scholarly journals Interannual Variability and Trends of Combustion Aerosol and Dust in Major Continental Outflows Revealed by MODIS Retrievals and CAM5 Simulations During 2003–2017

2019 ◽  
Author(s):  
Hongbin Yu ◽  
Yang Yang ◽  
Hailong Wang ◽  
Qian Tan ◽  
Mian Chin ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Fossil Fuels ◽  
North Atlantic Ocean ◽  
Tropical Indian Ocean ◽  
Atmospheric Model ◽  
Northwestern Pacific ◽  
The North ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Continental Outflow

Abstract. Emissions and long-range transport of mineral dust and combustion-related aerosol from burning fossil fuels and biomass vary from year to year, driven by the evolution of the economy and changes in meteorological conditions and environmental regulations. This study offers both satellite and model perspectives of interannual variability and possible trend of combustion aerosol and dust in major continental outflow regions over the past 15 years (2003–2017). The decade-long record of aerosol optical depth (AOD, denoted as τ), separately for combustion aerosol (τc) and dust (τd), over global oceans is derived from the Collection 6 aerosol products of the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard both Terra and Aqua. These MODIS/Aqua datasets, complemented by aerosol source-tagged simulations using the Community Atmospheric Model Version 5 (CAM5), are then analyzed to understand the interannual variability and potential trend of τc and τd in the major continental outflows. Both MODIS and CAM5 consistently yield a similar decreasing trend of −0.017 to −0.020 decade−1 for τc over the North Atlantic Ocean and the Mediterranean Sea that is attributable to reduced emissions from North America and Europe, respectively. On the contrary, both MODIS and CAM5 display an increasing trend of +0.017 to +0.036 decade−1 for τc over the tropical Indian Ocean, the Bay of Bengal, and the Arabian Sea, which reflects the influence of increased anthropogenic emissions from South Asia and Middle East in the last two decades. Over the northwestern Pacific Ocean that is often affected by East Asian emissions of pollution and dust, the MODIS retrievals show a decreasing trend of −0.021 decade−1 for τc and −0.012 decade−1 for τd, which is however not reproduced by the CAM5 model. In other outflow regions strongly influenced by biomass burning smoke or dust, both MODIS retrievals and CAM5 simulations show no statistically significant trends; and the MODIS observed interannual variability is usually larger than that of the CAM5 simulation.

scholarly journals Interannual variability and trends of combustion aerosol and dust in major continental outflows revealed by MODIS retrievals and CAM5 simulations during 2003–2017

2020 ◽  
Vol 20 (1) ◽  
pp. 139-161 ◽  
Author(s):  
Hongbin Yu ◽  
Yang Yang ◽  
Hailong Wang ◽  
Qian Tan ◽  
Mian Chin ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Fossil Fuels ◽  
North Atlantic Ocean ◽  
Tropical Indian Ocean ◽  
Atmospheric Model ◽  
Northwestern Pacific ◽  
The North ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Continental Outflow

Abstract. Emissions and long-range transport of mineral dust and combustion-related aerosol from burning fossil fuels and biomass vary from year to year, driven by the evolution of the economy and changes in meteorological conditions and environmental regulations. This study offers both satellite and model perspectives on the interannual variability and possible trends of combustion aerosol and dust in major continental outflow regions over the past 15 years (2003–2017). The decade-long record of aerosol optical depth (AOD, denoted as τ), separately for combustion aerosol (τc) and dust (τd), over global oceans is derived from the Collection 6 aerosol products of the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard both Terra and Aqua. These MODIS Aqua datasets, complemented by aerosol source-tagged simulations using the Community Atmospheric Model version 5 (CAM5), are then analyzed to understand the interannual variability and potential trends of τc and τd in the major continental outflows. Both MODIS and CAM5 consistently yield a similar decreasing trend of −0.017 to −0.020 per decade for τc over the North Atlantic Ocean and the Mediterranean Sea that is attributable to reduced emissions from North America and Europe, respectively. On the contrary, both MODIS and CAM5 display an increasing trend of +0.017 to +0.036 per decade for τc over the tropical Indian Ocean, the Bay of Bengal, and the Arabian Sea, which reflects the influence of increased anthropogenic emissions from South Asia and the Middle East in the last 2 decades. Over the northwestern Pacific Ocean, which is often affected by East Asian emissions of pollution and dust, the MODIS retrievals show a decreasing trend of −0.021 per decade for τc and −0.012 per decade for τd, which is, however, not reproduced by the CAM5 model. In other outflow regions strongly influenced by biomass burning smoke or dust, both MODIS retrievals and CAM5 simulations show no statistically significant trends; the MODIS-observed interannual variability is usually larger than that of the CAM5 simulation.

scholarly journals Extreme levels of Canadian wildfire smoke in the stratosphere over central Europe on 21–22 August 2017

2018 ◽  
Vol 18 (16) ◽  
pp. 11831-11845 ◽  
Author(s):  
Albert Ansmann ◽  
Holger Baars ◽  
Alexandra Chudnovsky ◽  
Ina Mattis ◽  
Igor Veselovskii ◽  
...  
Keyword(s):  
Central Europe ◽  
Volcanic Eruptions ◽  
Light Extinction ◽  
Ozone Monitoring Instrument ◽  
Wildfire Smoke ◽  
The North ◽  
Radiative Power ◽  
Peak Mass ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract. Light extinction coefficients of 500 Mm−1, about 20 times higher than after the Pinatubo volcanic eruptions in 1991, were observed by European Aerosol Research Lidar Network (EARLINET) lidars in the stratosphere over central Europe on 21–22 August 2017. Pronounced smoke layers with a 1–2 km vertical extent were found 2–5 km above the local tropopause. Optically dense layers of Canadian wildfire smoke reached central Europe 10 days after their injection into the upper troposphere and lower stratosphere which was caused by rather strong pyrocumulonimbus activity over western Canada. The smoke-related aerosol optical thickness (AOT) identified by lidar was close to 1.0 at 532 nm over Leipzig during the noon hours on 22 August 2017. Smoke particles were found throughout the free troposphere (AOT of 0.3) and in the pronounced 2 km thick stratospheric smoke layer at an altitude of 14–16 km (AOT of 0.6). The lidar observations indicated peak mass concentrations of 70–100 µg m−3 in the stratosphere. In addition to the lidar profiles, we analyzed Moderate Resolution Imaging Spectroradiometer (MODIS) fire radiative power (FRP) over Canada, and the distribution of MODIS AOT and Ozone Monitoring Instrument (OMI) aerosol index across the North Atlantic. These instruments showed a similar pattern and a clear link between the western Canadian fires and the aerosol load over Europe. In this paper, we also present Aerosol Robotic Network (AERONET) sun photometer observations, compare photometer and lidar-derived AOT, and discuss an obvious bias (the smoke AOT is too low) in the photometer observations. Finally, we compare the strength of this record-breaking smoke event (in terms of the particle extinction coefficient and AOT) with major and moderate volcanic events observed over the northern midlatitudes.

scholarly journals Investigating the frequency and interannual variability in global above-cloud aerosol characteristics with CALIOP and OMI

2016 ◽  
Vol 16 (1) ◽  
pp. 47-69 ◽  
Author(s):  
R. Alfaro-Contreras ◽  
J. Zhang ◽  
J. R. Campbell ◽  
J. S. Reid
Keyword(s):  
Interannual Variability ◽  
Orthogonal Polarization ◽  
Cloud Detection ◽  
Ozone Monitoring Instrument ◽  
Data Set ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
First Time ◽  
Aerosol Index

Abstract. Seven and a half years (June 2006 to November 2013) of Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) aerosol and cloud layer products are compared with collocated Ozone Monitoring Instrument (OMI) aerosol index (AI) data and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) cloud products in order to investigate variability in estimates of biannual and monthly above-cloud aerosol (ACA) events globally. The active- (CALIOP) and passive-based (OMI-MODIS) techniques have their advantages and caveats for ACA detection, and thus both are used to derive a thorough and robust comparison of daytime cloudy-sky ACA distribution and climatology. For the first time, baseline above-cloud aerosol optical depth (ACAOD) and AI thresholds are derived and examined (AI  =  1.0, ACAOD  =  0.015) for each sensor. Both OMI-MODIS and CALIOP-based daytime spatial distributions of ACA events show similar patterns during both study periods (December–May) and (June–November). Divergence exists in some regions, however, such as Southeast Asia during June through November, where daytime cloudy-sky ACA frequencies of up to 10 % are found from CALIOP yet are non-existent from the OMI-based method. Conversely, annual cloudy-sky ACA frequencies of 20–30 % are reported over northern Africa from the OMI-based method yet are largely undetected by the CALIOP-based method. Using a collocated OMI-MODIS-CALIOP data set, our study suggests that the cloudy-sky ACA frequency differences between the OMI-MODIS- and CALIOP-based methods are mostly due to differences in cloud detection capability between MODIS and CALIOP as well as QA flags used. An increasing interannual variability of  ∼  0.3–0.4 % per year (since 2009) in global monthly cloudy-sky ACA daytime frequency of occurrence is found using the OMI-MODIS-based method. Yet, CALIOP-based global daytime ACA frequencies exhibit a near-zero interannual variability. Further analysis suggests that the OMI-derived interannual variability in cloudy-sky ACA frequency may be affected by OMI row anomalies in later years. A few regions are found to have increasing slopes in interannual variability in cloudy-sky ACA frequency, including the Middle East and India. Regions with slightly negative slopes of the interannual variability in cloudy-sky ACA frequencies are found over South America and China, while remaining regions in the study show nearly zero change in ACA frequencies over time. The interannual variability in ACA frequency is not, however, statistically significant on both global and regional scales, given the relatively limited sample sizes. A longer data record of ACA events is needed in order to establish significant trends of ACA frequency regionally and globally.

scholarly journals A Study of the Distribution and Variability of Cloud Water Using ISCCP, SSM/I Cloud Product, and Reanalysis Datasets

2014 ◽  
Vol 27 (9) ◽  
pp. 3114-3128 ◽  
Author(s):  
Zhiwei Heng ◽  
Yunfei Fu ◽  
Guosheng Liu ◽  
Renjun Zhou ◽  
Yu Wang ◽  
...  
Keyword(s):  
Cloud Water ◽  
Positive Anomaly ◽  
Liquid Water Path ◽  
Water Path ◽  
The North ◽  
Increasing Trend ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Microwave Imager ◽  
Ice Water

Abstract In this paper, the global distribution of cloud water based on International Satellite Cloud Climatology Project (ISCCP), Moderate Resolution Imaging Spectroradiometer (MODIS), CloudSat Cloud Profiling Radar (CPR), European Center for Medium-Range Weather Forecasts Interim Re-Analysis (ERA-Interim), and Climate Forecast System Reanalysis (CFSR) datasets is presented, and the variability of cloud water from ISCCP, the Special Sensor Microwave Imager (SSM/I), ERA-Interim, and CFSR data over the time period of 1995 through 2009 is discussed. The results show noticeable differences in cloud water over land and over ocean, as well as latitudinal variations. Large values of cloud water are mainly distributed over the North Pacific and Atlantic Oceans, eastern ITCZ, regions off the west coast of the continents as well as tropical rain forest. Cloud water path (CWP), liquid water path (LWP), and ice water path (IWP) from these datasets show a relatively good agreement in distributions and zonal means. The results of trend analyzing show an increasing trend in CWP, and also a significant increasing trend of LWP can be found in the dataset of ISCCP, ERA-Interim, and CFSR over the ocean. Besides the long-term variation trend, rises of cloud water are found when temperature and water vapor exhibit a positive anomaly. EOF analyses are also applied to the anomalies of cloud water, the first dominate mode of CWP and IWP are similar, and a phase change can be found in the LWP time coefficient around 1999 in ISCCP and CFSR and around 2002 in ERA-Interim.

scholarly journals Relative Roles of Background Moisture and Vertical Shear in Regulating Interannual Variability of Boreal Summer Intraseasonal Oscillations

2016 ◽  
Vol 29 (19) ◽  
pp. 7009-7025 ◽  
Author(s):  
Li Deng ◽  
Tim Li
Keyword(s):  
Interannual Variability ◽  
Intraseasonal Oscillation ◽  
Longwave Radiation ◽  
Tropical Indian Ocean ◽  
Atmospheric Model ◽  
Vertical Shear ◽  
Boreal Summer ◽  
Moisture Condition ◽  
Intensity Index ◽  
Intraseasonal Oscillations

Abstract The interannual variability of the boreal summer intraseasonal oscillation (BSISO) is investigated using observed outgoing longwave radiation (OLR) and ERA-Interim data for the period of 1980–2012. It is found that the interannual variability of BSISO intensity is much stronger in the tropical western Pacific (TWP) than the tropical Indian Ocean (TIO). A BSISO intensity index is defined based on a multivariate EOF analysis in TWP. It is found that strong BSISO years are associated with El Niño–like sea surface temperature anomalies in the tropical Pacific, anomalous easterly shear, and enhanced background moisture condition in the region. Using a 2.5-layer atmospheric model with a specified idealized background mean state, the authors further examine the relative roles of background moisture and vertical shear fields in modulating the BSISO intensity. Sensitivity numerical experiments indicate that the background moisture change is most important in regulating the BSISO intensity, whereas the background vertical shear change also plays a role.

scholarly journals Sensitivity of Limiting Hurricane Intensity to SST in the Atlantic from Observations and GCMs

2013 ◽  
Vol 26 (16) ◽  
pp. 5949-5957 ◽  
Author(s):  
James B. Elsner ◽  
Sarah E. Strazzo ◽  
Thomas H. Jagger ◽  
Timothy LaRow ◽  
Ming Zhao
Keyword(s):  
Climate Models ◽  
North Atlantic Ocean ◽  
Global Climate ◽  
Atmospheric Model ◽  
Global Climate Models ◽  
Lower Sensitivity ◽  
Hurricane Intensity ◽  
University Center ◽  
The North ◽  
Low Sensitivity

Abstract A statistical model for the intensity of the strongest hurricanes has been developed and a new methodology introduced for estimating the sensitivity of the strongest hurricanes to changes in sea surface temperature. Here, the authors use this methodology on observed hurricanes and hurricanes generated from two global climate models (GCMs). Hurricanes over the North Atlantic Ocean during the period 1981–2010 show a sensitivity of 7.9 ± 1.19 m s−1 K−1 (standard error; SE) when over seas warmer than 25°C. In contrast, hurricanes over the same region and period generated from the GFDL High Resolution Atmospheric Model (HiRAM) show a significantly lower sensitivity with the highest at 1.8 ± 0.42 m s−1 K−1 (SE). Similar weaker sensitivity is found using hurricanes generated from the Florida State University Center for Ocean–Atmospheric Prediction Studies (FSU-COAPS) model with the highest at 2.9 ± 2.64 m s−1 K−1 (SE). A statistical refinement of HiRAM-generated hurricane intensities heightens the sensitivity to a maximum of 6.9 ± 3.33 m s−1 K−1 (SE), but the increase is offset by additional uncertainty associated with the refinement. Results suggest that the caution that should be exercised when interpreting GCM scenarios of future hurricane intensity stems from the low sensitivity of limiting GCM-generated hurricane intensity to ocean temperature.

scholarly journals Radiometric Intercomparison between Suomi-NPP VIIRS and Aqua MODIS Reflective Solar Bands Using Simultaneous Nadir Overpass in the Low Latitudes

2013 ◽  
Vol 30 (12) ◽  
pp. 2720-2736 ◽  
Author(s):  
Sirish Uprety ◽  
Changyong Cao ◽  
Xiaoxiong Xiong ◽  
Slawomir Blonski ◽  
Aisheng Wu ◽  
...  
Keyword(s):  
Infrared Imaging ◽  
Atmospheric Transmission ◽  
Imaging Spectrometer ◽  
The North ◽  
Swir Band ◽  
Low Latitudes ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Shortwave Infrared ◽  
The Impact

Abstract On-orbit radiometric performance of the Suomi National Polar-Orbiting Partnership (Suomi-NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) is studied using the extended simultaneous nadir overpass (SNO-x) approach. Unlike the traditional SNO analysis of data in the high latitudes, this study extends the analysis to the low latitudes—in particular, over desert and ocean sites with relatively stable and homogeneous radiometric properties—for intersatellite comparisons. This approach utilizes a pixel-by-pixel match with an efficient geospatial matching algorithm to map VIIRS data into the Moderate Resolution Imaging Spectroradiometer (MODIS). VIIRS moderate-resolution bands M-1 through M-8 are compared with Aqua MODIS equivalent bands to quantify radiometric bias over the North African desert and over the ocean. Biases exist between VIIRS and MODIS in several bands, primarily because of spectral differences as well as possible calibration uncertainties, residual cloud contamination, and bidirectional reflectance distribution function (BRDF). The impact of spectral differences on bias is quantified by using the Moderate Resolution Atmospheric Transmission (MODTRAN) and hyperspectral measurements from the Earth Observing-1 (EO-1) Hyperion and the Airborne Visible and Infrared Imaging Spectrometer (AVIRIS). After accounting for spectral differences and bias uncertainties, the VIIRS radiometric bias over desert agrees with MODIS measurements within 2% except for the VIIRS shortwave infrared (SWIR) band M-8, which indicates a nearly 3% bias. Over ocean, VIIRS agrees with MODIS within 2% by the end of January 2013 with uncertainty less than 1%. Furthermore, VIIRS bias relative to MODIS is also computed at the Antarctica Dome C site for validation and the result agrees well within 1% with the bias estimated using SNO-x over desert.

scholarly journals Estimates of the vertical distribution of desert dust and conden-sation nuclei over the Mediterranean, with the synergistic use of active and passive remote sensing techniques

2017 ◽  
Author(s):  
Ελένη Μαρίνου
Keyword(s):  
Atmospheric Model ◽  
Satellite Observations ◽  
Desert Dust ◽  
Passive Remote Sensing ◽  
Regional Atmospheric Model ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Remote Sensing Techniques ◽  
The Vertical Distribution

Ο πρωταρχικός στόχος αυτής της εργασίας είναι να καλύψει υπάρχοντα κενά στην αντίληψή μας σχετικά με το ρόλο της ερημικής σκόνης στις κλιματικές παραμέτρους της Μεσογείου χρησιμοποιώντας προηγμένες μεθόδους τηλεπισκόπησης. Αρχικά, η ερημική σκόνη διαχωρίζεται από τα συνολικά αερολύματα που παρέχονται από σύγχρονους δορυφορικούς αισθητήρες τηλεπισκόπησης. Το προϊόν σκόνης που παράγεται χρησιμοποιείται στην ανάπτυξη της τρισδιάστατης κατανομής του φόρτου της σκόνης πάνω από τη Μεσόγειο και τη Βόρεια Αφρική, η οποία είναι πολύ σημαντική για την επίδραση της σκόνης στην ηλιακή ακτινοβολία. Τέλος, αναπτύσσουμε κλιματολογίες των συγκεντρώσεων της σκόνης που ενεργούν ως πυρήνες παγoποίησης, για τη μελέτη της επίδρασης της σκόνης στο σχηματισμό νεφών.Η μεθοδολογία μας περιλαμβάνει τη συνέργεια παθητικών και ενεργών μετρήσεων τηλεπισκόπησης, με έμφαση στις κατακόρυφες μετρήσεις των αερολυμάτων που παρέχονται από το δορυφορικό lidar του CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations). Αρχικά, αναπτύσσουμε ένα νέο προϊόν σκόνης χρησιμοποιώντας τις μετρήσεις του CALIPSO, βασιζόμενοι σε μεθοδολογίες που έχουν αναπτυχθεί στο πλαίσιο του Ευρωπαικού επίγειου δικτύου lidar EARLINET (AErosol RObotic NETwork). Ο διαχωρισμός της σκό-νης από τους άλλους τύπους αερολυμάτων γίνεται χρησιμοποιώντας τα προφίλ του συντελεστή οπισθοσκέδασης και του λόγου αποπόλωσης του CALIPSO, καθώς και τις μετρήσεις και τις μεθόδους του EARLINET. Το προϊόν αξιολογείται με μετρήσεις από το δίκτυο AERONET (AEr-osol RObotic NETwork) και συγκρίνεται με δορυφορικές παρατηρήσεις από το MODIS (Moderate Resolution Imaging Spectroradiometer) και με κατακόρυφα προφίλ από το μοντέλο BSC-DREAM8b (Barcelona Supercomputer Center - Dust Regional Atmospheric Model). Το νέο προϊόν σκόνης χρησιμοποιείται για την παραγωγή μιας τρισδιάστατης κλιματολογίας της εξέλιξης της Σαχαριανής σκόνης πάνω από την Βόρεια Αφρική και την Ευρώπη, χρησιμοποιώντας τις δορυφορικές παρατηρήσεις του CALIPSO από το 2007 έως το 2015. Τα αποτελέσματα αναδεικνύουν την τρισδιάστατη εξέλιξη της σκόνης και τις εποχιακές διαδρομές της μεταφοράς της από τη Σαχάρα προς τη Μεσόγειο και την ηπειρωτική Ευρώπη. Το νέο προϊόν σκόνης είναι ελεύθερα διαθέσημο (κατόπιν αιτήσεως αλλά και από διάφορες ιστοσελίδες) και έχει ήδη χρησιμοποιηθεί από την παγκόσμια μετεωρολογική οργάνωση, την ευρωπαϊκή υπηρεσία διαστήματος και από συνεργάτες ερευνητές για την αξιολόγηση 3 μοντέλων μεταφοράς σκόνης, νέων προϊόντων από δορυφόρους πολικής και γεωστατικής τροχιάς και για την μελέτη της επίδρασης της σκόνης στο ισοζύγιο της ακτινοβολίας. Εδώ παρουσιάζονται τρία παραδείγματα τέτοιων εφαρμογών, με πρώτο (α) τη βελτιστοποίηση των παραμέτρων ενός μοντέλου μεταφοράς σκόνης προκειμένου να περιγραφεί η καταιγίδα σκόνης στη Μέση Ανατο-λή και την Ανατολική Μεσόγειο συνέβει το 2015, β) την κατηγοριοποίηση αερολυμάτων από το διάστημα με σκοπό τον διαχωρισμό των αερολυμάτων ανθρωπογενούς και φυσικής προέλευσης και (γ) την αξιολόγηση διαφορετικών παραμετροποιήσεων σκόνης σε περιφερειακά κλιματικά μοντέλα. Τέλος, ανακτώνται οι κατακόρυφες κατανομές συγκέντρωσης πυρήνων παγοποίησης στην περιοχή της μελέτης. Αυτό το αποτέλεσμα παρέχει μια μοναδική ευκαιρία για μελλοντική έρευνα πάνω στον ετερογενή σχηματισμού του πάγου, χρησιμοποιώντας παρατηρήσεις νεφών.

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