Welcome to AEROCENTER
Aerosol research is one of the nine cross-cutting themes of the Earth Sciences Division at NASA's Goddard Space Flight Center. AeroCenter is an interdisciplinary union of researchers at NASA Goddard and other organizations in the Washington DC metropolitan area (including NOAA, University of Maryland, and other insititutions) who are interested in many facets of atmospheric aerosols. Interests include aerosol effects on radiative transfer, clouds and precipitation, climate, the biosphere, and atmospheric chemistry the aerosol role in air quality and human health; and the atmospheric correction of aerosol blurring of satellite imagery of the ground. Our regular activities include strong collaborations among aerosol community, informal weekly AeroCenter Forum (seminars, discussions, posters, and paper reviews) and annual aerosol research update.
AeroCenter 2016 seminar series
We are looking for speakers for the AeroCenter 2016 seminar series. If you are interested in showing your research (completed or in progress) please contact one of the AeroCenter committee members:
We are pleased to announce that the ‘Deep Blue’ aerosol project now has its own website: http://deepblue.gsfc.nasa.gov/
The site is intended to act as a single resource for the various current and forthcoming Deep Blue satellite aerosol data products (e.g. SeaWiFS, MODIS, VIIRS). It includes information and links related to the data products, such as file formats, publications, and data access locations, as well as some background information on aerosols and aerosol remote sensing for the non-specialist. There is also an RSS feed, to which you can subscribe for updates relating to the project, such as new publications or data versions. The page was put together with the support of three interns from NASA’s high school internship program.
Please feel free to get in touch with Andy Sayer if you have any comments or questions about the website, or Deep Blue in general.
Levy, R. C., Munchak, L. A., Mattoo, S., Patadia, F., Remer, L. A., and Holz, R. E.: Towards a long-term global aerosol optical depth record: applying a consistent aerosol retrieval algorithm to MODIS and VIIRS-observed reflectance, Atmos. Meas. Tech., 8, 4083-4110, doi:10.5194/amt-8-4083-2015, 2015.
To answer fundamental questions about aerosols in our changing climate, we must quantify both the current state of aerosols and how they are changing. Although NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) sensors have provided quantitative information about global aerosol optical depth (AOD) for more than a decade, this period is still too short to create an aerosol climate data record (CDR). The Visible Infrared Imaging Radiometer Suite (VIIRS) was launched on the Suomi-NPP satellite in late 2011, with additional copies planned for future satellites. Can the MODIS aerosol data record be continued with VIIRS to create a consistent CDR? When compared to ground-based AERONET data, the VIIRS Environmental Data Record (V_EDR) has similar validation statistics as the MODIS Collection 6 (M_C6) product. However, the V_EDR and M_C6 are offset in regards to global AOD magnitudes, and tend to provide different maps of 0.55 μm AOD and 0.55/0.86 μm-based Ångström Exponent (AE). One reason is that the retrieval algorithms are different. Using the Intermediate File Format (IFF) for both MODIS and VIIRS data, we have tested whether we can apply a single MODIS-like (ML) dark-target algorithm on both sensors that leads to product convergence. Except for catering the radiative transfer and aerosol lookup tables to each sensor's specific wavelength bands, the ML algorithm is the same for both. We run the ML algorithm on both sensors between March 2012 and May 2014, and compare monthly mean AOD time series with each other and with M_C6 and V_EDR products. Focusing on the March–April–May (MAM) 2013 period, we compared additional statistics that include global and gridded 1° × 1° AOD and AE, histograms, sampling frequencies, and collocations with ground-based AERONET. Over land, use of the ML algorithm clearly reduces the differences between the MODIS and VIIRS-based AOD. However, although global offsets are near zero, some regional biases remain, especially in cloud fields and over brighter surface targets. Over ocean, use of the ML algorithm actually increases the offset between VIIRS and MODIS-based AOD (to ~ 0.025), while reducing the differences between AE. We characterize algorithm retrievability through statistics of retrieval fraction. In spite of differences between retrieved AOD magnitudes, the ML algorithm will lead to similar decisions about "whether to retrieve" on each sensor. Finally, we discuss how issues of calibration, as well as instrument spatial resolution may be contributing to the statistics and the ability to create a consistent MODIS → VIIRS aerosol CDR.
Dr. Yoram Kaufman
Dr. Joseph Adesina will present a seminar on the investigation of southern African aerosol distribution and properties using multi-satellite data and AERONET measurements…
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The Aerocenter Calendar is compatible with Apple's iCal and other applications that can read V-Card formatted calendar files. To subscribe to the Aerocenter Calendar, use the following URL: http://aerocenter.gsfc.nasa.gov/ical/aerocenter.ics