Study of the relationship between the intertropical convergence zone expansion and the precipitation in the southern half of Iran

Jafari, Mahnaz; Lashkari, H

doi:10.1016/j.jastp.2020.105439

Cited by 8 publications

(4 citation statements)

References 36 publications

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“…As the ITCZ is one of the large-scale precipitating systems that greatly influences the climate of coastal tropical regions [17,46,47] , the main objective of this study was to present an algorithm developed to locate both the primary and secondary bands (double ITCZ) of the ITCZ over the Atlantic basin. The algorithm identifies the initial (Li) and final (Lf) limits of the bands, providing information for the calculation of the average position, width, and intensity of the two bands.…”

Section: Discussionmentioning

confidence: 99%

Assessment of the Intertropical Convergence Zone over the Atlantic Ocean through an Algorithm Based on Precipitation

Chrysostomo de Oliveira Nogueira,

Gomes Machado,

Simões Reboita

et al. 2024

j. of atmos. sci. res.

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The Intertropical Convergence Zone (ITCZ) is a key atmospheric system on a global scale, primarily driven by trade wind convergence near the equator. The ITCZ plays a crucial role in modulating the climate of the borders of tropical continental areas. For instance, Northeastern Brazil experiences a climate influenced by the ITCZ over the Atlantic Ocean. In some periods, the ITCZ exhibits double bands, known as the double ITCZ. While the features of the ITCZ have been described using various approaches and atmospheric variables, there is still a lack of regional studies focusing on the ITCZ and double ITCZ in the Atlantic Ocean. In this context, the main goals of this study are (1) to describe a simple algorithm based on precipitation to identify the ITCZ and double ITCZ, (2) to present a climatology (1997–2022) of the position, width, and intensity of these two convective bands, and (3) to investigate variabilities in the ITCZ characteristics associated with anomalies of sea surface temperature (SST) in the tropical Pacific and Atlantic oceans. The double ITCZ typically occurs southward of the main cloud band, and between February and April, both bands are more distant (~4.5°). In the western sector of the Atlantic Ocean, the ITCZ and its double band extend to more southerly latitudes in austral autumn. Considering the entire Atlantic basin, the annual mean of the latitudinal position, width, and intensity of the ITCZ is 4.9°N, 4.2°, and 11 mm/day, respectively, while for the double ITCZ, it is 0.4°N, 2.6°, 10.3 mm/day, respectively. While the SST anomalies in the Pacific Ocean (El Niño and La Niña episodes) affect more the ITCZ width, the SST anomalies in the Tropical South Atlantic affect both its position and width.

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Section: Discussionmentioning

confidence: 99%

Assessment of the Intertropical Convergence Zone over the Atlantic Ocean through an Algorithm Based on Precipitation

Chrysostomo de Oliveira Nogueira,

Gomes Machado,

Simões Reboita

et al. 2024

j. of atmos. sci. res.

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“…However, the rainfall anomaly associated with ITCZ represents only 10% of the total rainfall that typically occurs during the monsoon season (Waliser and Jiang, 2015). Moreover, ITCZ, which is the low‐pressure region near equator (5°N–5°S), affects the tropical climate by interacting with the planetary‐scale atmospheric circulation (Yan, 2005) and are often assessed primarily by precipitation and by specific humidity and the winds at the lower pressure levels (Byrne et al ., 2018; Jafari and Lashkari, 2020). The performance of the climate models in simulating these atmospheric variables at 850 hPa have been considered along with the rainfall metrics during the model evaluation.…”

Section: Methodsmentioning

confidence: 99%

An evaluation of CMIP5 and CMIP6 climate models in simulating summer rainfall in the Southeast Asian monsoon domain

Khadka

Babel

Abatan

et al. 2021

Intl Journal of Climatology

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In this study, 28 climate models from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) and 32 models from the sixth phase (CMIP6) have been evaluated for their ability to simulate large‐scale atmospheric circulations (using rainfall, wind fields, geopotential height, temperature, and moisture flux convergence) for the summer monsoon in Southeast Asia. Using a multi‐criteria decision making technique, models have been ranked based on 25 metrics which compare their performances with observation data. Results indicate a better representation of annual rainfall cycles as well as spatial pattern by CMIP6 models compared to CMIP5. Though majority of the models from both CMIPs show late onset and early retreat of the rainy season, CMIP6 GCMs simulate the onset, retreat, and the length of the rainy season closer to the observation. Large‐scale circulation patterns evaluated using spatial correlation and root mean square error (RMSE) show improvements in CMIP6 across all metrics, especially for the moisture flux convergence. Performances for large‐scale circulation are generally reflected in rainfall simulation; however, few models showed that better simulations of rainfall do not exclusively depend on their performance for large‐scale variables. Overall, CMIP6 models are found to be superior to CMIP5 models in simulating rainfall and large‐scale circulation, which is likely attributable to CMIP6 model's higher spatial resolutions, increased number of vertical levels, improved atmospheric and land surface parameterization, etc. Finally, subsets of optimal models from CMIP5 and CMIP6 that proved to be better at representing the summer monsoons in the study area are identified. These models are recommended to develop robust future projections that can be used for climate change impact and adaptation studies.

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“…Numerous studies attributed the alterations in the ITCZ, and thereby paleoclimate over the Sahara, to orbital forcing [12][13][14]48]. The millennial orbital forcing played a key role in the gradual southward displacement of the ITCZ position in the Northern Hemisphere's summer (Figure 11a,b).…”

Section: Drivers Of Paleoclimatic Variabilitymentioning

confidence: 99%

“…However, this gift was a consequence of climatic changes that occurred 12,000 years ago. The relocation of the Inter-Tropical Convergence Zone (ITCZ) 800 km to the south resulted in the transformation of the savannah forests in Egypt's Western Desert into an arid desert, compelling the population to migrate eastward in search of fertile soil and rivers [11][12][13][14]. Geological and archaeological evidence from the Egyptian Western Desert showcases the region's dramatic climatic variability, leading to a gradual drying over thousands of years.…”

Section: Introductionmentioning

confidence: 99%

Echoes of the Past: Unveiling the Kharga Oasis’ Cultural Heritage and Climate Vulnerability through Millennia

Ismael,

Abbas,

Ghaly

et al. 2023

Heritage

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The civilization and tangible cultural heritage of the Kharga Oasis has a historical precedence over that of the old Nile Valley civilization. Approximately 12,000 years ago, a significant prehistoric migration occurred from the Kharga Oasis to the Nile Valley. This event was motivated by climate change and the southward shift of the Inter-Tropical Convergence Zone (ITCZ), which caused a shift in Egypt’s savannah forests from abundant vegetation to an extremely dry desert. The present study investigates the progressive deterioration of the tangible cultural and civilized legacy of the Kharga Oasis over the course of several millennia, positing that this phenomenon can be attributed to the area’s vulnerability to paleoclimatic fluctuations. The evaluation of the Kharga Oasis’ susceptibility to climate change was predicated on the scrutiny of petroglyphs that were unearthed at different sites within the Oasis. This analysis was reinforced by paleoclimate information and radiocarbon dating (C14). The utilization of an interdisciplinary approach yielded significant insights into the dynamic climate patterns and their effects on the Kharga Oasis across temporal scales. The results illustrated a noteworthy alteration in climate, which caused the conversion of the Oasis terrain from being heavily wooded to becoming arid, mainly due to extended periods of drought. The present research postulates a novel and alternate hypothesis concerning the archaeological chronology of human habitation in the Kharga Oasis from ancient eras, predicated on the analysis of pictorial depictions on rock surfaces. The findings of this study made a noteworthy contribution to the current corpus of knowledge regarding the vulnerability of the ancient Egyptian society to the impacts of climate variability. Moreover, the petroglyphs’ depictions provided a distinctive viewpoint on the climatic fluctuations that occurred in the Sahara and North Africa throughout the Holocene epoch, as well as the fundamental causative factors.

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Study of the relationship between the intertropical convergence zone expansion and the precipitation in the southern half of Iran

Cited by 8 publications

References 36 publications

Assessment of the Intertropical Convergence Zone over the Atlantic Ocean through an Algorithm Based on Precipitation

Assessment of the Intertropical Convergence Zone over the Atlantic Ocean through an Algorithm Based on Precipitation

An evaluation of CMIP5 and CMIP6 climate models in simulating summer rainfall in the Southeast Asian monsoon domain

Echoes of the Past: Unveiling the Kharga Oasis’ Cultural Heritage and Climate Vulnerability through Millennia

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