scholarly journals Mechanisms of hydrological responses to volcanic eruptions in the Asian monsoon and westerlies-dominated subregions

2021 ◽  
Author(s):  
Zhihong Zhuo ◽  
Ingo Kirchner ◽  
Ulrich Cubasch
Keyword(s):  
Response Pattern ◽  
Asian Monsoon ◽  
Coupled Model ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Cloud Formation ◽  
Radiative Effect ◽  
Asian Monsoon Region ◽  
Hydrological Responses ◽  
Near Term

Abstract. Explosive volcanic eruptions affect surface climate especially in monsoon regions, but responses vary in different regions and to volcanic aerosol injection (VAI) in different hemispheres. Here we use six ensemble members from last millennium experiment of the Coupled Model Intercomparison Project Phase 5, to investigate the mechanism of regional hydrological responses to different hemispheric VAI in the Asian monsoon region (AMR). It brings a significant drying effect over the AMR after northern hemisphere VAI (NHVAI), spatially, a distinct “wet get drier, dry gets wetter” response pattern emerges with significant drying effect in the wettest area (RWA) but significant wetting effect in the driest area (RDA) of the AMR. After southern hemisphere VAI (SHVAI), it shows a significant wetting effect over the AMR, but spatial response pattern is not that clear due to small aerosol magnitude. The mechanism of the hydrological impact relates to the indirect change of atmospheric circulation due to the direct radiative effect of volcanic aerosols. The decreased thermal contrast between the land and the ocean after NHVAI results in weakened EASM and SASM. This changes the moisture transport and cloud formation in the monsoon and westerlies-dominated subregions. The subsequent radiative effect and physical feedbacks of local clouds lead to different drying and wetting effects in different areas. Results here indicate that future volcanic eruptions may alleviate the uneven distribution of precipitation in the AMR, which should be considered in the near-term decadal prediction and future strategy of local adaptation to global warming. The local hydrological responses and mechanisms found here can also provide reference to stratospheric aerosol engineering.

scholarly journals Implementation of Aerosol-Cloud Interaction within WRF-CHIMERE Online Coupled Model: Evaluation and Investigation of the Indirect Radiative Effect from Anthropogenic Emission Reduction on the Benelux Union

Atmosphere ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 20 ◽  
Author(s):  
Paolo Tuccella ◽  
Laurent Menut ◽  
Régis Briant ◽  
Adrien Deroubaix ◽  
Dmitry Khvorostyanov ◽  
...  
Keyword(s):  
Indirect Effects ◽  
Coupled Model ◽  
Sensitivity Study ◽  
Cloud Formation ◽  
Radiative Effect ◽  
Satellite Measurements ◽  
Aerosol Cloud ◽  
Order Of Magnitude ◽  
Surface Measurements ◽  
The Impact

The indirect effects of aerosol are particularly important over regions where meteorological conditions and aerosol content are favourable to cloud formation. This was observed during the Intensive Cloud Aerosol Measurement Campaign (IMPACT) (European Integrated project on Aerosol Cloud Climate and Air quality Interaction (EUCAARI) project) in the Benelux Union during May 2008. To better understand this cloud formation variability, the indirect effects of aerosol have been included within the WRF-CHIMERE online model. By comparing model results to the aircraft measurements of IMPACT, to surface measurements from EMEP and AIRBASE and to MODIS satellite measurements, we showed that the model is able to simulate the variability and order of magnitude of the observed number of condensation nuclei (CN), even if some differences are identified for specific aerosol size and location. To quantify the impact of the local anthropogenic emissions on cloud formation, a sensitivity study is performed by halving the surface emissions fluxes. It is shown that the indirect radiative effect (IRE) at the surface is positive for both shortwave and longwave with a net warming of +0.99 W/m2. In addition, important instantaneous changes are modelled at local scale with up to ±6 °C for temperatures and ±50 mm/day for precipitation.

Volcanic forcing of climate since 1850 in an interactive aerosol-chemistry-climate model

2021 ◽  
Author(s):  
Thomas Aubry ◽  
Anja Schmidt ◽  
Alix Harrow ◽  
Jeremy Walton ◽  
Jane Mulcahy ◽  
...  
Keyword(s):  
Optical Properties ◽  
Radiative Forcing ◽  
Climate Models ◽  
Climate Model ◽  
Coupled Model ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Aerosol Model ◽  
Volcanic Forcing

<p>Reconstructions of volcanic aerosol forcing and its climatic impacts are undermined by uncertainties in both the models used to build these reconstructions as well as the proxy and observational records used to constrain those models. Reducing these uncertainties has been a priority and in particular, several modelling groups have developed interactive stratospheric aerosol models. Provided with an initial volcanic injection of sulfur dioxide, these models can interactively simulate the life cycle and optical properties of sulfate aerosols, and their effects on climate. In contrast, most climate models that took part in the Coupled Model Intercomparison Project Phase 5 and 6 (CMIP6) directly prescribe perturbations in atmospheric optical properties associated with an eruption. However, before the satellite era, the volcanic forcing dataset used for CMIP6 mostly relies on a relatively simple aerosol model and a volcanic sulfur inventory derived from ice-cores, both of which have substantial associated uncertainties.</p><p>In this study, we produced a new set of historical simulations using the UK Earth System Model UKESM1, with interactive stratospheric aerosol capability (referred to as interactive runs hereafter) instead of directly prescribing the CMIP6 volcanic forcing dataset as was done for CMIP6 (standard runs, hereafter). We used one of the most recent volcanic sulfur inventories as input for the interactive runs, in which aerosol properties are consistent with the model chemistry, microphysics and atmospheric components. We analyzed how the stratospheric aerosol optical depth, the radiative forcing and the climate response to volcanic eruptions differed between interactive and standard runs, and how these compare to observations and proxy records. In particular, we investigate in detail the differences in the response to the large-magnitude Krakatoa 1883 eruption between the two sets of runs. We also discuss differences for the 1979-2015 period where the forcing data in standard runs is directly constrained from satellite observations. Our results shed new light on uncertainties affecting the reconstruction of past volcanic forcing and highlight some of the benefits and disadvantages of using interactive stratospheric aerosol capabilities instead of a unique prescribed volcanic forcing dataset in CMIP’s historical runs.</p>

scholarly journals Variability and evolution of the midlatitude stratospheric aerosol budget from 22 years of ground-based lidar and satellite observations

2017 ◽  
Vol 17 (3) ◽  
pp. 1829-1845 ◽  
Author(s):  
Sergey M. Khaykin ◽  
Sophie Godin-Beekmann ◽  
Philippe Keckhut ◽  
Alain Hauchecorne ◽  
Julien Jumelet ◽  
...  
Keyword(s):  
Asian Monsoon ◽  
Infrared Imaging ◽  
Imaging System ◽  
Late Summer ◽  
Stratospheric Aerosol ◽  
Atmospheric Composition ◽  
Orthogonal Polarization ◽  
Asian Monsoon Region ◽  
Lidar Measurements ◽  
Ground Based Lidar

Abstract. The article presents new high-quality continuous stratospheric aerosol observations spanning 1994–2015 at the French Observatoire de Haute-Provence (OHP, 44° N, 6° E) obtained by two independent, regularly maintained lidar systems operating within the Network for Detection of Atmospheric Composition Change (NDACC). Lidar series are compared with global-coverage observations by Stratospheric Aerosol and Gas Experiment (SAGE II), Global Ozone Monitoring by Occultation of Stars (GOMOS), Optical Spectrograph and InfraRed Imaging System (OSIRIS), Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), and Ozone Mapping Profiling Suite (OMPS) satellite instruments, altogether covering the time span of OHP lidar measurements. Local OHP and zonal-mean satellite series of stratospheric aerosol optical depth are in excellent agreement, allowing for accurate characterization of stratospheric aerosol evolution and variability at northern midlatitudes during the last 2 decades. The combination of local and global observations is used for a careful separation between volcanically perturbed and quiescent periods. While the volcanic signatures dominate the stratospheric aerosol record, the background aerosol abundance is found to be modulated remotely by the poleward transport of convectively cleansed air from the deep tropics and aerosol-laden air from the Asian monsoon region. The annual cycle of background aerosol at midlatitudes, featuring a minimum during late spring and a maximum during late summer, correlates with that of water vapor from the Aura Microwave Limb Sounder (MLS). Observations covering two volcanically quiescent periods over the last 2 decades provide an indication of a growth in the nonvolcanic component of stratospheric aerosol. A statistically significant factor of 2 increase in nonvolcanic aerosol since 1998, seasonally restricted to late summer and fall, is associated with the influence of the Asian monsoon and growing pollution therein.

scholarly journals Variability and evolution of mid-latitude stratospheric aerosol budget from 22 years of ground-based lidar and satellite observations

2016 ◽  
Author(s):  
Sergey M. Khaykin ◽  
Sophie Godin-Beekmann ◽  
Philippe Keckhut ◽  
Alain Hauchecorne ◽  
Julien Jumelet ◽  
...  
Keyword(s):  
Asian Monsoon ◽  
Infrared Imaging ◽  
Imaging System ◽  
Late Summer ◽  
Stratospheric Aerosol ◽  
Orthogonal Polarization ◽  
Asian Monsoon Region ◽  
Lidar Measurements ◽  
Global Coverage ◽  
Ground Based Lidar

Abstract. The article presents new high-quality continuous stratospheric aerosol observations spanning 1994–2015 at the French Observatoire de Haute-Provence (OHP, 44° N, 6° E) obtained by two independent regularly-maintained lidar systems. Lidar series are compared with global-coverage observations by Stratospheric Aerosol and Gas Experiment (SAGE II), Global Ozone Monitoring by Occultation of Stars (GOMOS), Optical Spectrograph and InfraRed Imaging System (OSIRIS), Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and Ozone Mapping Profiling Suite (OMPS) satellite instruments, altogether covering the time span of OHP lidar measurements. Local OHP and zonal-mean satellite series of stratospheric aerosol optical depth are in excellent agreement, allowing for accurate characterization of stratospheric aerosol evolution and variability at Northern mid-latitudes during the post-Pinatubo era. The combination of local and global observations is used for careful separation between volcanically-perturbed and quiescent periods. While the volcanic signatures dominate the stratospheric aerosol record, the background aerosol abundance is found to be modulated remotely by poleward transport of convectively-cleansed air from the deep tropics and aerosol-laden air from the Asian monsoon region. The annual cycle of background aerosol at mid-latitudes, featuring a minimum during late spring and a maximum during late summer, correlates with that of water vapour from Microwave Limb Sounder (MLS). Observations covering two volcanically-quiescent periods over the last two decades provide indication of a growth in the non-volcanic component of stratospheric aerosol. A statistically-significant factor of two increase of non-volcanic aerosol since 1998, seasonally restricted to late-summer and fall, is associated with the influence of the Asian monsoon and growing pollution therein.

scholarly journals The CMIP6 Historical Simulation Datasets Produced by the Climate System Model CAMS-CSM

2020 ◽  
Author(s):  
Xinyao Rong ◽  
Jian Li ◽  
Haoming Chen ◽  
Jingzhi Su ◽  
Lijuan Hua ◽  
...  
Keyword(s):  
Air Temperature ◽  
Initial Conditions ◽  
Coupled Model ◽  
Surface Air Temperature ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Climate System ◽  
System Model ◽  
Model Description ◽  
Climate System Model

AbstractThis paper describes the historical simulations produced by the Chinese Academy of Meteorological Sciences (CAMS) climate system model (CAMS-CSM), which are contributing to phase 6 of the Coupled Model Intercomparison Project (CMIP6). The model description, experiment design and model outputs are presented. Three members’ historical experiments are conducted by CAMS-CSM, with two members starting from different initial conditions, and one excluding the stratospheric aerosol to identify the effect of volcanic eruptions. The outputs of the historical experiments are also validated using observational data. It is found that the model can reproduce the climatological mean states and seasonal cycle of the major climate system quantities, including the surface air temperature, precipitation, and the equatorial thermocline. The long-term trend of air temperature and precipitation is also reasonably captured by CAMS-CSM. There are still some biases in the model that need further improvement. This paper can help the users to better understand the performance and the datasets of CAMS-CSM.

scholarly journals Influence of volcanic eruptions on the climate of the Asian monsoon region

2010 ◽  
Vol 37 (22) ◽  
pp. n/a-n/a ◽  
Author(s):  
K. J. Anchukaitis ◽  
B. M. Buckley ◽  
E. R. Cook ◽  
B. I. Cook ◽  
R. D. D'Arrigo ◽  
...  
Keyword(s):  
Asian Monsoon ◽  
Volcanic Eruptions ◽  
Monsoon Region ◽  
Asian Monsoon Region

Impact of Subdaily Air–Sea Interaction on Simulating Intraseasonal Oscillations over the Tropical Asian Monsoon Region

2015 ◽  
Vol 28 (3) ◽  
pp. 1057-1073 ◽  
Author(s):  
Wenting Hu ◽  
Anmin Duan ◽  
Guoxiong Wu
Keyword(s):  
General Circulation ◽  
Asian Monsoon ◽  
Intraseasonal Oscillation ◽  
Phase Relationship ◽  
Coupled Model ◽  
Circulation Model ◽  
Boreal Summer ◽  
Lag Phase ◽  
Asian Monsoon Region ◽  
Coupling Frequency

Abstract The off-equatorial boreal summer intraseasonal oscillation (ISO) is closely linked to the onset, active, and break phases of the tropical Asian monsoon, but the accurate simulation of the eastward-propagating low-frequency ISO by current models remains a challenge. In this study, an atmospheric general circulation model (AGCM)–ocean mixed layer coupled model with high (10 min) coupling frequency (DC_10m) shows improved skill in simulating the ISO signal in terms of period, intensity, and propagation direction, compared with the coupled runs with low (1 and 12 h) coupling frequency and a stand-alone AGCM driven by the daily sea surface temperature (SST) fields. In particular, only the DC_10m is able to recreate the observed lead–lag phase relationship between SST (SST tendency) and precipitation at intraseasonal time scales, indicating that the ISO signal is closely linked to the subdaily air–sea interaction. During the ISO life cycle, air–sea interaction reduces the SST underlying the convection via wind–evaporation and cloud–radiation feedbacks, as well as wind-induced oceanic mixing, which in turn restrains convection. However, to the east of the convection, the heat-induced atmospheric Gill-type response leads to downward motion and a reduced surface westerly background flow because of the easterly anomalies. The resultant decreased oceanic mixing, together with the increased shortwave flux, tends to warm the SST and subsequently trigger convection. Therefore, the eastward-propagating ISO may result from an asymmetric east–west change in SST induced mainly by multiscale air–sea interactions.

Monitoring the Variability of the Stratospheric Aerosol Layer over Tomsk in 2016–2018 Based on Lidar Data

2021 ◽  
pp. 61-72
Author(s):  
V. N. Marichev ◽  
◽  
D. A. Bochkovskiia ◽  
Keyword(s):  
Volcanic Eruptions ◽  
Temperature Inversion ◽  
Cold Season ◽  
Stratospheric Aerosol ◽  
Single Frequency ◽  
Winter Period ◽  
Lidar Data ◽  
Aerosol Layer ◽  
Time Data ◽  
Academy Of Sciences

The results of observations of the features of intraannual variability for the vertical structure of background aerosol in the stratosphere over Western Siberia in 2016–2018 are presented and analyzed. Experimental data were obtained at the lidar complex of Zuev Institute of Atmospheric Optics (Siberian Branch, Russian Academy of Sciences) with a receiving mirror diameter of 1 m. The objective of the study is to investigate the dynamics of background stratospheric aerosol, since during this period there were no volcanic eruptions leading to the transport of eruptive aerosol into the stratosphere. The results of the study confirm a stable intraannual cycle of maximum aerosol filling of the stratosphere in winter, a decrease in spring to the minimum, practical absence in summer, and an increase in autumn. At the same time, the variability of stratification and aerosol filling is observed for different years. It was found that aerosol is concentrated in the layer up to 30 km all year round, except for the winter period. It is shown that the vertical aerosol stratification is largely determined by the thermal regime of the tropo- sphere–stratosphere boundary layer. The absence of a pronounced temperature inversion at the tropopause contributes to an increase in the stratosphere–troposphere exchange and, as a result, to the aerosol transport to the stratosphere. This situation is typical of the cold season. For the first time, data on the quantitative content of stratospheric aerosol (its mass concentration) were obtained from single- frequency lidar data.

scholarly journals Stratospheric aerosol radiative forcing simulated by the chemistry climate model EMAC using Aerosol CCI satellite data

2018 ◽  
Vol 18 (17) ◽  
pp. 12845-12857 ◽  
Author(s):  
Christoph Brühl ◽  
Jennifer Schallock ◽  
Klaus Klingmüller ◽  
Charles Robert ◽  
Christine Bingen ◽  
...  
Keyword(s):  
Optical Depth ◽  
Radiative Forcing ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Radiative Heating ◽  
Aerosol Radiative Forcing ◽  
Tropospheric Aerosol ◽  
Model Aerosol ◽  
Atmospheric Sounding ◽  
Aerosol Radiative

Abstract. This paper presents decadal simulations of stratospheric and tropospheric aerosol and its radiative effects by the chemistry general circulation model EMAC constrained with satellite observations in the framework of the ESA Aerosol CCI project such as GOMOS (Global Ozone Monitoring by Occultation of Stars) and (A)ATSR ((Advanced) Along Track Scanning Radiometer) on the ENVISAT (European Environmental Satellite), IASI (Infrared Atmospheric Sounding Interferometer) on MetOp (Meteorological Operational Satellite), and, additionally, OSIRIS (Optical Spectrograph and InfraRed Imaging System). In contrast to most other studies, the extinctions and optical depths from the model are compared to the observations at the original wavelengths of the satellite instruments covering the range from the UV (ultraviolet) to terrestrial IR (infrared). This avoids conversion artifacts and provides additional constraints for model aerosol and interpretation of the observations. MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) SO2 limb measurements are used to identify plumes of more than 200 volcanic eruptions. These three-dimensional SO2 plumes are added to the model SO2 at the eruption times. The interannual variability in aerosol extinction in the lower stratosphere, and of stratospheric aerosol radiative forcing at the tropopause, is dominated by the volcanoes. To explain the seasonal cycle of the GOMOS and OSIRIS observations, desert dust simulated by a new approach and transported to the lowermost stratosphere by the Asian summer monsoon and tropical convection turns out to be essential. This also applies to the radiative heating by aerosol in the lowermost stratosphere. The existence of wet dust aerosol in the lowermost stratosphere is indicated by the patterns of the wavelength dependence of extinction in observations and simulations. Additional comparison with (A)ATSR total aerosol optical depth at different wavelengths and IASI dust optical depth demonstrates that the model is able to represent stratospheric as well as tropospheric aerosol consistently.

scholarly journals Effect of volcanic aerosol on stratospheric NO<sub>2</sub> and N<sub>2</sub>O<sub>5</sub> from 2002–2014 as measured by Odin-OSIRIS and Envisat-MIPAS

2016 ◽  
Author(s):  
Cristen Adams ◽  
Adam E. Bourassa ◽  
Chris A. McLinden ◽  
Chris E. Sioris ◽  
Thomas von Clarmann ◽  
...  
Keyword(s):  
Infrared Imaging ◽  
Pearson Correlation ◽  
Michelson Interferometer ◽  
Correlation Coefficients ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Volcanic Aerosol ◽  
Quasi Biennial Oscillation ◽  
El Chichón ◽  
El Chichon

Abstract. Following the large volcanic eruptions of Pinatubo in 1991 and El Chichón in 1982, decreases in stratospheric NO2 associated with enhanced aerosol were observed. The Optical Spectrograph and InfraRed Imaging Spectrometer (OSIRIS) likewise measured widespread enhancements of stratospheric aerosol following seven volcanic eruptions between 2002 and 2014, although the magnitudes of these eruptions were all much smaller than the Pinatubo and El Chichón eruptions. In order to isolate and quantify the relationship between volcanic aerosol and NO2, NO2 anomalies were calculated using measurements from OSIRIS and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). In the tropics, variability due to the quasi-biennial oscillation was subtracted from the timeseries. OSIRIS profile measurements indicate that the strongest relationships between NO2 and volcanic aerosol extinction were for the layer ~ 3–7 km above the tropopause, where OSIRIS stratospheric NO2 partial columns for ~ 3–7 km above the tropopause were found to be smaller than baseline levels during these aerosol enhancements by up to ~ 60 % with typical Pearson correlation coefficients of R ~ −0.7. MIPAS also observed decreases in NO2 partial columns during periods of affected by volcanic aerosol, with percent differences of up to ~ 25 %. An even stronger relationship was observed between OSIRIS aerosol optical depth and MIPAS N2O5 partial columns, with R ~ −0.9, although no link with MIPAS HNO3 was observed. The variation of OSIRIS NO2 with increasing aerosol was found to be quantitatively consistent with simulations from a photochemical box model in terms of both magnitude and degree of non-linearity.

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