Folks, Welcome to the AERONET
Quarterly. This is a rather informal
note sent more or less quarterly to those involved in the AERONET program. This and past issues maybe found on the
AERONET website (Link to “papers and presentations). This issue is
largely geared to the PIs and site managers.
Cheers, Brent Holben
The following highlights are discussed:
1.
Comment
2.
Operational Summary-(site managers and PIs please read 2-4)
3.
Field Maintenance
4.
Shipping, instrument
return and calibration
5.
Personnel
6.
Website Updates
7.
AERONET Proposal
Submitted
8.
Staff Research and
Bibliography
One of the principle goals of
developing AERONET into an international program was to provide validation of
satellite aerosol retrievals representing a variety of aerosol types at a great
diversity of geographic locations. Our
collective public domain data-base clearly has allowed us to achieve that
goal. So far AERONET data has provided
published validation for aerosol retrievals from AVHRR, TOMS, POLDER, GOES,
Landsat, SeaWiFS, GOMES and ATSR-2 (see
bibliography). Shortly we’ll be seeing
published validations from MODIS, MISR, and perhaps ASTR. Further validation studies of Airborne
instruments and model simulations have also occurred. In short, I feel that the program has been tremendously
successful and all participants should feel gratified with their effort. Thanks to all the PIs, PHOTON, AEROCAN,
LTER, SIMBIOS, DOE, the many collaborators and especially the dedicated AERONET
staff.
Operational
Summary:
As of 12/5/00 there were 68
instruments operating in the field, 15 not functioning in the field and 32 on
the roof at GSFC, for a total of 115.
AERONET staff calibrate and maintain the roof instruments, analyze field
instrument performance weekly, troubleshoot any instruments as needed with the
site managers, and coordinate shipping.
We also process and quality assure these data. With this many instruments, we need the PI’s and site managers to
be actively engaged with their instrument and data. By all means please follow the weekly instrument maintenance
inspection (~10 min); an ounce of prevention is worth a pound of cure. See the website (http://aeronet.gsfc.nasa.gov/Operational/pictures/Checklist.html)
for the checklist.
Field Maintenance:
We
changed (effective 12/9/00) our automatic troubleshooting reports to facilitate
field maintenance. We have developed a
comprehensive daily website troubleshooting report which is available for each
transmitting instrument (GMS sites will be active in January). We have eliminated the daily email reports
to site managers but they will automatically be sent when certain problem
thresholds are reached that require site manager attention. Thus folks will not be overwhelmed with
irrelevant information. AERONET staff make a comprehensive weekly evaluation of
all instruments performance (usually on Monday) from which we’ll contact site
managers directly to address the problems.
This is very time consuming so we ask your cooperation to provide an
ounce of prevention by:
1.
Perform the weekly
instrument inspection (http://aeronet.gsfc.nasa.gov/Operational/pictures/Checklist.html)
2. Check your instrument on our webpage trouble shooting report once per week (suggest Monday) (http://aeronet.gsfc.nasa.gov/Operational/current_report.html) [~2 min]
3.
If you receive an
individualized e-mail troubleshooting report, read it and take action as soon
as possible
4.
Become familiar with our
help page (Link under “Installation, Packing and Shipping Instructions”) on the
AERONET website.
Tip: We find the most common problems are
associated with under charged batteries, incorrectly set clocks and tripped
failsafe switches which sometimes arise when an instrument is exchanged. We are all very much aware that active
attentive site managers save the AERONET staff a great deal of time and greatly
improves data collection.
Our turn-around for calibrating instruments for field readiness has varied from as little as three days to as much as 4 months, our goal is 4 weeks from the time of arrival to the time it’s shipped out the door. Factors affecting our backlog, weather, the condition of instruments returned, the availability of replacement parts, and staff and facility schedules. Delays associated with international shipments usually involve clearing customs. To expedite the calibration of your field instrument please follow the list below which now appears on our website: http://aeronet.gsfc.nasa.gov/Operational/Active_intercal.html
1.
Pack sensor head,
control box, sensor head cable, collimator, internal battery pack and cable
connector panel. Add the robot to speed
roof access See
(http://aeronet.gsfc.nasa.gov/Operational/pictures/packing.html) for directions.
This is very important.
2.
Follow shipping
directions given on the website
(http://aeronet.gsfc.nasa.gov/Operational/pictures/shipping.html)
or contact Dee Jones (djones@aeronet.gsfc.nasa.gov).
This is very important.
3.
Monitor progress at:
http://aeronet.gsfc.nasa.gov/Operational/Active_intercal.html
4.
Priority concerns:
contact Ross Nelson at ross@aeronet.gsfc.nasa.gov
5.
If you have more than
one instrument, please send them individually and only as they need
calibration, please don’t group them.
Personnel
changes have occurred relatively rapidly of late. Our technician Adam Naji left in October and our senior Engineer
and good friend, Nader Abuhassan, gave notice for a Jan. 1 departure. I expect the transition to be smooth as
Mikhail Sorokine, our development
engineer, will temporarily assume Nader’s duties. Our best wishes go Nader and Adam. Dee Jones came on board in June as our Admin. I’m sure most of you have communicated with
her.
Website Updates
Ilya Slutsker has completed a major programming effort for tracking, assigning instrument ID’s, and transmission ID’s. Although this has little effect for most PIs, it is a significant time saver for our staff and will aid in troubleshooting instruments that are not transmitting properly. He will be turning his attention to the website which should significantly change its appearance, products available and organization. Any suggestions for this upgrade will be appreciated and should be sent to Oleg Dubovik (dubovik@aeronet.gsfc.nasa.gov) who is coordinating the upgrade.
The
AERONET program is a federation of independently funded PI’s and projects
primarily glued together by the GSFC operation. A proposal was submitted to NASA HQ for an additional five year
funding cycle for AERONET GSFC. The
program was reviewed by the AERONET science steering committee in April
resulting in a positive statement and recommendation for future operation. The committee report is available on the
AERONET website
(http://aeronet.gsfc.nasa.gov/Publications/Conference.html).
Staff Research and
Bibliography
The
polarization data-base has largely been brought up to a quality assured status
by Anne Vermeulen. We expect to be
presenting these data on the AERONET website in the new-year. Similarly additional inversion products will
appear on the website. In this regard
Dubovik’s two papers on inversions were published. The group AOD climatology paper has been accepted and several
field campaign papers by Eck, Smirnov and O’Neille were published since the
last AERONET Quarterly. Significant
papers by Kaufman,(diurnal variation of AOD) and Tanre (optical properties of
desert dust) have been published or accepted.
Please see the bibliography below and PDF files on the website.
Research
activities include characterizing aerosol optical properties using all the
retrievals from AERONET, collaboration with lidar retrievals, optical properties
of specific airmasses. We’ve completed
our participation in the SAFARI2000 dry season campaign and are planning
deployments for the Ace-Asia campaign which begins in March.
Bibliography
Dubovik, O., and M.D.King,
A flexible inversion algorithm for retrieval of aerosol optical properties from
sun and sky radiance measurements, J.Geophys.Res.,
105, 20,673-20,696, 2000.
Dubovik, O., A.Smirnov,
B.N.Holben, M.D.King, Y.J.Kaufman, T.F.Eck, and I.Slutsker, Accuracy
assessments of aerosol optical properties retrieved from AERONET sun and sky
radiance measurements, J.Geophys.Res.,
105, 9791-9806, 2000a.
Eck, T.F., B.N.Holben,
O.Dubovik, A.Smirnov, I.Slutsker, J.M.Lobert, and V.Ramanathan, Column
integrated aerosol optical properties over the Maldives during the NE monsoon
for 1998-2000, J.Geophys.Res., 2000
(submitted).
Eck, T.F., B.N. Holben,
D.E. Ward, O. Dubovik, J.S. Reid, A. Smirnov, M.M. Mukelabai, N.C. Hsu, N.T.
O'Neill, and I. Slutsker, Characterization of biomass burning aerosols in
Zambia during the 1997 ZIBBEE Experiment,
J. Geophys. Res., 2000
(accepted)
Ferrare, R., S.Ismail,
E.Browell, V.Brackett, M.Clayton, S.Kooi, S.H.Melfi, D.Whiteman, G.Schwemmer,
K.Evans, P.Russell, J.Livingston, B.Schmid, B.Holben, L.Remer, A.Smirnov, and
P.Hobbs, Comparison of aerosol optical properties and water vapor among ground
and airborne lidars and sun photometers during TARFOX, J.Geophys.Res., 105,
9917-9934, 2000.
Higurashi, A., T.Nakajima,
B.N.Holben, A.Smirnov, R.Frouin, and B.Chatenet, A study of global aerosol
optical climatology with two channel AVHRR remote sensing, J. Clim., 13,
2011-2027, 2000.
Holben, B.N., D.Tanre,
A.Smirnov, T.F.Eck, I.Slutsker, N.Abuhassan, W.W.Newcomb, J.Schafer,
B.Chatenet, F.Lavenue, Y.J.Kaufman, J.Vande Castle, A.Setzer, B.Markham,
D.Clark, R.Frouin, R.Halthore, A.Karnieli, N.T.O'Neill, C.Pietras, R.T.Pinker,
K.Voss, G.Zibordi, An emerging ground-based aerosol climatology: Aerosol
Optical Depth from AERONET, J. Geophys.
Res., 2000 (accepted).
Hsu, N.C., J.R.Herman,
O.Torres, B.N.Holben, D.Tanre, T.F.Eck, A.Smirnov, B.Chatenet, and F.Lavenu,
Comparisons of the TOMS aerosol index with sunphotometer aerosol optical
thickness: results and applications, J.
Geophys. Res, 104, 6269-6280,
1999.
Kaufman, Y.J.,
B.N.Holben, D.Tanré, I.Slutzker, T.F.Eck, A.Smirnov, How well can aerosol
measurements from the Terra morning polar orbiting satellite represent the
daily aerosol abundance and properties?, Geoph.
Res. Lett., 23, 3861-3864, 2000.
Kreidenweis S. M., L. A.
Remer, R. Bruitjes, R. Kleidman, R. Halthore, B. N. Holben and O. Dubovik,
"Observations of smoke aerosol from biomass burning in Mexico, J. Geophys. Res., 2000 (accepted).
Kinne, S., B.N.Holben,
T.F.Eck, A.Smirnov, O.Dubovik, I.Slutsker, U.Lohmann, S.Ghan, M.Chin, P.Ginoux,
T.Takemura, R.Kahn, E.Vermote, D.Tanre, L.Stowe, O.Torres, M.Mischenko, How
well do aerosol retrievals from satellites and representation in global
circulation models match ground-based AERONET aerosol statistics, 2001 (in
press).
Ouaidrari, H. and E.F.
Vermote. Operational atmospheric
correction of Landsat TM data, Rem. Sens. Env., 70(1), 1999.
O'Neill, N.T., T.F.Eck,
B.N.Holben, A.Smirnov, O.Dubovik, and A.Royer, Uni. and bi-modal size
distribution influences on the variation of Angstrom derivatives in spectral and
optical depth space, J. Geophys. Res.,
2000a (accepted).
O'Neill, N.T., A.Ignatov,
B.N.Holben, and T.F.Eck, The lognormal distribution as a reference for
reporting aerosol optical depth statistics; Empirical tests using multi-year,
multi-site AERONET sunphotometer data, Geophys.Res.Lett.,
27, 3333-3336, 2000b.
O'Neill, N.T., T.F.Eck,
B.N.Holben, A.Smirnov, A.Royer, and Z.Li, Optical properties of Canadian forest
fire smoke derived from sunphotometry, J.
Geophys. Res., 2000d (submitted).
Schmid, B., J.J.Michaslky,
D.W.Slater, J.C.Barnard, R.N.Halthore, J.C.Liljegren, B.N.Holben, T.F.Eck,
J.M.Livingston, P.B.Russell, T.Ingold, and I.Slutsker, Comparison of columnar
water vapor measurements during the fall 1997 ARM Intensive Observation Period:
solar transmittance methods, Appl. Opt.,
2000 (submitted).
Smirnov, A., B.N.Holben,
T.F.Eck, O.Dubovik, and I.Slutsker, Cloud screening and quality control
algorithms for the AERONET data base, Rem.
Sens. Env., 73(3), 337-349, 2000a.
Smirnov, A., B.N.Holben,
D.Savoie, J.M.Prospero, Y.J.Kaufman, D.Tanre, T.F.Eck, and I.Slutsker,
Relationship between column aerosol optical thickness and in situ ground based
dust concentrations over Barbados, Geophys.
Res. Lett., 27, 1643-1646, 2000b.
Smirnov, A., B.N.Holben,
O.Dubovik, N.T.O'Neill, L.A.Remer, T.F.Eck, I.Slutsker, and D.Savoie,
Measurement of atmospheric optical parameters on US Atlantic coast sites, ships
and Bermuda during TARFOX, J. Geophys.
Res., 105, 9887-9901, 2000d.
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, Atmospheric aerosol optical properties in the Persian Gulf region, Geophys.Res.Lett., 2000e (submitted).