 |
Laboratoire d'aérologie |  |
|
Laboratoire d'aérologie | |
| HAL: hal-00708982, version 1 |
| DOI: 10.1029/2011JD017121 |
| Detailed view |  Export this paper |
 |
| Journal of Geophysical Research 117 (2012) D12301 |
|
|
|
|
| Transport and chemistry of formaldehyde by mesoscale convective systems in West Africa during AMMA 2006 |
|
|
| A. Borbon 1M. Ruiz 1 |
|
|
| (2012) |
|
|
|
| In situ measurements of formaldehyde (CH2O) onboard four European research aircraft in August 2006 as part of the African Monsoon Multidisciplinary Analysis (AMMA) experiment in West Africa are used (1) to examine the redistribution of CH2O by mesoscale convective systems (MCS) in the tropical upper troposphere (UT), (2) to evaluate the scavenging efficiency (SE) of CH2O by MCS and (3) to quantify the impact of CH2O on UT photooxidant production downwind of MCS. The intercomparison of CH2O measurements is first tested, providing a unique and consistent 3-D-spatially resolved CH2O database in background and convective conditions. While carbon monoxide (CO) is vertically uplifted by deep convection up to 12 km, CH2O is also affected by cloud processing as seen from its ratio relative to CO with altitude. A new observation-based model is established to quantify the SE of CH2O. This model shows that convective entrainment of free tropospheric air cannot be neglected since it contributes to 40% of the convective UT air. For the 4 studied MCS, SE shows a large variability within a 4% to 39% range at a relative standard deviation of 30%, which is consistent with MCS features. A time-dependent photochemical box model is applied to convective UT air. After convection, 60% of CH2O is due to its photochemical production rather than to its direct transport. Model results indicate that CH2O directly injected by convection does not impact ozone and HOx production in the tropical UT of West Africa. NOx and anthropogenic hydrocarbon precursors dominate the secondary production of CH2O, ozone and HOx. |
|
|
|
|
|
|
|
|
|
|
|
| 1: | Laboratoire inter-universitaire des systèmes atmosphèriques (LISA) |
|
|
|
CNRS : UMR7583 – INSU – Université Paris VII - Paris Diderot – Université Paris-Est Créteil Val-de-Marne (UPEC) |
|
|
| 2: | Laboratoire d'aérologie (LA) |
|
|
|
CNRS : UMR5560 – Observatoire Midi-Pyrénées – INSU – Université Paul Sabatier [UPS] - Toulouse III |
|
|
| 3: | Deutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre (DLR) |
|
|
|
Deutsches Zentrum für Luft- und Raumfahrt |
|
|
| 4: | School of Environmental Sciences (UEA) |
|
|
|
University of East Anglia |
|
|
| 5: | Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) |
|
|
|
CNRS : UMR8190 – Université Pierre et Marie Curie [UPMC] - Paris VI – Université de Versailles Saint-Quentin-en-Yvelines – INSU |
|
|
| 6: | Institut Pierre-Simon-Laplace (IPSL) |
|
|
|
CNRS : FR636 – Institut de recherche pour le développement [IRD] – CEA – CNES – INSU – Université Pierre et Marie Curie [UPMC] - Paris VI – Université de Versailles Saint-Quentin-en-Yvelines – Ecole normale supérieure de Paris - ENS Paris |
|
|
| 7: | Department of Applied Environmental Science |
|
|
|
Stockholm University |
|
|
| 8: | NOAA Earth System Research Laboratory (NOAA ESRL) |
|
|
|
U.S. Department of Commerce – National Oceanic & Atmospheric Administration |
|
|
| 9: | Cooperative Institute for Research in Environmental Sciences (CIRES) |
|
|
|
University of Colorado – NOAA |
|
|
| 10: | Department fo Chemistry, Faculty of Sciences |
|
|
|
Saint Joseph University |
|
|
|
|
|
|
|
|
|
| space |
|
|
|
|
| Subject | : | Physics/Physics/Atmospheric and Oceanic Physics |
|
|
| West Africa – Atmospheric chemistry – Cloud uptake – Deep convection – Formaldehyde – Tropical upper troposphere |
|
| hal-00708982, version 1 | |
| http://hal.archives-ouvertes.fr/hal-00708982 | |
| oai:hal.archives-ouvertes.fr:hal-00708982 | |
| From: Catherine Cardon | |
| Submitted on: Saturday, 16 June 2012 15:05:05 | |
| Updated on: Tuesday, 12 March 2013 18:32:09 | |
