Atmosphere

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Open AccessEditorial

Acknowledgement to Reviewers of Atmosphere in 2015

by Atmosphere Editorial Office

Atmosphere 2016, 7(1), 13; https://doi.org/10.3390/atmos7010013 - 21 Jan 2016

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The editors of Atmosphere would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2015. [...] Full article

1159 KiB

Open AccessArticle

Joint Inversion of Atmospheric Refractivity Profile Based on Ground-Based GPS Phase Delay and Propagation Loss

by Qixiang Liao, Zheng Sheng and Hanqing Shi

Atmosphere 2016, 7(1), 12; https://doi.org/10.3390/atmos7010012 - 21 Jan 2016

Cited by 5 | Viewed by 4414

Abstract

In this paper, we present a new estimation of the atmospheric refractivity profile combining the scattering signal (electromagnetic wave propagation loss) and the direct signal (phase delay). The refractivity profile is modeled using four parameters, i.e., the gradient of the refractivity profile [...] Read more.

In this paper, we present a new estimation of the atmospheric refractivity profile combining the scattering signal (electromagnetic wave propagation loss) and the direct signal (phase delay). The refractivity profile is modeled using four parameters, i.e., the gradient of the refractivity profile (c₁, c₂) and the vertical altitude (h₁, h₂). We apply the NSGA-II (Non-dominated Sorting Genetic Algorithm II), a multiobjective optimization algorithm, to achieve the goals of joint optimization inversion in the inverting process, and compare this method with traditional individual inversion methods. The anti-noise ability of joint inversion is investigated under the noiseless condition and adding noise condition, respectively. The numerical experiments demonstrate that joint inversion is superior to individual inversion. The adding noise test further suggests that this method can estimate synthesized parameters more efficiently and accurately in different conditions. Finally, a set of measured data is tested in the new way and the consequence of inversion shows the joint optimization inversion algorithm has feasibility, effectiveness and superiority in the retrieval of the refractivity profile. Full article

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Open AccessArticle

Time-Reversibility in Atmospheric Dispersion

by Tímea Haszpra

Atmosphere 2016, 7(1), 11; https://doi.org/10.3390/atmos7010011 - 19 Jan 2016

Cited by 3 | Viewed by 4355

Abstract

Due to the chaotic nature of atmospheric dispersion, small deviations, e.g., numerical errors in dispersion simulations, increase rapidly over time. Therefore, the accuracy of backward simulations is limited. In the paper, the degree of the fulfillment of time-reversibility over different time periods is [...] Read more.

Due to the chaotic nature of atmospheric dispersion, small deviations, e.g., numerical errors in dispersion simulations, increase rapidly over time. Therefore, the accuracy of backward simulations is limited. In the paper, the degree of the fulfillment of time-reversibility over different time periods is investigated by a Lagrangian dispersion model at a global scale using pollutant clouds consisting of a large number of particles. The characteristics of the pollutant clouds in the backward simulation are compared to those in the forward simulation. In order to characterize the degree of time-reversibility, Lagrangian quantities, such as the fraction of particles that return to the initial volume, the center of mass and the standard deviation of the pollutant clouds, are determined. Furthermore, the overlap and the Pearson’s correlation coefficient between the forward and backward clouds are also investigated. Both a case study and global results are presented. Simulations reveal that the accuracy of time-reversibility decreases in general exponentially in time. We find that after the Lyapunov time of the dispersion (in our case three to four days), the results of the backward tracking become unreliable, and any sign of time-reversibility is lost. Full article

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578 KiB

Open AccessArticle

“It Was Raining All the Time!”: Ex Post Tourist Weather Perceptions

by Stefan Gössling, Bruno Abegg and Robert Steiger

Atmosphere 2016, 7(1), 10; https://doi.org/10.3390/atmos7010010 - 15 Jan 2016

Cited by 36 | Viewed by 7478

Abstract

The importance of weather for tourism is now widely recognized. However, no research has so far addressed weather events from retrospective viewpoints, and, in particular, the role of “extreme” events in longer-term holiday memories. To better understand the character of ex post weather [...] Read more.

The importance of weather for tourism is now widely recognized. However, no research has so far addressed weather events from retrospective viewpoints, and, in particular, the role of “extreme” events in longer-term holiday memories. To better understand the character of ex post weather experiences and their importance in destination image perceptions and future travel planning behavior, this exploratory study addressed a sample of 50 tourists from three globally important source markets: Austria, Germany and Switzerland. Results indicate that weather events do not dominate long-term memories of tourist experiences. Yet, weather events are important in shaping destination image, with “rain” being the single most important weather variable negatively influencing perceptions. Results also suggest that weather events perceived as extreme can involve considerable emotions. The study of ex post traveler memories consequently makes a valuable contribution to the understanding of the complexity of “extreme weather” events for tourist demand responses. Full article

(This article belongs to the Special Issue Tourism Climatology)

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5046 KiB

Open AccessArticle

Analysis of the Error in Retrievals of Aerosol Optical Properties from Sunphotometer Measurements of CARSNET Due to a Variety of Objective Factors

by Ke Gui, Huizheng Che, Quanliang Chen, Jie Yu, Yu Zheng, Sai Lu, Hong Wang, Yaqiang Wang, Xiaoye Zhang and Guangyu Shi

Atmosphere 2016, 7(1), 9; https://doi.org/10.3390/atmos7010009 - 13 Jan 2016

Cited by 16 | Viewed by 5167

Abstract

In situ observation of the aerosol optical properties is important to the validations of satellite and modeling results; however, the operational measurements can be affected by some objective factors. An experiment study has been performed in order to analyze the error in retrievals [...] Read more.

In situ observation of the aerosol optical properties is important to the validations of satellite and modeling results; however, the operational measurements can be affected by some objective factors. An experiment study has been performed in order to analyze the error in retrievals of aerosol optical properties from sunphotometer measurements caused by a variety of in situ objective factors. The standard instrument relative error analysis method was used to determine the relative error of aerosol optical depth (AOD) and Ångström exponent (AE) under the effects of five factors: spider web inside the collimator (F1); collimator bending (F2); dust inside the optical head (F3); incrustation scale inside the optical head (F4); and dust and incrustation scale inside the optical head (F5). The results showed that the five factors caused error for AOD retrieved at 1020, 870, 670 and 440 nm, with the maximum error occurring at 870 nm due to the more sensitive measurement signals. The error ranges of AOD derived from the direct solar measurements in the four bands were −0.34%–8.77%, −6.22%–9.68%, −0.05%–2.52%, −0.96%–3.48% and 5.42%–13.38% for F1, F2, F3, F4 and F5, respectively. The maximum error occurred under the influence of F5 with an average error value of 10%, while the minimum occurred owing to F3 with an average error value of 1%. All of the AEs retrieved from the experimental instruments were smaller than that from the reference instrument. The AE error values were 15.19%, 25.57%, 4.56%, 4.41% and 8.83% for F1, F2, F3, F4 and F5, respectively. The average AE retrieval error value was 11.7%. Full article

(This article belongs to the Special Issue Atmospheric Aerosols and Their Radiative Effects)

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754 KiB

Open AccessArticle

Convection of Moist Saturated Air: Analytical Study

by Robert Zakinyan, Arthur Zakinyan, Roman Ryzhkov and Kristina Avanesyan

Atmosphere 2016, 7(1), 8; https://doi.org/10.3390/atmos7010008 - 5 Jan 2016

Cited by 6 | Viewed by 4944

Abstract

In the present work, the steady-state stationary thermal convection of moist saturated air in a lower atmosphere has been studied theoretically. Thermal convection was considered without accounting for the Coriolis force, and with only the vertical temperature gradient. The analytical solution of geophysical [...] Read more.

In the present work, the steady-state stationary thermal convection of moist saturated air in a lower atmosphere has been studied theoretically. Thermal convection was considered without accounting for the Coriolis force, and with only the vertical temperature gradient. The analytical solution of geophysical fluid dynamics equations, which generalizes the formulation of the moist convection problem, is obtained in the two-dimensional case. The stream function is derived in the Boussinesq approximation with velocity divergence taken as zero. It has been shown that the stream function is asymmetrical in vertical direction contrary to the dry and moist unsaturated air convection. It has been demonstrated that the convection in moist atmosphere strongly depends on the vapor mass fraction gradient. Full article

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Open AccessArticle

The Role of Highly-Resolved Gust Speed in Simulations of Storm Damage in Forests at the Landscape Scale: A Case Study from Southwest Germany

by Christopher Jung, Dirk Schindler, Axel Tim Albrecht and Alexander Buchholz

Atmosphere 2016, 7(1), 7; https://doi.org/10.3390/atmos7010007 - 4 Jan 2016

Cited by 20 | Viewed by 6425

Abstract

Routinely collected booking records of salvaged timber from the period 1979–2008 were used to empirically model the (1) storm damage probability; (2) proportions of storm-damaged timber and (3) endemic storm damage risk in the forest area of the German federal state of Baden-Wuerttemberg [...] Read more.

Routinely collected booking records of salvaged timber from the period 1979–2008 were used to empirically model the (1) storm damage probability; (2) proportions of storm-damaged timber and (3) endemic storm damage risk in the forest area of the German federal state of Baden-Wuerttemberg by applying random forests. Results from cross-validated predictor importance evaluation demonstrate that the relative impact of modeled gust speed fields on the predictive accuracy of the random forests models was greatest compared to the impact of forest and soil features. Forest areas prone to storm damage occurring within a period of five years were mainly located in mountainous upland regions where maximum gust speed exceeds 31 m/s in a five-year return period and conifers dominate the tree species composition. While mean storm damage probability continuously increased with increasing statistical gust speed proportions of storm-damaged timber peaked at a statistical maximum gust speed value of 29 m/s occurring in a five-year return period. Combining the statistical gust speed field with daily gust speed fields of two exceptional winter storms improved model accuracy and considerably increased the explained variance. Endemic storm damage risk was calculated from endemic storm damage probability and proportions of endemically storm-damaged timber. In combination with knowledge of local experts the storm damage risk modeled in a 50 m × 50 m resolution raster dataset can easily be used to identify areas prone to storm damage and to adapt silvicultural management regimes to make forests more windfirm. Full article

(This article belongs to the Special Issue Biometeorology)

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8539 KiB

Open AccessArticle

Comprehensive Evaluation of High-Resolution Satellite-Based Precipitation Products over China

by Hao Guo, Sheng Chen, Anming Bao, Junjun Hu, Banghui Yang and Phillip M. Stepanian

Atmosphere 2016, 7(1), 6; https://doi.org/10.3390/atmos7010006 - 31 Dec 2015

Cited by 51 | Viewed by 7701

Abstract

Characterizing the errors in satellite-based precipitation estimation products is crucial for understanding their effects in hydrological applications. Six precipitation products derived from three algorithms are comprehensively evaluated against gauge data over mainland China from December 2006 to November 2010. These products include three [...] Read more.

Characterizing the errors in satellite-based precipitation estimation products is crucial for understanding their effects in hydrological applications. Six precipitation products derived from three algorithms are comprehensively evaluated against gauge data over mainland China from December 2006 to November 2010. These products include three satellite-only estimates: the Global Satellite Mapping of Precipitation Microwave-IR Combined Product (GSMaP_MVK), the Climate Prediction Center (CPC) MORPHing (CMORPH), and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN), as well as their gauge-corrected counterparts: the GSMaP Gauge-calibrated Product (GSMaP_Gauge), bias-corrected CMORPH (CMORPH_CRT), and PERSIANN Climate Data Record (PERSIANN-CDR). Overall, the bias-correction procedures largely reduce various errors for the three groups of satellite-based precipitation products. GSMaP_Gauge produces better fractional coverage with the highest correlation (0.95) and the lowest RMSE (0.53 mm/day) but also high RB (15.77%). In general, CMORPH_CRT amounts are closer to the gauge reference. CMORPH shows better performance than GSMaP_MVK and PERSIANN with the highest CC (0.82) and the lowest RMSE (0.93 mm/day), but also presents a relatively high RB (−19.60%). In winter, all six satellite precipitation estimates have comparatively poor capability, with the IR-based PERSIANN_CDR exhibiting the closest performance to the gauge reference. Both satellite-only and gauge-corrected satellite products show poor capability in detecting occurrence of precipitation with a low POD (<50%) and CSI (<35%) and a high FAR (>40%). Full article

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7156 KiB

Open AccessArticle

Variation Characteristics of Rainfall in the Pre-Flood Season of South China and Its Correlation with Sea Surface Temperature of Pacific

by Suxiang Yao, Qian Huang and Chen Zhao

Atmosphere 2016, 7(1), 5; https://doi.org/10.3390/atmos7010005 - 31 Dec 2015

Cited by 18 | Viewed by 6235

Abstract

The characteristics of rainfall variation in the pre-flood season of South China (PFSSC) and its correlation with the sea surface temperature (SST) of the Pacific are studied in this paper. The results show that in the last 50 years, rainfall in PFSSC clearly [...] Read more.

The characteristics of rainfall variation in the pre-flood season of South China (PFSSC) and its correlation with the sea surface temperature (SST) of the Pacific are studied in this paper. The results show that in the last 50 years, rainfall in PFSSC clearly has interannual and interdecadal oscillations, primarily in the 4a and 8a cycles. Interannual correlation analysis indicate that the rainfall in PFSSC displays a significantly negative correlation with the SST of the warm pool region in January–March and April–June. The interdecadal correlation analysis reveals that the rainfall in PFSSC is negatively correlated to the SST of the warm pool region, but has a significant positive interdecadal correlation with the Middle Eastern Pacific Ocean. For NINO1 + 2 and NINO3 regions, when the background ocean temperature is warm, the SST is significantly positively correlated to the rainfall in PFSSC; however, when the background ocean temperature is cold, there is no significant correlation between the two, even the correlation coefficients are negative. For the warm pool region, the SST demonstrates a significantly negative correlation to the rainfall in PFSSC, which is not dependent on the background SST. It is a remarkable fact that under the different SST backgrounds, the interannual variation of SST will bring different atmospheric response, and it is the reason that under the warm SST background, the correlation is more significant between the SST in tropical Pacific and the rainfall in PFSSC. Under the background of global warming, more attention should be given to study the rainfall in PFSSC and its correlation with the SST in the eastern tropical Pacific. Full article

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Open AccessArticle

Multi-Scale Observations of Atmosphere Environment and Aerosol Properties over North China during APEC Meeting Periods

by Xi Wei, Xingfa Gu, Hao Chen, Tianhai Cheng, Ying Wang, Hong Guo, Fangwen Bao and Kunsheng Xiang

Atmosphere 2016, 7(1), 4; https://doi.org/10.3390/atmos7010004 - 31 Dec 2015

Cited by 10 | Viewed by 4618

Abstract

This paper reveals a study on air pollution process over North China, applying remote sensing technology, using satellite observation and in situ measurements during the twenty-first Asia-Pacific Economic Cooperation (APEC) meeting, which was held in Beijing between 6 and 12 November when the [...] Read more.

This paper reveals a study on air pollution process over North China, applying remote sensing technology, using satellite observation and in situ measurements during the twenty-first Asia-Pacific Economic Cooperation (APEC) meeting, which was held in Beijing between 6 and 12 November when the clear weather was called “APEC-Blue”. In the meantime, pollutants concentrations including PM_2.5 and PM₁₀ in Beijing were lower than 100 μg/m³ owing to the effective government measures and policies, as well as meteorological conditions. High aerosol loading (AOD > 1) was observed over south of Beijing and vertical observations showed that the pollutants were prominent near the land surface. Different from the meeting period, high pollutants concentrations with explosive growth (the values of PM_2.5 and PM₁₀ peaking at 291 μg/m³ and 360 μg/m³ respectively) appeared over Beijing after the meeting period, accompanied by strong temperature inversion and high Relative Humidity (RH) values. The pollution particles transferred from Beijing area to south part of North China. Otherwise, fine-mode particles with strong absorption characteristic (UVAI > 1.5, AOD > 1) covered the Beijing sky in the meantime, indicating the existence of black carbon aerosols. Full article

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139 KiB

Open AccessErratum

Erratum: Hassan, M.; et al. An Assessment of the South Asian Summer Monsoon Variability for Present and Future Climatologies Using a High Resolution Regional Climate Model (RegCM4.3) under the AR5 Scenarios. Atmosphere 2015, 6, 1833–1857

by Atmosphere Editorial Office

Atmosphere 2016, 7(1), 3; https://doi.org/10.3390/atmos7010003 - 28 Dec 2015

Viewed by 3063

Abstract

The published date in the paper [1] should be 23 November 2015. We apologize to the authors of the paper and readers of Atmosphere for any inconvenience caused. [...] Full article

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Open AccessArticle

Winter Dew Harvest in Mexico City

by Arias-Torres Jorge Ernesto and Flores-Prieto Jose Jasson

Atmosphere 2016, 7(1), 2; https://doi.org/10.3390/atmos7010002 - 23 Dec 2015

Cited by 17 | Viewed by 5114

Abstract

This study presents experimental and theoretical results of winter dew harvest in México City in terms of condensation rate. A simplified theoretical model based on a steady-state energy balance on a radiator-condenser was fitted, as a function of the ambient temperature, the relative [...] Read more.

This study presents experimental and theoretical results of winter dew harvest in México City in terms of condensation rate. A simplified theoretical model based on a steady-state energy balance on a radiator-condenser was fitted, as a function of the ambient temperature, the relative humidity and the wind velocity. A glass sheet and aluminum sheet white-painted were used as samples over the outdoor experiments. A good correlation was obtained between the theoretical and experimental data. The experimental results show that there was condensation in 68% of the winter nights on both condensers. The total winter condensed mass was 2977 g/m² and 2888 g/m² on the glass sheet and aluminum sheet white-painted, respectively. Thus, the condensed mass on the glass was only 3% higher than that on the painted surface. The maximum nightly dew harvests occurred during December, which linearly reduced from 50 g/m² night to 22 g/m² night as the winter months went by. The condensation occurred from 1:00 a.m. to 9:00 a.m., with maximum condensation rates between 6:00 a.m. and 7:00 a.m. The dew harvest can provide a partial alternative to the winter water shortage in certain locations with similar climates to the winter in Mexico City, as long as pollution is not significant. Full article

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Open AccessArticle

Frequency and Character of Extreme Aerosol Events in the Southwestern United States: A Case Study Analysis in Arizona

by David H. Lopez, Michael R. Rabbani, Ewan Crosbie, Aishwarya Raman, Avelino F. Arellano and Armin Sorooshian

Atmosphere 2016, 7(1), 1; https://doi.org/10.3390/atmos7010001 - 23 Dec 2015

Cited by 26 | Viewed by 6204

Abstract

This study uses more than a decade’s worth of data across Arizona to characterize the spatiotemporal distribution, frequency, and source of extreme aerosol events, defined as when the concentration of a species on a particular day exceeds that of the average plus two [...] Read more.

This study uses more than a decade’s worth of data across Arizona to characterize the spatiotemporal distribution, frequency, and source of extreme aerosol events, defined as when the concentration of a species on a particular day exceeds that of the average plus two standard deviations for that given month. Depending on which of eight sites studied, between 5% and 7% of the total days exhibited an extreme aerosol event due to either extreme levels of PM₁₀, PM_2.5, and/or fine soil. Grand Canyon exhibited the most extreme event days (120, i.e., 7% of its total days). Fine soil is the pollutant type that most frequently impacted multiple sites at once at an extreme level. PM_10, PM_2.5, fine soil, non-Asian dust, and Elemental Carbon extreme events occurred most frequently in August. Nearly all Asian dust extreme events occurred between March and June. Extreme Elemental Carbon events have decreased as a function of time with statistical significance, while other pollutant categories did not show any significant change. Extreme events were most frequent for the various pollutant categories on either Wednesday or Thursday, but there was no statistically significant difference in the number of events on any particular day or on weekends versus weekdays. Full article

(This article belongs to the Special Issue Atmospheric Composition Observations)

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