East Asian Study of Tropospheric Aerosols and their Impact on Regional Clouds, Precipitation, and Climate (EAST‐AIR_CPC)

Journal of Geophysical Research Atmospheres, Journal Year: 2019, Volume and Issue: 124(23), P. 13026 - 13054

Published: Oct. 23, 2019

Abstract Aerosols have significant and complex impacts on regional climate in East Asia. Cloud‐aerosol‐precipitation interactions (CAPI) remain most challenging studies. The quantitative understanding of CAPI requires good knowledge aerosols, ranging from their formation, composition, transport, radiative, hygroscopic, microphysical properties. A comprehensive review is presented here centered the based chiefly, but not limited to, publications special section named EAST‐AIRcpc concerning (1) observations aerosol loading properties, (2) relationships between aerosols meteorological variables affecting CAPI, (3) mechanisms behind (4) quantification impact climate. Heavy Asia has radiative effects by reducing surface radiation, increasing air temperature, lowering boundary layer height. key factor absorption, which particularly strong central China. This absorption can a wide range such as creating an imbalance forcing at top bottom atmosphere, leading to inconsistent retrievals cloud space‐borne ground‐based instruments. Aerosol delay or suppress initiation development convective clouds whose microphysics be further altered effect aerosols. For same thickness, likelihood precipitation influenced aerosols: suppressing light rain enhancing heavy rain, delaying intensifying thunderstorms, onset isolated showers parts Rainfall become more inhomogeneous extreme heavily polluted urban regions.

Language: Английский

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A Global High‐Resolution Mesoscale Convective System Database Using Satellite‐Derived Cloud Tops, Surface Precipitation, and Tracking

Journal of Geophysical Research Atmospheres, Journal Year: 2021, Volume and Issue: 126(8)

Published: April 7, 2021

Abstract A new methodology is developed to construct a global (60°S–60°N) long‐term (2000–2019) high‐resolution (∼10‐km h) mesoscale convective system (MCS) database by tracking MCS jointly using geostationary satellite infrared brightness temperature ( T b ) and precipitation feature (PF) characteristics from the Integrated Multi‐satellitE Retrievals for GPM data sets. Independent validation shows that satellite‐based set able reproduce important statistics derived ground‐based radar network observations in United States China. We show carefully considering key PF addition signatures, method significantly improves upon previous ‐only methods detecting MCSs midlatitudes all seasons. Results account over 50% of annual total rainfall across most tropical belt selected regions midlatitudes, with strong seasonality many globe. The allows Lagrangian aspects such as lifetime translational speed direction be analyzed. longest‐lived preferentially occur subtropical oceans. land have higher cloud‐tops associated more intense convection, oceanic much production. While are observed globe, there fundamental differences their dynamic thermodynamic structures warrant better understanding processes control evolution. This provides significant opportunities observational modeling studies MCSs, characteristics, roles regional water energy cycles, well hydrologic other impacts.

Language: Английский

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The formation, character and changing nature of mesoscale convective systems

Nature Reviews Earth & Environment, Journal Year: 2020, Volume and Issue: 1(6), P. 300 - 314

Published: June 2, 2020

Language: Английский

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A Possible Dynamic Mechanism for Rapid Production of the Extreme Hourly Rainfall in Zhengzhou City on 20 July 2021

Journal of Meteorological Research, Journal Year: 2022, Volume and Issue: 36(1), P. 6 - 25

Published: Feb. 1, 2022

In this study, the unprecedented extreme rainfall event during 19–20 July 2021, which caused devastating flooding in Zhengzhou City and its nearby areas, is examined based on observational data analysis WRF model 40-h simulations 1-km horizontal resolution. The results show that successfully reproduces (i) major synoptic-scale weather systems (i.e., western Pacific subtropical high, Tibetan two typhoons, Huang-Huai cyclone), (ii) convective initiation along east to north edge of Songshan Mountain, where orographic lifting obvious, (iii) subsequent formation storm producing Zhengzhou. particular, generates maximum rate 233 mm h−1 accumulated 704 mm, corresponding well observed values 201.9 818 at nearly timing location. Importantly, an intense quasi-stationary, well-organized meso-γ-scale system, surrounded by arc-shaped convergence zone, allowing development updrafts a three-quarter circle around way similar "multidirectional pumping," attracting all associated precipitation overlaid concentrated into same trailing region generate hourly over Our study emphasizes significant contribution unique dynamic structure system record-high rainfall. A possible mechanism for short-time production proposed. That is, zone mesoscale acting like multidirectional pumps, transports from different directions region, thus produces gained herein may shed new light better understanding forecasting

Language: Английский

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Ambitious partnership needed for reliable climate prediction

Nature Climate Change, Journal Year: 2022, Volume and Issue: 12(6), P. 499 - 503

Published: June 1, 2022

Language: Английский

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Monsoons, ITCZs, and the Concept of the Global Monsoon

Reviews of Geophysics, Journal Year: 2020, Volume and Issue: 58(4)

Published: Oct. 31, 2020

Abstract Earth's tropical and subtropical rainbands, such as Intertropical Convergence Zones (ITCZs) monsoons, are complex systems, governed by both large‐scale constraints on the atmospheric general circulation regional interactions with continents orography, coupled to ocean. Monsoons have historically been considered sea breeze circulations, driven land‐sea contrast. More recently, a perspective has emerged of global monsoon, global‐scale solstitial mode that dominates annual variation precipitation. This results from seasonal overturning migration associated convergence zone. Regional subsystems embedded in this localized surface boundary conditions. Parallel this, much theoretical progress made fundamental dynamics Hadley cells zones via use hierarchical modeling approaches, including aquaplanets. Here we review explore extent which these advances can help synthesize theory observations better understand differing characteristics monsoons their responses certain forcings. After summarizing dynamical energetic balances distinguish an ITCZ show framework provides strong support for migrating zone picture allows be identified momentum energy budgets. Limitations current theories discussed, need understanding influence zonal asymmetries transients circulation.

Language: Английский

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Sensitivity of organized convective storms to model grid spacing in current and future climates

Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences, Journal Year: 2021, Volume and Issue: 379(2195), P. 20190546 - 20190546

Published: March 1, 2021

Mesoscale convective systems (MCSs) are complexes of thunderstorms that become organized and cover hundreds kilometres over several hours. MCSs prolific rain producers in the tropics mid-latitudes major cause warm-season flooding. Traditionally, climate models have difficulties simulating partly due to misrepresentation complex process interactions operate across a large range scales. Significant improvements been found kilometre-scale explicitly simulate deep convection. However, these grey zone turbulent motion known deficiencies small-scale processes (e.g. entrainment, vertical mass transport). Here, we perform mid-latitude idealized ensemble MCS simulations under current future conditions three atmospheric regimes: hydrostatic (12 km horizontal grid spacing; Δx), non-hydrostatic (Δx = 4, 2 1 km) eddy scale 500 m 250 m). Our results show dramatic improvement precipitation, movement, cold pools, cloud properties when transitioning from 12 4 Δx. Decreasing Δx beyond modest except for up- downdraft sizes, average fluxes, top height temperature, which continue change. Most important modelling is reliably capture most change signals compared those runs. Significantly different runs overestimate extreme precipitation changes by up 100%. This article part discussion meeting issue 'Intensification short-duration rainfall extremes implications flash flood risks'.

Language: Английский

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100 Years of Progress in Forecasting and NWP Applications

Meteorological Monographs, Journal Year: 2019, Volume and Issue: 59, P. 13.1 - 13.67

Published: Jan. 1, 2019

Abstract Over the past 100 years, collaborative effort of international science community, including government weather services and media, along with associated proliferation environmental observations, improved scientific understanding, growth technology, has radically transformed forecasting into an effective global regional prediction capability. This chapter traces evolution forecasting, starting in 1919 [when American Meteorological Society (AMS) was founded], over four eras separated by breakpoints at 1939, 1956, 1985. The current state could not have been achieved without essential collaboration within among countries pursuing common Earth-system challenge. AMS itself had a strong role enabling this collaboration.

Language: Английский

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Can the GPM IMERG Final Product Accurately Represent MCSs’ Precipitation Characteristics over the Central and Eastern United States?

Journal of Hydrometeorology, Journal Year: 2019, Volume and Issue: 21(1), P. 39 - 57

Published: Nov. 22, 2019

Abstract Mesoscale convective systems (MCSs) play an important role in water and energy cycles as they produce heavy rainfall modify the radiative profile tropics midlatitudes. An accurate representation of MCSs’ is therefore crucial understanding their impact on climate system. The V06B Integrated Multisatellite Retrievals from Global Precipitation Measurement (IMERG) half-hourly precipitation final product a useful tool to study characteristics MCSs because its global coverage fine spatiotemporal resolutions. However, errors uncertainties IMERG should be quantified before applying it hydrology applications. This evaluates performance capturing detecting central eastern United States during 3-yr period against radar-based Stage IV product. tracked are divided into four seasons analyzed separately for both datasets. shows wet bias total but dry hourly mean all due false classification nonprecipitating pixels precipitating. These alarm events possibly caused by evaporation under cloud base or misrepresentation MCS cold anvil regions precipitating clouds algorithm. agrees reasonably well with terms seasonal spatial distribution diurnal cycle precipitation. A relative humidity (RH)-based correction has been applied product, which helps reduce number improves overall respect IV.

Language: Английский

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Declining Summertime Local‐Scale Precipitation Frequency Over China and the United States, 1981–2012: The Disparate Roles of Aerosols

Geophysical Research Letters, Journal Year: 2019, Volume and Issue: 46(22), P. 13281 - 13289

Published: Oct. 16, 2019

Abstract The local‐scale precipitation (LSP) is mainly driven by thermal convection. Here we reveal a decreasing trend in the summertime LSP frequency over both China and United States utilizing hourly rain gauge data from 1981 to 2012. contrasting aerosol likely contributes this same declining of countries. As optical depth (AOD) goes beyond turning zone 0.25–0.30, impact on changes invigoration suppression. mean AOD generally less larger than range opposite trends States, respectively, which accounts for hours two observed boomerang shape points importance loading, matters as much as, if not more trend, thereby potentially serving constraint climate model evaluation.

Language: Английский

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