Post on 06-Jan-2016
description
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
The GLOBE Aerosol Monitoring Project
Joris de Vroom, Tim Vlemmix, Folkert Boersma, Ellen Brinksma, Pieternel Levelt
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
Outline The GLOBE program Measurement principle Campaign approach 2007 validation results
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
GLOBAL
LEARNING AND
OBSERVATIONS TO
BENEFIT THE
ENVIRONMENT
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
The international GLOBE program Students collect data that can be used for scientific research Students report on the internet 18,000 schools worldwide Elementary and secondary school students Various subjects: water, soil, vegetation, atmosphere,…
The GLOBE program at KNMI Since 2002 at KNMI Together with SME Aerosol Optical Thickness (AOT) Focus on OMI validation Goals
Education Science Public outreach
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
LED used as a photo cell: V ~ I
508 nm
625 nm
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
Comparison of
GLOBE Instrument
with
Professional instruments
Aero
sol O
pti
cal Th
ickn
ess
at
440
nm
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
year measurements
collocations
2002 0 0
2003 75 0
2004 41 0 (OMI launch)
2005 152 3
2006 66 19
2007 227 73
2008 124 41
Measurement campaigns
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
Validation
• jan-dec 2007
• N = 73
• t < 10 min
• CF < 0.1
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
•R(508) = 0.68
•R(625) = 0.77
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
tiviteitrepresentaomiglobeGauss222
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
tiviteitrepresentaomiglobeGauss222
)(
σ(Gauss) = 0.1 fit result
σ(globe) = 0.036
σ(omi) + σ(representativiteit) : 0.09 (= 34%)
Comparison with MODIS (over sea) σ(omi) = 30%
σ(omi) < 0.09
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
Seasonal cycle
Figures by Remco Braak
OMI AOT 483 nm MAM 2007
OMI AOT 483 nm SON 2007
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
Seasonal cycle
Spring bias (GLOBE-OMI):
Figures by Remco Braak
OMI AOT 483 nm MAM 2007
OMI AOT 483 nm SON 2007
globeomi *25.1
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
Conclusions σ(omi) < 0.09 In spring OMI overestimates AOT First quantitative validation of OMI AOD with
student measurements Campaign stategy very successful
Outlook Spring and autumn campaign 2008 Extend with 20 new schools New approach: combining of two channels quantitative OMI validation results into (JGR)
paper
AK-CK praatje 20080529
The GLOBE aerosol measurement campaign
Lopussa…….