Sea surface winds from reanalysis （NCEP-2 and ERA-40 datasets） and satellite-based products （QuikSCAT and NCDC blended sea winds） are evaluated using in situ ship measurements from the Chinese National Antarctic R...Sea surface winds from reanalysis （NCEP-2 and ERA-40 datasets） and satellite-based products （QuikSCAT and NCDC blended sea winds） are evaluated using in situ ship measurements from the Chinese National Antarctic Research Expeditions （CH1NAREs） from 1989 through 2006, with emphasis on the Southern Ocean （south of 45°S）. Compared with ship observations, the reanalysis winds have a positive mean bias （0.32 m·s-1 for NCEP-2 and 0.13 m·s-1 for ERA-40）, and this bias is more pronounced in the Southern Ocean （0.57 m·s-1 and 0.45 m·s-1, respectively）. However, mean biases are negative in the tropics and subtropics. The satellite-based winds also show positive mean biases, larger than those of the reanalysis data. All four wind products overestimate ship wind speed for weak winds （〈4 m·s-1） but underestimate for strong winds （〉10 m·s-1）. Differences between the reanalysis and satellite winds are examined to identify regions with large discrepancies.展开更多
The spatial distribution of soil moisture, especially the temporal variation at seasonal and interannual scales, is difficult for many land surface models （LSMs） to capture partly due to the deficiencies of the LSMs...The spatial distribution of soil moisture, especially the temporal variation at seasonal and interannual scales, is difficult for many land surface models （LSMs） to capture partly due to the deficiencies of the LSMs and the highly spatial variability of soil moisture, which makes it problematic to simulate the moisture for climate studies. However the soil moisture plays an important role in influencing the energy and hydrological cycles between the land and air, so it should be considered in land surface models. In this paper, a soil moisture simulation in China with a T213 resolution （about 0.5625°× 0.5625°） is compared to the observational data, and its relationship to precipitation is explored. The soil moisture distribution agrees roughly with the observations, and the soil moisture pattern reflects the variation and intensity of the precipitation. In particular, for the 1998 summer catastrophic floods along the Yangtze River, the soil moisture remains high in this region from July to August and represents the flood well. The seasonal cycle of soil moisture is roughly consistent with the observed data, which is a good calibration for the ground simulation capacity of the Atmosphere-Vegetation Interaction Model （AVIM） with respect to this tough problem for land surface models.展开更多
The ground-based Atmospheric Emitted Radiance Interferometer(AERI)was deployed in Shouxian,China in 2008 to measure down-welling infrared radiances with high resolution.Based on AERI observations,we propose a new meth...The ground-based Atmospheric Emitted Radiance Interferometer(AERI)was deployed in Shouxian,China in 2008 to measure down-welling infrared radiances with high resolution.Based on AERI observations,we propose a new method for retrieving vertical temperature and water vapor profiles in the planetary boundary layer(PBL).The method exclusively uses NCEP-2,a global reanalysis data as a first-guess profile in an iterative recursive algorithm.The PBL profiles of temperature and moisture under clear sky conditions in Shouxian have been retrieved using this new method.Compared with coincident radiosonde measurements,we find that AERI is able to obtain more accurate temperature and water vapor profiles in the PBL.The retrieval results with high temporal resolution can be used to monitor the PBL stability and evolution.展开更多
基金supported by the National Natural Science Foundation of China(Grant nos.41006115,41076128,41206184)the Marine Science Youth Fund of SOA(Grant no.2010215)the Chinese Polar Environmental Comprehensive Investigation and Assessment Programmes (Grant no.CHINARE2013-04-01).
文摘Sea surface winds from reanalysis （NCEP-2 and ERA-40 datasets） and satellite-based products （QuikSCAT and NCDC blended sea winds） are evaluated using in situ ship measurements from the Chinese National Antarctic Research Expeditions （CH1NAREs） from 1989 through 2006, with emphasis on the Southern Ocean （south of 45°S）. Compared with ship observations, the reanalysis winds have a positive mean bias （0.32 m·s-1 for NCEP-2 and 0.13 m·s-1 for ERA-40）, and this bias is more pronounced in the Southern Ocean （0.57 m·s-1 and 0.45 m·s-1, respectively）. However, mean biases are negative in the tropics and subtropics. The satellite-based winds also show positive mean biases, larger than those of the reanalysis data. All four wind products overestimate ship wind speed for weak winds （〈4 m·s-1） but underestimate for strong winds （〉10 m·s-1）. Differences between the reanalysis and satellite winds are examined to identify regions with large discrepancies.
基金This work was supported by the Special Project of the China Meteorological Administration for Climate Change(Grant No.CCSF2005-1)various projects of the National Natural Science Foundation of China(Grant No.40205013 and 40005005).Thanks are given to Mr.Haibin Li for providing the in situ observations of soil moisture in China and for discussing them with us.
文摘The spatial distribution of soil moisture, especially the temporal variation at seasonal and interannual scales, is difficult for many land surface models （LSMs） to capture partly due to the deficiencies of the LSMs and the highly spatial variability of soil moisture, which makes it problematic to simulate the moisture for climate studies. However the soil moisture plays an important role in influencing the energy and hydrological cycles between the land and air, so it should be considered in land surface models. In this paper, a soil moisture simulation in China with a T213 resolution （about 0.5625°× 0.5625°） is compared to the observational data, and its relationship to precipitation is explored. The soil moisture distribution agrees roughly with the observations, and the soil moisture pattern reflects the variation and intensity of the precipitation. In particular, for the 1998 summer catastrophic floods along the Yangtze River, the soil moisture remains high in this region from July to August and represents the flood well. The seasonal cycle of soil moisture is roughly consistent with the observed data, which is a good calibration for the ground simulation capacity of the Atmosphere-Vegetation Interaction Model （AVIM） with respect to this tough problem for land surface models.
基金supported by the Chinese Academy of Sciences(XDA05040300)the External Cooperation Program of the Chinese Academy of Sciences(GJHZ1207)
文摘The ground-based Atmospheric Emitted Radiance Interferometer(AERI)was deployed in Shouxian,China in 2008 to measure down-welling infrared radiances with high resolution.Based on AERI observations,we propose a new method for retrieving vertical temperature and water vapor profiles in the planetary boundary layer(PBL).The method exclusively uses NCEP-2,a global reanalysis data as a first-guess profile in an iterative recursive algorithm.The PBL profiles of temperature and moisture under clear sky conditions in Shouxian have been retrieved using this new method.Compared with coincident radiosonde measurements,we find that AERI is able to obtain more accurate temperature and water vapor profiles in the PBL.The retrieval results with high temporal resolution can be used to monitor the PBL stability and evolution.
