Proceedings of the International
SKYNET Workshop 2013
(and the 19th CEReS International
Symposium on Remote Sensing)

July 4th (Thu) and 5th (Fri), 2013
Nishi-Chiba Campus, Chiba University, Chiba, Japan

Proceedings of the International
SKYNET Workshop 2013
(and the 19th CEReS International
Symposium on Remote Sensing)

July 4th (Thu) and 5th (Fri), 2013
Nishi-Chiba Campus, Chiba University, Chiba, Japan

International SKYNET workshop 2013
(and the 19th CEReS International Symposium on Remote Sensing)

Scope of this workshop(1) To discuss the administration and strategy of SKYNET as a GAW contributing network.
SKYNET is planned to join contributing network of Global Atmosphere Watch (GAW)
program of World Meteorological Organization (WMO) and to distribute data throughthe World Data Center for Aerosols (WDCA) of WMO/GAW.
(2) To present recent results and findings of studies related to science and technology
in the field of aerosol-cloud-radiation interaction and to share their knowledge.

Remarks
In Science Sessions, each presentation has 12-min talk and 3-min discussion (15-minin total). Basically, speakers must use a projector provided at the venue and their own
laptop computer. Please connect your computer to the projector and confirm the proper
operation before your presentation. Ensure that your computer is equipped with theproper monitor connector (mini D-sub 15 pins). If your computer does not have it,
please bring an appropriate converter with you. Be sure to bring an AC adaptor withyou. Japanese standard AC voltage is 100V 50 Hz. The secretariat is not responsible forany projection troubles caused by computer technical difficulties. Your computer can beplaced on a podium for your presentation. You should connect your computer to theprojector during the previous presentation. Please pick up your computer at the podium
after your presentation. Slide and overhead projectors will not be available.

Local Organizing Committee*Hitoshi Irie (CEReS, Chiba Univ., Japan)
Kazuma Aoki (Univ. of Toyama,Japan)
Pradeep Khatri (CEReS, Chiba Univ., Japan)
Tomoaki Nishizawa (NIES, Japan)
Tamio Takamura (CEReS,Chiba Univ., Japan)
Nobuo Sugimoto (NIES, Japan)

International SKYNET Workshop 2013
(and the 19th CEReS International Symposium on Remote Sensing)
July 04 - 05, 2013
Multi-media Conference Room
Graduate School of Humanities and Social Sciences
Chiba University, 1-33 Yayoicho, Inage-ku, Chiba 263-8522, Japan■Day 1, July 04, 2013 (Thu)
09:00-09:30 Arrival, Registration
09:30 Opening/Welcome, H. Kuze (Chiba Univ.)
09:40 Logi, etc., H. Irie (Chiba Univ.)(Group photo)
Administration Session 1 [Chair: K. Aoki (Univ. Toyama)]
10:00 Thoughts for Skynet system development – toward future- & Proposal on administration andstrategy of the SKYNET as a GAW contributing network, T. Nakajima (Univ. of Tokyo)
10:20 About WMO/GAW, N. Sugimoto (NIES)
10:30 Status in Japan, Thai, and Mongolia, T. Takamura (Chiba Univ.), T. Boossarasiri (Chulalongkorn
Univ.), and N.Tugjsuren (Mongolian Univ. of S&T)
10:50 Status in China, H. Che (CAMS/CMA)
11:00 Status in Korea, S.-W. Kim (SNU) (on behalf of B.-J. Sohn)
11:10 Current status and future of the European Skynet Radiometers network, V. Estellés (Univ. of
València) (on behalf of M. Campanelli)
11:20 Skynet-India: Preliminary results from Skyradiometer network of India Meteorological
Department, V. K. Soni (IMD)
11:30 Lunch break(A meeting of country/region representatives)
Administration Session 2
13:00 Discussion about the proposal, led by T. Nakajima (Univ. of Tokyo)
14:45 Coffee break
15:15 Concluding remarks, T. Nakajima (Univ. of Tokyo)
Science Session – Algorithm 1 [Chair: T. Nishizawa (NIES)]
15:30 Aerosol optical properties retrieved by SKYRAD.pack Version5 based on skyradiometermeasurements of Beijing, China, H. Che (CAMS/CMA)
15:45 An estimation of single scattering albedo retrieved from SKYNET sky radiometer data anddevelopment of a quality control algorithm for the SKYNET data analysis, M. Hashimoto(Univ. of Tokyo)
16:00 Use of 315nm channel of sky radiometer to retrieve columnar ozone amount, P. Khatri (Chiba
Univ.)

16:15 Column water vapor retrievals from skyradiometer (POM-02) 940nm channel data, A.
Uchiyama (MRI)
16:30 Retrieval of calibration parameters for ground based Sun-Sky radiometric measurements ofcolumnar water vapor using operational surface meteorological measurements, V. Estellés(Univ. of València) (on behalf of M. Campanelli
16:45 An improved cloud screening algorithm for skyradiometer measurement analysis andapplication to Asian dust detection, H.-J. Song (SNU) (on behalf of B.-J. Sohn)
17:00 Combined use of SKYNET observations for retrieving microphysical properties, S. Katagiri(Tohoku Univ.)
17:15 Development of a SKYNET based methodology for the CIMEL CE318 radiometer in the frame of
the ESR network, V. Estellés (Univ. of València)
18:00 Party at Restaurant CORZA■Day 2, July 05, 2013 (Fri)Science Session – Algorithm 2 [Chair: K. Aoki (Univ. Toyama)]
08:30 Ground-based lidar network observation of aerosols and clouds in AD-Net, T. Nishizawa (NIES)
08:45 Development of an algorithm to estimate the aerosol vertical profile from Sky radiometer andLidar measurements, R. Kudo (MRI)
Science Session – Cal/Val/Comparison [Chair: K. Aoki (Univ. Toyama)]
09:00 Calibration and performance of Prede Skyradiometer, S. S. Ningombam (Indian Institute of
Astrophysics)
09:15 Comparison of aerosol optical properties between CE 318-1 of AERONET and POM-02 of
SKYNET, Y. Choi (Hankuk Univ. of Foreign Studies)
09:30 The validation and comparison of aerosol properties retrieved by CARSNET algorithm with the
AERONET, H. Che (Institute of Atmospheric Composition, CAMS/CMA)
09:45 Comparison of CALIPSO aerosol optical depth retrievals to sky radiometer and space-based
passive measurements, and characteristics of the lidar ratio, S.-W. Kim (SNU)
10:00 Coffee break
Science Session – General 1 [Chair: R. Kudo (MRI)]
10:15 Aerosol variations in urban atmosphere: case studies in Beijing and Dunhuang, B. Chen
(IAP/CAS)
10:30 Ground-based remote sensing of aerosol seasonal character over Hefei in East China, Z. Wang
(AIOFM/CAS)
10:45 Sun-sky radiometer study of monsoon activity over Pune, India, P.C.S. Devara (Indian Instituteof Tropical Meteorology)
11:00 Identification of aerosol types over the Indo-Gangetic Basin using ground-basedsunphotometer measurements, A. K. Srivastava (Indian Institute of Tropical Meteorology)
11:15 Optical and chemical properties of atmospheric aerosols at Phimai in Thailand by surface
measurements, CALIOP data, and the SPRINTARS model, H. Tsuruta (Univ. of Tokyo)
11:30 Lunch break
Science Session – General 2 [Chair: M. Kuji (Nara Women's Univ.)]
13:00 Sky-radiometer measurements for monitoring the aerosol optical properties in the Arctic andAntarctica, M. Shiobara (NIPR)

13:15 One year of measurements with a POM02 sun-sky radiometer at an Alpine Euroskyrad station,
H. Diémoz (ARPA Valle d'Aosta)
13:30 Continuous ground-based observation of aerosol optical properties in Tsukuba, Japan, A.
Uchiyama (MRI)
13:45 Characterization of atmospheric phenomena with SKYNET aerosol properties at Fukue-jimaand Amami-Oshima islands, S. Kitakoga (Nara Women's Univ.)
14:00 Optical and in-situ measurements of aerosol, nitrogen dioxide, and water vapor in relation toweather and sky radiation conditions in Chiba, H. Saito (Chiba Univ.)
14:15 Coffee break
Science Session – Climate 1 [Chair: P. Khatri (Chiba Univ.)]
14:45 A study of vertical profiles of aerosol radiative parameters and aerosol direct effects over the
East China Sea region using a combination of aircraft and ground based observation data, P.
Khatri (Chiba Univ.)
15:00 Investigate the single scattering albedo of dust aerosols and their impact on climate inNorthwest China, J. Bi (Lanzhou Univ.)
15:15 Cirrus clouds measurement by a three-wavelength lidar over Hefei in China, D. Liu(AIOFM/CAS)
15:30 Coffee break
Science Session – Climate 2 [Chair: P. Khatri (Chiba Univ.)]
16:00 Surface aerosol radiative forcing at the Observatory for Atmospheric Research, Thailand during
2009-2011, T. Boossarasir (Chulalongkorn Univ.)
16:15 Climate change trends and desertification in Mongolia, N.Tugjsuren (Mongolian Univ. of
Science and Technology)
16:30 Cloud Radiative Effect on the Earth's Surface, K. Yamada (Tohoku Univ.)
16:45 The research on global anthropogenic heat release, B. Chen (Institute of Remote Sensing andDigital Earth, CAS)
17:00 Closing remarks, T. Takamura (Chiba Univ.)

Thoughts for Skynet system development -toward futureTeruyuki Nakajima
Center for Earth Surface System Dynamics, Atmosphere and Ocean
Research Institute, The University of Tokyo
5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japane-mail: teruyuki.nakajima@aori.u-tokyo.ac.jp
Abstracts
This paper discusses several my thoughts for future development of theSkynet system. The Skynet system is a grass roots initiative for networking
the skyradiometer and accompanying instruments to measure theatmospheric aerosols and radiation budget. In the course of the development
we have had several supporters such as JAXA ADEOS-II/GLI, GCOM-C andEarthCARE

satellite

projects,

JST/CREST/APEX

project,

MOEJ/GER/ACECAP project, and MEXT Earth observation systemdevelopment program. The Skynet has been also supported by theinternational society with user communities in Europe, China, Korea andrecently India. This background made the Skynet recognized in 2013 as acontributing network of the WMO Global Atmospheric Watch program. I liketo raise the following points to be discussed in this workshop for future
development of the Skynet.
Efforts for world's standardization: We should have more consistency inthe protocols of operation and calibration similar to those of NASA
Aeronet system, which is regarded as the world standard for theskyradiometer network. Two sided sky scanning is a good idea to assure
the good quality of data. But, this needs faster scanning system to reduce
the scanning time. A transfer of calibration constants from Aeronet willbring a benefit to Skynet to increase the reliability of long-term accuracyof solar direct irradiance and diffuse radiance measurements.

Development of a better integrated system: International collaboration

has to be sought to establish better coordination of the management of
the Skynet, such as establishment of the international steeringcommittee, integrated data server structure and operation. Instrument
calibration program has to be developed to assure the homogeneous
quality of the instruments.
Continued effort for improving the data quality: The accuracy of theaerosol single scattering albedo, water vapor, and ozone have to be
improved through better radiometric calibration and better a priori
aerosol models for the retrieval process.



Expanding new sciences: Important are development of cloud retrieval
system, comprehensive comparison with chemical data and satellite
remote sensing data, use of data for aerosol data assimilation, andothers.

Current status and future of the European Skynet
Radiometers network

1Monica Campanelli, 2Víctor Estellés, and 1 Gian Paolo Gobbi
1

Institute of Atmospheric Climate and Sciences, National Research Council, Rome, Italy2

Dept. Fisica de la Terra y Termodinamica, Facultat de Fisica, Burjassot (Valencia), Spain

Correspondence to: Monica Campanelli (m.campanelli@isac.cnr.it)

Abstract
The European Skynet Radiometers network (ESR, www.euroskyrad.net) is a volunteer
European observational network of Prede POM sun sky radiometers federated with SKYNET
and established and maintained by several universities and research institutes. ESR is also a"multi-instrumental" network, as radiometers other than Prede POM (such as Cimel CE318 orothers) can take part. Actually the network consists of 13 sites, some of which are alreadyoperative. Thanks to the collaboration with the Italian Air Force, 3 more sites will be part of
the network in the next future, even if more restricted access to their database will benecessary. ESR is able to provide two different daily data processing: 1) mirroring of the
SKYNET inversion; 2) elaboration with the ESR.pack.
The present status of ESR web page and data processing system will be shown in detail,together with some aspects related to the future improvement of the procedure for analysing
data. Particularly the following aspects will be discussed: a) the new code for the estimationof precipitable water vapour content will be presented b) critical points in the development ofhigher quality levels of the inversion products, related to the low aerosol optical thickness
recorded in most of the ESR sites; c) many ESR sites are located in North Europe whereclouds are more frequently present during the year . Since none of the ESR sites has colocated Pyranometer and Pyrgeometers (needed to apply the cloud screening procedure set up
by SKYNET) it is important to discuss other methodologies for detecting clouds
contaminated measurements of diffuse sky radiance; d) all the ESR POM-01 instruments arenow able to perform vertical measurements for deriving cloud optical thickness at 1020 nm,
therefore there is a need to carry on the development of the dedicated software.
Another future development of ESR foresees the simultaneous presence of PREDE POM sunsky radiometers and Lidar Ceilometers in some sites of Italy with the aim of providing acomplete characterization of aerosol properties. The same possibility will be explored for theother ESR sites.

Skynet-India: Preliminary results from Skyradiometer network of India
Meteorological Department
S. D. Attri1, V. K. Soni1* and G. Pandithurai2
India Meteorological Department, New Delhi
soni_vk@yahoo.com*Corresponding author and presenting author
Abstract
Tropospheric aerosols have a short lifetime; as a result they have high degree ofvariability in both space and time in their composition, number and size distribution. The
geography of India is quite diverse, with everything from mountains, deserts andrainforests. For a good assessment of aerosol characteristics such measurements have to be
performed frequently in locations with different aerosol types and in varying meteorologicalconditions in automatic mode. In order to examine aerosol impact on the local and global
climate in addition to understanding and modeling the impact of aerosol on radiation budget
and precipitation efficiency, India Meteorological Department has established a network ofsun-skyradiometer consisting of twelve stations located in different geographic regions andnamed as Skynet-India. The sun-skyradiometer POM-02 acquires direct solar spectral
irradiance and circum-solar radiance distribution within a 1o full field-of-view at elevenbands of 315, 340, 380, 400, 500, 670, 870, 940, 1225, 1600, and 2200 nm at every 10 minute.
This paper presents the preliminary results from Skynet-India Network. The main propertiesof the aerosols which are being monitored from this network and important for climate
studies are; Aerosol Optical Depth, Angstrom Exponent, Size Distribution of the aerosols,
Scattering Phase Function, Single Scattering Albedo and Refractive Indices etc. Ranichauri isa high altitude background site with AOT as low as 0.03 on clear sky days. The Aerosol
content is two to three orders lower as compared to Delhi. Single Scattering Albedo is morethan 0.9 in all seasons as compared to Delhi where it is found to vary between 0.7 – 0.85.
Rohtak is close to Delhi but the AOT is significantly lower and SSA higher as compared to
Delhi. Jodhpur is located in desert area and shows significant variability in AOT, highest
being during summer and lowest during rainy season. Guwahati is mostly affected by cloudy
conditions but during clear sky conditions AOT as low as 0.1 is observed. Port Blair is an
island station in the Bay of Bengal, Visakapatnam and Thiruvanantapuram are coastal
stations and are dominated by sea salt aerosol as seen from the size distribution. Pune islocated on leeward side of Western Ghats and relatively clean city with AOT values as low as
0.09 during clear sky days.

Aerosol optical properties retrieved by SKYRAD.pack
Version5 based on skyradiometer measurements of Beijing,
China

1Huizheng Che, 2Guangyu Shi, 3Xiaoye Zhang, 4Hujia Zhao, 5Junying Sun
1

Key Laboratory of Atmospheric Chemistry (LAC), Institute of Atmospheric Composition.

Chinese Academy of Meteorological Sciences (CAMS), CMA, Beijing, 100081, China
2State Key Laboratory of Numerical Modeling for Atmospheric Sciences and GeophysicalFluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences,
Beijing, 100029, China

Correspondence to: Huizheng Che (chehz@cams.cma.gov.cn)

Abstract
A PREDE POM-02 skyradiometer (SKYNET) has been installed in May 2008 at Chinese
Academy of Meteorological Sciences (116.32˚ E, 39.93˚ N, 106.0 m) in Beijing, China tomeasure the aerosol optical properties. Both the version 4.2 and 5.0 of SKYRAD.pack code
have been used to retrieve the columnar aerosol features. The intercomparison results of theaerosol optical properties from version 4.2 and 5show that aerosol optical depth (AOD) has
good consistence each other. Single scattering albedo values from version 5 is lower thanthose from version 4. 2 systematically, but there have good consistence with R-square about
0.85. This difference of SSA suggests that more strict cloud screening implementation should
be used in future. The volume size distribution from version 5 has been improved muchcomparing with that from version 4.2, especially for the coarse mode particles.
The aerosol optical properties at Beijing during May, 2008 to October, 2012 including
monthly means of AOD, SSA, volume size distribution, refractive index have been analyzed.
The elementery results show AOD is higher during spring and summer seasons but lower infall and winter seasons. SSA is lower during fall and winer season but higher during springand summer seasions which indicates the aerosol particles have more absorption in winterthan summer. This reflects the aerosol chemical composition of Beijing has significant
distribution characteristics. Large coarse mode volume size distribution in spring at Beijing
reprensent the dust aerosol particle contribution.

An estimation of single scattering albedo retrieved fromSKYNET sky radiometer data and development of a quality
control algorithm for the SKYNET data analysis.
1

Makiko Hashimoto, 1Teruyuki Nakajima

1

Atmosphere and Ocean Research Institute (AORI), the University of Tokyo, Japan

Correspondence to: Makiko Hashimoto (m_hashi@aori.u-tokyo.ac.jp)

Abstract
It is important to accurately estimate the columnar aerosol optical properties in assessing theeffect on the radiation budget associated with the aerosol direct radiative forcing. The
SKYNET network is one of the ground-based aerosol monitoring networks for this purpose.
In the SKYNET, the direct and diffuse solar irradiances are measured by using sky radiometer(Prede Co., Ltd, Tokyo, Japan), and the columnar aerosol optical properties, such as aerosol
optical depth, single scattering albedo, real and imaginary part of refractive index and phasefunction, and size distribution, are retrieved by using its own inversion software called
SKYRAD.pack version4.2 (Nakajima et al., 1996). However, it is pointed out that the valueof single scattering albedo (SSA) from SKYNET is systematically larger than that fromNASA AERONET (Holben et al., 1998), which is also well-known network similar to
SKYNET, and that sometime SSA from SKYNET is unnaturally close to unity (Badarinath etal., 2011). To investigate the cause of above problems, we conducted sensitivity tests for the
possible causes of error in SSA in the retrieval process of SKYRAD.pack. We also checked adifference in SSA between the inversion algorithms. From the sensitivity tests, it is found thaterror of -0.1 in surface albedo, -5% in solid view angle or -5% in the calibration constantresult in errors of +3.0%, +2.3%, or +4.7% in SSA, respectively. As to the type of inversion
method, this study used SKYRAD.pack version 4.2 with either the Phillips-Twomey method(Phillips, 1962; Twomey, 1963, standard method) or the maximum a posteriori (MAP)
method (which is similar to the AERONET inversion algorithm). From the simulation results
it is found that there are two cases of large deviation of the retrieved SSA from the true SSA
value, i.e., 1) the Phillips-Twomey method overestimates the SSA value when cirrus particles
clouds exist in the atmosphere because this method regards the cirrus particle size distribution
as a coarse aerosol size distribution. 2) When aerosol a priori size distribution in the analysis

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using the MAP method does not include the coarse particle mode, the SSA value isunderestimated in the case the large coarse particles in the size range larger than 10 µm in
radius exist dominantly. Then we analyzed the real data at Pune (18.6˚N/73.8˚E) and Beijing
sites (36.0˚N/140.1˚E) and compared the results with those of AERONET. From the result, it
is found that in cases of the cirrus contamination detected by CALIPSO lidar, the SSA values
retrieved by SKYNET Phillips-Twomey method is lager than that from the MAP method
and/or AERONET. And we found one significant dust case that Phillips-Twomey method
seems to retrieved the size distribution of coarse dust particle mode more reasonably than thatfrom MAP method with suppressed a priori particle size distribution in coarse mode.
Therefore, we propose a new data screening method that rejects data in cases of 1) the aerosol
optical depth at 0.5 µm is less than 0.4, 2) the reconstruction error of sun and sky irradiances
is equal or larger than 7%, and 3) significantly large coarse mode size distribution. We
applied above data screening to the data at Pune (April to December, 2008) and Beijing.)"/)01)#&'()$*$+,-&!"#$%&'()*$+,-./)0$%&'()*$(February
to September, 2004).
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panel) data screening in May and October 2008 at Pune and in April and September 2004 at Beijing.

Use of 315nm channel of sky radiometer to retrieve columnar
ozone amount1

Pradeep Khatri, 1Tamio Takamura, 2Akihiro Yamazaki, and 2Akihiro
Uchiyama

1

Center for Environmental Remote Sensing, Chiba University, Chiba, Japan

2

Meteorological Research Institute, Tsukuba, Japan

Correspondence to: Pradeep Khatri (pradeep@restaff.chiba-u.jp)

Abstract
Sky radiometer data are being used to study aerosol and cloud parameters as well as water
vapor content of our atmosphere. In order to further extend the utility of this instrument tomeasure columnar ozone concentration, we propose ozone concentration retrieval method
using 315nm channel data of sky radiometer. The proposed method consists of (i) calculating
calibration constant of direct intensity at 315nm using in situ observation data, which is analternation of traditional Langley method, and (ii) retrieval technique of ozone concentration
using sky radiometer observation data. For the limited set of data, the retrieved ozone
concentrations using proposed method agreed well with directly measured ozone
concentration by Brewer Spectro-photometer with root mean square error (RMSE) of
0.02atm-cm, validating the reasonable accuracies of in situ calibration and ozone retrieval
techniques. The proposed method will be further validated using more observation data.The
error analysis study suggests that the proposed method can have low retrieval error at highsolar zenith angle and vice versa. The retrieval error differs with magnitudes of error

associated with calibration constant, measured direct intensity and aerosol and Rayleighoptical thicknesses.

Column water vapor retrievals from skyradiometer (POM02) 940nm channel data.

1
1

Akihiro Uchiyama, 1Akihiro Yamazaki, 1Rei Kudo, and 1Daisaku Uesawa

Japan Meteorological Agency, Meteorological Research Institute, Tsukuba, Japan

Correspondence to: Akihiro Uchiyama (uchiyama@mri-jma.go.jp)

Abstract
Skyradiometer (POM-02, Prede Co., ldt.) is used to retrieve aerosol optical properties and to
estimate the radiative effect of aerosol properties on the surface solar irradiance. The
skyradiometer (POM-02) has a 940nm channel in the water vapour absorption band. This
channel data is not fully utilized until now. The column water vapour is one of the importantfactors to determine the surface radiation budget and in addition when we use the nearinfrared channels, 1225, 1627, 2200nm, the transmittances by water vapour in these channels
are necessary. In this study, the 940nm channel was calibrated by the Langley method, which
is taken into account of gas absorption. The relation between column water vapour isdetermined using the simulation data; McClatchey’s (1972) five atmospheric models, U.S.
standard atmosphere 1962, and four modified McClatchey’s atmospheric models were used to
calculate the transmittance at 10 different times in order to simulate a large range of path
length. Once the transmittance is obtained, we can retrieve column water vapour using thisrelation. This method was applied to the data at Tsukuba, Japan in 2010 and the comparison
between column water vapours from POM-02 and GPS was made. The results show that bias
error is 0.09 (g/cm2), root means square error is 0.179(g/cm2), and correlation coefficient is
0.966. The coefficients of linear regression line (POM-02=C1*GPS+C2) between them are
C1=0.957 and C2=0.169.

Retrieval of calibration parameters for ground based SunSky radiometric measurements of columnar water vapor
using operational surface meteorological measurements

1Monica Campanelli, 2T. Nakajima, 3P. Khatri, 3T.Takamura, 5A. Uchiyama, 4V.

Estelles, 1G.L. Liberti, and 1*V.Malvestuto
1

Consiglio Nazionale delle Ricerche (CNR), Institute of Atmospheric Science and Climate(ISAC), Rome, Italy.
2

Center for Climate System Research (CCSR), The University of Tokyo, Kashiwa, Japan.

3

Center for Environmental Remote Sensing(CEReS), Chiba University, CHIBA, Japan.

4

Dept. Fisica de la Terra y Termodinamica, Facultat de Fisica, Burjassot (Valencia), Spain.

5

Meteorological Research Institute, Tsukuba-city, Japan.

* died on May 2011

Correspondence to: Monica Campanelli (m.campanelli@isac.cnr.it)

AbstractSun-sky radiometers are instruments created for aerosol study, but they can measure in thewater vapour absorption band allowing the estimation of columnar water vapour W in clear
sky simultaneously with aerosol characteristics, with high temporal resolution. A new
methodology, cheap and easy to implement, is presented for estimating calibration parameters(i.e. characteristic parameters of the atmospheric transmittance and solar calibration constant)directly from the sun-sky radiometers measurements. To initiate the proposed methodology
some seasonal independent measurements of columnar water vapour taken over a large rangeof solar zenith angle simultaneously with the sun-sky radiometer measurements, are needed.
In this work the Surface Humidity Method (SHM) was developed allowing to initiate theprocedure with columnar water vapour estimated by standard surface meteorologicalobservation (temperature, pressure and relative humidity). The time pattern of columnar watervapour from sun-sky radiometer was compared with simultaneous measurements frommicrowave radiometer and radiosondings showing respectively a total correlation of 0.98,
0.96 and a total median difference of 2.24 mm and -0.65 mm. The accordance withradiosondings was found within the uncertainty of the methodology (varying from 10 to16 %) independently on the amount of atmospheric water vapour.
Results were also validated against the columnar water vapour estimated by using theprocedure adopted by the University of Uchiyama, that is similar to the one adopted by
AERONET network, and consists in retrieving the characteristic parameters from a fitting
procedure of simulated transmittance versus the product mW, were m is the optical airmass.
Also in this case the accordance against microwave radiometer and radiosondings is good for
different water vapour classes, but we like to emphasize that the introduction of a water
vapour dependence in the characteristic parameters of the atmospheric transmittance,
improved the agreement with the Microwave Radiometer measurements especially in thecases with the lowest water vapour content.

An improved cloud screening algorithm for skyradiometermeasurement analysis and application to Asian dust
detection

1Byung-Ju Sohn, 1Hwan-Jin Song, and 2Myoung-Seok Suh
1

School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea
2

Department of Atmospheric Sciences, Kongju National University, Kongju, Korea

Correspondence to: B.J. Sohn (sohn@snu.ac.kr)

Abstract
Cloud screening algorithm including variability test and coarse mode test was developed forremoving cloud-affected data in the skyradiometer measurements. The results compared tocloud amount from weather station reports and lidar measurements show that the variability
test appears to effectively remove thick and low-level clouds. On the other hand, the use of
size distribution appears to effectively remove thin and high-level clouds. The new algorithm
based only on using skyradiometer measurements demonstrated that cloud screening can be
improved in comparison to the SKYNET data processing algorithm.
The developed cloud screening method is then applied for the dust detection fromskyradiometer measurements. Validating results with SYNOP dust reports and the yellow
sand index from lidar measurements, it was shown that the developed cloud screening
methods helps to detect dust cases, effectively removing cloud-contaminated signals from thedust signals that determined from current SKYNET algorithm. In turn this algorithm
contributes to improved accuracy of the dust influence on radiative forcing and its efficiency
by reducing uncertainties in the AOT and SSA retrievals.

Combined use of SKYNET observations for retrieving
microphysical properties of cirrus clouds

1Shuichiro

Katagiri, 1Hironobu Iwabuchi, 1Tadahiro Hayasaka, and 2Kazuma

Aoki
1Center for Atmospheric and Oceanic Studies, Tohoku University, Sendai, Japan2

Department of Earth Science, University of Toyama, Toyama, Japan

Correspondence to: Shuichiro Katagiri (katagiri@m.tohoku.ac.jp)

Abstract
SKYNET has been collecting radiation data for more than ten years with several instruments.
Especially at the super sites such as Cape Hedo and Fukue Isle observatory, intensive
measurements have been carried out with a lot of instruments (e.g. skyradiometer,
pyrheliometer, pyranometer, pyrgeometer, microwave radiometer, sunphotometer, and lidar).
Synergetic analysis of cloud and aerosol properties using these instruments together were not
performed sufficiently. We will analyse optical properties of cirrus clouds by the synergetic
use of several instruments and will compare the derived properties to the ones from MODIS
analysis.
The first target is an improvement of the i-skyradiometer algorithm developed by Kikuchi(2006) to retrieve cirrus cloud microphysical parameters. The second is to use data taken byother instruments to reduce uncertainties caused by the existence of aerosols and/or broken
clouds. Finally we would like to compare the results with MODIS results.

Development of a SKYNET based methodology for the
CIMEL CE318 radiometer in the frame of the ESR network
1VíctorEstellés,

2Monica

Campanelli,

3Francisco

Expósito,

4PilarUtrillas,and 4José Antonio Martínez-Lozano
1

Departament de Didàctica de les Ciències Experimentals, University of València, Spain.

2

Institute for Atmospheric Physics, Consiglio Nazionale delle Richerche, Rome, Italy

3

Departamento de Física Fundamental y Experimental, Electrónica y Sistemas, University of

La Laguna, Spain
4

Department de Física de la Terra i Termodinàmica, University of València, Spain.

Correspondence to: Víctor Estellés (victor.estelles@uv.es)

Abstract
The European Skynet Radiometers network was recently established by several European
universities and research institutes as a volunteer network of Prede POM sun sky radiometers,
federated with SKYNET in Asia for international homogeneity. However, ESR is also
conceived as a “multi-instrumental” network in the sense that other sunphotometers than
PREDE POM can be included in the network.
With this aim, in ESR we are developing specific algorithms for other instruments (such as
the well-known CIMEL CE318 sunphotometer) based on the methodology proposed by
SKYNET for the PREDE instruments, but including also the methodology proposed by
AERONET for the CIMEL instruments (including cloud screening for direct and diffuse
measurements). These algorithms are components of the so called ESR.pack, and can be
currently applied to both CIMEL and PREDE datasets. In this way, we can homogeneously
process data from both instruments within the network, providing a good benchmark for thesynergistic analysis of other international networks such as AERONET, and the comparative
analysis of both inversion algorithms from AERONET and SKYNET, reducing instrumental
effects in the inversion process.

Specifically, the ESR.pack is composed of two main programs for the analysis of the direct
sun and the diffuse sky radiance components. Both programs are named sunrad and skyrad(the later based on the SKYRAD.PACK version 4.2), respectively. In this presentation wewill show the main results of the application of this software to the CIMEL CE318
sunphotometer, including the validation and comparison with AERONET derived properties.
Furthermore, a comparison between results for PREDE and CIMEL is included. In thiscontribution we also show results from the application of the in situ improved Langley plot.
We will also describe future developments, in relation with the cloud screening algorithms,
estimation of aerosol radiative forcing, and cloud properties retrieval.

Ground-based lidar network observation of aerosols
and clouds in AD-Net
Tomoaki Nishizawa, Nobuo Sugimoto, Ichiro Matsui,
Atsushi Shimizu, and Akiko Higurashi
National Institute for Environmental Studies, Tsukuba, Japan
Correspondence to Tomoaki Nishizawa (nisizawa@nies.go.jp)
Abstract
The recent status and future strategy of the ground based lidar network
observation in AD-Net is presented. We have constructed lidar network using
dual-wavelength (532 and 1064nm) polarization (532nm) Mie lidars covering awide area in East Asia (AD-Net: the Asian Dust and aerosol lidar observation
NETwork) and conducted aerosol and cloud observation for more than ten years
in cooperation with many researchers. Some sites in AD-Net have joined in
SKYNET and provided information on vertical structures of aerosols and clouds.
An algorithm to estimate vertical profiles of spherical aerosols (air pollution) andnonspherical aerosols (mineral dust) separately using the lidar data has beendeveloped. The derived aerosol component data have been recently used inassimilation of numerical models and evaluation of impacts on human healthand vegetation. Further, we have proceeded to improve the network lidar system
by introducing more advanced lidar techniques (Raman lidar and High spectral
resolution lidar techniques) in order to obtain more detailed optical properties ofaerosols and clouds and to develop aerosol retrieval algorithms to classify moreaerosol components using the lidar data. Synergy algorithms using data of thelidars and passive sensors such as a skyradiometer are essential forunderstanding complicated optical and microphysical properties of aerosols
comprehensively. We will develop a synergy algorithm to estimate vertical
distributions of several aerosol components and their vertically mean mode radii
using lidar and skyradiometer data. In the workshop, we will present ideas of thesynergy algorithms as well as reporting recent development of AD-Net.

Development of an algorithm to estimate the aerosol
vertical profile from Sky radiometer and Lidar
measurements
1Rei Kudo, 1Toshinori Aoyagi, and 2Tomoaki Nishizawa
1

Meteorological Research Institute, Japan Meteorological Agency

2

National Institute of Environmental Studies

Correspondence to: Rei Kudo (reikudo@mri-jma.go.jp)
Abstract
We have developed an algorithm to estimate the vertical profiles of refractive indexes andvolume size distribution from the routine measurements of SKYNET (sky radiometer anddual wavelength polarization Mie lidar). Optical properties of aerosols such as extinction
coefficient, single scattering albedo, and asymmetry factor are further evaluated from thederived refractive indexes and size distribution. The algorithm consists of two steps. In thefirst step, the refractive indexes (real and imaginary parts) at sky radiometer wavelengths (340,
380, 400, 500, 675, 870, 1020 nm) and the volume size distribution in the column are
estimated from sky radiometer measurements. The size distribution is assumed to be bi-modal
lognormal distribution. In the second step, the vertical profiles of the refractive indexes (realand imaginary parts) at lidar wavelengths (532, 1064 nm) and the size distribution are
estimated from the attenuated back scatter measurements, and optical depth and single
scattering albedo obtained from the results of the first step. The size distribution is also
assumed to be bi-modal lognormal distribution. At each step, the aerosol parameters are
estimated on the basis of the Maximum Likelihood Method. The developed algorithm wastested for vertically non-homogeneous profiles (e.g., dust in the upper layer). The verticalprofiles of extinction coefficient, single scattering albedo, and asymmetry factor at 532 nm
were well estimated but those at 1064 nm were not. The vertical profiles of the size
distribution were also well estimated. We also developed the algorithm with HSRL (HighSpectral Resolution Lidar) which is being developed in NIES. In the presentation, we willshow the algorithm with HSRL, and the results for the actual observations of sky radiometerand Mie lidar.

Calibration and performance of Prede Skyradiometer
Rajendra B. Singh, Shantikumar S. Ningombam@, Sangita K. Padhy*, and S. P. Bagare
Indian Institute of Astrophysics, II Block Koramangala, Bangalore, 560 034, INDIA@
shanti@iiap.res.in (corresponding author); * previously she was associated with IIA

Introduction:
Recently, skyradiometer (model, POM-01L), made of PREDE Co., Ltd, Japan was installed at a highaltitude pristine station, Merak (33048/ N and 78037/ E, 4310 m, amsl), in Ladakh region and of Jammu
and Kashmir state of India. The station exhibits a cold-desert climatic condition with little snow coverand free from any kinds of anthropogenic activities. Further, the station is located adjacent to the
Pangong Lake. The lake is surrounded by 5 km wide and 134 km long and it extends from India to
China. Two thirds length of the lake lies in China. During winter, the surface of the lake is completely
frozen. Since the station is located at a high altitude, having cold-desert and dry atmosphericconditions, the amount of water vapor present at the site is very low. Further, aerosol concentration at
the station is very low and is similar with Hanle [32047/ N and 78058/ E, 4500 m amsl], where anotherhigh altitude station in Ladakh region and the same instrument was operating for more than three yearsof continuous data as a part of astronomical site survey program [Veram et al., 2010]. Figure 1 shows
the Prede Skyradiometer at the present observing station, located adjacent to the Pangong Lake.
Instrumentation:
The instrument consists of an automatic sun tracking system, a spectral scanning radiometer, a rain
detector, and a sun sensor. It has seven filters (315, 400, 500, 675, 870, 940 and 1020 nm) with band
widths ranging from 2 to 10 nm. The instrument measures both direct and diffuse sky radiances at predefined scattering angles at regular intervals. These data are further processed using Skyrad.Pack(version 4.2) code [Nakajima et al., 1998]. The code consists of a multiple scattering radiative transfer
scheme in a plane-parallel atmosphere and an inversion procedure to retrieve aerosol optical depth(AOD), aerosol size distribution, aerosol phase function at several scattering angles, and single
scattering aledo (SSA) from the direct and diffuse solar irradiance measurements in almucantar andprincipal plane geometries. The unique features of the instrument include an in-built calibration
capability, an automatic solar disk scanner for calibration of solid view angle, and a single detector
design. Further, AOD is measured on the basis of the Lambert-Bouger low including the calibration
constant of the instrument, solid view angles of each channel, correction factor of Sun-Earth distance,correction for Rayleigh scattering and total column of ozone.
Results:
Calibration of skyradiometer is performed periodically by estimating solid view angle for each channel
by performing disk scan and estimating the solar radiometer constant from the improved Langleymethod. Disk scan of each channel is performed in an area of 2 degree X 2 degree around the solar disk
with an angular resolution of 0.1 degree. The disk scan is performed periodically for more than twice or
thrice in a month and the result of the solid view angles for each channel is nearly stable with less than
0.5% deviation. The maximum and minimum pressure difference at the site is around 1% of daily
mean. The difference of AOD due to 2% variation in station pressure is around 0.004 to 0.002 at 400
and 500 nm, respectively and rest of the filter shows negligibly small. The Calibration constants (F0Is)

obtained during two years of data shows drifting with a relative standard deviation (RSD) of 5.8 %,
4.7%, 4.4 %, 5.0 % and 3.9 % at 400, 500, 675, 870 and 1020 nm, respectively through the improved
Langley method (Verma et al., 2010).

Figure 1: Prede Skyradiometer at the present observing station (Merak), located adjacent to the
Pangong Lake.
Due to pristine and clean environment, the difference between improved and normal Langley plot is
quite similar with a negligible difference. The ratio of the calibration constants obtained by the two
methods varies in between 0.99 to 1.00. Due to pristine environment and far from any kinds ofanthropogenic sources, these sites (Merak and Hanle) can be a considered as ideal stations like theMauna Loa [3400 m amsl] in the Pacific Ocean for calibration of sunphotometer instruments.
References:
1. Nakajima T., G. Tonna, R. Rao, P. Boi, Y. Kaufman, and B. N. Holben (1996), Use of skybrightness measurements from ground for remote sensing of particulate polydispersions, App.
Opt., 35, 2672-2786.
2. Verma, N., S. P. Bagare, Shantikumar S. Ningombam, and R. B. Singh (2010), Aerosol Optical
Properties retrieved using Skyradiometer at hanle in western Himalayas, J. Atmos. SolarTerrestrial Phys., 72, 115-124.

Comparison of aerosol optical properties between CE 318-1
of AERONET and POM-02 of SKYNET

1Yongjoo Choi, 1Young Sung Ghim, 2Brent Holben
1

Department of Environmental Science, Hankuk University of Foreign Studies, Yongin, 449-

791, Korea
2

NASA Goddard Space Flight Center, Greenbelt, MD, USA

Correspondence to: Young Sung Ghim (ysghim@hufs.ac.kr)

Abstract
The Distributed Regional Aerosol Gridded Observation Networks (DRAGON) campaign forcomparison/validation of satellite aerosol products with ground-based aerosol retrievals was
conducted in Korea between March and May 2012. During the campaign CIMEL
sunphotometers were operated at around 20 sites throughout the country. The Hankuk
University of Foreign Studies site (Hankuk_UFS, 37.02oN, 127.16oE, 167 m above sea level)
is located about 35 km southeast of downtown Seoul. A PREDE skyradiometer (POM-02)
was operated along with CIMEL sunphotometer (CE 318-1) to compare the aerosol opticalproperties derived from the two instruments. Intercomparison operation started with the
DRAGON-Korea campaign and has continued for a year. POM-02 and CE 318-1 measured
diffuse radiation at 11 wavelengths at 6-minute intervals and 4 wavelengths at 1-hourintervals, respectively. Aerosol optical depths (AOD) from these two instruments werecompared at 440, 675, 870, and 1020 nm when the measurement time coincided within 3
minutes. Because AOD at 440 nm was not available for POM-02, it was obtained frominterpolation of AOD at 400 nm and 500 nm. Other aerosol optical properties such as
Angstrom exponent, single scattering albedo (SSA), absorption AOD, and absorption AE
from the two instruments were compared in a similar way. AOD had a good correlation
between the two instrument. However, SSA from the skyradiometer tended to be larger thanthat from sunphotometer. Larger SSAs seemed to be due to underestimation of absorbing

parameters such as imaginary part of refractive index. It was presumed that factors causing
the difference were different assumption of retrieval algorithm of each network regarding
refrative index, radii bin of volume size distribution, and the shape of aerosols.

The validation and comparison of aerosol properties retrieved
By CARSNET algorithm with the AERONET
Huizheng Che 1, Jun Zhu 2, Xiangao Xia 2, Hongbin Chen 2, Oleg Dubovik 3,
1 Key Laboratory of Atmospheric Chemistry (LAC), Institute of Atmospheric Composition, Chinese Academy of
Meteorological Sciences (CAMS), CMA, Beijing, 100081, China
2 Laboratory for Middle Atmosphere and Global Environment Observation (LAGEO), Institute of AtmosphericPhysics, Chinese Academy of Sciences, Beijing, 100029, Beijing, 100029, China.
3 Laboratoire d’Optique Amosphérique, Université des Sciences et Technologies de Lille, 59655 Villeneuve d’Ascq,
France.

Correspondence to: Jun Zhu (zhujun@mail.iap.ac.cn);
Huizheng Che (chehz@cams.cma.gov.cn).
Abstract: the 3 months data (15 Aug 2012 to 15 Nov 2012) retrieved by two CE-318 radiometersin the same position were used to validate the stability of the algorithm and the one-year outcome
from Apr 2008 to Feb 2009 retrieved by the algorithm in Beijing (not the same position for
AERONET station) were compared with data from the AERONET. For the stability validation, thealgorithm showed a high stability for sun direct part but a little drift for sky inversion part. The
slope of straight line fit close to 1.0 and correlations were all larger than 0.99 for aerosol opticaldepth (AOD) at all wavelength. The single scattering albedo (SSA) showed high similarity at
AOD~1.01-1.33 and obvious difference at AOD~0.56-1.01. The volume size distribution at peak
was inconsistent for the two instruments. The slopes of effective radius were 0.993, 0.899 and
0.728 for total, fine and coarse particles, respectively. The SSA was consistent at AOD~ 0.8-2.0
for the two algorithms. The volume concentration was agreed well. For the comparison withAERONET, the correlations of AOD were decreased to 0.98. The differences of volume size
distribution and volume concentration become lager. These can be explained by the differences ofthe position of the two stations, the meteorological conditions and the parameters of twoalgorithms.

Comparison of CALIPSO aerosol optical depth retrievals to
sky radiometer and space-based passive measurements,
and characteristics of the lidar ratio

1Sang-Woo

Kim,

1Man-Hae

Kim,

1Soon-Chang

Yoon,

1B.-J.

Sohn,

2NobuoSugimoto, and 3Ali Omar
1

School of Earth and Environmental Sciences, Seoul National University, Korea

2

Atmospheric Environment Division, National Institute for Environmental Studies, Japan

3

NASA Langley Research Center, Hampton, Virginia, USA

Correspondence to: Sang-Woo Kim (sangwookim@snu.ac.kr)

Abstract
The aerosol optical depth (AOD) obtained by the Cloud-Aerosol Lidar with Orthogonal
Polarization (CALIOP) level-2 aerosol product has been compared with the AOD from theModerate Resolution Imaging Spectroradiometer (MODIS)-Aqua level-2 product. Suchcomparisons have been performed for five different aerosol subtypes namely, clean marine,
dust, polluted dust, polluted continental, and biomass burning, over the ocean from June 2006
to December 2010. MODIS AOD at 550 nm (0.108 ± 0.081) for the collocated data pairs isabout 61% higher than CALIOP AOD at 532 nm (0.067 ± 0.074). For the clean marine,
MODIS AOD (0.107 ± 0.066) is almost twice the CALIOP AOD (0.056 ± 0.041), and thedifference between the AOD values has a strong latitude dependence likely related to thesurface wind speed over the ocean. The difference in AOD for dust (~12.4%) is observed tobe the lowest among the five aerosols types under consideration, but it shows slight regionalvariation. The discrepancy of AOD for dust also shows strong dependency on the layer meanof the particulate depolarization ratio. The differences of AOD for polluted dust and polluted
continental show similar tendency of higher CALIOP AOD than MODIS AOD for most partof the ocean. One of the possible reasons for the difference is the misclassification of cleanmarine as polluted dust and polluted continental in CALIOP algorithm. In addition, thediscrpency of AOD may suggest that assumptions made in satellite retrievals, such as theassumed lidar ratios (i.e., extinction-to-backscatter ratio) for CALIPSO retrievals, or thesurface reflectance information and/or the aerosol model utilized by MODIS algorithm, are
not appropriate. In the operational CALIPSO data analysis, lidar-derived aerosol opticaldepths are typically estimated using a single lidar ratio for each aerosol. type. Hence, we
computed the lidar ratio at 532 nm using 4-year measurements of elastic backscatter lidar and
SKYNET sky radiometer in Seoul, Korea. The annual mean lidar ratio (with standard
deviation) is found to be 61.7±16.5 sr, and weak seasonal variations are noted with amaximum in summer (68.1±16.8 sr) and a minimum in winter (57.2±17.9 sr). The lidar ratios
for clean, dust, and polluted conditions are estimated to be 45.0±9.5 sr, 51.7±13.7 sr, and62.2±13.2 sr, respectively. While the lidar ratio for the polluted condition is appears to beconsistent with previous studies (50-70), clean and dust conditions tend to have larger values,
compared to previous estimates (clean: 30-40, dust: 40-50). Also, we used the SKYNET and
AERONET retrievals to compute a lidar ratio climatology. Detailed results will be presented.

Aerosol Variations in Urban Atmosphere: Case Studies in Beijing and Dunhuang
Chen Bin
Institute of Atmospheric Physics, Chinese Academy of Sciences, China
chen_bin@mail.iap.ac.cn
Atmospheric aerosols play important roles in climate and atmospheric chemistry:
They scatter sunlight, provide condensation nuclei for cloud droplets, and participate
in heterogeneous chemical reactions. To enable better understanding of the verticalphysical, chemical and optical feathers of the aerosols in East Asia, using some
atmospheric and chemical instruments on board the tethered-balloon system, a seriesof measurements were operated in some typical places of East Asia, incluing
Dunhuang, which is located in the source origin district of Asian dust and Beijing,which is the representative of large inland city in the years of 2007-2011, some ofwhich was compared with the simultaneous Lidar observations. The simultaneous
observations over the districts of China, Japan and Korea by using the tethered
balloon systems are highly expected.
Referances：
Daizhou Zhang, Bin Chen, Maromu Yamada, Hongya Niu, Biao Wang, Yasunobu
Iwasaka and Guangyu Shi, Elevated Soot Layer in Polluted Urban Atmosphere: aCase Study in Beijing. Journal of the Meteorological Society of Japan(SCI), Vol. 90,
No. 3, pp. 361–375, 2012
G. Shi, D. Zhang, B. Wang, B. Chen, M. Yamada, and H. Niu. Elevated aerosol layer
embedded with aged soot particles in a polluted urban atmosphere. Atmos. Chem.
Phys. Discuss., Vol. 11(2011), p1641-1669.
Bin Chen, Fumihisa Kobayashi, Maromu Yamada, Yang-Hoon Kim, Yasunobu
Iwasaka and Guang-Yu Shi, Identification of Culturable Bioaerosols Collected overDryland in Northwest China: Observation using a Tethered Balloon. Asian Journal of
Atmospheric Environment(SCIE), Vol. 5-3, pp.172-180, September 2011
Bin Chen, Guang-Yu Shi, Maromu Yamada, Dai-Zhou Zhang, Masahiko Hayashi andYasunobu Iwasaka Dependence of Visibility on Particle Sizes in Different Boundary
Layers over Beijing. Asian Journal of Atmospheric Environment, Vol. 4-3, pp.141-149,
December 2010
Bin Chen, Maromu Yamada, Guang-Yu Shi, Dai-Zhou Zhang, Atsushi Matsuki andYasunobu Iwasaka Vertical Changes in Mixing State of Aerosol Particles in the
Boundary Layer in Beijing, China: Balloon-borne Measurements in Summer andSpring. Journal of Ecotechnology Research, in press.

Ground-based remote sensing of aerosol seasonal character
over Hefei in East China
Zhenzhu WANG1*, Dong LIU1, Yingjian Wang1, Pradeep KHATRI2, Tamio TAKAMURA2,
Guangyu SHI3
1
Key Laboratory of Atmospheric Composition and Optical Radiation, Anhui Institute of Optics
and Fine Mechanics, Chinese Academy of Sciences, Hefei 20031, China
2Center for Environmental Remote Sensing, Chiba University, Chiba, Japan
3
LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China*

zzwang@aiofm.ac.cn

Atmospheric aerosols have a significant impact on climate due to their imporatant rolein modifying atmosphere energy budget. The ground-based remote sensing
instruments give great opportunity for better understanding of aerosol effects on
climate. We start the long-term monitoring of aerosols by using a prede sky radiometer(POM-02) on SKYNET. The seasonal characters for aerosols are collected over Hefei
Radiation Observatory (HeRO) from Mar. 2007 to Aug. 2012. The result shows thatthe seasonal mean aerosol optical depth (AOD) at 500 nm is 0.80, 1.01, 0.79, and 0.76
in MAM, JJA, SON, and DJF respectively. And the corresponding aerosol angstrom
exponent (AAE) using spectral AOD from 340 nm to 1020 nm is 0.97, 1.24, 1.30, and1.12. The averaged value of single scattering albedo (SSA) at 500 nm for all seasons
is more than 0.95. The averaged asymmetry factor (ASY) at 500 nm is about 0.7
during each season. The frequency distributions of AOD and AAE for each season are
shown, which indicate obvious seasonal variations, especially, on AAE. Due to dust
events through North-West and/or North airflow, the aerosol loading contains much
more lager particles of dust in MAM and DJF than in others. The relationshipbetween AOD and AAE in different time span of day for each season is also
discussed.

No. of Meas.
(days)

ASY(500nm)

SSA(500nm)AAE(340-1020nm)

AOD(500nm)

1

2

3

4

5

6

7

8

9 10 11 12

1.5

1.5

1.0

1.0

0.5

0.5

1.5

1.5

1.2

1.2

0.9

0.9

0.6

0.6

0.99

0.99

0.96

0.96

0.93

0.93

0.90
0.75

0.90
0.75

0.72

0.72

0.69

0.69

0.66
120

0.66

MAM

JJA

MAM

JJA

SON

DJF

ANNUALSON

DJF

ANNUAL

900

90
600

60

300

30
0

0
1

2

3

4

5

6

7

Month

8

9 10 11 12

SeasonFig. Averaged value of AOD, AAE, SSA and ASY monthly and seasonally (left), and relationshipbetween AOD and AAE (right) over HeRO from Mar. 2007 to Aug. 2012

SUN-SKY RADIOMETER STUDY OF MONSOON ACTIVITYOVER PUNE, INDIA

P.C.S. Devara, Sumit Kumar, K. Vijayakumar and G. Pandithurai
Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pune 411008, India

Correspondence to: Panuganti C.S. Devara (devara@tropmet.res.in)

Abstract
Aerosol-cloud-radiation interactions modulate monsoon activity, and related studies could
serve as indicators for possible prediction and assessment of weather and climate on different
spatial and temporal scales through circulation. Besides several thematic campaigns utilizing
a variety of platforms including satellites, ground-based networks have been established to
improve our understanding of the role of aerosols in the changing monsoon climate. Twosuch widely known networks over the globe are ‘SKYNET’ and ‘AERONET’ with Sun-sky
radiometer as the principal equipment that characterizes aerosols and gases over different
geographical locations under varied air mass conditions. Pune (18o43′ N, 73o51′ E, 559 m
above mean sea level), a fast growing urban city in India, is one of the sites where Prede(POM-01L, SKYNET) and Cimel (CE-318, AERONET) Sun-sky radiometers have been in
operation since 2004. These radiometers have been extensively used in several studies related
to stand-alone and coupled aerosol-cloud-climate processes. The Prede instrument at this site
is being augmented to the network of Global Atmospheric Watch (GAW) program of World
Meteorological Organization (WMO) to facilitate data coordination through the World Data
Center for Aerosols (WDCA).
The present study envisages to understand the response of atmospheric constituents, throughsimultaneous operation of the radiometers amongst others, to the rainfall activity over Pune
during two contrasting monsoon years of 2008 (active / normal, 98% of long period average(LPA) rainfall over the whole country) and 2009 (break / drought, 78% of LPA). The
synthesis of data indicates that, apart from excellent agreement between the direct sun

observations, both radiometers capture well the monsoon features within the instrument
density and efficacy of data retrieval algorithms involved. The aerosol products from satellitedata, meteorological fields from NCEP/NCAR re-analysis and NOAA-HYSPLIT air-masstrajectory analysis during the study period have also been utilized. The chief results of thestudy include the following:•

Relatively higher aerosol optical depths (AODs) associated with larger Angstrom
exponents (dominance of smaller particles) during 2009 by both Sun-sky radiometers,
which corroborate lower precipitable water content, higher ground temperature andlower rainfall amount during the period.

•

Relatively greater asymmetry factor (g) and lower single scattering albedo (SSA)
during 2008 and vice-versa during 2009 observed by the Prede radiometer andconverse in the case of Cimel radiometer, which coincide with smaller real andimaginary parts of aerosol refractive index of Prede as compared to those of Cimel
during 2008 and 2009.

•

Similar contribution to the monsoon activity from fine-mode segments of volume size
distribution observed by Prede and Cimel, while significantly larger contribution fromcoarse-mode segment in the case of Prede during both years under study.

•

The association between AOD and Angstrom exponent revealed abundance of desert
dust (about 25 per cent), next to urban industrial aerosols (about 70 per cent), over theexperimental station during drought year (2009) as opposed to the active monsoon
year (2008).

More results of the analysis of data, extending to other monsoon years, from both Prede andAeronet Sun-sky radiometers and in-situ observations will be presented. Such results would
be useful for multi-parameter mapping of aerosols and their role in climate change.

Identification of aerosol types over the Indo-Gangetic Basinusing ground-based sunphotometer measurements

A. K. Srivastava1*, S. N. Tripathi2, S. Tiwari1 and B. N. Holben3

1

Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi,

India
2

Center for Environmental Science and Engineering, Indian Institute of Technology Kanpur,

Kanpur, India
3

NASA Goddard Space Flight Center, Greenlelt, USA*

Correspondence to: A. K. Srivastava (atul@tropmet.res.in)

Abstract
A discrimination of aerosol types over the Indo-Gangetic Basin (IGB) region during premonsoon period was made using multi-year ground-based sunphotometer measurements.
Based on the measured aerosol parameters, five different aerosol types were identified aspolluted dust (PD), polluted continental (PC), mostly black carbon (MBC), mostly organiccarbon (MOC) and non-absorbing (NA) aerosols at the two typical locations over IGB. Studysuggests high dust enriched aerosols (i.e. PD) were contributed more over the central IGB
station at Kanpur (~62%) as compared to the eastern IGB station at Gandhi College (~31%).
However, opposite was observed for polluted continental aerosols at these two stations, whichcontain high anthropogenic and less dust aerosols. Contributions of carbonaceous particles
having high absorbing (MBC) and low absorbing (MOC) aerosols were found to be ~11% and10%, respectively at Gandhi College. This was ~46% and 62% higher than the observed
contributions at Kanpur. However, very less contribution of NA aerosols was observed only
at Gandhi College (2%). Variability in aerosol types together with single scattering albedo(SSA) at both the stations suggests their strong association with emission sources. Results
were well substantiated with the air mass back-trajectories and the fire products. The

estimated absorption Ångström exponent (AAE) values suggest relative dominance ofabsorbing type aerosols over the central part of IGB (due to dominant dust absorption) as
compared to the eastern part during pre-monsoon period.

Optical and chemical properties of atmospheric aerosols at
Phimai in Thailand by surface measurements, CALIOP data,
and the SPRINTARS model

1HaruoTsuruta,Takamura,
Yonemura,
Hashimoto,
Oikawa,2Jinchula

3Pradeep

Khatri,

6Yuichiro
7Daisuke

1Toshiro

Chotpitayasunon,

Shirasuna,

Goto,

Inoue,

4Koichiro

8Toshihiko

1Shugo2Boossarasiri

Sera,

5Shigeto

6Koichiro

Takemura,

Watanabe,

Sudo,

5Seiichiro

Hirano,1Makiko

9Masanori

7Nobuo3TamioThana,

Yabuki,

Sugimoto,

1Eiji

10Tadahiro

Hayasaka, 1Teruyuki Nakajima
1

Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan2

Department of Geology, Chulalongkorn University, Bangkok, Thailand

3

Center for Environmental Remote Sensing (CEReS), Chiba University, Chiba, Japan

4

Cyclotron Center, Iwate medical University, Morioka, Japan

5

National Institute for Agro-Environmental Sciences, Tsukuba, Japan

6

Environmental Research Institute of Yokohama City, Yokohama, Japan

7

National Institute for Environmental Studies, Tsukuba, Japan

8

Research Institute for Applied Mechanics, Kyushu University, Fukuoka, Japan

9

Research Institute for Sustainable Humanosphere, Kyoto University, Japan

10

Center for Atmospheric and Oceanic Studies, Tohoku University, Sendai, Japan

Correspondence to: Haruo Tsuruta (haru2004@aori.u-tokyo.ac.jp)

Abstract
Atmospheric aerosols were measured at the Observatory of Atmospheric Research, in Phimai,
Thailand, a station of SKYNET, during 2006-2008. The mass concentrations and major
chemical components in fine and coarse aerosols were analyzed, and the optical properties

such as AOT and SSA were calculated from the data measured by skyradiometer. Surface
wind data typically showed a wet season (from May to September), and a dry season (fromOctober to April) which is divided into early (October-November), middle (December-early
March), and latter (middle March-April) periods. In this paper, the following topics are
summarized;
1. Chemical characterization: For PM2.5 aerosols in the dry season, the air pollutants emitted
by fossil fuel combustion was dominant in the early season, which was transported from east
Asia. In contrast, in the latter period, the aerosols emitted by biomass burning in Indochina
Peninsular were predominant. The middle period showed a mixture state between the earlyand latter periods. The concentration ratio of EC/nss-SO 4 showed a large difference between
the early and latter periods, and which was consistent with the result simulated by the
SPRINTARS model.
2. Optical properties: AOT in the field study showed a clear seasonal variation, and was muchhigher in the dry season than in the wet season. The AOT in the dry season could be positively
correlated with the mass concentration of PM2.5 near the surface. And SSA was comparedwith that independently calculated with a shell-core model using the measured chemicalcomposition.
3. Comparison between the SPRINTARS model and the field measurements: The seasonalvariation in the concentration of elemental and organic carbons, ammonium sulfate, sea-salt
particles and dust particles, calculated by the SPRINTARS model generally showed a good
agreement with the field measurements. The dust concentration in the dry season, however,was much lower in the model than in the measurements, and which may be attributed to the
local dust particles which lifted up by thermal plumes generated from biomass burning.
4. Long range transport of dust aerosols in the wet season: Trace elements such as Si and Ti
which are good indicators of dust aerosols showed high concentrations during 17-20 June2008 even in the wet season, comparable with those in the dry season. CALIOP data and theresult of the SPRINTARS model showed a large amount of dust aerosols over Indian Ocean
up to the height of 5km, and backward trajectory analysis by using the NOAA HYSPLIT
model showed a long range transport of polluted air massess rich in dust aerosols from thedesert areas in west Asia/east coast of North Africa.

Sky-radiometer measurements for monitoring the aerosol
optical properties in the Arctic and Antarctica

1

Masataka Shiobara, 2Masanori Yabuki, 3Hiroshi Kobayashi,

4

Makoto Kuji,

5

Kazuma Aoki, 6Maki Yamano, and 7Yoshitaka Muraji

1

National Institute of Polar Research, Tachikawa, Japan

2

Kyoto University, Uji, Japan

3

University of Yamanashi, Kofu, Japan

4

Nara Women’s University, Nara, Japan

5

Universty of Toyama, Toyama, Japan

6

Miyazaki, Japan

7

ESCoT, Tokyo, Japan

Correspondence to: Masataka Shiobara (shio@nipr.ac.jp)

Abstract
Atmospheric aerosol has a potential to change the global climate by direct and indirect effects
on radiation balance in the planetary atmosphere. The direct effect is generally expected to besmall in the polar regions, but the indirect effect may cause a large difference of cloudproperties between the Arctic and Antarctic regions. National Institute of Polar Research(NIPR) promotes the atmospheric research in both polar regions, and employs remote-sensing
instruments for aerosol and cloud studies. For investigating the aerosol optical properties, skyradiometry based on a radiation inversion algorithm is powerful to retrieve the columnaveraged aerosol volume size distribution, single scattering albedo and complex refractive
index as well as aerosol optical thickness and Angstrom exponent. In order for long-termmonitoring of the aerosol properties, NIPR operates Prede POM-02 sky-radiometers at bothpolar sites, i.e., Ny-Alesund Station (78.9N, 11.9E) in the Arctic and Syowa Station (69.0S,
39.6E) in Antarctica. And further we recently developed a new sky-radiometer POM-01 MK

III for ship-based measurements. In this paper, we will present a summary of the project andresults from surface-based measurements in the polar regions and also those from ship-based
measurements during the Antarctic cruises by the Icebreaking R/V Shirase for the Japanese
Antarctic Research Expedition activities.

One year of measurements with a POM02 sun-sky
radiometer at an Alpine Euroskyrad station

1Henri Diémoz, 2Monica Campanelli, 1Tiziana Magri
1

ARPA Valle d'Aosta, Loc. Grande Charrière 44, 11020 Saint-Christophe, Italy

2

ISAC-CNR, via Fosso del Cavaliere 100, 00133 Roma, Italy

Correspondence to: Henri Diémoz (h.diemoz@arpa.vda.it)

Abstract
A new PREDE POM02 sun-sky radiometer was installed in Aosta (7.3570E, 45.7422N, 570
m a.s.l.), northern Italy, in May 2012. The site is located in an Alpine valley, in a semi-ruralcontext, just out-of-town and partially influenced by anthropogenic activity both on local(emissions from vehicles, heating systems, steel mill) and regional (advection from the Po
Valley) scales. Local meteorological phenomena such as thermal inversions, mountain-valley
breezes and Föhn winds strongly condition the aerosol load at the measurement site.
The instrument, managed by the Environmental Protection Agency (ARPA) of the Aosta
Valley, is used as ancillary instrumentation in the framework of the research at the solar
observatory and as a fundamental data source for radiative transfer modeling. Furthermore, it
represents an original link between solar and air quality monitoring programs. Indeed,measuring the aerosol optical properties may help in identifying possible sources ofparticulate matter and in characterizing it.
The site has joined the EuroSkyRad network (www.euroskyrad.net) and both Skyrad 4.2 andESR.pack inversion products are daily available. Retrievals from Skyrad 4.2 are obtained byusing both direct and diffuse radiation measurements, mirroring the Skynet inversions(atmos.cr.chiba-u.ac.jp). The products (aerosol optical thickness, Angstrom exponent, single
scattering albedo, refractive index and volume size distribution) are presently provided at
Level L0 and Level L1.1, since the cloud screening by means of measurements ofpyranometer/pyrgeometer instruments needed in order to provide Level 1.2 data can not beperformed, yet. Retrievals from ESR.pack are obtained by using only direct measurements(Sunrad module) and cloud screening is performed according to Estelles et al. (2012).
The inversion of direct-only measurements resulted very important in the Aosta site. Indeed,
two typical effects of the Alpine region prevent the inversion of almucantar scans, strongly
reducing (>50%) the number of measurement days: the recurring presence of scattered clouds
due to the complex orography and the mountain obstruction for solar zenith angles larger than70°.
First results from one year of measurements (processed by both Skyrad4.2 and ESR/Sunrad)
will be presented. Correlations with in-situ measurements of fine particulate matter (PM),wind direction and speed and long-range trajectories will be shown based on several casestudies. Finally, AOD measurements by our POM02 and a colocated Brewer
spectrophotometer will be compared in the UV and visible range.

V. Estelles, M. Campanelli, T. J. Smyth, M. P. Utrillas, and J. A. Martınez-Lozano,
AERONET and ESR sun direct products comparison performed on Cimel CE318 and PredeContinuous ground-based observation of aerosol opticalproperties in Tsukuba, Japan

1
1

Akihiro Uchiyama, 1Akihiro Yamazaki, 1Rei Kudo, and 1Daisaku Uesawa

Japan Meteorological Agency, Meteorological Research Institute, Tsukuba, Japan

Correspondence to: Akihiro Uchiyama (uchiyama@mri-jma.go.jp)

Abstract
In order to investigate optical properties of aerosol, scattering coefficients and absorption
coefficients have been continuously measured since January, 2002 using integrating
nephelometer (TSI model 3563) and absorption photometer (Radiance Research PSAP,
PSAP3λ) on dry condition at Tsukuba, Japan. Using these data, the recent 10 years trend ofaerosol properties and climatology was investigated.
The results show that the aerosol characteristics have seasonal variation and the tendencies
to decrease or increase. These tendencies were significant in the confidence level 95%. The
extinction, scattering, and absorption coefficients (1/m) had trends to decrease in the period
from 2002 to 2012; -6.05x10-6, -4.94x10-6(1/year) at wavelength of 550nm and -1.11x106(1/year) at wavelength 526nm, respectively. The Single scattering albedo has the trends toincrease in the same period; 4.27x10-3(1/year) at wavelength of 550nm. Asymmetry factors
have the trends to decrease in the same period; -2.22 x10-3(1/year) at wavelength 550nm. The
extinction Ångström exponent has the tendency to increase, and the effective radius has thetendency to decrease. These tendencies are consistent with the tendency of asymmetry factor.
The values of absorption Ångström exponent were about 1.0 and have seasonal variation.
The absorption Ångström exponent had the trend to increase in the period from 2006 to 2012;
1.15x10-2(1/year). The change of absorption Ångström exponent suggests the change in thecomposition of light absorbing aerosol.

Characterization of atmospheric phenomena with
SKYNET aerosol properties at Fukue-jima andAmami-Oshima islands
1

Shiho Kitakoga, 1Ayano Ota, and 2Makoto Kuji

1

Graduate School of Humanities and Sciences, Nara Women's University, Nara, Japan

2

Division of Natural Sciences, Faculty, Nara Women's University, Nara, Japan

Correspondence to: Shiho Kitakoga (kitakoga-shiho0814@ics.nara-wu.ac.jp)

Abstract
Recently, it is apprehended that aerosols emitted from factories, vehicles andslash-and-burn farming influence environment in East Asia. Atmospheric phenomena
such as haze, mist and yellow sand, accompanied with aerosols, have been observed byeye at meteorological observatories and reported operationally for a long time because
they usually cause severe visual hindrance. Many studies pointed out that yellow sandphenomena contained not only dust but also air pollution materials such as sulphate
particles from megacities in East Asia. Accordingly, it is important to characterize theatmospheric phenomena quantitatively with mechanical or optical observation. In thisstudy, characteristics of the aerosol with the atmospheric phenomena were investigatedwith sky radiometer observation at Fukue-jima island, Nagasaki (32.75°N, 128.68°E)
and Amami-Oshima island, Kagoshima (28.44°N, 129.70°E) from 2003 to
2004.Statistical analyses were carried out with the retrieved aerosol optical properties in
9:00, 12:00, 15:00 (Japan Standard Time; JST=UTC+9) when meteorological data wereavailable. Further, clear sky data with cloud amount less than unity were selected tosuppress cloud contamination.As a result of the statistical analyses, it turned out that the
average ± standard deviation for aerosol optical depth τ, Ångström exponent α, andsingle scattering albedo ω were 0.56 ± 0.19 (0.48), 1.26 ± 0.09 (0.69), and 0.97 ± 0.02

(0.99) for four haze events (for a yellow sand event), respectively. Comparing theresults, it is suggested that haze consisted of smaller particles from the Ångström
exponent α, while light-absorptivity is stronger with the haze events than the yellow
sand one, even with fewer events around western islands in Japan from 2003 to 2004.
Additional results of the synergetic data analyses with Optical Particle Counter (OPC)and LIDAR, and so on, will be carried out and discussed in terms of the aerosol
characteristics in detail.
Acknowledgment: The authors are grateful for a lot of useful comments to Prof.
Tadahiro Hayasaka in Tohoku University, Dr. Kazuma Aoki in Toyama University,
Prof. Tamio Takamura and Dr. Pradeep Khatri in Chiba University, Dr. Akihiro
Uchiyama in Meteorological Research Institute / Japan Meteorological Agency, Dr.
Nobuo Sugimoto and Dr. Atsushi Shimizu in National Institute for Environmental
Studies, and Ms. Yoshimi Azuma in Nara Women's University. The aerosol opticalproperties and meteorological data were kindly provided by SKYNET project and Japan
Meteorological Agency, respectively.

Optical and in-situ measurements of aerosol, nitrogendioxide, and water vapor in relation to weather and sky
radiation conditions in Chiba

1Hayato Saito, 1Yusaku Mabuchi, 1Hiroaki Iwanade, 1Naohiro Manago,
1Hitoshi Irie, 2Ippei Harada, 1Hiroaki Kuze
1

Center for Environmental Remote Sensing, Chiba University

2

Tokyo University of Information Sciences

Correspondence to: Hayato Saito (haya_saito@graduate.chiba-u.jp)

Abstract
Aerosols and trace gases affect air quality in large cities. Theri monitoring is important also
from the viewpoint of radiation budget studies. Although ground-based, in-situ samplingmeasurenment can provide local data on air pollutants, such data do not always represent theactual condition in a wider region. In this paper we report our recent results of differential
optical absorption spectroscopy (DOAS) measurement conducted at Chiba University. Bothnitrogen dioxide (NO 2 ) and aerosol can be continuously measured along an optical path ofseveral kilometers using a xenon flashlight as a light source. The results are compared withthe data from government-operated sampling stations located nearby. Also, aerosol
characterization data taken with a three-wavelength nephelometer and optical particle counterare compared with the DOAS data to study if the sampling process in such instruments
influences the aerosol quality in relation to the humidity difference between the atmosphericand laboratory conditions. In addition, data from a weather monitor, a multi-wavelength lidar
system, a sunphotometer, and imaging measurements of the solar irradiance and sky radianceare exploited for the interpretation of the air quality data obtained from DOAS and related
schemes.

A study of vertical profiles of aerosol radiative parameters andaerosol direct effects over the East China Sea region using a
combination of aircraft and ground based observation data

1Pradeep Khatri, 1Tamio Takamura, 2Yutaka Kondo, 2Makoto Koike,2Nobuhiro Moteki, 3Atsushi Shimizu, and 3 Nobuo Sugimoto

1

Center for Environmental Remote Sensing, Chiba University, Chiba, Japan2

Department of Earth and Planetary Science, The University of Tokyo, Tokyo, Japan

3

National Institute for Environmental Studies, Tsukuba, Japan

Correspondence to: Pradeep Khatri (pradeep@restaff.chiba-u.jp)

Abstract
We studied the vertical profiles of aerosol radiative parameters and aerosol direct effects over
the China Sea region in the spring season using a combination of aircraft and ground based
observation data. A method was developed to retrieve the vertical profiles of aerosol radiative
parameters by fully utilizing the precious data collected by aircraft and a wide range ofground based instruments. Thus retrieved vertical profiles of aerosol radiative parameters
were then used to study the vertical profiles of aerosol direct effects. Our results suggest that
dust aerosols may prevail in the free troposphere of the East China Sea region in the spring
season, though there appears no dust event near the surface and aerosols are not optically very
thick. With the increase of dust aerosol volume fraction, we observed the increase in lightabsorption capacity of aerosol mixture, which indicates the important implication of Asian
dust on aerosol climatology. The study shows that not only aerosols near the surface, but also
aerosols above the boundary layer can play important roles on aerosol direct effects in thisregion in the spring season. The study also discusses the necessity of taking into account thevertical profiles of aerosol radiative parameters while estimating aerosol direct effects.

Investigate the single scattering albedo of dust aerosols and theirimpact on climate in Northwest China
1

1

2

1

1

Jianrong Bi , Jianping Huang , Tamio Takamura2, Kahatri Pradeep , Jinsen Shi , Yongkun Xie ,1

1

Zhiyuan Hu and Yuzhi Liu
1

Key Laboratory for Semi-Arid Climate Change of the Ministry of Education andCollege of Atmospheric Sciences, Lanzhou University, Lanzhou, 730000, PRC
2
Center for Environmental Remote Sensing (CEReS), Chiba University, 1-33
Yayoi-cho, Inage-ku, Chiba 263-8522, JAPAN
Correspondence to: Jianrong Bi (bijr @lzu.edu.cn)

Abstract
Arid and semi-arid areas comprise about 30% of the earth surface. Changes inclimate and climate variability will likely have a significant impact on these regions.
Gobi and desert region over Northwest China is one of major dust aerosol sources in
East Asia. To improve our understanding of the impact of dust aerosol on climate, anintensive field experiment has been conducted by Semi-Arid Climate & Environment
Observatory of Lanzhou University (SACOL) in Dunhuang (40.49°N/94.95°E,
1061m ASL) over Northwestern China from April 1th to June 30th, 2012. There are
two sites deployed in Dunhuang: SACOL’s mobile facility (SMF) is set up nearby the
farmland (located in the Gobi Desert), and a set of spectra and broadband radiometers
are installed at the top of a three-floor building (about 10 meter above the ground and
1 km away from the SMF). A suite of active and passive ground-based remote sensing
instruments are deployed in the field campaign, such as Micro-Pulse Lidar (MPL),
Cimel sun photometer (CE318), Prede sky radiometer (POM-01), grating
spectroradiometer (MS-700) and Multi-Filter Rotating Shadowband Radiometer(MFRSR). We can retrieve aerosol optical depth, Ångström exponent, volume size
distribution, single scattering albedo, and asymmetry factor from these ground-basedmeasurements. Furthermore, aerosol optical properties can be inter-compared andvalidated for each other. Surface radiation quantities estimated from SBDART
radiative transfer model can be compared with a dozen of the state-of-the-art
ground-based radiometers’ observations. The dust aerosol radiative forcing andheating rate in Gobi desert over Northwest China are estimated using the Fu-Liouradiative transfer model. This campaign is vital to understand the characteristics andvariations of dust aerosols in East Asian so that we can evaluate more accurately theeffect of mineral dust aerosols on global and regional climate change in the future.
Keywords: Dust aerosols, aerosol optical properties, regional climate effect, field
campaign

Acknowledgements. This work was jointly supported by the National Basic Research
Program of China (2012CB955302) and Fundamental Research Funds for the Central
Universities lzujbky-2013-207. We are grateful to Prof. Nakajiama for supplying
SKYRAD software. We are also greatly appreciated the big help and support of Prof.
Guangyu Shi (IAP, China).

Cirrus clouds measurement by a three-wavelength lidar
over Hefei in China
1Dong Liu, 1Yingjian Wang, 1Zongming Tao, 1Zhenzhu Wang, 1Dechen Wu

and 1Jun Zhou
1

Key Laboratory of Atmospheric Composition and Optical Radiation, Anhui Instituteof Optics and Fine Mechanics, Chinese Academy of Sciences
Correspondence to: Dong Liu (dliu@aiofm.ac.cn)

Abstract
Cirrus clouds play an important role in Earth-atmosphere radiation budget throughabsorbing long-wavelength outgoing radiation from the earth and scattering
short-wavelength incoming solar radiation which determined by their optical property.
The optical parameters such as scattering and extinction of the cirrus clouds are
related to their microphysical properties such as the complex refractive index, shape,and size distribution. A three-wavelength lidar is built in Hefei in China to study the
optical and microphysical properties of the cirrus clouds which is a bistatic lidar
system transmitting three laser beams at 355nm, 532nm and 1064nm wavelength
simultaneously with a receiving Cassegrainian 14-inch telescope in diameter.
For optical thin cirrus clouds, a transmittance method (Young 1995) combined by the
Fernald (1984) backward interactive method is used to retrieve the optical depth andthe backscatter coefficient of the cirrus clouds. Fig. 1(a) shows the attenuatedbackscatter of the measured cirrus clouds at three wavelengths, demonstrating that thecirrus cloud altitude is approximately 13 km with a physical depth of about 1.5 km.
Using the previously introduced methods, three backscatter color ratios(β 1064 / β 532 ; β 532 / β 355 ; β 1064 / β 355 ) are given in Fig. 1(b), and the retrieved opticaldepth and the lidar ratio are summarized in Table 1.
a)b)

Fig 1 Attenuated backscatter(a) and backscatter color ratio(a) profiles

Table 1 retrieved parameters of the measured cirrus clouds

For the optical thick cirrus clouds, attenuated backscatter color ratio is good toapproximate the backscatter color ratio. From January to October in 2011, we selected
the cirrus lidar data of 51 days to analysis the statistic pattern of the three different
wavelength pairs as showing in Fig. 2. We found that these three pairs of color ratios
almost in normal distribution mode with different peak locations, i.e. color ratio of thepeak value of β 1064 / β 532 , β 532 / β 355 and β 1064 / β 355  is 0.9, 0.7 and 0.6.

Fig 2 the statistic of the color ratio of the three different wavelength pairs
Assuming the Г distrbution of the cirrus particle size, the ray tracing method (Yong2000, 2005) is used to calculate the optical parameters of the six difference shapes(aggregate, bullet rosette, dendrite, solid column, hollow column and plate) of thecirrus clouds. From the relation between the color ratio and the mean effective radius
as shown in Fig. 3, one can tell that the measured cirrus clouds over Hefei in thisperiod most likely in the aggregate shape with the mean effective radius greater than
20 um.

Fig 3 the relation between cirrus backscatter color ratios of aggregate shape and themean effective radiusSurface aerosol radiative forcing at the Observatory for
Atmospheric Research, Thailand during 2009-2011
1

Boossarasiri Thana, 2Thawatchai Sudjai, 3Puttinun Sukumolchan and1

Sathon Vijarnwannaluk

1

Faculty of Science, Chulalongkorn University

2

Mahidol Wittayanusorn School3

Bureau of Royal Rainmaking and Agricultural Aviation (BRRAA)

Correspondence to: Boossarasiri Thana (boossarasiri.t@chula.ac.th)

ABSTRACT
Surface radiation measurements were made at Phimai Observatory for Atmospheric Research,
Thailand between 2009 and 2011 aimed to assess the impact of aerosols on the climate. The
study area is located in agricultural activities surround the observatory. There are cassava fieldaround there. The remaining crop during/after harvesting are burnt then more aerosols werereleased through the atmosphere.

Downwelling total, direct, and diffuse radiative fluxes were

measured. Aerosol optical depth measurements at 500 nm were also made by using askyradiometer. Surface radiative forcing values were determined during 14 days of clear-sky
conditions in the period of study. The maximum of aerosol optical depth was in summer in therange between 0.772  0.368 and followed by winter (0.255  0.151) and rainy season (0.255 
0.151) in respectively. Single scattering albedo in 500 nm average was 0.946  0.037. It impliedthat aerosol in the study area has optical properties as non-absorbing aerosol. From the 14 days
clear sky condition, the diurnal forcing efficiency, determined by taking the slope of the best
linear fit through the flux versus optical depth plot, was found to be -32.590  9.264 watts per
square meter in November 2010 and , -33.429  11.368 watts per square meter in December
2010.

CLIMATE CHANGE TRENDS AND DESERTIFICATION IN MONGOLIA
N.Tugjsuren and J.Batbayar
E-mail: tugjsurn@must.edu.mn, btbayar@yahoo.com
Abstract
World climate change and global warming became one of the causes to have low precipitation in Mongolia.
As a result, the intensive desertification were causing damages to our economy and society, as well as environment.
The main factors affecting land degradation and desertification of land are reduction of precipitation due to theclimate change, increase in transpiration, reduction of water supply, thus leading to poor vegetation. The focus of
this study is: to analyze present and future tendency of degradation and desertification of the drylands of Mongolia.
The results of continuous study on Mongolia’s climate reveal that on a average the air temperature on surface from1940 to 2012 has become warmer by 2.10C throughout the whole territory; by 1.9-2.30C in the mountainous regions;and 1.60-1.70C in Gobi and steppe regions. The warmer climate was observed in all seasons; however, the colder
seasons of the year had temperature increases of 3.60C, spring and fall seasons had temperature increases of 1.801.90C. In summer season, the temperature increase was 1.10C. Rapid increases in the air temperature in warmer
seasons and no significant increases in the level of precipitation are the main reasons for desertification in Mongolia.
Even tough, through the history, Mongolian agricultural activities such as animal husbandry and arable
land development have adapted continuously to the risks associated with climate variability, the climate change
requires the government efforts to increase the diversity of crops and innovate the technologies. Due to geographicalshift in the agricultural land base, pasture availability and land development could be changed, and some farmers
may benefit locally improved yields while others might suffer from high investment to adjust farming to climatechange. The climate change may raise the competition for water in water limited region which may affect thewelfare of people. There are still many uncertainness in direct and indirect effects of climate change on natural
resource base and agriculture components, in evaluation and development adaptation options, and in adaptation
technologies.

Cloud Radiative Effect on the Earth's Surface

1Kyohei Yamada, 1Tadahiro Hayasaka, and 1Hironobu Iwabuchi
1

Center for Atmospheric and Oceanic Studies, Tohoku University, Sendai, Japan

Correspondence to: Kyohei Yamada (yamada@caos-a.geophys.tohoku.ac.jp)

Abstract
Cloud has strong influence on radiation budget at the surface. For shortwave radiation, cloudreflects downward shortwave radiation (DSR) and shows cooling effect on surface
atmosphere. On the other hand, cloud absorbs upward longwave radiation and emits
downward longwave radiation (DLR). The absorption and emission make surface atmospherewarm up. The cooling and warming effects offset each other. Warming effect is strong in the
low latitude because of frequent appearance of high cloud. Conversely, low cloud causes
cooling effect stronger than warming effect, especially in the high latitude (Slingo and Slingo,
1988). On the global average, the cooling effect is greater than the warming effect. However,
our understanding of the cloud effect on surface radiation budget is limited because cloud
microphysics, cloud amount, and cloud position are sensitive to the local climate condition.
In the present study, we quantify cloud radiative effect (CRE) both on DSR and DLR. CRE is
defined with the subtraction of the calculated value assumed clear-sky from the observed
value under all-sky condition. To calculate radiation at the surface, we use mstrnX (Sekiguchi
and Nakajima, 2008), which is two-stream one-dimensional radiative transfer calculation
model considering vertical profiles of temperature and humidity obtained with radiosonde
observation. Observation sites are eight stations of Baseline Surface Radiation Network(BSRN; Ohmura et al. 1998) from the subtropics to polar regions. Observation period is from1994 to 2012 and each station has at least 1 year data. Calculated value is compensated withthe subtraction of the average under clear-sky condition.
Cloud cover (CC) is one of the factors which affect on CRE both on shortwave and longwave.
For longwave radiation, the average of CRE increased with the increment of CC, but the CRE

varies largely with climate condition. The effect of CC on DSR is more complex than DLR
because the cloud position is important for reflection of sunlight. Therefore, in order toestimate CRE on shortwave radiation, we evaluated the cloud position using sunshine
duration.
CRE on DSR normally takes negative value because cloud reflects incoming solar radiation.
However, CRE on DSR sometimes took positive value because of three-dimensional effects.
If cloud does not obstruct direct shortwave radiation, sunlight reflected at the cloud side andglobal solar radiation becomes strong. The three-dimensional effects were getting more
intense and occurred more frequently with increase of CC, but positive value was almost
never under complete cloudy condition without instrumental error.
For DLR, cloud base height (CBH) and cloud base temperature (CBT) are important factors
because thick cloud can be assumed to be block body and emits longwave radiation fromcloud base. However, the variation in CBT was small when CC is less than half of 8 oktas.
Height of cloud is not directly important, but albedo of water cloud is generally larger thanground albedo without ice surface.
Atmosphere is transparent but opaque for longwave radiation. Water vapor is one of theimportant absorbers. CRE on longwave increased with increase of precipitable water amount(PW) under dry condition, such that PW is less than 10 mm. In areas where PW is 10-40 mm,
CRE weakened with increasing PW. Under wet condition, which PW is larger 40 mm, CRE
was almost invariable. In comparison with CRE of A-train product by Stephens et al. (2012),
the present study showed large negative value under very dry condition and very small value
at the region with small PW around 10 mm. The former discrepancy was caused by strong
temperature inversion near the surface at polar regions, and the latter was caused by small
amount of CC which satellite missed. These discrepancies showed the importance of the local
and small climate condition which is too small for satellite resolution for CRE.

The research on global anthropogenic heat release
1,2

Chen Bing

1

2

Shi Guangyu

2Dong Li

Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing

100094
2

The State Key Laboratory of Numerical Modeling for Atmospheric Sciences andGeophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese
Academy of Sciences, Beijing 100029

Correspondence to: Chen Bing (chenbing@mail.iap.ac.cn)

Abstract
Anthropogenic heat is important in the research for climate change caused by humanactivities. The NOAA DMSP/OLS satellite data is used to estimate the distribution of
global anthropogenic heat release from 1992 to 2009. Additionally, the distribution of
global anthropogenic heat release in the future will be discussed. The climate effectby anthropogenic heat in global climate model GAMIL will be discussed. The results
show that global anthropogenic heat will affect global climate despite only in regional
climate.