Characteristics and Variability of Carbonaceous Aerosols over a Semi Urban Location in Garhwal Himalayas

K. Sandeep,R. S. Negi,A. S. Panicker,Alok Sagar Gautam,D. S. Bhist,G. Beig,B. S. Murthy,R. Latha,Santosh Singh,S. Das 한국기상학회 2020 Asia-Pacific Journal of Atmospheric Sciences Vol.56 No.3

Extraction of organic carbon (OC) and elemental carbon (EC) were carried out over Srinagar, India, an ecologically sensitive semi-urban site in Garhwal Himalays. The PM2.5 sampling was carried out during January to December, 2017 over the site. The OC and EC were extracted from PM2.5 samples using a thermo optical OC/EC analyzer. Highest OC and EC concncentrations were found during postmonsoon (17.67 ± 1.1 μg/m3 OC and 6.34 ± 0.75 EC) and Winter (17.31 ± 3.045 μg/m3 OC and 6.32 ± 0.585 μg/m3 EC) seasons are attributed to boundary layer dynamics and anthropogenic activities. The lower concentration of OC/ EC was observed during monsoon season (11.64 ± 1.75 μgm−3 OC and 3.46 ± 0.19μgm−3 EC) owing to wet scavenging of aerosols and minimum count of forest fire/biomass buring incidences. Both pre-monsoon and post-monsoon season concentrations are also influenced by biomass burning in the IGP (Indo-Gangetic Plain) region and forest fires in the adjecent areas. The OC/EC ratio sounds that vehicular exhaust and biomass burning are the major source of OC/EC over the site. Generation of secondary organic carbon (SOC) at the region causes variability in OC/EC ratio in different seasons. It is found that 24–32% of PM2.5 is contributed by carbonaceous aerosols (OC and EC) over Srinagar. The pivotal role of meteorology in modulating OC/ EC concentrations has been illustared in detail.

Aerosol indirect effect during successive contrasting monsoon seasons over Indian subcontinent using MODIS data

Panicker, A.S.,Pandithurai, G.,Dipu, S. Pergamon Press ; Elsevier [distribution] 2010 Atmospheric environment Vol.44 No.15

Aerosol indirect effect (AIE) was estimated over six Indian regions, which have been identified as main source regions of absorbing aerosol emissions, for four successive contrasting monsoon years, 2001 (normal monsoon rainfall year), 2002 (drought year), 2003 (excess monsoon rainfall year) and 2004 (below normal rainfall year). The AIE has been estimated both for fixed cloud liquid water path (CLWP) and for fixed cloud ice path (CIP) bins, ranging from 1 to 350 gm<SUP>-2</SUP> at 25 gm<SUP>-2</SUP> intervals obtained from Moderate resolution imaging spectroradiometer (MODIS). In 2002 and 2004, AIE found to be of positive (Twomey effect) in majority of the fixed CLWP and CIP bins, while in 2001 and 2003 majority of the bins were found to be showing negative indirect effect (Anti-Twomey effect). Changes in circulation patterns during contrasting monsoon seasons, bringing up air mass containing aerosols of different source origins may be the main reason for this positive and negative AIE. The study suggests that AIE could be one of the factors in modulating Indian summer monsoon. However, further research on this topic is to be carried out to establish the relationship between AIE and Indian monsoon rainfall and also AIE values may be parameterized in climate models for better prediction of monsoon.

Aerosol Modulation of Ultraviolet Radiation Dose over Four Metro Cities in India

Panicker, A. S.,Pandithurai, G.,Beig, G.,Kim, Dongchul,Lee, Dong-In Hindawi Limited 2014 Advances in meteorology Vol.2014 No.-

<P>This paper discusses the influence of aerosols on UV erythemal dose over four metro cities in India. Tropospheric Emission Monitoring Internet Service (TEMIS), archived UV-index (UV-I), and UV daily erythemal dose obtained from SCIAMACHY satellite were used in this study during June 2004 and May 2005 periods covering four important Indian seasons. UV-Index (UV-I), an important parameter representing UV risk, was found to be in the high to extreme range in Chennai (8.1 to 15.33), moderate to extreme range in Mumbai and Kolkata (5 to 16.5), and low to extreme over Delhi (3 to 15). Average UV erythemal dose showed seasonal variation from 5.9 to 6.3 KJm<SUP>−2</SUP>during summer, 2.9 to 4.4 KJm<SUP>−2</SUP>during postmonsoon, 3 to 4.5 KJm<SUP>−2</SUP>during winter, and 5.1 to 6.19 KJm<SUP>−2</SUP>during premonsoon seasons over the four cities. To estimate the influence of aerosols on reducing UV dose, UV aerosol radiative forcing and forcing efficiency were estimated over the sites. The average aerosol forcing efficiency was found to be from-1.38±0.33to-3.01±0.28 KJm<SUP>−2</SUP>AOD<SUP>−1</SUP>on different seasons. The study suggests that aerosols can reduce the incoming UV radiation dose by 30–60% during different seasons.</P>

PARTICULATE MATTER CHARACTERISTICS OVER A GLOBAL ATMOSPHERE WATCH SUPERSITE (ANMYEON) IN SOUTH KOREA

A.S. Panicker,S. Park,Dong-In Lee,Dong-Chul Kim,Yu-Won Kim,Eun-Sil Kim,Harrison Jeong 한국기상학회 2011 한국기상학회 학술대회 논문집 Vol.2011 No.10-2

On the contribution of black carbon to the composite aerosol radiative forcing over an urban environment

Panicker, A.S.,Pandithurai, G.,Safai, P.D.,Dipu, S.,Lee, Dong-In Elsevier 2010 Atmospheric environment Vol.44 No.25

<P><B>Abstract</B></P><P>This paper discusses the extent of Black Carbon (BC) radiative forcing in the total aerosol atmospheric radiative forcing over Pune, an urban site in India. Collocated measurements of aerosol optical properties, chemical composition and BC were carried out for a period of six months (during October 2004 to May 2005) over the site. Observed aerosol chemical composition in terms of water soluble, insoluble and BC components were used in Optical Properties of Aerosols and Clouds (OPAC) to derive aerosol optical properties of composite aerosols. The BC fraction alone was used in OPAC to derive optical properties of BC aerosols. The aerosol optical properties for composite and BC aerosols were separately used in SBDART model to derive direct aerosol radiative forcing due to composite and BC aerosols. The atmospheric radiative forcing for composite aerosols were found to be +35.5, +32.9 and +47.6Wm<SUP>−2</SUP> during post-monsoon, winter and pre-monsoon seasons, respectively. The average BC mass fraction found to be 4.83, 6.33 and 4μgm<SUP>−3</SUP> during the above seasons contributing around 2.2 to 5.8% to the total aerosol load. The atmospheric radiative forcing estimated due to BC aerosols was +18.8, +23.4 and +17.2Wm<SUP>−2</SUP>, respectively during the above seasons. The study suggests that even though BC contributes only 2.2–6% to the total aerosol load; it is contributing an average of around 55% to the total lower atmospheric aerosol forcing due to strong radiative absorption, and thus enhancing greenhouse warming.</P>

Estimates of Aerosol Indirect Effect from Terra MODIS over Republic of Korea

Jung, Woon-Seon,Panicker, A. S.,Lee, Dong-In,Park, Sung-Hwa Hindawi Limited 2013 Advances in meteorology Vol.2013 No.-

<P>Moderate resolution imaging spectroradiometer (MODIS) data have been analyzed over four different regions (Yellow sea, Korean inland, East Sea, and South Sea) in Republic of Korea to investigate the seasonal variability of aerosol-cloud properties and aerosol indirect effect during the past decade (2000–2009). Aerosol optical depth (AOD) was found to be consistently high during spring. Cloud ice radius (CIR) also showed higher values during spring, while an enhancement in cloud water radius (CWR) and fine mode fraction (FMF) was observed during summer. AOD and aerosol index (AI) were found to be higher during January to June. However, FMF and CWR showed enhancement during July to December. Aerosol indirect effect (AIE) in each year has been estimated and found to be showing positive and negative indirect effects. The AIE for fixed cloud ice path (CIP) showed positive indirect effect (Twomey effect) over Yellow sea, while the AIE for fixed cloud water path (CWP) showed a major negative indirect effect (anti-Twomey effect) over all regions. During Changma (summer monsoon) period, the AIE for both CIP and CWP showed dominant anti-Twomey effect in middle and low level clouds, indicating the growth of cloud droplet radius with changes in aerosols, enhancing the precipitation.</P>

THE FLUCTUATION OF AEROSOL SIZE DISTRIBUTION AT THE CHUJADO IN KOREA

SUNG-HWA PARK,DONG-IN LEE,A.S PANICKER,WOON-SEON JUNG,SANG-MIN JANG,JONG-HOON JEONG 한국기상학회 2011 한국기상학회 학술대회 논문집 Vol.2011 No.10-2

IPCC AR6 WGI 제4장 주요 내용과 핵심 결과

June-Yi Lee,J. Marotzke,G. Bala,L. Cao,S. Corti,J. P. Dunne,F. Engelbrecht,E. Fischer,J. C. Fyfe,C. Jones,A. Maycock,J. Mutemi,O. Ndiaye,S. Panickal,T. Zhou,Maycock,J. Mutemi,O. Ndiaye,S. Panickal,T. 한국기상학회 2021 한국기상학회 학술대회 논문집 Vol.2021 No.10

The chapter 4 of Working Group I contribution to the IPCC Sixth Assessment Report assesses simulations of future global climate change, spanning time horizons from the near term (2021-2040),mid-term (2041-2060), and long term (2081-2100) out to the year 2300. The chapter assesses physical indicators of global climate change, such as global surface air temperature, global land precipitation, Arctic sea-ice area and global mean sea level. Furthermore, the chapter covers indices and patterns of properties and circulation not only for mean fields but also for modes of variability that have global significance. Changes are assessed relative to both the recent past (1995-2014) and the 1850-1900 approximation to the pre-industrial period. The projections assessed in the chapter are mainly based on a new range of scenarios, the Shared Socio-economic Pathways (SSPs) used in the Coupled Model Intercomparison Project Phase 6 (CMIP6). Additional lines of evidence enter the assessment, especially for change in globally averaged surface air temperature and global mean sea level, while assessment for changes in other quantities is mainly based on CMIP6 results. After section 4.2 on the methodologies used in the assessment, Section 4.3 assesses projected changes inkey global climate indicators throughout the 21<SUP>st</SUP> century. Section4.4. covers near-term climate change and Section 4.5 assesses mid-term andlong-term climate change. Section 4.6 addresses the climate implications of climate policies including patterns of climate change expected for various global warming levels, climate goals, overshoot, and path-dependence, as well as the climate response the climate response to mitigation, Carbon Dioxide Removal, and Solar Radiation Modification. Section 4.7 assesses very long-term changes up to 2300 and climate-change commitment and the potential for irreversibility and abrupt climate change. The chapter concludes with Section4.8 on the potential for low-probability-high-impact changes.