Journal of Geophysical Research: Atmospheres最新文献

{"title":"Intensification of an Autumn Tropical Cyclone by Offshore Wind Farms in the Northern South China Sea","authors":"Shaokun Deng,&nbsp;Shengli Chen,&nbsp;Yi Sui,&nbsp;Zhen-Zhong Hu","doi":"10.1029/2024JD041489","DOIUrl":"https://doi.org/10.1029/2024JD041489","url":null,"abstract":"<p>The rapid development of the wind industry is accompanied by increasing environmental impacts. Currently, there is a lack of research on the impacts of offshore wind farm (OWF) on tropical cyclone (TC) intensity, including the mechanisms involved. This research is carried out by using a coupled and an uncoupled numerical model to investigate the impact of OWF on an autumn TC in the northeastern South China Sea. The results show that the wind speed deficit caused by OWF leads to an increase in surface pressure on the inflow side. This causes the surface pressure in the TC periphery to increase by advection, even if the TC is some distance away from the OWF. The increase in pressure gradient from the periphery to the TC center enhances the TC secondary circulation, thereby intensifying the TC. When the TC enters the OWF, the above mechanisms weaken and the ocean dominates the TC intensification. This is because the reduction in wind speed caused by the OWF results in a weaker sea surface current velocity, which weakens the flow of upstream cold water into the OWF, warming the sea surface temperature (SST) within the OWF. This implies that the horizontal gradient of the local SST is an important factor to be considered in the development of OWF. Sensitivity experiments indicate that OWF can also intensify other types of TC, and that higher cut-out wind speeds lead to stronger intensification effects. These results also provide a new perspective on TC intensity forecasts.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Processes Driving the Intermodel Spread of the Southern Hemisphere Hadley Circulation Expansion in CMIP6 Models","authors":"Ije Hur,&nbsp;Changhyun Yoo,&nbsp;Sang-Wook Yeh,&nbsp;Young-Ha Kim,&nbsp;Kyong-Hwan Seo","doi":"10.1029/2024JD041726","DOIUrl":"https://doi.org/10.1029/2024JD041726","url":null,"abstract":"<p>The Hadley circulation (HC) has been expanding poleward in recent decades. The Coupled Model Intercomparison Project Phase 6 (CMIP6) models predict that the expansion will accelerate in the future, more so in the Southern Hemisphere (SH). However, the extent of the expansion varies widely among the models. We investigate the mechanisms driving the intermodel spread in SH HC expansion predictions. The intermodel spread is obtained by an empirical orthogonal function analysis on the SH HC trend patterns of 16 CMIP6 model simulations using the historical and shared socioeconomic pathway 5–8.5 scenarios. The leading mode, showing a mean meridional stream function anomaly at the poleward SH HC extent, explains 49.73% of the variance and significantly correlates (<i>r</i> = 0.94) with the SH HC expansion. By analyzing the extended Kuo-Eliassen equation, we find that the intermodel difference in the representation of diabatic heating is responsible for about 14% of the intermodel spread. The meridional eddy momentum and heat fluxes contribute to about 21% and 18% of the intermodel spread, respectively. The models simulating a relatively large SH HC expansion tend to show increased precipitation in the Southern Pacific Convergence Zone, reduced baroclinic instability in the subtropics, and an enhanced poleward shift of jet stream in the midlatitudes. This suggests that the uncertainty in the HC projection may be constrained by reducing the bias in the trend of the mean fields.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041726","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Observed Responses of Gravity Wave Momentum Fluxes to the Madden‒Julian Oscillation Around the Extratropical Mesopause Using Mohe Meteor Radar Observations","authors":"Xu Zhou,&nbsp;Libo Liu,&nbsp;Xinan Yue,&nbsp;Guiwan Chen,&nbsp;Xian Lu","doi":"10.1029/2024JD041447","DOIUrl":"https://doi.org/10.1029/2024JD041447","url":null,"abstract":"<p>The 12-year continuous observation of gravity wave momentum fluxes (GWMFs) estimated by the Mohe meteor radar (53.5°N, 122.3°E) revealed prominent intraseasonal variability around the extratropical mesopause (82–94 km) during boreal winters. Composite analysis of the December‒January‒February (DJF) season according to the Madden‒Julian Oscillation (MJO) phases revealed that the zonal GWMFs notably increased in MJO Phase 4 (P4) by ∼2–4 m²/s², and a Monte Carlo test was designed to examine the statistical significance. The response in zonal winds lags behind the GWMF response by two MJO phases (i.e., 1/2π), indicating a “force‒response” interaction between them. Additionally, time-lagged composites revealed that strengthened westward GWMFs occurred ∼25–35 days after MJO P4, coincident with the MJO impact on the zonal winds in the stratosphere. The analysis results also suggested that the mechanism of MJO by which the MJO influences the stratospheric circulation might involve poleward propagating effects of stationary planetary waves with zonal wavenumber one. This work emphasizes the importance of GW intraseasonal variability, which impacts tropical sources from the troposphere to the extratropical mesopause.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041447","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retrieving Estimates of the Storm-Relative Wind Profile From the Vertical Variation of Hydrometeor Size Sorting Signatures","authors":"Scott D. Loeffler","doi":"10.1029/2024JD041175","DOIUrl":"https://doi.org/10.1029/2024JD041175","url":null,"abstract":"<p>Raindrop fall speed increases with raindrop size. Because larger raindrops fall through a given layer of the atmosphere more quickly compared to smaller raindrops, they spend less time in the layer and, therefore, have less time to be acted on and advected by the storm-relative winds. This results in hydrometeor size sorting which impacts the polarimetric radar variables such as differential reflectivity <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mfenced>\u0000 <msub>\u0000 <mi>Z</mi>\u0000 <mrow>\u0000 <mi>D</mi>\u0000 <mi>R</mi>\u0000 </mrow>\u0000 </msub>\u0000 </mfenced>\u0000 </mrow>\u0000 <annotation> $left({Z}_{DR}right)$</annotation>\u0000 </semantics></math> and specific differential phase <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mfenced>\u0000 <msub>\u0000 <mi>K</mi>\u0000 <mrow>\u0000 <mi>D</mi>\u0000 <mi>P</mi>\u0000 </mrow>\u0000 </msub>\u0000 </mfenced>\u0000 </mrow>\u0000 <annotation> $left({K}_{DP}right)$</annotation>\u0000 </semantics></math>. Previous work has shown a strong correlation between the mean storm-relative wind in the sorting layer and the separation between regions of enhanced <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>Z</mi>\u0000 <mrow>\u0000 <mi>D</mi>\u0000 <mi>R</mi>\u0000 </mrow>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${Z}_{DR}$</annotation>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>K</mi>\u0000 <mrow>\u0000 <mi>D</mi>\u0000 <mi>P</mi>\u0000 </mrow>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${K}_{DP}$</annotation>\u0000 </semantics></math> at the bottom of the sorting layer. This study leverages this finding, along with a simple size sorting model, to construct radar-derived estimates of the storm-relative wind profile. The radar-derived “pseudo-hodographs” are well-correlated with the magnitude and direction of the corresponding storm-relative wind profiles. Further, these radar-derived estimates of the storm-relative winds are used to calculate estimates of shear and storm-relative helicity, which also exhibit a strong correlation.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts of the Arctic Stratospheric Polar Vortex Weakening on Ural Blocking in Boreal Winter","authors":"Cheng Qian,&nbsp;Jinlong Huang,&nbsp;Wenshou Tian,&nbsp;Jinnian Liu,&nbsp;Yuanjing Song,&nbsp;Li He","doi":"10.1029/2024JD041362","DOIUrl":"https://doi.org/10.1029/2024JD041362","url":null,"abstract":"<p>Using the ERA5 reanalysis data, we analyzed the impacts of the Arctic stratospheric polar vortex weakening on Ural Blocking (UB). The results indicate that UB activities are suppressed following the weakening of the polar vortex. Specifically, the probability of UB is significantly reduced, with a maximum decrease of 30% observed around day 24 following the polar vortex weakening. The average life cycle of UB shortens by approximately one day. The amplitude of UB, as measured by the negative potential vorticity (PV) anomalies over the Urals, experiences a significant decrease, particularly with the presence of positive PV anomalies on the western side of Urals. Further analysis indicates that the suppression of UB following the weakened polar vortex is closely linked to both the equatorward horizontal transport of high-PV air over the Arctic across the dynamic tropopause, and the anomalous increase in static stability over the Urals resulting from a descent of the isentropic surface near the tropopause. Finally, we evaluate the relative roles of the polar vortex weakening and the negative phase of the Arctic Oscillation (AO) in suppressing the development of UB. Our analysis reveals that the impacts of the weak polar vortex on the suppression of UB are stronger and more long-lasting compared to the negative AO, suggesting that the impacts of the weakened polar vortex on UB cannot be simply explained by the AO response.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal and Local Time Variation in the Observed Peak of the Meteor Altitude Distributions by Meteor Radars","authors":"E. C. M. Dawkins,&nbsp;D. Janches,&nbsp;G. Stober,&nbsp;J. D. Carrillo-Sánchez,&nbsp;R. S. Lieberman,&nbsp;C. Jacobi,&nbsp;T. Moffat-Griffin,&nbsp;N. J. Mitchell,&nbsp;N. Cobbett,&nbsp;P. P. Batista,&nbsp;V. F. Andrioli,&nbsp;R. A. Buriti,&nbsp;D. J. Murphy,&nbsp;J. Kero,&nbsp;N. Gulbrandsen,&nbsp;M. Tsutsumi,&nbsp;A. Kozlovsky,&nbsp;M. Lester,&nbsp;J.-H. Kim,&nbsp;C. Lee,&nbsp;A. Liu,&nbsp;B. Fuller,&nbsp;D. O’Connor,&nbsp;S. E. Palo,&nbsp;M. J. Taylor,&nbsp;J. Marino,&nbsp;N. Rainville","doi":"10.1029/2024JD040978","DOIUrl":"https://doi.org/10.1029/2024JD040978","url":null,"abstract":"<p>Meteoroids of sub-milligram sizes burn up high in the Earth's atmosphere and cause streaks of plasma trails detectable by meteor radars. The altitude at which these trails, or meteors, form depends on a number of factors including atmospheric density and the astronomical source populations from which these meteoroids originate. A previous study has shown that the altitude of these meteors is affected by long-term linear trends and the 11-year solar cycle related to changes in our atmosphere. In this work, we examine how shorter diurnal and seasonal variations in the altitude distribution of meteors are dependent on the geographical location at which the measurements are performed. We use meteoroid altitude data from 18 independent meteor radar stations at a broad range of latitudes and investigate whether there are local time (LT) and seasonal variations in the altitude of the peak meteor height, defined as the majority detection altitude of all meteors within a certain period, which differ from those expected purely from the variation in the visibility of their astronomical source. We find a consistent LT and seasonal response for the Northern Hemisphere locations regardless of latitude. However, the Southern Hemisphere locations exhibit much greater LT and seasonal variation. In particular, we find a complex response in the four stations located within the Southern Andes region, which indicates that the strong dynamical atmospheric activity, such as the gravity waves prevalent here, disrupts, and masks the seasonality and dependence on the astronomical sources.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD040978","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142588060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intensified Western Pacific Convection Increases the Probability of Hot Extremes in the Middle East During the Boreal Spring","authors":"Ming Xia,&nbsp;Song Yang,&nbsp;Wei Wei,&nbsp;Hanjie Fan,&nbsp;Shuheng Lin,&nbsp;Kaiqiang Deng","doi":"10.1029/2024JD042048","DOIUrl":"https://doi.org/10.1029/2024JD042048","url":null,"abstract":"<p>Under global warming, the convective heating over the western Pacific (WP) has exhibited a significantly intensifying trend during the boreal spring, while the surface air temperatures in the Middle East (ME) have increased more rapidly than those in other tropical regions. Are these climate phenomena of the two regions physically connected? If yes, what are the responsible dynamical mechanisms involved? Utilizing the ERA5 reanalysis data and model simulations, this study reveals a significant seesaw variation in the convection and temperature trends between WP and ME. When convective heating intensifies over the WP, the ME tends to be drier and hotter during the spring, and vice versa. A further investigation indicates that the enhanced WP convective heating can induce anticyclonic circulation anomalies in the upper and middle troposphere over the Iranian and Tibetan plateaus. These anomalous high pressures extend westward, exhibiting a barotropic structure, which leads to stronger sinking motions, reduced cloud cover, and increased surface solar radiation over the ME. Consequently, these conditions result in drier and hotter soils and an increase in heatwave days in the ME. This study provides useful information for enhancing our understanding of the role of tropical WP climate change in influencing the upstream climate conditions with a focus on the ME.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD042048","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142588058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intrinsic Chemical Drivers of Organic Aerosol Volatility: From Experimental Insights to Model Predictions","authors":"Bin Jiang,&nbsp;Shizhen Zhao,&nbsp;Wei Chen,&nbsp;Lele Tian,&nbsp;Weiwei Hu,&nbsp;Jun Li,&nbsp;Gan Zhang","doi":"10.1029/2024JD041286","DOIUrl":"https://doi.org/10.1029/2024JD041286","url":null,"abstract":"<p>Accurately predicting the volatilities of molecules in aerosols is challenging but crucial for understanding the atmospheric effects of aerosols. We used negative and positive ion electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to identify differences in the molecular compositions of gas and particle phase samples from urban atmosphere. We aimed to identify intrinsic chemical parameters that determine and predict the organic aerosol volatility. We found higher average molecular weights, carbon mass percentages, and double bond equivalents (DBE) but lower average O/C ratios and oxygen mass percentages in the particle phase than the gas phase. We identified DBE, which display a significant negative correlation with volatility, as a key parameter. We proposed to improve the previous model for predicting organic aerosol volatility by incorporating DBE as a new variant; and the result showed that this subsequently improved the accuracy of the model, particularly for compounds with minimal or no heteroatoms (0–2) such as hydrocarbons (CH). The revised model offers insights into the contributions of DBE, carbon, nitrogen, oxygen, and sulfur atoms to the volatilities of diverse organic molecules in aerosols and could be applied to improve our understanding of the phase distributions of volatile organic compounds in the ambient air.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142588059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stratospheric Transit Time Distributions Derived From Satellite Water Vapor Measurements","authors":"William J. Randel,&nbsp;Aurelien Podglajen,&nbsp;Fei Wu","doi":"10.1029/2024JD041595","DOIUrl":"https://doi.org/10.1029/2024JD041595","url":null,"abstract":"<p>Stratospheric transit time distributions (age-of-air spectra) are estimated using time series of satellite water vapor (H₂O) measurements from the Microwave Limb Sounder over 2004 to 2021 assuming stationary transport. Latitude-altitude dependent spectra are derived from correlations of interannual H₂O anomalies with respect to the tropical tropopause source region, fitted with an inverse Gaussian distribution function. The reconstructions accurately capture interannual H₂O variability in the “tropical pipe” and near-global lower stratosphere, regions of relatively fast transport (∼1–2 years) in the Brewer-Dobson circulation. The calculations provide novel observational estimates of the corresponding “short transit-time” part of the age spectrum in these regions, including the mode. However, the H₂O results do not constrain the longer transit-time “tail” of the age spectra, and the mean age of air and spectral widths are systematically underestimated compared to other data. We compare observational results with parallel calculations applied to the WACCM chemistry-climate model and the CLaMS chemistry-transport model, and additionally evaluate the method in CLaMS by comparing with spectra from idealized pulse tracers. Because the age spectra accurately capture H₂O interannual variations originating from the tropical tropopause, they can be used to identify “other” sources of variability in the lower stratosphere, and we use these calculations to quantify H₂O anomalies in the Southern Hemisphere linked to the Australian New Years fires in early 2020 and the Hunga volcanic eruption in 2022.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142588057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regionally Coupled Climate Model ROM Projects More Plausible Precipitation Change Over Central Equatorial Africa","authors":"Alain T. Tamoffo,&nbsp;Torsten Weber,&nbsp;Daniel Abel,&nbsp;Katrin Ziegler,&nbsp;William Cabos,&nbsp;Dmitry V. Sein,&nbsp;Patrick Laux","doi":"10.1029/2024JD041466","DOIUrl":"https://doi.org/10.1029/2024JD041466","url":null,"abstract":"<p>Unraveling plausible future rainfall change (Δ<i>Pr</i>) patterns is crucial for tailoring societies' responses to climate change-induced hazards. This study compares rainfall projections from the regionally coupled ocean model (ROM) and its atmospheric component, the regional atmospheric model REMO, over Central Equatorial Africa (CEA). Both models are forced by the Earth system model MPI-ESM-LR following the Representative Concentration Pathway 8.5. Results reveal increased rainfall across most of CEA, with ROM projecting more widespread and intensified wetting than REMO, although REMO produces more precipitation under future conditions, underscoring the influence of historical biases on REMO's projection. Examining processes underpinning changes unveils strong controls of sea and land surface temperature changes in Δ<i>Pr</i> differences between the two models. Specifically, ROM mitigates warming more over the Atlantic than over CEA landmass compared to REMO, inducing enhancement of the Congo Basin cell and increased precipitable water content through specific humidity, affecting deep convection. Both models project enhanced Sahel and Kalahari thermal lows, with ROM better depicting the Kalahari low's warmer nature than the Sahel low. The resulting temperature gradients strengthen the northern and southern shallow meridional Hadley overturning circulation. ROM simulates the wetter conditions than REMO, attributed to its weaker northern Hadley Cell, which restricts the likelihood of northward moisture divergence toward the Sahel. Additionally, differences in mid-tropospheric moisture convergence differentiate between ROM and REMO's wetness relative to the historical period and under future conditions. ROM projections are more plausible, in association with the reliability of its added value under the historical climate and mechanisms underlying Δ<i>pr</i>.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"129 21","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JD041466","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142588199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}