Articles | Volume 21, issue 17
https://doi.org/10.5194/acp-21-12855-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-21-12855-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
31 Aug 2021
Research article |
| 31 Aug 2021
| 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
CORRESPONDING AUTHOR
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
Jonathon H. Jiang
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
Hui Su
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
Rong Fu
Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, USA
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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
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Jose A. Marengo, Gilberto F. Fisch, Lincoln M. Alves, Natanael V. Sousa, Rong Fu, and Yizhou Zhuang
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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
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Atmos. Chem. Phys., 14, 4087–4099, https://doi.org/10.5194/acp-14-4087-2014, https://doi.org/10.5194/acp-14-4087-2014, 2014
N. J. Livesey, J. A. Logan, M. L. Santee, J. W. Waters, R. M. Doherty, W. G. Read, L. Froidevaux, and J. H. Jiang
Atmos. Chem. Phys., 13, 579–598, https://doi.org/10.5194/acp-13-579-2013, https://doi.org/10.5194/acp-13-579-2013, 2013
Related subject area
Subject: Dynamics | Research Activity: Remote Sensing | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)
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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, https://doi.org/10.5194/acp-21-2981-2021, https://doi.org/10.5194/acp-21-2981-2021, 2021
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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.
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Atmos. Chem. Phys., 21, 2945–2958, https://doi.org/10.5194/acp-21-2945-2021, https://doi.org/10.5194/acp-21-2945-2021, 2021
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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, https://doi.org/10.5194/acp-21-2083-2021, https://doi.org/10.5194/acp-21-2083-2021, 2021
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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
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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.
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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, https://doi.org/10.5194/acp-19-15431-2019, https://doi.org/10.5194/acp-19-15431-2019, 2019
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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, https://doi.org/10.5194/acp-19-6659-2019, https://doi.org/10.5194/acp-19-6659-2019, 2019
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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, https://doi.org/10.5194/acp-19-4235-2019, https://doi.org/10.5194/acp-19-4235-2019, 2019
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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, https://doi.org/10.5194/acp-18-15643-2018, https://doi.org/10.5194/acp-18-15643-2018, 2018
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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, https://doi.org/10.5194/acp-18-4657-2018, https://doi.org/10.5194/acp-18-4657-2018, 2018
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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, https://doi.org/10.5194/acp-17-4093-2017, https://doi.org/10.5194/acp-17-4093-2017, 2017
Wanchun Zhang, Jianping Guo, Yucong Miao, Huan Liu, Yong Zhang, Zhengqiang Li, and Panmao Zhai
Atmos. Chem. Phys., 16, 9951–9963, https://doi.org/10.5194/acp-16-9951-2016, https://doi.org/10.5194/acp-16-9951-2016, 2016
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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, https://doi.org/10.5194/acp-16-4593-2016, https://doi.org/10.5194/acp-16-4593-2016, 2016
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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, https://doi.org/10.5194/acp-16-3265-2016, https://doi.org/10.5194/acp-16-3265-2016, 2016
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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, https://doi.org/10.5194/acp-16-2459-2016, https://doi.org/10.5194/acp-16-2459-2016, 2016
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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, https://doi.org/10.5194/acp-15-10239-2015, https://doi.org/10.5194/acp-15-10239-2015, 2015
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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, https://doi.org/10.5194/acp-15-8831-2015, https://doi.org/10.5194/acp-15-8831-2015, 2015
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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, https://doi.org/10.5194/acp-15-8037-2015, https://doi.org/10.5194/acp-15-8037-2015, 2015
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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, https://doi.org/10.5194/acp-15-7605-2015, https://doi.org/10.5194/acp-15-7605-2015, 2015
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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, https://doi.org/10.5194/acp-15-5181-2015, https://doi.org/10.5194/acp-15-5181-2015, 2015
H. Vogelmann, R. Sussmann, T. Trickl, and A. Reichert
Atmos. Chem. Phys., 15, 3135–3148, https://doi.org/10.5194/acp-15-3135-2015, https://doi.org/10.5194/acp-15-3135-2015, 2015
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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, https://doi.org/10.5194/acp-15-2867-2015, https://doi.org/10.5194/acp-15-2867-2015, 2015
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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, https://doi.org/10.5194/acp-14-13205-2014, https://doi.org/10.5194/acp-14-13205-2014, 2014
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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, https://doi.org/10.5194/acp-14-10741-2014, https://doi.org/10.5194/acp-14-10741-2014, 2014
T. Trickl, H. Vogelmann, H. Giehl, H.-E. Scheel, M. Sprenger, and A. Stohl
Atmos. Chem. Phys., 14, 9941–9961, https://doi.org/10.5194/acp-14-9941-2014, https://doi.org/10.5194/acp-14-9941-2014, 2014
F. Carminati, P. Ricaud, J.-P. Pommereau, E. Rivière, S. Khaykin, J.-L. Attié, and J. Warner
Atmos. Chem. Phys., 14, 6195–6211, https://doi.org/10.5194/acp-14-6195-2014, https://doi.org/10.5194/acp-14-6195-2014, 2014
A. Devasthale, J. Sedlar, T. Koenigk, and E. J. Fetzer
Atmos. Chem. Phys., 13, 7441–7450, https://doi.org/10.5194/acp-13-7441-2013, https://doi.org/10.5194/acp-13-7441-2013, 2013
S. P. Alexander, D. J. Murphy, and A. R. Klekociuk
Atmos. Chem. Phys., 13, 3121–3132, https://doi.org/10.5194/acp-13-3121-2013, https://doi.org/10.5194/acp-13-3121-2013, 2013
R. D. Hudson
Atmos. Chem. Phys., 12, 7797–7808, https://doi.org/10.5194/acp-12-7797-2012, https://doi.org/10.5194/acp-12-7797-2012, 2012
I. M. Lensky and U. Dayan
Atmos. Chem. Phys., 12, 6505–6513, https://doi.org/10.5194/acp-12-6505-2012, https://doi.org/10.5194/acp-12-6505-2012, 2012
R. Biondi, W. J. Randel, S.-P. Ho, T. Neubert, and S. Syndergaard
Atmos. Chem. Phys., 12, 5309–5318, https://doi.org/10.5194/acp-12-5309-2012, https://doi.org/10.5194/acp-12-5309-2012, 2012
F. Xie, D. L. Wu, C. O. Ao, A. J. Mannucci, and E. R. Kursinski
Atmos. Chem. Phys., 12, 903–918, https://doi.org/10.5194/acp-12-903-2012, https://doi.org/10.5194/acp-12-903-2012, 2012
S.-Y. Lee and T. Y. Koh
Atmos. Chem. Phys., 12, 669–681, https://doi.org/10.5194/acp-12-669-2012, https://doi.org/10.5194/acp-12-669-2012, 2012
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, https://doi.org/10.5194/acp-11-6687-2011, https://doi.org/10.5194/acp-11-6687-2011, 2011
A. Ansmann, J. Fruntke, and R. Engelmann
Atmos. Chem. Phys., 10, 7845–7858, https://doi.org/10.5194/acp-10-7845-2010, https://doi.org/10.5194/acp-10-7845-2010, 2010
G. Pearson, F. Davies, and C. Collier
Atmos. Chem. Phys., 10, 5891–5901, https://doi.org/10.5194/acp-10-5891-2010, https://doi.org/10.5194/acp-10-5891-2010, 2010
J. R. Ziemke, S. Chandra, L. D. Oman, and P. K. Bhartia
Atmos. Chem. Phys., 10, 3711–3721, https://doi.org/10.5194/acp-10-3711-2010, https://doi.org/10.5194/acp-10-3711-2010, 2010
S. Kirkwood, M. Mihalikova, T. N. Rao, and K. Satheesan
Atmos. Chem. Phys., 10, 3583–3599, https://doi.org/10.5194/acp-10-3583-2010, https://doi.org/10.5194/acp-10-3583-2010, 2010
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Short summary
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...
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