Global Navigation Satellite System （GNSS） radio occultation measurements have been assimilated into the four- dimensional variational data assimilation system （YH4DVAR） using a one-dimensional bending angle operat...Global Navigation Satellite System （GNSS） radio occultation measurements have been assimilated into the four- dimensional variational data assimilation system （YH4DVAR） using a one-dimensional bending angle operator （GBAO） as a new type of observation. For the sake of verifying the impact of GNSS radio occultation （RO） measurements to the data assimilation system, three experiments have been conducted. The statistical results of the analysis error experiment and forecast skill experiment show that the GNSS RO measurements have an impact on the analysis system. The typhoon forecast experiment shows the impact on the important weather process. They all have a positive impact on the weather forecast. Lastly, we look forward to future work on the observation system simulation experiment （OSSE） to investigate the impact of GNSS RO measurements as a function of observation number, which is an effective method to estimate the saturation of the observation number.展开更多
"Economic transformation"has become the main path to promote China's social and economic development,and many regions have increased the importance and attention to"economic transformation",and..."Economic transformation"has become the main path to promote China's social and economic development,and many regions have increased the importance and attention to"economic transformation",and the Southwest region is no exception.Many cities in Southwest China are developing new energy sources to promote economic development and economic transformation.Economic transformation and economic development in Southwest China are mutually influencing and interacting,while energy development in Southwest China and its local economic development are mutually promoting and influencing,so economic transformation also affects energy demand and development in Southwest China.The importance of economic transformation should be taken into consideration.展开更多
This paper reviews the data quality and impact of observations from the FY-3 satellite series used operationally in the ECMWF system. This includes data from the passive microwave radiometers MWHS-1, MWHS-2 and MWRI, ...This paper reviews the data quality and impact of observations from the FY-3 satellite series used operationally in the ECMWF system. This includes data from the passive microwave radiometers MWHS-1, MWHS-2 and MWRI, as well as observations from the radio occultation receiver GNOS. Evaluations against background equivalents show that the quality of the observations is broadly comparable to that of similar instruments on other polar-orbiting satellites, even though biases for the passive microwave observations can be somewhat larger and more complex for some channels. An observing system experiment shows that the FY-3 instruments jointly contribute significantly to the forecast skill in the ECMWF system. Positive impact of up to 2% is seen for most variables out to the day-2 forecasts over hemispheric scales, with significant benefits for total column water vapor or for temperature and wind in the stratosphere out to day 4.展开更多
Experiments were conducted to test the impact of a cloud diagnosis scheme in place of prescribed zonal average cloud on medium and long range integrations with the Australian Bureau of Meteorology Research Centre(BMRC...Experiments were conducted to test the impact of a cloud diagnosis scheme in place of prescribed zonal average cloud on medium and long range integrations with the Australian Bureau of Meteorology Research Centre(BMRC)global atmosphere model.The cloud scheme was shown to improve the temperature bias in the lower troposphere but there was deterioration in the upper troposphere,especially in the tropics,asso- ciated with underestimation of high cloud amount. Thirty day mean fields in a January integration showed greater amplitude in the Northern Hemisphere planetary waves and a deeper Antarctic circumpolar trough than the control experiment or a simulation with no cloud.The results for the diagnosed cloud case agree more closely with corresponding observed fields. There was also some reduction in the zonal average zonal wind component reflecting the additional zonal asymmetry introduced by the diagnostic cloud scheme.Similar trends were also noted in medium and long range forecasts for January and July conditions,although the impact on predictive skill was slight and in some cases detrimental. Areas for improving the diagnostic cloud scheme are noted.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.40775064,41105063,and 41375113)the Special Scientific Research Fund of Meteorological Public Welfare Profession of China(Grant Nos.GYHY201006015 and GYHY201206007)
文摘Global Navigation Satellite System （GNSS） radio occultation measurements have been assimilated into the four- dimensional variational data assimilation system （YH4DVAR） using a one-dimensional bending angle operator （GBAO） as a new type of observation. For the sake of verifying the impact of GNSS radio occultation （RO） measurements to the data assimilation system, three experiments have been conducted. The statistical results of the analysis error experiment and forecast skill experiment show that the GNSS RO measurements have an impact on the analysis system. The typhoon forecast experiment shows the impact on the important weather process. They all have a positive impact on the weather forecast. Lastly, we look forward to future work on the observation system simulation experiment （OSSE） to investigate the impact of GNSS RO measurements as a function of observation number, which is an effective method to estimate the saturation of the observation number.
文摘"Economic transformation"has become the main path to promote China's social and economic development,and many regions have increased the importance and attention to"economic transformation",and the Southwest region is no exception.Many cities in Southwest China are developing new energy sources to promote economic development and economic transformation.Economic transformation and economic development in Southwest China are mutually influencing and interacting,while energy development in Southwest China and its local economic development are mutually promoting and influencing,so economic transformation also affects energy demand and development in Southwest China.The importance of economic transformation should be taken into consideration.
基金We acknowledge funding from the EUMETSAT Fellowship Programme for Heather LAWRENCE,Katrin LONITZ and David DUNCAN.
文摘This paper reviews the data quality and impact of observations from the FY-3 satellite series used operationally in the ECMWF system. This includes data from the passive microwave radiometers MWHS-1, MWHS-2 and MWRI, as well as observations from the radio occultation receiver GNOS. Evaluations against background equivalents show that the quality of the observations is broadly comparable to that of similar instruments on other polar-orbiting satellites, even though biases for the passive microwave observations can be somewhat larger and more complex for some channels. An observing system experiment shows that the FY-3 instruments jointly contribute significantly to the forecast skill in the ECMWF system. Positive impact of up to 2% is seen for most variables out to the day-2 forecasts over hemispheric scales, with significant benefits for total column water vapor or for temperature and wind in the stratosphere out to day 4.
文摘Experiments were conducted to test the impact of a cloud diagnosis scheme in place of prescribed zonal average cloud on medium and long range integrations with the Australian Bureau of Meteorology Research Centre(BMRC)global atmosphere model.The cloud scheme was shown to improve the temperature bias in the lower troposphere but there was deterioration in the upper troposphere,especially in the tropics,asso- ciated with underestimation of high cloud amount. Thirty day mean fields in a January integration showed greater amplitude in the Northern Hemisphere planetary waves and a deeper Antarctic circumpolar trough than the control experiment or a simulation with no cloud.The results for the diagnosed cloud case agree more closely with corresponding observed fields. There was also some reduction in the zonal average zonal wind component reflecting the additional zonal asymmetry introduced by the diagnostic cloud scheme.Similar trends were also noted in medium and long range forecasts for January and July conditions,although the impact on predictive skill was slight and in some cases detrimental. Areas for improving the diagnostic cloud scheme are noted.
