Articles | Volume 21, issue 17
Research article 31 Aug 2021
Research article | 31 Aug 2021
On the role of aerosol radiative effect in the wet season onset timing over the Congo rainforest during boreal autumn
Sudip Chakraborty et al.
No articles found.
Joaquim V. Teixeira, Hai Nguyen, Derek J. Posselt, Hui Su, and Longtao Wu
Atmos. Meas. Tech., 14, 1941–1957,Short summary
Wind-tracking algorithms produce atmospheric motion vectors (AMVs) by tracking satellite observations. Accurately characterizing the uncertainties in AMVs is essential in assimilating them into data assimilation models. We develop a machine-learning-based approach for error characterization which involves Gaussian mixture model clustering and random forest using a simulation dataset of water vapor, AMVs, and true winds. We show that our method improves on existing AMV error characterizations.
Brigitte Rooney, Yuan Wang, Jonathan H. Jiang, Bin Zhao, Zhao-Cheng Zeng, and John H. Seinfeld
Atmos. Chem. Phys., 20, 14597–14616,Short summary
Wildfires have become increasingly prevalent. Intense smoke consisting of particulate matter (PM) leads to an increased risk of morbidity and mortality. The record-breaking Camp Fire ravaged Northern California for two weeks in 2018. Here, we employ a comprehensive chemical transport model along with ground-based and satellite observations to characterize the PM concentrations across Northern California and to investigate the pollution sensitivity predictions to key parameters of the model.
Amir Erfanian and Rong Fu
Atmos. Chem. Phys., 19, 15199–15216,Short summary
An eastward advection of dry and warm air in spring was identified as a major drought onset mechanism over the US Great Plains (GP). Further breakdown of the zonal advection into the dynamic versus thermodynamic contributions revealed dominance of the latter in the tropospheric drying observed during the onset of GP 2011 and 2012 droughts. The dependence of thermodynamic advection on moisture gradient links the spring precipitation in the Rockies and US southwest to the GP summer precipitation.
Pierre Gentine, Adam Massmann, Benjamin R. Lintner, Sayed Hamed Alemohammad, Rong Fu, Julia K. Green, Daniel Kennedy, and Jordi Vilà-Guerau de Arellano
Hydrol. Earth Syst. Sci., 23, 4171–4197,Short summary
Land–atmosphere interactions are key for the exchange of water, energy, and carbon dioxide, especially in the tropics. We here review some of the recent findings on land–atmosphere interactions in the tropics and where we see potential challenges and paths forward.
Jui-Lin Frank Li, Mark Richardson, Wei-Liang Lee, Eric Fetzer, Graeme Stephens, Jonathan Jiang, Yulan Hong, Yi-Hui Wang, Jia-Yuh Yu, and Yinghui Liu
The Cryosphere, 13, 969–980,Short summary
Observed summer Arctic sea ice retreat has been faster than simulated by the average CMIP5 models, most of which exclude falling ice particles from their radiative calculations. We use controlled CESM1-CAM5 simulations to show for the first time that snowflakes' radiative effects can accelerate sea ice retreat. September retreat rates are doubled above current CO2 levels, highlighting falling ice radiative effects as a high priority for inclusion in future modelling of the Arctic.
Jianping Guo, Huan Liu, Zhanqing Li, Daniel Rosenfeld, Mengjiao Jiang, Weixin Xu, Jonathan H. Jiang, Jing He, Dandan Chen, Min Min, and Panmao Zhai
Atmos. Chem. Phys., 18, 13329–13343,Short summary
Objective analysis has been used to discriminate between the local- and synoptic-scale precipitations based on wind and pressure fields at 500 hPa. Aerosol is found to be linked with changes in the vertical structure of precipitation, depending on precipitation regimes. There has been some success in separating aerosol and meteorological influences on precipitation.
Bin Zhao, Jonathan H. Jiang, David J. Diner, Hui Su, Yu Gu, Kuo-Nan Liou, Zhe Jiang, Lei Huang, Yoshi Takano, Xuehua Fan, and Ali H. Omar
Atmos. Chem. Phys., 18, 11247–11260,Short summary
We combine satellite-borne and ground-based observations to investigate the intra-annual variations of regional aerosol column loading, vertical distribution, and particle types. Column aerosol optical depth (AOD), as well as AOD > 800 m, peaks in summer/spring. However, AOD < 800 m and surface PM2.5 concentrations mostly peak in winter. The aerosol intra-annual variations differ significantly according to aerosol types characterized by different sizes, light absorption, and emission sources.
Sudip Chakraborty, Kathleen A. Schiro, Rong Fu, and J. David Neelin
Atmos. Chem. Phys., 18, 11135–11148,Short summary
This study shows the observational evidence of the role of humidity and associations from wind shear and aerosol concentrations on the evolution of deep convective clouds from shallow clouds. This study shows how humidity, wind shear, and aerosols influence a parcel's buoyancy before the clouds form.
Pengfei Tian, Lei Zhang, Jianmin Ma, Kai Tang, Lili Xu, Yuan Wang, Xianjie Cao, Jiening Liang, Yuemeng Ji, Jonathan H. Jiang, Yuk L. Yung, and Renyi Zhang
Atmos. Chem. Phys., 18, 7815–7825,Short summary
The mixing of dust and anthropogenic pollution over East Asia plays a significant yet poorly quantified role in aerosol radiative effects. We have found that radiative absorption of the East Asian aerosol mixtures are significantly enhanced. Our results show that the interaction between dust and anthropogenic pollution not only represents a viable aerosol formation pathway but also results in unfavorable dispersion conditions, both exacerbating the regional air pollution in East Asia.
Longtao Wu, Yu Gu, Jonathan H. Jiang, Hui Su, Nanpeng Yu, Chun Zhao, Yun Qian, Bin Zhao, Kuo-Nan Liou, and Yong-Sang Choi
Atmos. Chem. Phys., 18, 5529–5547,
Bin Zhao, Kuo-Nan Liou, Yu Gu, Jonathan H. Jiang, Qinbin Li, Rong Fu, Lei Huang, Xiaohong Liu, Xiangjun Shi, Hui Su, and Cenlin He
Atmos. Chem. Phys., 18, 1065–1078,Short summary
The interactions between aerosols and ice clouds represent one of the largest uncertainties among anthropogenic forcings on climate change. We find that the responses of ice crystal effective radius, a key parameter determining ice clouds' net radiative effect, to aerosol loadings are modulated by water vapor amount and vary from a significant negative correlation in moist conditions (consistent with the “Twomey effect” for liquid clouds) to a strong positive correlation in dry conditions.
Bin Zhao, Wenjing Wu, Shuxiao Wang, Jia Xing, Xing Chang, Kuo-Nan Liou, Jonathan H. Jiang, Yu Gu, Carey Jang, Joshua S. Fu, Yun Zhu, Jiandong Wang, Yan Lin, and Jiming Hao
Atmos. Chem. Phys., 17, 12031–12050,Short summary
Using over 1000 chemical transport model simulations in the Beijing–Tianjin–Hebei region, we find that the emissions of primary inorganic PM2.5 make the largest contribution to PM2.5 concentrations and thus should be prioritized in PM2.5 control strategies. Among the precursors, PM2.5 concentrations are primarily sensitive to the emissions of NH3, NMVOC+IVOC, and POA, and the sensitivities increase substantially for NH3 and NHx with the increase in emission reduction ratio.
Jose A. Marengo, Gilberto F. Fisch, Lincoln M. Alves, Natanael V. Sousa, Rong Fu, and Yizhou Zhuang
Atmos. Chem. Phys., 17, 7671–7681,Short summary
The onset and demise of the rainy season in Amazonia are assessed in this study using meteorological data from the GoAmazon experiment for the 2014–15 rainy season. The onset of the rainy season was strongly associated with changes in large-scale circulation in the region, and our analyses using regional thermodynamic indices suggest that local changes such the regional thermodynamic characteristics may have been less important on the occurrence of the onset compared to large-scale circulation.
Longtao Wu, Hui Su, Olga V. Kalashnikova, Jonathan H. Jiang, Chun Zhao, Michael J. Garay, James R. Campbell, and Nanpeng Yu
Atmos. Chem. Phys., 17, 7291–7309,Short summary
The WRF-Chem simulation successfully captures aerosol variations in the cold season in the San Joaquin Valley (SJV) but has poor performance in the warm season. High-resolution model simulation can better resolve nonhomogeneous distribution of anthropogenic emissions in urban areas, resulting in better simulation of aerosols in the cold season in the SJV. Poor performance of the WRF-Chem model in the warm season in the SJV is mainly due to misrepresentation of dust emission and vertical mixing.
Steven T. Massie, Julien Delanoë, Charles G. Bardeen, Jonathan H. Jiang, and Lei Huang
Atmos. Chem. Phys., 16, 6091–6105,Short summary
Changes in cloud vertical structure (i.e. the shape of cloud ice water content (IWC) vertical structure) due to variations in aerosol, observed by three different satellite experiments (MODIS, OMI, and MLS) are calculated in the Tropics during 2007–2010. This topic is of interest because aerosol-cloud interactions are the largest source of uncertainty in climate models. Analysis of the effects of MODIS aerosol, OMI absorptive aerosol, and MLS CO (an absorptive aerosol proxy) upon deep convective
Lei Huang, Jonathan H. Jiang, Lee T. Murray, Megan R. Damon, Hui Su, and Nathaniel J. Livesey
Atmos. Chem. Phys., 16, 5641–5663,Short summary
This study evaluates the distribution and variation of carbon monoxide (CO) in the upper troposphere and lower stratosphere (UTLS) during 2004–2012 on global and regional scales as simulated by two chemical transport models (GMI and GEOS-Chem), using the latest version (V4) of Aura Microwave Limb Sounder (MLS) observations. The impacts of surface emissions and convection on CO concentrations in the UTLS over different regions are investigated, using both model simulations and MLS observations.
L. Wu, H. Su, R. G. Fovell, T. J. Dunkerton, Z. Wang, and B. H. Kahn
Atmos. Chem. Phys., 15, 14041–14053,
P. Vergados, A. J. Mannucci, C. O. Ao, J. H. Jiang, and H. Su
Atmos. Meas. Tech., 8, 1789–1797,
L. Huang, R. Fu, and J. H. Jiang
Atmos. Chem. Phys., 14, 4087–4099,
Related subject area
Subject: Dynamics | Research Activity: Remote Sensing | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)Study of the seasonal variation in Aeolus wind product performance over China using ERA5 and radiosonde dataMeasurement report: characteristics of clear-day convective boundary layer and associated entrainment zone as observed by a ground-based polarization lidar over Wuhan (30.5° N, 114.4° E)Technical note: First comparison of wind observations from ESA's satellite mission Aeolus and ground-based radar wind profiler network of ChinaAssessment of vertical air motion among reanalyses and qualitative comparison with very-high-frequency radar measurements over two tropical stationsAsian summer monsoon anticyclone: trends and variabilityVery high stratospheric influence observed in the free troposphere over the northern Alps – just a local phenomenon?Long-lived high-frequency gravity waves in the atmospheric boundary layer: observations and simulationsVariability of temperature and ozone in the upper troposphere and lower stratosphere from multi-satellite observations and reanalysis dataIndications for a potential synchronization between the phase evolution of the Madden–Julian oscillation and the solar 27-day cycleMesoscale fine structure of a tropopause fold over mountainsTropical convection regimes in climate models: evaluation with satellite observationsWave modulation of the extratropical tropopause inversion layerPlanetary boundary layer height from CALIOP compared to radiosonde over ChinaExploring atmospheric blocking with GPS radio occultation observationsUpper tropospheric water vapour variability at high latitudes – Part 1: Influence of the annular modesMixing layer height and its implications for air pollution over Beijing, ChinaEffect of tropical cyclones on the tropical tropopause parameters observed using COSMIC GPS RO dataNew fire diurnal cycle characterizations to improve fire radiative energy assessments made from MODIS observationsTropospheric ozone variability in the tropics from ENSO to MJO and shorter timescalesA comprehensive investigation on afternoon transition of the atmospheric boundary layer over a tropical rural siteCharacterization of thermal structure and conditions for overshooting of tropical and extratropical cyclones with GPS radio occultationSpatiotemporal variability of water vapor investigated using lidar and FTIR vertical soundings above the ZugspitzeTemperature profiling of the atmospheric boundary layer with rotational Raman lidar during the HD(CP)2 Observational Prototype ExperimentDetermination and climatology of the planetary boundary layer height above the Swiss plateau by in situ and remote sensing measurements as well as by the COSMO-2 modelComparison of the diurnal variations of warm-season precipitation for East Asia vs. North America downstream of the Tibetan Plateau vs. the Rocky MountainsHow stratospheric are deep stratospheric intrusions?Impact of tropical land convection on the water vapour budget in the tropical tropopause layerThe thermodynamic state of the Arctic atmosphere observed by AIRS: comparisons during the record minimum sea ice extents of 2007 and 2012High resolution VHF radar measurements of tropopause structure and variability at Davis, Antarctica (69° S, 78° E)Measurements of the movement of the jet streams at mid-latitudes, in the Northern and Southern Hemispheres, 1979 to 2010Continuous detection and characterization of the Sea Breeze in clear sky conditions using Meteosat Second GenerationThermal structure of intense convective clouds derived from GPS radio occultationsAdvances and limitations of atmospheric boundary layer observations with GPS occultation over southeast Pacific OceanTeleconnection between Australian winter temperature and Indian summer monsoon rainfallFirst results from the GPS atmosphere sounding experiment TOR aboard the TerraSAR-X satelliteUpdraft and downdraft characterization with Doppler lidar: cloud-free versus cumuli-topped mixed layerRemote sensing of the tropical rain forest boundary layer using pulsed Doppler lidarA new ENSO index derived from satellite measurements of column ozoneTurbulence associated with mountain waves over Northern Scandinavia – a case study using the ESRAD VHF radar and the WRF mesoscale model
Siying Chen, Rongzheng Cao, Yixuan Xie, Yinchao Zhang, Wangshu Tan, He Chen, Pan Guo, and Peitao Zhao
Atmos. Chem. Phys., 21, 11489–11504,Short summary
In this study, the seasonal variation in Aeolus wind product performance over China is analyzed by using L-band radiosonde detection data and ERA5 reanalysis data. The results show that the Aeolus wind product performance is affected by seasonal factors, which may be caused by seasonal changes in wind direction and cloud distribution.
Fuchao Liu, Fan Yi, Zhenping Yin, Yunpeng Zhang, Yun He, and Yang Yi
Atmos. Chem. Phys., 21, 2981–2998,Short summary
Using high-resolution lidar measurements, this process-based study reveals that the clear-day convective boundary layer evolves in four distinct stages differing in depth growth rate and depth fluctuation magnitudes. The accompanying entrainment zone thickness (EZT) shows a discrepancy in statistical mean and standard deviation for different seasons and developing stages. Common EZT characteristics also exist. These findings help us understand the atmospheric boundary layer evolution.
Jianping Guo, Boming Liu, Wei Gong, Lijuan Shi, Yong Zhang, Yingying Ma, Jian Zhang, Tianmeng Chen, Kaixu Bai, Ad Stoffelen, Gerrit de Leeuw, and Xiaofeng Xu
Atmos. Chem. Phys., 21, 2945–2958,Short summary
Vertical wind profiles are crucial to a wide range of atmospheric disciplines. Aeolus is the first satellite mission to directly observe wind profile information on a global scale. However, Aeolus wind products over China have thus far not been evaluated by in situ comparison. This work is expected to let the public and science community better know the Aeolus wind products and to encourage use of these valuable data in future research and applications.
Kizhathur Narasimhan Uma, Siddarth Shankar Das, Madineni Venkat Ratnam, and Kuniyil Viswanathan Suneeth
Atmos. Chem. Phys., 21, 2083–2103,Short summary
Reanalysis data of vertical wind (w) are widely used by the atmospheric community to determine various calculations of atmospheric circulations, diabatic heating, convection, etc. There are no studies that assess the available reanalysis data with respect to observations. The present study assesses for the first time all the reanalysis w by comparing it with 20 years of radar data from Gadanki and Kototabang and shows that downdrafts and peaks in the updrafts are not produced in the reanalyses.
Ghouse Basha, M. Venkat Ratnam, and Pangaluru Kishore
Atmos. Chem. Phys., 20, 6789–6801,Short summary
This study explores the variability of the Asian summer monsoon anticyclone (ASMA) spatial variability and trends using long-term observational and reanalysis data sets. The decadal variability of the anticyclone is very large at the edges compared with the core region. We propose that the transport process over the Tibetan Plateau and the Indian region is significant in active monsoon, strong monsoon and strong La Niña years. Thus, different phases of the monsoon are important in UTLS analyses.
Thomas Trickl, Hannes Vogelmann, Ludwig Ries, and Michael Sprenger
Atmos. Chem. Phys., 20, 243–266,Short summary
Ozone transfer from the stratosphere to the troposphere seems to to have grown over the past decade, parallel to global warming. Lidar measurements, carried out in Garmisch-Partenkirchen, Germany, between 2007 and 2016 show a considerable stratospheric influence in the free troposphere over these sites, with observations of stratospheric layers in the troposphere on 84 % of the measurement days. This high fraction is almost reached also in North America, but frequently not throughout the year.
Mingjiao Jia, Jinlong Yuan, Chong Wang, Haiyun Xia, Yunbin Wu, Lijie Zhao, Tianwen Wei, Jianfei Wu, Lu Wang, Sheng-Yang Gu, Liqun Liu, Dachun Lu, Rulong Chen, Xianghui Xue, and Xiankang Dou
Atmos. Chem. Phys., 19, 15431–15446,Short summary
Gravitational waves (GWs) with periods ranging from 10 to 30 min over 10 h and 20 wave cycles are detected within a 2 km height in the atmospheric boundary layer (ABL) by a coherent Doppler wind lidar. Observations and computational fluid dynamics (CFD) simulations lead to a conclusion that the GWs are excited by the wind shear of a low-level jet under the condition of light horizontal wind. The GWs are trapped in the ABL due to a combination of thermal and Doppler ducts.
Ming Shangguan, Wuke Wang, and Shuanggen Jin
Atmos. Chem. Phys., 19, 6659–6679,Short summary
A significant warming in the troposphere and cooling in the stratosphere are found in satellite measurements (2002–2017). The newest ERA5 data are first used for analyzing temperature and ozone trends in the UTLS and show the best quality compared to other reanalyses. According to model simulations, the temperature increase in the troposphere and ozone decrease in the NH stratosphere are mainly connected to a surface warming of the ocean and subsequent changes in atmospheric circulation.
Christoph G. Hoffmann and Christian von Savigny
Atmos. Chem. Phys., 19, 4235–4256,Short summary
We examine a possible statistical linkage between atmospheric variability in the tropical troposphere on the intraseasonal timescale, which is known as Madden–Julian oscillation, and known variability of the solar radiation with a period of 27 days. This helps to understand tropospheric variability in more detail, which is generally of interest, e.g., for weather forecasting. We find indications for such a linkage; however, more research has to be conducted for an unambiguous attribution.
Wolfgang Woiwode, Andreas Dörnbrack, Martina Bramberger, Felix Friedl-Vallon, Florian Haenel, Michael Höpfner, Sören Johansson, Erik Kretschmer, Isabell Krisch, Thomas Latzko, Hermann Oelhaf, Johannes Orphal, Peter Preusse, Björn-Martin Sinnhuber, and Jörn Ungermann
Atmos. Chem. Phys., 18, 15643–15667,Short summary
GLORIA observations during two crossings of the polar front jet stream resolve the fine mesoscale structure of a tropopause fold in high detail. Tracer–tracer correlations of H2O and O3 are presented as a function of potential temperature and reveal an active mixing region. Our study confirms conceptual models of tropopause folds, validates the high quality of ECMWF IFS forecasts, and suggests that mountain waves are capable of modulating exchange processes in the vicinity of tropopause folds.
Andrea K. Steiner, Bettina C. Lackner, and Mark A. Ringer
Atmos. Chem. Phys., 18, 4657–4672,Short summary
We evaluate the representation of tropical convection regimes in atmospheric climate models with satellite-based observations from GPS radio occultation. We find that models have large temperature biases in the tropopause region. In moist convection regions, models underestimate moisture up to 40 % over oceans whereas in dry regions they overestimate it by 100 %. Our findings show that RO observations are a valuable data source for the evaluation and development of next generation climate models.
Robin Pilch Kedzierski, Katja Matthes, and Karl Bumke
Atmos. Chem. Phys., 17, 4093–4114,
Wanchun Zhang, Jianping Guo, Yucong Miao, Huan Liu, Yong Zhang, Zhengqiang Li, and Panmao Zhai
Atmos. Chem. Phys., 16, 9951–9963,Short summary
The PBL height retrieval from CALIOP aboard CALIPSO can significantly complement the traditional ground-based methods, which is only for one site. Our study, to our current knowledge, is the first intercomparison study of PBLH on a large scale using long-term radiosonde observations in China. Three matchup schemes were proposed based on the position of radiosondes relative to CALIPSO ground tracks in China. Results indicate that CALIOP is promising for reliable PBLH retrievals.
Lukas Brunner, Andrea K. Steiner, Barbara Scherllin-Pirscher, and Martin W. Jury
Atmos. Chem. Phys., 16, 4593–4604,Short summary
Atmospheric blocking refers to persistent high-pressure systems which block the climatological flow at midlatitudes. We explore blocking with observations from GPS radio occultation (RO), a satellite-based remote-sensing system. Using two example cases, we find that RO data robustly capture blocking, highlighting the potential of RO observations to complement models and reanalysis as a basis for blocking research.
Christopher E. Sioris, Jason Zou, David A. Plummer, Chris D. Boone, C. Thomas McElroy, Patrick E. Sheese, Omid Moeini, and Peter F. Bernath
Atmos. Chem. Phys., 16, 3265–3278,Short summary
The AM (annular mode) is the most important internal mode of climatic variability at high latitudes. Upper tropospheric water vapour (UTWV) at high latitudes increases by up to ~ 50 % during the negative phase of the AMs. The response of water vapour to the AMs vanishes above the tropopause. The ultimate goal of the study was to improve UTWV trend uncertainties by explaining shorter-term variability, and this was achieved by accounting for the AM-related response in a multiple linear regression.
Guiqian Tang, Jinqiang Zhang, Xiaowan Zhu, Tao Song, Christoph Münkel, Bo Hu, Klaus Schäfer, Zirui Liu, Junke Zhang, Lili Wang, Jinyuan Xin, Peter Suppan, and Yuesi Wang
Atmos. Chem. Phys., 16, 2459–2475,Short summary
This is the first paper to validate and characterize mixing layer height and discuss its relationship with air pollution, using a ceilometer in Beijing. The novelty, originality, and importance of this paper are as follows: (1) the applicable conditions of the ceilometer; (2) the variations of mixing layer height; (3) thermal/dynamic structure inside mixing layers with different degrees of pollution; and (4) critical meteorological conditions for the formation of heavy air pollution.
S. Ravindra Babu, M. Venkat Ratnam, G. Basha, B. V. Krishnamurthy, and B. Venkateswararao
Atmos. Chem. Phys., 15, 10239–10249,Short summary
The effect of tropical cyclones (TCs) that occurred over the north Indian Ocean in the last decade on the tropical tropopause parameters has been quantified for the first time. The vertical structure of temperature and tropopause parameters within the 5º radius away from the cyclone centre during TC period is also presented. The water vapour variability in the vicinity of TC is investigated. It is demonstrated that the TCs can significantly affect the tropical tropopause and thus STE processes.
N. Andela, J. W. Kaiser, G. R. van der Werf, and M. J. Wooster
Atmos. Chem. Phys., 15, 8831–8846,Short summary
The polar orbiting MODIS instruments provide four daily observations of the fire diurnal cycle, resulting in erroneous fire radiative energy (FRE) estimates. Using geostationary SEVIRI data, we explore the fire diurnal cycle and its drivers for Africa to develop a new method to estimate global FRE in near real-time using MODIS. The fire diurnal cycle varied with climate and vegetation type, and including information on the fire diurnal cycle in the model significantly improved the FRE estimates.
J. R. Ziemke, A. R. Douglass, L. D. Oman, S. E. Strahan, and B. N. Duncan
Atmos. Chem. Phys., 15, 8037–8049,Short summary
Aura OMI and MLS measurements are combined to produce daily maps of tropospheric ozone beginning October 2004. We show that El Niño Southern Oscillation (ENSO) related inter-annual change in tropospheric ozone in the tropics is small compared to combined intra-seasonal/Madden-Julian Oscillation (MJO) and shorter timescale variability. Outgoing Longwave Radiation indicates that deep convection is the primary driver of the observed ozone variability on all timescales.
A. Sandeep, T. N. Rao, and S. V. B. Rao
Atmos. Chem. Phys., 15, 7605–7617,Short summary
The afternoon-evening transition (AET) in the atmospheric boundary layer has been studied in an integrated approach using 3 years of tower, sodar and wind profiler measurements. Such a long-term data set has been used for the first time to understand the behavior of AET. It allowed us to study the seasonal variation. In contrast to the common belief that the transition evolves from bottom to top, the present study clearly showed that the start time of transition follows top-to-bottom evolution.
R. Biondi, A. K. Steiner, G. Kirchengast, and T. Rieckh
Atmos. Chem. Phys., 15, 5181–5193,
H. Vogelmann, R. Sussmann, T. Trickl, and A. Reichert
Atmos. Chem. Phys., 15, 3135–3148,Short summary
We quantitatively analyzed the spatiotemporal variability (minutes to hours, 500m to 10km) of water vapor (IWV and profiles) in the free troposphere recorded at the Zugspitze (Germany) with lidar and solar FTIR. We found that long-range transport of heterogeneous air masses may cause relative short-term variations of the water-vapor density which exceed the impact of local convection by 1 order of magnitude. Our results could be useful for issues of model parametrization and co-location.
E. Hammann, A. Behrendt, F. Le Mounier, and V. Wulfmeyer
Atmos. Chem. Phys., 15, 2867–2881,Short summary
Measurements and upgrades of the rotational Raman lidar of the University of Hohenheim during the HD(CP)2 Observational Prototype Experiment are presented in this paper. This includes 25h long time series of temperature gradients and water vapor mixing ratio. Through simulation, optimum wavelengths for high- and low-background cases were identified and tested successfully. Low-elevation measurements were performed to measure temperature gradients at altitudes around 100m above ground level.
M. Collaud Coen, C. Praz, A. Haefele, D. Ruffieux, P. Kaufmann, and B. Calpini
Atmos. Chem. Phys., 14, 13205–13221,Short summary
An operational planetary boundary layer height detection method with several remote sensing instruments (wind profiler, Raman lidar, microwave radiometer) and algorithms (Parcel and bulk Richardson number methods, surface-based temperature inversion, aerosol and humidity gradient analysis) was validated against radio sounding. A comparison with the numerical weather prediction model COSMO-2 and the seasonal cycles of the day- and nighttime PBL for two stations on the Swiss plateau are presented.
Yuanchun Zhang, Fuqing Zhang, and Jianhua Sun
Atmos. Chem. Phys., 14, 10741–10759,
T. Trickl, H. Vogelmann, H. Giehl, H.-E. Scheel, M. Sprenger, and A. Stohl
Atmos. Chem. Phys., 14, 9941–9961,
F. Carminati, P. Ricaud, J.-P. Pommereau, E. Rivière, S. Khaykin, J.-L. Attié, and J. Warner
Atmos. Chem. Phys., 14, 6195–6211,
A. Devasthale, J. Sedlar, T. Koenigk, and E. J. Fetzer
Atmos. Chem. Phys., 13, 7441–7450,
S. P. Alexander, D. J. Murphy, and A. R. Klekociuk
Atmos. Chem. Phys., 13, 3121–3132,
R. D. Hudson
Atmos. Chem. Phys., 12, 7797–7808,
I. M. Lensky and U. Dayan
Atmos. Chem. Phys., 12, 6505–6513,
R. Biondi, W. J. Randel, S.-P. Ho, T. Neubert, and S. Syndergaard
Atmos. Chem. Phys., 12, 5309–5318,
F. Xie, D. L. Wu, C. O. Ao, A. J. Mannucci, and E. R. Kursinski
Atmos. Chem. Phys., 12, 903–918,
S.-Y. Lee and T. Y. Koh
Atmos. Chem. Phys., 12, 669–681,
G. Beyerle, L. Grunwaldt, S. Heise, W. Köhler, R. König, G. Michalak, M. Rothacher, T. Schmidt, J. Wickert, B. D. Tapley, and B. Giesinger
Atmos. Chem. Phys., 11, 6687–6699,
A. Ansmann, J. Fruntke, and R. Engelmann
Atmos. Chem. Phys., 10, 7845–7858,
G. Pearson, F. Davies, and C. Collier
Atmos. Chem. Phys., 10, 5891–5901,
J. R. Ziemke, S. Chandra, L. D. Oman, and P. K. Bhartia
Atmos. Chem. Phys., 10, 3711–3721,
S. Kirkwood, M. Mihalikova, T. N. Rao, and K. Satheesan
Atmos. Chem. Phys., 10, 3583–3599,
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Boreal autumn is the main wet season over the Congo basin. Thus, changes in its onset date have a significant impact on the rainforest. This study provides compelling evidence that the cooling effect of aerosols modifies the timing and strength of the southern African easterly jet that is central to the boreal autumn wet season over the Congo rainforest. A higher boreal summer aerosol concentration is positively correlated with the boreal autumn wet season onset timing.
Boreal autumn is the main wet season over the Congo basin. Thus, changes in its onset date have...