• Issue

    Journal of Geophysical Research: Atmospheres: Volume 123, Issue 22

    12,489-12,490, 12491-12508, 12,509-12,828, 12829-12856, 12,857-13,029
    27 November 2018

Issue Information

Free Access

Issue Information

  • Pages: 12,489-12,490
  • First Published: 13 December 2018

Research Articles

Climate and Dynamics

Free Access

Volcanic Radiative Forcing From 1979 to 2015

  • Pages: 12491-12508
  • First Published: 24 October 2018
Key Points

  • Small-magnitude eruptions caused a global-mean ERF of −0.08 W/m2 during 2005–2015 relative to the volcanically quiescent 1999–2002 period
  • In our model rapid adjustments act to reduce the total volcanic forcing per unit SAOD change by 13–21% for large-magnitude eruptions
  • On average, frequent small-magnitude eruptions increase the nonvolcanic background SAOD by 0.004, equating to a volcanic ERF of −0.10 W/m2

Free Access

Radiosondes Show That After Decades of Cooling, the Lower Stratosphere Is Now Warming

  • Pages: 12,509-12,522
  • First Published: 23 October 2018
Key Points

  • Radiosonde profiles show that after decades of cooling, the lower stratosphere is now warming
  • Over all continents radiosonde measured TLS trends since 2000 are larger than satellite-observed trends

Free Access

Analysis of the Ozone Reduction Event Over the Southern Tip of South America in November 2009

  • Pages: 12,523-12,542
  • First Published: 29 October 2018
Key Points

  • The dynamical fields in the Southern Hemisphere associated with a low total ozone event at Rio Gallegos in November of 2009 were analyzed
  • The 2009 event occurred due to polar vortex migration toward South America and blocking in the troposphere over the Pacific
  • The total O3 anomaly in November 2009 was one of the largest for 1979–2015 in association with a large negative geopotential height anomaly

Free Access

Short-Term Precipitation Forecast Based on the PERSIANN System and LSTM Recurrent Neural Networks

  • Pages: 12,543-12,563
  • First Published: 29 October 2018
Key Points

  • Artificial intelligence techniques are useful tools in support of forecasting complex precipitation in short range (0–6 hr)
  • Long Short-Term Memory structure is capable of learning spatial and temporal correlations, efficiently
  • The framework provides accurate precipitation forecasts, especially for the convective systems that have complex evolving dynamics

Free Access

An Integrated Hydrological Model for the Restoration of Ecosystems in Arid Regions: Application in Zhangye Basin of the Middle Heihe River Basin, Northwest China

  • Pages: 12,564-12,582
  • First Published: 26 October 2018
Key Points

  • An integrated multiprocess model was proposed and applied in the Zhangye basin
  • The integrated model could well reflect the dynamic interactions among hydrological processes
  • Ecological restoration strategies were suggested based on scenario predictions considering interactions of multi-hydrological processes

Free Access

Enhancing the Fast Radiative Transfer Model for FengYun-4 GIIRS by Using Local Training Profiles

  • Pages: 12,583-12,596
  • First Published: 05 November 2018
Key Points

  • The weighted least squares method improves the accuracy of RTTOV GIIRS simulation over the ordinary least squares method
  • Local training profiles improves GIIRS simulation over the global training profiles, which is beneficial to local weather related applications
  • The methods can be applied to develop the fast radiative transfer models for sensors onboard the geostationary weather satellites

Free Access

Formation Features of Steps and Branches of an Upward Negative Leader

  • Pages: 12,597-12,605
  • First Published: 05 November 2018
Key Points

  • The detailed luminosity decrease and reillumination of the leader channel between two consecutive steps are presented for the first time
  • The so-called stem can be the reilluminated streamer which then develops to become a new leader tip
  • Leader steps and branches share a similar formation process

Free Access

Long-Range Correlation Analysis of Soil Temperature and Moisture on A'rou Hillsides, Babao River Basin

  • Pages: 12,606-12,620
  • First Published: 24 October 2018
Key Points

  • Comparison of long-range correlations of soil moisture between the shady slope and sunny slope. Comparison of long-range correlations of soil temperature between the shady slope and sunny slope. Comparison of long-range cross correlation between the soil moisture and soil temperature between the shady slope and sunny slope
  • Long-range correlation and long-range cross correlation display vertical depth variation and timescale variation
  • We seek out driving factors of stratification heterogeneity of LRC and LRCC in different soil depths

Open Access

Sensitivity of the Amazonian Convective Diurnal Cycle to Its Environment in Observations and Reanalysis

  • Pages: 12,621-12,646
  • First Published: 31 October 2018
Key Points

  • Higher morning convective inhibition shifts the precipitation phase later and increases the amplitude for GOAmazon observations
  • The radiative diurnal cycle is less biased in ERA than MERRA-2 for the GOAmazon domain, but MERRA-2 is less biased over the entire Amazon
  • Differences in nocturnal middle tropospheric vertical velocity in models influence diurnal biases in column humidity and radiative fluxes

Free Access

Impact of Spectral Nudging on Real-Time Tropical Cyclone Forecast

  • Pages: 12,647-12,660
  • First Published: 09 November 2018
Key Points

  • The spectral nudging generally improves the TC track forecast with advanced large-scale fields
  • Simulated TC intensity is weakened by spectral nudging, and sensitivity test on nudging options reduces the suppression of TC intensity
  • Track forecasts can be further improved by selectively applying spectral nudging based on TC characteristics

Free Access

Skillful Subseasonal Forecasts of Weekly Tornado and Hail Activity Using the Madden-Julian Oscillation

  • Pages: 12,661-12,675
  • First Published: 12 November 2018
Key Points

  • An active Madden-Julian Oscillation (MJO) modulates springtime tornado and hail activity over the next 2–5 weeks across the United States
  • Using the MJO as a predictor, skillful weekly forecasts of severe weather with lead times of 2–5 weeks can be realized
  • These subseasonal to seasonal (S2S) forecasts offer important forewarning to stakeholders of when and where severe weather is likely

Free Access

Snow Hydrology in the Upper Yellow River Basin Under Climate Change: A Land Surface Modeling Perspective

  • Pages: 12,676-12,691
  • First Published: 08 November 2018
Key Points

  • Snow hydrological responses to climate change were projected in the UYR basin through a climate-land surface hydrologic modeling framework
  • Snow depth and SWE in the UYR basin would decline with regional climate warming and wetting
  • Biased ISI-MIP-GCMs-outputted air temperature leads to impractical simulation of changes in snow seasonality

Free Access

On the Formation Mechanism for Wintertime Extreme Precipitation Events Over the Southeastern Tibetan Plateau

  • Pages: 12,692-12,714
  • First Published: 14 November 2018
Key Points

  • The circumglobal teleconnection pattern played a key role in the development of extreme precipitation over the southeastern Tibetan Plateau
  • The evolution of precipitable water delayed the timing and increased the intensity of extreme precipitation events
  • Land areas to the south of the Tibetan Plateau contributed 78.7% of the moisture for the extreme precipitation

Free Access

Life Cycle of Atmospheric Rivers: Identification and Climatological Characteristics

  • Pages: 12,715-12,725
  • First Published: 24 October 2018
Key Points

  • Most of the North Pacific AR events originate in the subtropics and terminate in higher latitudes including western North America
  • Long AR events travel 7 times longer in distance and have stronger intensity than short AR events
  • An accumulated AR intensity index is developed to summarize the overall impact of AR events

Free Access

Modeling Neutron Emissions in High Energy Atmospheric Phenomena

  • Pages: 12,726-12,737
  • First Published: 01 November 2018
Key Points

  • We calculate neutron densities on ground for arbitrary spectra, altitudes, and durations of gamma-ray sources
  • Neutron detection on ground indicates high gamma-ray energies at source altitude
  • When the gamma-ray source is a directed beam, the effective neutron source is a cone of km length

Aerosol and Clouds

Free Access

Multiband Simulations of Multistream Polarimetric Microwave Radiances Over Aspherical Hydrometeors

  • Pages: 12,738-12,761
  • First Published: 01 November 2018
Key Points

  • The applicability of the UMRT model is extended over aspherical hydrometeors with inherent numerical stability
  • An OpenSSP-based scattering function matrix database for broadband radiances simulation was established
  • Considerable impact of complex hydrometeors versus simple Mie spheres on predicted microwave radiances is demonstrated

Free Access

The Role of Secondary Ice Processes in Midlatitude Continental Clouds

  • Pages: 12,762-12,777
  • First Published: 09 October 2018
Key Points

  • Ice nucleation efficiency of natural ice nucleation particles is controlled by K-feldspar
  • Secondary ice processes have a large influence on the ice content in midlatitude orographic-triggered convective clouds
  • The effect of secondary ice processes on Earth's radiative budget is possibly greater than previously assumed

Free Access

Sizing of Ambient Particles From a Single-Particle Soot Photometer Measurement to Retrieve Mixing State of Black Carbon at a Regional Site of the North China Plain

  • Pages: 12,778-12,795
  • First Published: 31 October 2018
Key Points

  • The mixing state of black carbon at a polluted suburban area in China indicates fast aging process and strong absorbing capacity
  • Sizing ability of using leading-edge-only fit combining with Mie calculation is validated in the range of ~200–600 nm
  • The density and reflective index of refractory black carbon and the reflective index of coatings are retrieved by closure study

Free Access

Radar Reflectivity and Altitude Distributions of Lightning as a Function of IC, CG, and HY Flashes: Implications for LNOx Production

  • Pages: 12,796-12,813
  • First Published: 05 November 2018
Key Points

  • Two-dimensional radar reflectivity and altitude distributions of intercloud/intracloud, cloud-to-ground, and hybrid flashes vary with storm type
  • The new altitude and reflectivity distributions of lightning by flash and storm types are more accurate than the legacy approach
  • Flash sizes vary as a function of flash type and storm type with hybrid flashes having the largest sizes, irrespective of storm type

Free Access

Radar Reflectivity and Altitude Distributions of Lightning Flashes as a Function of Three Main Storm Types

  • Pages: 12,814-12,828
  • First Published: 05 November 2018
Key Points

  • New two-dimensional reflectivity and altitude distributions show that where flashes initiate and propagate vary as a function of storm type
  • Flashes propagate in lower reflectivities compared to where they initiate, irrespective of storm type
  • Root-mean-square errors and Pearson product moment correlation coefficients show good agreement among the new distributions and test cases

Open Access

Representing Cloud Water Content of Extensive Cloud Systems Over Land Using Satellite-Based Passive Microwave Observations With a Coupled Land and Atmosphere Assimilation Method

  • Pages: 12829-12856
  • First Published: 09 November 2018
Key Points

  • A method to estimate cloud water content over land using satellite passive microwave observations at kilometer scale was proposed
  • Estimations using coupled atmosphere and land assimilation were in good accordance with CloudSat products over both land and ocean
  • Additional use of cloud top information has great potential to represent vertical distributions of cloud water content with high accuracy

Free Access

Properties of Negative Initial Leaders and Lightning Flash Size in a Cluster of Supercells

  • Pages: 12,857-12,876
  • First Published: 09 November 2018
Key Points

  • An objective, automated method to identify the negative initial leaders (NILs) and retrieve their parameters is proposed
  • Properties of NILs and flash size are counted, while their differences between supercells and normal storms are noted
  • Charge distribution pattern and density may determine the special characteristics of NILs and flash size in supercells

Composition and Chemistry

Free Access

Wintertime Transport of Reactive Trace Gases From East Asia Into the Deep Tropics

  • Pages: 12,877-12,896
  • First Published: 11 October 2018
Key Points

  • Elevated levels of anthropogenic trace gases transported in the lower atmosphere from East Asia were found behind shear lines in the deep tropical West Pacific during winter
  • The chemical impact of the pollutants associated with the shear line depends on source strength, shear line organization, speed of advancement, and background conditions
  • Anthropogenic Enhancement Factor is a metric developed to quantify the chemical impact of the air behind the shear line on the local background conditions

Free Access

Wintertime Gas-Particle Partitioning and Speciation of Inorganic Chlorine in the Lower Troposphere Over the Northeast United States and Coastal Ocean

  • Pages: 12,897-12,916
  • First Published: 24 October 2018
Key Points

  • Airborne observations show that HCl and particle chloride are dominant tropospheric Cly compounds in wintertime boundary layer
  • Chlorine gas-particle partitioning can be modeled, assuming a small, unmeasured fraction of NaCl mass from sea salt is internally mixed
  • Lower-limit equilibrium constant is derived for HCl from observations: Keq = 2.5 × 106 exp[5,208 (1/T − 1/T0)] mol2·kg−2·atm−1

Free Access

Spectroscopic Diagnostic of Halos and Elves Detected From Space-Based Photometers

  • Pages: 12,917-12,941
  • First Published: 23 October 2018
Key Points

  • We provide new spectroscopic diagnostic methods to analyze optical signals from TLEs reported by space-based photometers such as ASIM-MMIA
  • The optical signals emitted by halos and elves can provide information about the temporal evolution of the reduced electric field
  • The optical signal emitted by an elve can be used to deduce the electrical characteristics of the parent lightning

Free Access

Current and Future Arctic Aerosols and Ozone From Remote Emissions and Emerging Local Sources—Modeled Source Contributions and Radiative Effects

  • Pages: 12,942-12,963
  • First Published: 27 October 2018
Key Points

  • Arctic shipping and gas flaring significantly contribute to present-day and future surface Arctic pollution
  • Ozone from shipping cools the atmosphere due to the near-surface temperature inversions in the Arctic
  • Future Arctic diversion shipping causes significant negative summertime aerosol indirect effects (-0.8 W/m2)

Open Access

Direct Observations of Fine Primary Particles From Residential Coal Burning: Insights Into Their Morphology, Composition, and Hygroscopicity

  • Pages: 12,964-12,979
  • First Published: 05 November 2018
Key Points

  • Residential burning of low- and medium-maturity coals emitted abundant carbonaceous particles, while high-maturity coals emitted OM-S
  • Coal maturity and burning temperature substantially affect particulate properties in coal emissions
  • Primary organic and soot particles display extremely weak hygroscopicity, and inorganic salts determine hygroscopic growth of mixed particles

Free Access

Decadal Shifts in Wind Patterns Reduced Continental Outflow and Suppressed Ozone Trend in the 2010s in the Lower Troposphere Over Japan

  • Pages: 12,980-12,993
  • First Published: 04 November 2018
Key Points

  • Tropospheric ozone level at Mt. Happo, Japan, dropped in the late 2000s, despite increasing Chinese emissions
  • Persistent La Niña-like wind pattern has reduced long-range transport from East Asia via weakened westerly winds
  • Without the persistent La Niña-like wind pattern, the ozone trend over Japan would have been further upward in the late 2000s

Free Access

ClNO2 Yields From Aircraft Measurements During the 2015 WINTER Campaign and Critical Evaluation of the Current Parameterization

  • Pages: 12,994-13,015
  • First Published: 05 November 2018
Key Points

  • Box modeling of wintertime measurements over the eastern United States provides the first determinations of ClNO2 yields (ϕ(ClNO2)) from aircraft
  • The median ϕ(ClNO2) value derived from the box model is overpredicted by 75-84% by the current laboratory-based ϕ(ClNO2) parameterization
  • Modeled and parameterized ϕ(ClNO2) values show opposite trends with aerosol water, suggesting an incorrectly parameterized dependence

Free Access

Vertical Characterization of Aerosol Particle Composition in Beijing, China: Insights From 3-Month Measurements With Two Aerosol Mass Spectrometers

  • Pages: 13,016-13,029
  • First Published: 12 November 2018
Key Points

  • Vertical differences in aerosol particle composition between ground level and 260 m in Beijing are characterized
  • Substantially different vertical distributions between primary and secondary aerosol species in the low atmosphere are observed
  • The evolution of vertical distributions for aerosol composition during typical haze episodes are elucidated