The quasi-biennial oscillation (QBO) and semi-annual oscillation (SAO) characteristics of O3, NO2, and NO3 from 2002 to 2008 were analyzed using Global Ozone Monitoring by Occultation of Stars (GOMOS) satellite observ...The quasi-biennial oscillation (QBO) and semi-annual oscillation (SAO) characteristics of O3, NO2, and NO3 from 2002 to 2008 were analyzed using Global Ozone Monitoring by Occultation of Stars (GOMOS) satellite observations. From investigations of the vertical and latitudinal structures of interannual anomalies for O3 and the vertical velocity of the residual circulation (w-star), we conclude that dynamic transport is the principal factor controlling the QBO pattern of O3. Under the influence of vertical transport, the QBO signals of O3 originate in the middle stratosphere and propagate downward along with the wstar anomalies over the equator. The residual circulation has a significant role in tropical regions, regardless of altitude, while in extratropical regions, dynamic effects are important in some years in the lower stratosphere. In the middle stratosphere, dynamic transport is most efficient in the Southern Hemisphere. We also analyzed NO2 anomalies and found that their QBO pattern was deep and sta- tionary in the middle and upper stratosphere over the equator. This was due to the large depth over which w-star was anomalous. The latitudinal structure of NO2 was asymmetric in extratropical areas in the middle stratosphere, but in the upper layers, the QBO pattern and dynamic influences were only observed in tropical zones. The interannual anomalies of NO3 had an apparent SAO pattern in the tropical upper stratosphere because of different dynamic and chemical effects in different SAO phases. Chemical reactions may also have contributed to the QBO-type distribution of NO2 and the SAO-type distribution of NO3.展开更多
Stratospheric water vapor variations,which may play an important role in surface climate,have drawn extensive studies.Here,the variation in stratospheric water vapor is investigated by using data from observations of ...Stratospheric water vapor variations,which may play an important role in surface climate,have drawn extensive studies.Here,the variation in stratospheric water vapor is investigated by using data from observations of the Microwave Limb Sounder(MLS)on the Aura satellite,from the ECMWF Interim Reanalysis(ERAI),and simulations by the Whole Atmosphere Community Climate Model(WACCM).We find that the differences of annual mean stratospheric water vapor among these datasets may be partly caused by the differences in vertical transports.Using budget analysis,we find that the upward transport of water vapor at 100 h Pa is mainly located over the Pacific warm pool region and South America in the equatorial tropics in boreal winter and over the southeast of the South Asian high and south of North America in boreal summer.It is found that temperature averaged over regions with upward transport is a better indicator of interannual variability of tropical mean stratospheric water vapor than the tropical mean temperature.It seems that the distributions of the seasonal cycle amplitude of lower stratospheric water vapor in the tropics can also be impacted by the vertical transport.The radiative effects of the interannual changes in water vapor in the lowermost stratosphere are underestimated by approximately 29%in both ERAI and WACCM compared to MLS,although the interannual variations of water vapor in the lowermost stratosphere are dramatically overestimated in ERAI and WACCM.The results here indicate that the radiative effect of long-term changes in water vapor in the lowermost stratosphere may be underestimated in both ERAI and WACCM simulations.展开更多
基金supported by the National Basic Research Program of China (2010CB428604)Dragon 2 Program (ID:5311)+1 种基金the National Natural Science Foundation of China (40633015)The meteorological analysis was kindly provided by ECMWF
文摘The quasi-biennial oscillation (QBO) and semi-annual oscillation (SAO) characteristics of O3, NO2, and NO3 from 2002 to 2008 were analyzed using Global Ozone Monitoring by Occultation of Stars (GOMOS) satellite observations. From investigations of the vertical and latitudinal structures of interannual anomalies for O3 and the vertical velocity of the residual circulation (w-star), we conclude that dynamic transport is the principal factor controlling the QBO pattern of O3. Under the influence of vertical transport, the QBO signals of O3 originate in the middle stratosphere and propagate downward along with the wstar anomalies over the equator. The residual circulation has a significant role in tropical regions, regardless of altitude, while in extratropical regions, dynamic effects are important in some years in the lower stratosphere. In the middle stratosphere, dynamic transport is most efficient in the Southern Hemisphere. We also analyzed NO2 anomalies and found that their QBO pattern was deep and sta- tionary in the middle and upper stratosphere over the equator. This was due to the large depth over which w-star was anomalous. The latitudinal structure of NO2 was asymmetric in extratropical areas in the middle stratosphere, but in the upper layers, the QBO pattern and dynamic influences were only observed in tropical zones. The interannual anomalies of NO3 had an apparent SAO pattern in the tropical upper stratosphere because of different dynamic and chemical effects in different SAO phases. Chemical reactions may also have contributed to the QBO-type distribution of NO2 and the SAO-type distribution of NO3.
基金Supported by the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0604)Key Laboratory of Middle Atmosphere and Global Environment Observation(LAGEO-2020-09)+3 种基金Fundamental Research Funds for the Central Universitiessupported by the National Natural Science Foundation of China(41530423,41761144072,and 41888101)grants from the Discovery Program of the Natural Sciences and Engineering Research Council of Canada(RGPIN-2019-04511)from the Canadian Space Agency(16SUASURDC)。
文摘Stratospheric water vapor variations,which may play an important role in surface climate,have drawn extensive studies.Here,the variation in stratospheric water vapor is investigated by using data from observations of the Microwave Limb Sounder(MLS)on the Aura satellite,from the ECMWF Interim Reanalysis(ERAI),and simulations by the Whole Atmosphere Community Climate Model(WACCM).We find that the differences of annual mean stratospheric water vapor among these datasets may be partly caused by the differences in vertical transports.Using budget analysis,we find that the upward transport of water vapor at 100 h Pa is mainly located over the Pacific warm pool region and South America in the equatorial tropics in boreal winter and over the southeast of the South Asian high and south of North America in boreal summer.It is found that temperature averaged over regions with upward transport is a better indicator of interannual variability of tropical mean stratospheric water vapor than the tropical mean temperature.It seems that the distributions of the seasonal cycle amplitude of lower stratospheric water vapor in the tropics can also be impacted by the vertical transport.The radiative effects of the interannual changes in water vapor in the lowermost stratosphere are underestimated by approximately 29%in both ERAI and WACCM compared to MLS,although the interannual variations of water vapor in the lowermost stratosphere are dramatically overestimated in ERAI and WACCM.The results here indicate that the radiative effect of long-term changes in water vapor in the lowermost stratosphere may be underestimated in both ERAI and WACCM simulations.
