maritime Continent in a high‐resolution atmospheric model

Love

Matthews

Lister

2011

Quart J Royal Meteoro Soc

177

200

View full text Add to dashboard Cite

show abstract

“…The feeder related to the low-level clouds off the coast of western mountainous region is enhanced by receiving the seeder associated with the stratiform clouds (e.g., anvil cloud) in the mid-upper (500-200 hPa) troposphere advected by the ambient wind. As we focus on the different aspects, wave dynamics have been discussed by previous studies, e.g., gravity waves associated with upper level heating and lower level cooling of the stratiform rainfall [Mapes, 2000] or induced by diurnal heating of the daytime mixed layer on land [Mapes et al, 2003]. The propagation speeds of their results are 20 m s À1 and 15 m s À1 , respectively.…”

Section: Comparison Between Diurnal Rainfall Propagation and Zonal Wimentioning

confidence: 99%

“…Many features of these variations have been well documented to date, e.g., the initiation of convection in a mountainous area in the afternoon, the peak of rainfall early in the night, and the movement of rain areas from the mountains to coast or offshore areas around midnight [Nitta and Sekine, 1994;Nesbitt and Zipser, 2003;Mori et al, 2004;Sakurai et al, 2005;Ichikawa and Yasunari, 2006;Love et al, 2011]. However, several fundamental issues still remain unexplained, such as the offshore shift mechanism, interactions with large-scale (longer-period) variations, and local orography effects, although they have been discussed by some previous studies [Ohsawa et al, 2001;Mapes et al, 2003;Ichikawa and Yasunari, 2008;Wu et al, 2009]. Owing to our poor understanding of diurnal rainfall variation, current state-of-the-art general circulation models, which are used for weather forecasting and climate projection, still have difficulty reproducing the diurnal precipitation cycle (e.g., amplitude and phase of rainfall).…”

Section: Introductionmentioning

confidence: 99%

“…The relevant processes reported in previous studies include land breeze convergence [Houze et al, 1981], advection by background wind [Mori et al, 2004;Sakurai et al, 2009Sakurai et al, , 2011, self-replication of convective cells [Sakurai et al, 2009[Sakurai et al, , 2011, convergence of cold outflows produced by rainfall systems [Fujita et al, 2010], and gravity waves triggered by daytime heating of the mixed layer on land [Mapes et al, 2003] or convection on land [Love et al, 2011]. effects of seasonality on the diurnal propagation of precipitation systems.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Relationship between the direction of diurnal rainfall migration and the ambient wind over the Southern Sumatra Island

Yanase

Yasunaga

Masunaga

2017

Earth and Space Science

View full text Add to dashboard Cite

This study investigates the climatological relationship between diurnal rainfall migration and the ambient wind over the southern Sumatra by using observation and reanalysis of 15 years of data from the Tropical Rainfall Measuring Mission satellite precipitation radar. When winds in the lower troposphere (1000-500 hPa) are westerly, convective rainfall systems migrate eastward, while rainfall systems dominated by stratiform precipitation propagate to the west in association with mid-upper level easterly winds. When the winds are easterly throughout the troposphere, both convective and stratiform precipitation systems propagate only to the west. Rainfall system migration appears to be generally consistent with ambient zonal wind. It is suggested that the advection by background wind is, in general, a dominant component of the propagation mechanism of diurnal rainfall.

show abstract

Seasonal precipitation patterns along pathways of South American low-level jets and aerial rivers

2014

View full text Add to dashboard Cite

[1] We study the seasonal dynamics of the eastern Pacific (CHOCO) and Caribbean lowlevel jets (LLJ), and aerial rivers (AR) acting on tropical and subtropical South America. Using the ERA-Interim reanalysis , we show that the convergence of both LLJs over the eastern Pacific-western Colombia contributes to the explanation of the region's world-record rainfall. Diverse variables involved in the transport and storage of moisture permit the identification of an AR over northern South America involving a midtropospheric easterly jet that connects the Atlantic and Pacific Oceans across the Andes, with stronger activity in April to August. Other major seasonal AR pathways constitute part of a large gyre originating over the tropical North Atlantic, veering to the southeast over the eastern Andes and reaching regions of northern Argentina and southeastern Brazil. We illustrate the distribution of average seasonal precipitation along the LLJs and AR pathways with data from the Tropical Rainfall Measuring Mission (1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011), combined with considerations of CAPE, topography, and land cover. In addition, the theory of the biotic pump of atmospheric moisture (BiPAM) is tested at seasonal time scales, and found to hold in 8 out of 12 ARs, and 22 out of 32 forest-covered tracks (64% in distance) along the ARs. Deviations from BiPAM's predictions of rainfall distribution are explained by the effects of topography, orography, and land cover types different from forests. Our results lend a strong observational support to the BiPAM theory at seasonal time scales over South American forested flat lands.

show abstract

Diurnal Patterns of Rainfall in Northwestern South America. Part III: Diurnal Gravity Waves and Nocturnal Convection Offshore

Cited by 253 publications

References 33 publications

The diurnal cycle of precipitation over the Maritime Continent in a high‐resolution atmospheric model

The diurnal cycle of precipitation over the Maritime Continent in a high‐resolution atmospheric model

Relationship between the direction of diurnal rainfall migration and the ambient wind over the Southern Sumatra Island

Seasonal precipitation patterns along pathways of South American low-level jets and aerial rivers

Contact Info

Product

Resources

About