89th American Meteorological Society Annual Meeting

Wednesday, 14 January 2009
New Results from FLASHFlux: A Case Study of the Observed Radiative Anomalies In the Arctic for 2007 and 2008 Summer Seasons
Hall 5 (Phoenix Convention Center)
Paul W. Stackhouse Jr., NASA/LRC, Hampton, VA; and S. Kato, D. P. Kratz, S. K. Gupta, A. C. Edwards, and A. C. Wilber
The Clouds and the Earth's Radiant Energy System (CERES) project is currently producing highly accurate surface and top-of-atmosphere (TOA) radiation budget datasets from measurements taken by CERES broadband radiometers and a subset of imaging channels on the Moderate-resolution Imaging Spectroradiometer (MODIS) instrument operating onboard Terra and Aqua satellites. The primary objective of CERES is to produce highly accurate and stable time-series of radiation budget parameters to meet the stringent requirements of climate change research. As a result, CERES products are delayed six months to a year from the time of satellite observation. To bridge this gap, currently more than 2 years, between the real-time observation and the CERES data sets, the Fast Longwave And SHortwave radiative Flux from Global CERES and MODIS measurements project (FLASHFlux) was developed and is producing fluxes accurate enough to assess regional perturbations relative to CERES and other radiative flux data sets. FLASHFlux currently produces reliable surface and TOA radiative parameters within one week of the satellite observations using CERES “quicklook” data stream and fast surface flux algorithms. Data products are available both at the footprint level and then on daily averaged 1°x1° grid from the LaRC Atmospheric Sciences Data Center (ASDC) at: eosweb.larc.nasa.gov/PRODOCS/flashflux/table_flashflux.html. These data are being used for a number of scientific and applied science purposes.

In this presentation, we give a brief overview of the accuracy, uses and availability of the FLASHFlux data products. Then we present a radiative flux anomaly analysis of the 2007 and 2008 Arctic summer seasons compared with CERES and the NASA/Global Energy and Water Cycle Experiment (GEWEX) Surface Radiative Budget Project fluxes for the same months from 2000 - 2004. In 2007, comparisons in the Western Arctic (120 W to 180 W, 70 N to pole) of the June-July-August (JJA) 2007 average FLASHFlux radiative fluxes to the CERES JJA 2000-2004 averages showed that the mean cloud fraction decreased nearly 13.8% and that this decrease was associated with a relative increase in TOA net (24.2 W m^-2) and surface net fluxes (21.4 W m^-2). These results agree very well with the CloudSat-based analysis of Kay et al. (2008), but are more detailed containing the daily averaged fluxes throughout the period. A similar comparison for the currently evolving Arctic summer season will be contrasted to 2007 and to the years 2000-2004. Additionally, perturbations of the implied heat transport are estimated for these time periods. Thus, the presentation shows the magnitude of the observed Arctic anomalies and the usefulness of using a more real-time project like FLASHFlux to assess the radiative impact of large climate related anomalies.

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