1. Sun-Earth System Interaction studies over Vietnam: an international cooperative project
- Author
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C. Amory-Mazaudier, M. Le Huy, Y. Cohen, V. Doumbia, A. Bourdillon, R. Fleury, B. Fontaine, C. Ha Duyen, A. Kobea, P. Laroche, P. Lassudrie-Duchesne, H. Le Viet, T. Le Truong, H. Luu Viet, M. Menvielle, T. Nguyen Chien, A. Nguyen Xuan, F. Ouattara, M. Petitdidier, H. Pham Thi Thu, T. Pham Xuan, N. Philippon, L. Tran Thi, H. Vu Thien, P. Vila, Centre d'étude des environnements terrestre et planétaires ( CETP ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Institute of Geophysics [Hanoi], Vietnam Academy of Science and Technology ( VAST ), Institut de Physique du Globe de Paris ( IPGP ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -IPG PARIS-Université Paris Diderot - Paris 7 ( UPD7 ) -Université de la Réunion ( UR ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Physique de l'Atmosphère [Abidjan] ( LAPA ), Université de Cocody, Institut d'Electronique et de Télécommunications de Rennes ( IETR ), Université de Nantes ( UN ) -Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -Institut National des Sciences Appliquées - Rennes ( INSA Rennes ) -CentraleSupélec-Centre National de la Recherche Scientifique ( CNRS ), Département Micro-Ondes ( MO ), Institut Mines-Télécom [Paris]-Télécom Bretagne-Université européenne de Bretagne ( UEB ), Traitement Algorithmique et Matériel de la Communication, de l'Information et de la Connaissance ( TAMCIC ), Ecole Nationale Supérieure des Télécommunications de Bretagne-Centre National de la Recherche Scientifique ( CNRS ), Centre de Recherches de Climatologie ( CRC ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), ONERA - The French Aerospace Lab ( Palaiseau ), ONERA, Université de Koudougou, Université de kOUDOUGOU, Conservatoire National des Arts et Métiers - Paris ( CNAM Paris ), Conservatoire National des Arts et Métiers [CNAM] ( CNAM ), Administateur, HAL Sorbonne Université, Centre d'étude des environnements terrestre et planétaires (CETP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Vietnam Academy of Science and Technology (VAST), Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de l'Atmosphère [Abidjan] (LAPA), Institut d'Électronique et des Technologies du numéRique (IETR), Nantes Université (NU)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Département Micro-Ondes (MO), Université européenne de Bretagne - European University of Brittany (UEB)-Télécom Bretagne-Institut Mines-Télécom [Paris] (IMT), Traitement Algorithmique et Matériel de la Communication, de l'Information et de la Connaissance (TAMCIC), Ecole Nationale Supérieure des Télécommunications de Bretagne-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches de Climatologie (CRC), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), ONERA - The French Aerospace Lab [Palaiseau], ONERA-Université Paris Saclay (COmUE), Université Norbert ZONGO de Koudougou, Laboratoire Signaux et systèmes, Conservatoire National des Arts et Métiers [CNAM] (CNAM), Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES), laboratoire de physique de l'atmosphère, (LPA), université d'Abidjan Cocody, École Normale Supérieure - Koudougou (ENSK), No affiliation (No affiliation), Institut Mines-Télécom [Paris] (IMT)-Télécom Bretagne-Université européenne de Bretagne - European University of Brittany (UEB), Université de Nantes (UN)-Université de Rennes 1 (UR1), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Université de Nantes (UN)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), and HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,Meteorology ,[SDE.MCG]Environmental Sciences/Global Changes ,Context (language use) ,Monsoon ,01 natural sciences ,[SDU.STU.CL] Sciences of the Universe [physics]/Earth Sciences/Climatology ,0103 physical sciences ,Earth and Planetary Sciences (miscellaneous) ,lcsh:Science ,010303 astronomy & astrophysics ,diurnal to secular) ,0105 earth and related environmental sciences ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,lcsh:QC801-809 ,Geology ,Astronomy and Astrophysics ,Equatorial electrojet ,Orography ,lcsh:QC1-999 ,International Heliophysical Year ,Ionosphere (Electric fields and currents) ,lcsh:Geophysics. Cosmic physics ,[SDE.MCG] Environmental Sciences/Global Changes ,[ SDE.MCG ] Environmental Sciences/Global Changes ,Geography ,13. Climate action ,Space and Planetary Science ,[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology ,Geomagnetism and paleomagnetism (Time variations ,Meteorology and dynamics (Tropical meteorology) ,lcsh:Q ,Tropical cyclone ,Ionosphere ,[ SDU.STU.CL ] Sciences of the Universe [physics]/Earth Sciences/Climatology ,Longitude ,lcsh:Physics - Abstract
International audience; During many past decades, scientists from various countries have studied separately the atmospheric motions in the lower atmosphere, in the Earth's magnetic field, in the magnetospheric currents, etc. All of these separate studies lead today to the global study of the Sun and Earth connections, and as a consequence, new scientific programs (IHY- International Heliophysical Year, CAWSES- Climate and Weather in the Sun-Earth System) are defined, in order to assume this new challenge. In the past, many scientists did not have the possibility to collect data at the same time in the various latitude and longitude sectors. Now, with the progress of geophysical sciences in many developing countries, it is possible to have access to worldwide data sets. This paper presents the particularities of geophysical parameters measured by the Vietnamese instrument networks. It introduces a cooperative Vietnamese-IGRGEA (International Geophysical Research Group Europe Africa) project, and presents, for the first time, to the international community, the geophysical context of Vietnam. Concerning the ionosphere: since 1963, during four solar cycles, the ionosonde at Phu Thuy (North Vietnam) was operating. The Phu Thuy data exhibits the common features for the ionospheric parameters, previously observed in other longitude and latitude sectors. The critical frequencies of the E, F1 and F2 ionospheric layers follow the variation of the sunspot cycle. F2 and E critical frequencies also exhibit an annual variation. The first maps of TEC made with data from GPS receivers recently installed in Vietnam illustrate the regional equatorial pattern, i.e. two maxima of electronic density at 15 N and 15 S from the magnetic equator and a trough of density at the magnetic equator. These features illustrate the equatorial fountain effect. Concerning the Earth's magnetic field: a strong amplitude of the equatorial electrojet was first observed by the CHAMP satellite at the height of 400 km in the Vietnamese longitude sector. In this paper we compare the ground magnetic observations of the Indian and Vietnamese magnetometer networks. This comparison highlights the regional structure of the amplitude of the equatorial electrojet, which is stronger in Vietnam than in India. Concerning the monsoon: Vietnam exhibits a strong monsoon and has mainly one rainy season peaking in August, hence associated with the southwest monsoon flow. But some monsoon variability from one place to another is related to the orography. In the mountainous northern regions of Vietnam, there is an "early" monsoon peaking in July. In the coastal regions between 12 N and 19 N the monsoon season is centered on October. Concerning lightning: Vietnam is a country of strong atmospheric storms with some areas of very intense lightning in North Vietnam (22,5 N, 105 E) and in South Vietnam (11 N, 107 E). In North Vietnam strong lightning is associated with the most intense rainy region. Keywords. Ionosphere (Electric fields and currents) - Meteorology and dynamics (Tropical meteorology) - Geomagnetism and paleomagnetism (Time variations, diurnal to secular)
- Published
- 2006