Welcome to the AERONET quarterly.
Highlights:
Project Growth:
Project growth remains capped for new instrument requests except in
regions of poor spatial coverage that includes
The overall federated network currently maintains approximately 175
instruments deployed at 125 permanent sites.
As of this writing 98 sites were reporting field data, 34 instruments
are at GSFC and ~9 in
Field Maintenance:
Our network is highly regarded by the scientific community for its accuracy and distribution of column integrated aerosol retrievals. Despite the processing and calibration that we support at Goddard, the results are only as good as the data collected in the field. All in, data have been of exceptional quality, but we need to be vigilant in our field collection. Recently we received some instruments that contained months old spider webs in the collimators. At worst this can cause us to reject these data for level 2.0 status. Often we can see the effects of webs in the data however there are cases when we cannot and it can bias the data. Site managers and PIs, please check your collimators weekly. If you clean the collimator, please let us know the date of the action. Please note the revised weekly maintenance procedures available on the AERONET website (Operations, operating the sun photometer, weekly maintenance, procedures).
Instrumentation:
Mikhail Sorokin has successfully hardened an instrument for very cold weather (Barrow, AK that is currently operating well). It’s a custom modification that could be used for extreme cases.
Cimel Electronique has nearly completed development and testing of a prototype instrument with a 1.6 mm channel in addition to the standard channels. Improved electronics, RAM and air pressure. Should this be accepted by AERONET it will provide important data for dust aerosol characterization.
PHOTON news: ~33 instruments in western Europe and
AEROCAN News: Nine instruments are mostly distributed across southern
PI: Norm O’Neill, co-PI Alain Royer, AEROCAN network coordinator; Jim Freemantle.
AOD climatology: (DATA, Climatology 2.0):
Our web based AOD monthly climatology has been upgraded to include AOD for all wavelengths measured for all level 2.0 data. Kudos to Dave Giles for developing this data set. Please note that Pw is included in the climatology however the latest spectroscopic information is not included in our processing and that the uncertainty of our retrievals is ~±10%. Results of test applications of recent 940 nm region spectroscopy have actually increased the Pw differences between sun photometer retrievals and “ground truth’ (i.e. microwave radiometer). Until general scientific acceptance of ‘improved’ H2O spectroscopy is achieved, AERONET will maintain the current processing.
Complimentary Data:
We are working with other groups to include complimentary data products on the AERONET website on an exploratory basis. This includes back trajectories (GSFC Code 916 Shadoz Project) and lidar extinction profiles (GSFC Code 912, MPLNET). These data appear for single days under the AOD window.
New Retrieval
Products/Quality assured data products:
Fine and coarse mode AOD, SSA, Cv, Rv and Re are provisionally available through the demonstrat. They are expected to be available on the AEROENT website by the end of summer as a level 2.0 product.
Non-sphericity:
Inversion products from Dubovik’s new non-sphereical inversion code is in the research and development phase. A GRL paper is accepted.
Recent Papers:
Eight papers using AERONET data appeared in the Feb. Journal of the Atmospheric Sciences, two JGR special issues are in preparation for the SAFARI2000 and PRIDE campaigns that will include several AERONET papers. Two LBA papers were accepted by JGR and GRL.
Dubovik, O., B.N.Holben, T.F.Eck, A.Smirnov, Y.J.Kaufman, M.D.King, D.Tanre, and I.Slutsker, 2002: Variability of absorption and optical properties of key aerosol types observed in worldwide locations, J.Atm.Sci., 59, 590-608 .
Smirnov, A., B.N.Holben, O.Dubovik, N.T.O'Neill, T.F.Eck, D.L.Westphal, A.K.Goroch, C.Pietras, and I.Slutsker, 2002: Atmospheric Aerosol Optical Properties in the Persian Gulf, J. Atm. Sci., 59, 620-634.
Smirnov, A., B.N.Holben, Y.J.Kaufman, O.Dubovik, T.F.Eck, I.Slutsker, C.Pietras, and R.Halthore, 2002: Optical Properties of Atmospheric Aerosol in Maritime Environments, J.Atm.Sci., 59, 501-523.
AGU Special Session:
A special session on all aspects of AERONET related research will be
held in
Thanks Everyone!
Brent Holben