• Issue
    Volume 128, Issue 22
    27 November 2023

Issue Information

Free Access

Issue Information

  • First Published: 09 November 2023

Research Article

Composition and Chemistry

Open Access

Development and Evaluation of a North America Ensemble Wildfire Air Quality Forecast: Initial Application to the 2020 Western United States “Gigafire”

  • First Published: 20 November 2023
Key Points

  • Ensemble mean of models provides reliable aerosol optical depth and PM2.5 forecasts with stronger correlation, lower bias, and the highest overall RANKs

  • The ensemble approach provides a well suited exceedance probability forecast during the 2020 Gigafire events

  • The multi-model ensemble approach can reduce uncertainties in air quality forecasts and improve model predictability during wildfire events

Aerosol and Clouds

A New CCN Number Concentration Prediction Method Based on Multiple Linear Regression and Non-Negative Matrix Factorization: 1. Development, Validation, and Comparison Using the Measurement Data Over the Korean Peninsula

  • First Published: 21 November 2023

Key Points

  • A new cloud condensation nuclei (CCN) number concentration prediction method was developed

  • The results of the CCN number concentration prediction method over the Korean Peninsula were very good

  • The newly developed method showed strength in robustness and capability to take into account external mixing

Open Access

The Effects of Aerosol on Small-Scale Cloud-Environment Mixing: Implications for Simulating and Observing Inhomogeneous Mixing

  • First Published: 20 November 2023
Key Points

  • Because sufficiently large haze particles can be misinterpreted as droplets, mixing can appear more homogeneous

  • Solute and curvature effects initiate microphysical changes (Ostwald ripening) that can be confounded with inhomogeneous mixing

  • Haze particles are shown to buffer the negative impacts of inhomogeneous mixing on the cloud albedo

Climate and Dynamics

Open Access

Recent Tangible Natural Variability of Monsoonal Orographic Rainfall in the Eastern Himalayas

  • First Published: 27 November 2023
Key Points

  • The study highlights the natural variability in the eastern Himalayan hydroclimate over the past 43 years, emphasizing its significance as a recurring natural hazard that affects the region

  • The research identifies extreme monsoonal rainy years, with monsoon rainfall as a major contributor to river discharge. Notably, the study rules out the role of melting snow in these extreme events

  • This research underscores the dominant influence of atmospheric dynamics as the primary modulating factor in the Eastern Himalayan monsoon

VogCast: A Framework for Modeling Volcanic Air Pollution and Its Application to the 2022 Eruption of Mauna Loa Volcano, Hawai'i

  • First Published: 10 November 2023
Key Points

  • VogCast is a Python-based modular open-source air quality modeling framework for volcanic gas emissions

  • VogCast incorporates a dynamic plume-rise scheme for estimating plume injection height

  • Comparison with remotely sensed data from 2022 Mauna Loa eruption suggests VogCast is able to accurately capture regional-scale vog dispersion

Composition and Chemistry

Observations and Modeling of Gaseous Nitrated Phenols in Urban Beijing: Insights From Seasonal Comparison and Budget Analysis

  • First Published: 14 November 2023
Key Points

  • Gas-phase nitrated phenols (NPs) were observed and modeled in winter and summer in Beijing, China

  • NPs mainly originate from secondary productions via oxidation by OH and NO3 radicals and are removed mostly by photolysis

  • NPs constitute a significant source of nitrous acid with implications for atmospheric oxidative capacity

Open Access

Significant Impact of Reactive Chlorine on Complex Air Pollution Over the Yangtze River Delta Region, China

  • First Published: 14 November 2023
Key Points

  • The impact of new chlorine emissions from disinfectant usage in the Weather Research and Forecasting-Community Multiscale Air Quality (WRF-CMAQ) model was evaluated against observations in the Yangtze River Delta

  • The Cl chemistry of WRF-CMAQ was updated by adding 21 new reactions, including 13 gas-phase and eight heterogeneous reactions

  • Chlorine chemistry has different impacts on O3 and PM2.5 in different seasons, with higher impacts found in autumn and winter

Climate and Dynamics

High Production of Gigantic Jets by a Thunderstorm Over Indian Ocean

  • First Published: 16 November 2023
Key Points

  • A storm produced 13 events in about 1 hr and in a restricted area of about 590 km2 over Indian Ocean 500 km from La Réunion island

  • The jets were produced during short pulses of convection in cells with dominant positive cloud-to-ground lightning flashes

  • The rapid surge in the current moment waveform corresponds with the established fully developed jet (FDJ) and a second peak with a slower charge transfer after the FDJ

Open Access

An Assessment of Southern Hemisphere Extratropical Cyclones in ERA5 Using WindSat

  • First Published: 10 November 2023
Key Points

  • Cyclone composites derived from ERA5 and WindSat show strong spatial correlations and small relative biases for winds and water vapor

  • In the cold sector ERA5 underestimates cloud liquid water (CLW) yet overestimates precipitation, while warm sector precipitation is underestimated

  • Our comparison with WindSat shows that ERA5 represents the cyclone lifecycle well over the ocean

Summertime Near-Surface Temperature Biases Over the Central United States in Convection-Permitting Simulations

  • First Published: 17 November 2023
Key Points

  • Convection Permitting Models have surface warm biases mainly because of evaporation underestimation, similar to coarser-resolution models

  • The simulations of mesoscale convective systems can be degraded by the evaporative fraction biases, which also influence surface warm biases

  • The land surface impacts precipitation via its influence on evapotranspiration whereas spring precipitation impacts summertime soil moisture

Open Access

Subseasonal Clustering of Atmospheric Rivers Over the Western United States

  • First Published: 15 November 2023
Key Points

  • Atmospheric rivers (ARs) temporally cluster at a greater-than-random rate across the western United States (US) with a distinct geographical pattern

  • Compared to the Northwest, Southwest clusters are longer-lived, consist of more ARs and account for a larger fraction of total AR occurrence

  • A considerable fraction of western US total and extreme hourly precipitation is attributable to AR clusters

Aerosol and Clouds

Open Access

Drivers of Cloud Condensation Nuclei in the Eastern North Atlantic as Observed at the ARM Site

  • First Published: 27 November 2023
Key Points

  • Data suggest aerosol measurements at the Atmospheric Radiation Measurement Eastern North Atlantic site are affected by local emissions when the wind direction is between 90° and 310°

  • Lower ambient wintertime Cloud Condensation Nuclei (CCN) concentrations compared to summer are primarily driven by advection and precipitation

  • CCN variability at sub-monthly timescales is driven by clouds and precipitation upstream of the site

Climate and Dynamics

Open Access

Spatiotemporal Trends of Extreme Temperature Events Along the Qinghai-Tibet Plateau Transportation Corridor From 1981 to 2019 Based on Estimated Near-Surface Air Temperature

  • First Published: 10 November 2023
Key Points

  • Spatial trends of extreme temperature events were detected using the gridded temperature product

  • Extreme hot events generally increase with altitude

  • The intensification of extreme hot events in the low-altitude areas is likely due to human activities and urbanization

Aerosol and Clouds

Fast Calculation on Atmospheric Rayleigh Scattering Extinction Optical Depth for Day/Night Band Radiative Transfer Model With Periodic Lunar Illumination

  • First Published: 17 November 2023
Key Points

  • Developing a new equivalent optimal central wavelength algorithm for calculating the Rayleigh scatter extinction effect of Day/Night Band

  • Nuances in reflectance can be found between the new equivalent optimal central wavelength algorithm and the true values

  • New algorithm can correct about 1% relative error at dark surface induced by periodic changes in lunar spectral irradiance

Climate and Dynamics

Stratospheric Aerosol Injection Can Reduce Risks to Antarctic Ice Loss Depending on Injection Location and Amount

  • First Published: 15 November 2023
Key Points

  • Antarctic atmospheric circulation responds differently to stratospheric aerosol injections that vary by amount and injection latitude(s)

  • Changes to the coastal winds impacts surface ice accumulation and shelf ocean temperatures near ice shelves

  • Specific injection strategies can slow 21st century ice loss and avoid identified thresholds pertaining to Antarctic tipping points

Aerosol and Clouds

Microphysics of Heavy Rain Associated With the Eyewall and Inner Rainbands of Typhoon Meranti (2016)

  • First Published: 10 November 2023
Key Points

  • More efficient ice- and warm-cloud microphysical processes were found in tropical cyclone (TC) eyewall than in inner rainbands

  • More ice and rain particles appear to be produced in TC eyewall, but not all raindrops can fall to the ground

  • Unique dynamics (e.g., stronger updrafts) in TC eyewall are responsible for the microphysical difference with the inner-rainband rain

High Concentration of Atmospheric Sub-3 nm Particles in Polluted Environment of Eastern China: New Particle Formation and Traffic Emission

  • First Published: 10 November 2023
Key Points

  • High number concentration of sub-3 nm particles was observed in eastern China, with obvious diurnal and seasonal variations

  • Sulfuric acid-driven new particle formation is the dominant source of sub-3 nm particles during the daytime

  • Traffic emission contributes over 30% of sub-3 nm particles, while the origin of 62% of sub-3 nm particles remains unclear during the night

Climate and Dynamics

Variation in the Impact of ENSO on the Western Pacific Pattern Influenced by ENSO Amplitude in CMIP6 Simulations

  • First Published: 14 November 2023
Key Points

  • The CMIP6 models display notable discrepancies in portraying the winter El Niño-Southern Oscillation (ENSO) and the Western Pacific pattern connection

  • Diversity of the ENSO and Western Pacific pattern relation across models is intrinsically linked to the spread of the ENSO amplitude

  • Enhanced atmospheric convective anomalies in the TWP associated with stronger ENSO lead to a stronger Western Pacific pattern response

Open Access

Antecedent Hydrometeorological Conditions of Wildfire Occurrence in the Western U.S. in a Changing Climate

  • First Published: 11 November 2023
Key Points

  • Wildfires are clustered into four types, each featuring distinct antecedent surface pressure, radiation, and soil moisture conditions

  • The distinct relations of the wildfire clusters to geographic, hydrometeorological, and vegetation conditions improve their predictability

  • Wildfire increases during 1984–2018 are dominated by the low-pressure and longwave type fires, offset by the reduction of wet-soil fires

Future Projections of Low-Level Atmospheric Circulation Patterns Over South Tropical South America: Impacts on Precipitation and Amazon Dry Season Length

  • First Published: 21 November 2023
Key Points

  • Circulation Patterns (CPs) provide a new perspective of the lengthening of the dry season in southern Amazonia

  • General circulation models (GCMs) show significant future changes in the main dry-to-wet transitional atmospheric states

  • GCMs indicate a projected increase in the frequency of CPs typically observed during the Amazon dry season by the mid-21st century

Aerosol and Clouds

A New CCN Number Concentration Prediction Method Based on Multiple Linear Regression and Non-Negative Matrix Factorization: 2. Application to Obtain CCN Spectra in and Around the Korean Peninsula

  • First Published: 27 November 2023

Key Points

  • Evaluation of a new cloud condensation nuclei number concentration prediction method is made

  • This method is applicable to regions where the organic/inorganic fraction does not differ greatly from that of the training data set

  • Parameterizations of cloud condensation nuclei spectra representing various regions in and around the Korean Peninsula are formulated

Open Access

Improving the Estimation of the Diffuse Component of Photosynthetically Active Radiation (PAR)

  • First Published: 11 November 2023
Key Points

  • Diffuse component of photosynthetically active radiation can be modeled even when no continuous measurements are available

  • Diffuse photosynthetically active radiation can be modeled from the total solar spectrum with high performance

  • Artificial neural networks and empirical models have similar results modeling from total range

Open Access

Fine and Coarse Dust Effects on Radiative Forcing, Mass Deposition, and Solar Devices Over the Middle East

  • First Published: 16 November 2023
Key Points

  • Models and reanalysis products underestimate coarse dust emission and dust deposition by 2–3 times

  • Fine dust affects radiation, but coarse dust dominates mass deposition rates

  • Atmospheric dust dims solar radiation, and coarse dust causes the soiling of solar panels

Climate and Dynamics

Open Access

Drift Correction and Sub-Ensemble Predictive Skill Evaluation of the Decadal Prediction Large Ensemble With Application to Regional Studies

  • First Published: 13 November 2023
Key Points

  • Generally, the initial condition-based drift correction (ICDC) shows the best performance for all the domains, climate variables and indices analyzed

  • The ICDC contributes to improve the predictive skill of the North Atlantic Oscillation index and reduces the loss of predictive skill observed in El Niño/Southern Oscillation indices

  • Despite the loss of predictive skill after ensemble size reduction, ENS3 performs similar to ENS10 and ENS40 for sea surface temperature (SST) at lead years 2–9

Open Access

Atmospheric Climatologies Over Isfjorden, Svalbard

  • First Published: 10 November 2023
Key Points

  • Climatologies of near-surface variables over Isfjorden are strongly impacted by the land-sea contrast and orography

  • Temporal variability dominates over spatial variability, but both depend on the season and the synoptic-scale flow

Open Access

Seasonal and Interannual Variations in the Schumann Resonance Observed in the ELF Electromagnetic Networks in China

  • First Published: 15 November 2023
Key Points

  • Long-periodic variation in the Schumann resonance (SR) parameters is examined at 10 extremely low-frequency electromagnetic stations in China

  • Correlations are confirmed among the SR parameters, global climate change, and the solar activity cycle

Initiations of Mesoscale Convective Systems in the Middle Reaches of the Yangtze River Basin Based on FY-4A Satellite Data: Statistical Characteristics and Environmental Conditions

  • First Published: 20 November 2023
Key Points

  • The initiations of mesoscale convective systems (MCSs) are backward tracked through a hybrid method of areal overlapping and optical flow

  • Quasistationary and outward-moving MCSs show notable differences in initiation and developments

  • A synoptic circulation pattern associated with the Mei-yu front is most favorable for the initiation of MCSs

Composition and Chemistry

Detailed Modeling and Evaluation of the Potential Impact of Blue Jet on the Atmospheric Chemistry

  • First Published: 21 November 2023
Key Points

  • Ozone enhanced in the middle stratosphere by the impact of blue jet (BJ) discharge during the first 100 s

  • Ozone depletion appears in the middle and upper stratosphere after 48 hr of BJ discharge, and the ozone layer “shifts” to a lower altitude

  • The enhancement of chlorine and bromine reservoirs can be transported over long distances and be reactivated later to destroy ozone

Climate and Dynamics

Atmospheric Wave Radiation by Vibrations of an Ice Shelf

  • First Published: 10 November 2023
Key Points

  • Vibrations of large ice shelves radiate atmospheric waves that can travel in a wide range of directions from near-horizontal to near-zenith

  • Simple, numerically efficient model is developed of atmospheric wave generation by finite sources at the ground level

  • With the surface vibrations' spectrum as the input, the model quantifies atmospheric perturbations from the troposphere to the thermosphere

Open Access

The Diurnal Cycle of Rainfall and Deep Convective Clouds Around Sumatra and the Associated MJO-Induced Variability During Austral Summer in Himawari-8

  • First Published: 10 November 2023
Key Points

  • Rainfall Potential Areas have shown semi-diurnal structures of deep convective clouds over the Indian Ocean

  • An explicit sea-ward propagation pattern of deep convective clouds and complex interactions between island were found in the Java Sea

  • The cloud top height reaches a maximum in the Madden-Julian Oscillation convective enhanced phase

Aerosol and Clouds

Open Access

Ice Supersaturation Variability in Cirrus Clouds: Role of Vertical Wind Speeds and Deposition Coefficients

  • First Published: 10 November 2023
Key Points

  • This study presents a process-based, systematic investigation of key factors controlling ice supersaturation statistics within cirrus

  • Gravity wave-induced mesoscale temperature fluctuations cause a remarkably large variability in ice supersaturation

  • Ice supersaturation statistics are not strongly modified by depositional growth with supersaturation-dependent deposition coefficients

Composition and Chemistry

Open Access

Exploring Deposition Observations of Oxidized Sulfur and Nitrogen as a Constraint on Emissions in the United States

  • First Published: 23 November 2023
Key Points

  • The GEOS-Chem model captures the substantial decrease in deposition of sulfur oxides and inorganic nitrate over the United States from 1990 to 2021

  • Derived dry deposition observations constrain local anthropogenic emission trends, while wet deposition measurements reflect total sources

  • The GEOS-Chem model is unable to simultaneously replicate ambient and deposited nitrate, providing evidence for under-explored sinks of NOy

Climate and Dynamics

Open Access

Winter Subtropical Highs, the Hadley Circulation and Baroclinic Instability

  • First Published: 23 November 2023
Key Points

  • Winter subtropical highs get stronger and shift polewards when the Eady Growth Rate (EGR) shifts polewards and the Hadley Cell strengthens

  • The EGR shift is dominated by the vertical wind shear, in thermal wind balance with the variations and trends of temperature

  • Similar mechanisms are at play on interannual and longer time scales and the Pacific subtropical highs are strengthening over time

Aerosol and Clouds

Robust Susceptibility of Cloud Cover and Radiative Effects to Biases in Retrieved Droplet Concentrations

  • First Published: 20 November 2023
Key Points

  • 40% higher cloud droplet concentration (Nd) retrieval of Visible Infrared Imaging Radiometer Suite than Moderate Resolution Imaging Spectroradiometer due to the differences in resolution and cloud detectability

  • The differences in Nd retrieval increase with increasing cloud top inhomogeneity

  • Despite the significant difference in Nd, the susceptibilities of cloud fraction and cloud radiative effects to Nd are repeatable

Composition and Chemistry

Shipboard Observations of Aerosol Chemical Properties Over the Western Pacific Ocean in Winter 2018

  • First Published: 22 November 2023
Key Points

  • The compositions of aerosol presented a significant change from anthropogenic source to marine sea salt from coast to remote oceans

  • Dust from North Africa acted as catalyst to promote the intensive formation of secondary organic aerosols in equatorial area

  • There was a significant chlorine loss in the offshore coast, and a pronounced chlorine excess in remote seas

Climate and Dynamics

Open Access

Sensitivity of African Easterly Waves to Dust Forcing

  • First Published: 23 November 2023
Key Points

  • African easterly waves (AEWs) are highly sensitive to dust shortwave absorption

  • Wave track intensifies, broadens, and shifts southward in response to dust shortwave absorption

  • AEW sensitivity to dust stems primarily from baroclinic and barotropic energy conversions and energy generation by adiabatic heating

Composition and Chemistry

Modeling the Air Pollution and Aerosol-PBL Interactions Over China Using a Variable-Resolution Global Model

  • First Published: 23 November 2023
Key Points

  • The MUSICAv0 model with regional refinement over East Asia improves haze event simulations, especially in complex terrain areas

  • Finer grids can resolve a greater range of NOx and volatile organic compounds (VOC) chemical regimes, significantly reducing the ozone overestimation in coarser grids

  • Finer grids improve the boundary layer representation of black carbon featured by stronger inverse temperature structure in the lower atmosphere

Different Response Mechanisms of N-Bearing Components to Emission Reduction Across China During COVID-19 Lockdown Period

  • First Published: 20 November 2023
Key Points

  • Three distinct response mechanisms of N-bearing components were revealed in China during the lockdown period

  • Increased relative humidity (RH) and abundant NH3 promoted the simultaneous increases of NO 3 and NH 4 + ${{\text{NO}}_{3}}^{-}\text{and}\,{{\text{NH}}_{4}}^{+}$ in Northeast China

  • Strong atmospheric oxidation capacity coupled with high RH promoted the increases of NO 3 and NH 4 + ${{\text{NO}}_{3}}^{-}\text{and}\,{{\text{NH}}_{4}}^{+}$ despite low NH3 level

Aerosol and Clouds

Toward an Interpretable CNN Model for the Classification of Lightning-Produced VLF/LF Signals

  • First Published: 23 November 2023
Key Points

  • The proposed model achieves an accuracy of 98.56% for a four-type lightning waveform classification task and shows good robustness

  • The model is interpretable by visualizing the contribution of different waveform parts to the classification results

  • The proposed model aligns with human-expert classifications and suggests potential to link waveform features with lightning processes

Climate and Dynamics

Evaluating the Representations of Atmospheric Rivers and Their Associated Precipitation in Reanalyses With Satellite Observations

  • First Published: 20 November 2023
Key Points

  • Developed a novel method to detect atmospheric rivers (ARs) using moisture and wind data from satellite observations

  • Reanalyses and satellite observations show high agreement with each other in AR frequency distributions

  • Under AR conditions, reanalyses tend to precipitate too often and too lightly

Open Access

Investigation of Added Value in Regional Climate Models for East Asian Storm Track Analysis

  • First Published: 20 November 2023
Key Points

  • Regional climate models improve accuracy of climate projections for East Asia by simulating local climates at higher resolution than global climate models

  • Regional climate models effectively evaluate potential impacts of local climate variability on specific regions and inform local adaptation strategies

  • The added value of regional climate models in improving global climate models' bias and agreement with high-resolution reanalysis in mountainous regions is shown

A Typical Weakly Forced Mountain-To-Plain Extreme Precipitation Event Exacerbated by Urbanization in Beijing

  • First Published: 27 November 2023
Key Points

  • Gridded urban canopy parameters have a limited effect on model's skill in simulating a typical mountain-to-plain rainfall event in Beijing

  • Urbanization-induced rainfall increase is linked to urban surface dynamics under a weak urban heat island

  • The high urban surface roughness and drag force of urban canopy collectively contribute to the precipitation intensification in urban areas

Targeted Observations on Arctic Sea Ice Concentration for Improving Extended-Range Prediction of Ural Blocking

  • First Published: 22 November 2023
Key Points

  • Extended-range prediction of long-lasting and strong Ural blocking (UB) can be improved through targeted observations on Arctic sea ice

  • Targeted observations based on the conditional nonlinear optimal perturbation method are an efficient strategy for improving forecast skills

  • Barents Sea, Greenland Sea, and Okhotsk Sea are the sensitive areas for UB extended-range predictions

Stratospheric Climate Anomalies and Ozone Loss Caused by the Hunga Tonga-Hunga Ha'apai Volcanic Eruption

  • First Published: 22 November 2023
Key Points

  • Large-scale stratospheric cooling and circulation changes are observed following the Hunga Tonga-Hunga Ha'apai eruption

  • Observations show ozone reduction in the Southern Hemisphere wintertime midlatitudes and large springtime Antarctic ozone losses in 2022

  • A chemistry-climate model can track the plumes and capture observed responses to the volcanic eruption

Characteristics and Attribution of Spatiotemporal Changes in Qilian Mountains' Runoff Over the Past Six Decades

  • First Published: 27 November 2023
Key Points

  • Average annual total river runoff on the Qilian Mountains was estimated at approximately 15.671 km3, decreasing from northeast to southwest

  • A downward trend in annual runoff was observed in the eastern region, while an upward trend was observed in its central and western regions

  • River replenishment types changed from rainfall dominant (eastern) to mixed replenishment (central) to meltwater dominant (western)

Aerosol and Clouds

Open Access

Characteristics and Variability of Precipitation Across Different Sectors of an Extra-Tropical Cyclone: A Case Study Over the High-Latitudes of the Southern Ocean

  • First Published: 23 November 2023
Key Points

  • Distinctive characteristics of precipitation across different sectors of an extra-tropical cyclone are observed

  • Largest precipitation was recorded during the cyclone period where its phases were largely constituted of mixed-phase and snow

  • WRF reproduced the frontal precipitation intensity, while it is underestimated during the cyclone period

Climate and Dynamics

Reducing Winter Precipitation Biases Over the Western Tibetan Plateau in the Model for Prediction Across Scales (MPAS) With a Revised Parameterization of Orographic Gravity Wave Drag

  • First Published: 22 November 2023
Key Points

  • Winter precipitation biases in western Tibetan Plateau (TP) are reduced using a nonhydrostatic orographic gravity wave drag (OGWD) scheme

  • Accounting for the nonhydrostatic effects produces weaker zonal OGWD which induces a plateau-scale cyclonic circulation to the north of TP

  • The cyclonic circulation counters the northern branch of bifurcated westerlies, leading to a reduced water vapor transport into western TP

Defining Arctic Stratospheric Polar Vortex Intensification Events

  • First Published: 27 November 2023
Key Points

  • The statistics of strong and weak vortex events as defined by several easily calculated indices of stratospheric variability are compared

  • Statistical and dynamical properties of strong events are found to be more sensitive to the choice of definition than are weak events

  • The character of stratosphere-troposphere coupling near the central date of strong events depends strongly on the choice of definition

Aerosol and Clouds

High-Resolution Mapping of Regional NMVOCs Using the Fast Space-Time Light Gradient Boosting Machine (LightGBM)

  • First Published: 27 November 2023
Key Points

  • A space-time LightGBM (STLGB) model in machine learning is used to estimate NMVOCs reliably

  • Hourly NMVOCs maps were produced at 1 km resolution by the STLGB model

  • The STLGB model shows good performance with cross-validation R2 of 0.92

Climate and Dynamics

A Structured Graph Neural Network for Improving the Numerical Weather Prediction of Rainfall

  • First Published: 27 November 2023
Key Points

  • A graph neural network for extracting features from the output variables of the numerical weather prediction (NWP) model for rainfall forecasting

  • A level-specific training label and a weighted loss function based on the relative frequency of rainfall amount to better training the model

  • The proposed method improves the forecast skill at all rainfall intensity levels and can yields more reasonable location and intensity of rainfall

Ocean Dynamics Causes the Equatorial Pacific SST Bias in CAS-ESM2-0

  • First Published: 27 November 2023
Key Points

  • The annual equatorial Pacific SST bias in CAS-ESM2-0 is caused by ocean dynamics rather than surface heat flux

  • Bias in ocean currents is contributed by both the standalone ocean model and atmospheric surface winds

  • Bias in atmospheric precipitation impacts surface winds as equatorial Rossby-gravity wave response to latent heating

Aerosol and Clouds

Open Access

Spatiotemporal Variations in Summertime Arctic Aerosol Optical Depth Caused by Synoptic-Scale Atmospheric Circulation in Three Reanalyses

  • First Published: 10 November 2023
Key Points

  • Arctic summertime synoptic variability of total aerosol optical depth (AOD) strongly correlated with observations in three reanalyses

  • Location and development of synoptic disturbances has a predominant effect on the poleward transport, aging, and deposition of aerosols

  • Primary and secondary predominant synoptic-scale AOD variability is related to two types of Arctic cyclone