北京师范大学全球变化与地球系统科学研究院

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全球变化与地球系统研究院2013年学术报告

The 4th GCESS Open Seminar of 2013

全球变化与地球系统科学研究院2013年第四次学术报告会将于5月31日（星期五）举行，会上将由我院李占清教授的团队讲述最新研究成果与进展，欢迎各位老师、同学莅临指导。

To enhance the academic exchange among GCESS, the second open GCESS seminar of 2013 will kick off on May 31th (Friday). Please join us and share the new achievements and challenges from Prof. Li group.

时间：5月31日（星期五）上午09:30-11:30

Time: 09:30-11:30 AM, May 31(Friday), 2013

地点：北京师范大学教八楼108

Venue: 108 room of Jiao 8 Buildling, BNU

报告人：翁富忠、赵传峰

Speaker: Fuzhong Weng ; Chuanfeng Zhao

Fuzhong Weng, chief of Satellite Meteorology and Climatology Division of NOAA/NESDIS/Center for Satellite Applications and Research, adjunct dean of the College of Remote Sensing at the Nanjing University of Information Science and Technology. He is the Sensor Science Chair of US Joint Polar Satellite System (JPSS) program. His research areas include satellite instrument calibration, microwave remote sensing, radiative transfer theory and satellite data assimilation. He was the first winner of the 2000 NOAA David Johnson Award for his outstanding contributions to satellite microwave remote sensing fields and the utilization of satellite data in the NWP models. He also received 2002 SPIE Scientific Achievement Award for Excellence in Developing Operational Satellite Microwave Products and Algorithms. He was awarded in 2004 by US Dept of Commerce with Bronze Medal, winner of Department of Commerce Gold Medal Award in 2005 for his achievement in satellite data assimilation and also received the NOAA bronze medal for leading successful NOAA-18 instrument calibration. He has published over 110 papers in the international peer-reviewed journals. He is associate editor of the J. Geophy. Res – Atmos.

Dr. Chuanfeng Zhao is a professor at College of Global Change and Earth Science, working within the group of Dr. Zhanqing Li. Dr. Zhao got his BS and MS degrees from Peking University in 1999 and 2002, respectively; received his PhD degree in 2007 from University of Utah under the direction of Dr. Timothy Garrett. After graduations, Dr. Zhao works in DOE Lawrence Berkeley and Lawrence Livermore National Labs, with studies focusing on the clouds, aerosols, and greenhouse gases (GHGs). Dr. Zhao’s research interests are focused on the cloud-aerosol-precipitation properties, interactions, and their climate impacts, including both observational and model studies. Particularly, Dr. Zhao has earned good reputation in the study of cloud and precipitation retrievals, uncertainty quantification of cloud retrievals, interactions between clouds and aerosols, and the inverse of greenhouse gases. Most of Dr. Zhao’s studies involves the observations from DOE Atmospheric Radiation Measurement (ARM) program. Dr. Zhao has published 13 papers in top journals like Nature, JGR, GRL, Tellus B, and J. Climate.

Topic:

− 翁富忠：利用业务卫星建立高质量的气候资料数据集

Fuzhong Weng：Building A High Quality of Climate Data Records from Operational Satellites

Abstract: Current long-term climate data records are based mainly on the observations of the operational satellite systems. These satellites are designed primarily to provide measurements for short-term weather and environmental prediction. Instrument calibrations lack traceability to International Standards (SI) units, sensors and onboard calibration sources degrade in orbit, long term data sets must be stitched together from a series of overlapping satellite observations, orbital drift—leading to a changing time of satellite observing time during the satellite’s lifetime—introduces artifacts into long term time series, and, most importantly, insufficient attention is paid to pre- and post-launch instrument characterization and calibration. This study presents a series of efforts conducted in our research lab to reduce inter-satellite instrument measurement biases and bias uncertainties to help meet climate monitoring and NWP requirements. In the past decades, we have developed advanced algorithms for cross-calibration of microwave and infrared measurements to their respective reference instruments. Microwave sounding instruments from MSU, AMSU and ATMS are spatially re-sampled prior to simultaneous nadir overpassing (SNO) collocations. The resulted climate data records after cross calibration display continuity and reasonable trends. For the infrared instruments, hyperspectral sensors on the polar-orbiting satellites are used to calibrate broad imagers on board geostationary and polar satellites. CrIS and IASI are spectrally well calibrated and are now being used as the reference instruments. With well-calibrated hypespectral infrared sounding measurements from satellites, the in-situ and airborne observations can be integrated for improving the global greenhouse gas (GHG) monitoring and trending.

− 赵传峰：极地地区云和降水物理特性的地基遥感观测和应用研究

Chuanfeng Zhao：Ground-based cloud and precipitation properties and their application in the Arctic

Abstract: Representation of clouds in climate models remains one of the largest uncertainties for future climate prediction. Accurate cloud properties and better understanding of cloud processes (particularly cloud-aerosol interactions) are highly demanded. This talk first shows the ground-based remote sensing observations of thin stratus cloud properties and precipitation properties, then shows the implications of these properties in studies of cloud-aerosol interaction and their climate impacts. All results shown here are based on observational studies in the Arctic, which has more rapid climate change than global. The cloud retrieval algorithm is mainly based on the infrared spectral radiation measurements; and the precipitation retrieval algorithm is mainly based on millimeter cloud radar measurements. The talk also shows that haze mode aerosols in the Arctic can increase cloud droplet number concentration and decrease cloud droplet effective radius clearly with aerosol first indirect effect values of 0.11-0.19, which is slightly larger than those at midlatitude SGP site. Based on 4 years observations, our study also shows that the seasonal variation of Arctic aerosol pollution is strongly affected by precipitation scavenging effect, and shows an Arctic warming associated with the aerosol-cloud interactions, particularly during the dark winter and spring period.