Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Records 1 - 3 / 3

  • help
  • print

    Print search results

  • export

    Export search results

  • alert
    We will mail you new results for this query: q=Pinardi
Check title to add to marked list
Improved aerosol correction for OMI tropospheric NO2 retrieval over East Asia : Constraint from CALIOP aerosol vertical profile
Liu, Mengyao ; Lin, Jintai ; Folkert Boersma, K. ; Pinardi, Gaia ; Wang, Yang ; Chimot, Julien ; Wagner, Thomas ; Xie, Pinhua ; Eskes, Henk ; Roozendael, Michel Van; Hendrick, François ; Wang, Pucai ; Wang, Ting ; Yan, Yingying ; Chen, Lulu ; Ni, Ruijing - \ 2019
Atmospheric Measurement Techniques 12 (2019)1. - ISSN 1867-1381 - p. 1 - 21.

Satellite retrieval of vertical column densities (VCDs) of tropospheric nitrogen dioxide (NO2) is critical for NOx pollution and impact evaluation. For regions with high aerosol loadings, the retrieval accuracy is greatly affected by whether aerosol optical effects are treated implicitly (as additional effective clouds) or explicitly, among other factors. Our previous POMINO algorithm explicitly accounts for aerosol effects to improve the retrieval, especially in polluted situations over China, by using aerosol information from GEOS-Chem simulations with further monthly constraints by MODIS/Aqua aerosol optical depth (AOD) data. Here we present a major algorithm update, POMINO v1.1, by constructing a monthly climatological dataset of aerosol extinction profiles, based on level 2 CALIOP/CALIPSO data over 2007-2015, to better constrain the modeled aerosol vertical profiles. We find that GEOS-Chem captures the month-to-month variation in CALIOP aerosol layer height (ALH) but with a systematic underestimate by about 300-600 m (season and location dependent), due to a too strong negative vertical gradient of extinction above 1 km. Correcting the model aerosol extinction profiles results in small changes in retrieved cloud fraction, increases in cloud-top pressure (within 2 %-6 % in most cases), and increases in tropospheric NO2 VCD by 4 %-16 % over China on a monthly basis in 2012. The improved NO2 VCDs (in POMINO v1.1) are more consistent with independent ground-based MAX-DOAS observations (R2=0.80, NMB =-3.4 %, for 162 pixels in 49 days) than POMINO (R2=0.80, NMB =-9.6 %), DOMINO v2 (R2=0.68, NMB =-2.1 %), and QA4ECV (R2=0.75, NMB =-22.0 %) are. Especially on haze days, R2 reaches 0.76 for POMINO v1.1, much higher than that for POMINO (0.68), DOMINO v2 (0.38), and QA4ECV (0.34). Furthermore, the increase in cloud pressure likely reveals a more realistic vertical relationship between cloud and aerosol layers, with aerosols situated above the clouds in certain months span id=page2 instead of always below the clouds. The POMINO v1.1 algorithm is a core step towards our next public release of the data product (POMINO v2), and it will also be applied to the recently launched S5P-TROPOMI sensor.

Improving algorithms and uncertainty estimates for satellite NO2 retrievals : Results from the quality assurance for the essential climate variables (QA4ECV) project
Boersma, K.F. ; Eskes, Henk J. ; Richter, Andreas ; Smedt, Isabelle De; Lorente, Alba ; Beirle, Steffen ; Geffen, Jos H.G.M. van; Zara, Marina ; Peters, Enno ; Roozendael, Michel Van; Wagner, Thomas ; Maasakkers, Joannes D. ; A, Ronald J. van der; Nightingale, Joanne ; Rudder, Anne De; Irie, Hitoshi ; Pinardi, Gaia ; Lambert, Jean Christopher ; Compernolle, Steven C. - \ 2018
Atmospheric Measurement Techniques 11 (2018)12. - ISSN 1867-1381 - p. 6651 - 6678.

Global observations of tropospheric nitrogen dioxide (NO2) columns have been shown to be feasible from space, but consistent multi-sensor records do not yet exist, nor are they covered by planned activities at the international level. Harmonised, multi-decadal records of NO2 columns and their associated uncertainties can provide crucial information on how the emissions and concentrations of nitrogen oxides evolve over time. Here we describe the development of a new, community best-practice NO2 retrieval algorithm based on a synthesis of existing approaches. Detailed comparisons of these approaches led us to implement an enhanced spectral fitting method for NO2, a 1°  ×  1° TM5-MP data assimilation scheme to estimate the stratospheric background and improve air mass factor calculations. Guided by the needs expressed by data users, producers, and WMO GCOS guidelines, we incorporated detailed per-pixel uncertainty information in the data product, along with easily traceable information on the relevant quality aspects of the retrieval. We applied the improved QA4ECV NO2 algorithm to the most current level-1 data sets to produce a complete 22-year data record that includes GOME (1995–2003), SCIAMACHY (2002–2012), GOME-2(A) (2007 onwards) and OMI (2004 onwards). The QA4ECV NO2 spectral fitting recommendations and TM5-MP stratospheric column and air mass factor approach are currently also applied to S5P-TROPOMI. The uncertainties in the QA4ECV tropospheric NO2 columns amount to typically 40 % over polluted scenes. The first validation results of the QA4ECV OMI NO2 columns and their uncertainties over Tai'an, China, in June 2006 suggest a small bias (−2 %) and better precision than suggested by uncertainty propagation. We conclude that our improved QA4ECV NO2 long-term data record is providing valuable information to quantitatively constrain emissions, deposition, and trends in nitrogen oxides on a global scale.

The Changing Earth : new scientific challenges for ESA's living planet programme
Simon, P.C. ; Hollingsworth, A. ; Carli, B. ; Källen, E. ; Rott, H. ; Partington, K. ; Moreno, J. ; Schaepman, M.E. ; Mauser, W. ; Flemming, N.C. ; Visbeck, M. ; Vermeersen, B.L.A. ; Dam, T. van; Reigber, C. ; Grassl, H. ; Bougeault, P. ; England, P. ; Friis-Christensen, F. ; Johannessen, J. ; Kelder, H. ; Kosuth, P. ; Pinardi, N. ; Quegan, S. ; Sobrino, J.A. - \ 2006
Noordwijk : ESA (ESA Publication SP-1304) - ISBN 9290924578 - 83 p.
Check title to add to marked list

Show 20 50 100 records per page

 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.