新型船载气象卫星接收系统   总被引：8，自引：0，他引：8  

解思梅  郝春江  邹斌  盛晓文  张灿荣  荆其一  廖晓宏 《海洋学报》2000,22(4):31-40

新型船载气象卫星接收系统为南极考察船的航海气象保障和在南大洋冰区中航行导航专门研制.该系统能够适应高温、高湿和低温超饱和的气候环境,在12级以上大风和船在破冰时剧烈摇摆和振动以及有雷达等强磁场信号干扰的情况下,具有自我保护能力.有极轨高分辨和静止低分辨卫星的双套接收和图像处理系统.该系统的关键创新之处:(1)采用了有源陀螺仪稳定平台.利用惯性测量和三轴伺服机构控制天线和隔离船摇.解决极轨卫星低仰角和过顶轨道高仰角跟踪丢线的矛盾,解决了船在运动状态下,不断改变位置、方向以及摇摆的状态下,准确地跟踪和捕捉到卫星,接收到清晰的卫星云图.(2)图像处理系统用了最新的BORLAND-DELPHI语言编程,采用两行元素的轨道模式计算动态定位套网格系统.利用电子地图网格数据,用迭代法画出地形海岸线.计算出每一像元素的位置;能够在图上显示任意一点的经纬度,标出任意目标物.解决了在海洋中航行找不到参照物时的困惑.能够监测云和温度、林火、海洋及陆地的异常变化.能够输出24位真彩色的高清晰度的卫星云图.该系统整体结构技术先进,体积小,重量轻,适应恶劣气候和海洋环境,图像处理系统功能齐全、分辨率高,操作方便.既适用于各种船只,也适用于陆地.  相似文献   

西太平洋暖池区低层大气气象学特征的观测分析     

吴增茂  盛立芳  张庆荣  蔡亲炳  林锡贵  石志雄  张凌 《中国海洋大学学报(自然科学版)》1993,(Z2)

根据TOGA—COARE强化观测资料分析西太平洋暖地区低层大气的气象学特征。讨论北半球冬季(11月-2月)该区域海面风和温度的特征,ITCZ及其有中尺度动力学特征的赤道大气涡(Eddy)的演变特征,对流混合边界层大气和低层正压大气层特征,以及云形态及降水特征等。指出,对于赤道大气,把正压大气层顶取为700hPa是合适的。  相似文献   

Effects of Meteorological Factors on Toxic Red Tide Events in Sabah, Malaysia     

Gires Usup  Yu Kim Lung 《Marine Ecology》1991,12(4):331-339

Abstract. Red tides of the toxic dinoflagellate Pyrodinium bahamense var. compressum have occurred almost annually since 1976 in the coastal waters of the west coast of Sabah, Malaysia. Field obSérvations have indicated that the timings of these outbreaks could be linked to meteorological forcings. All the red tides have occurred during either the northeast or southwest monsoon periods. Matching of red tide outbreaks with total monthly rainfall, monthly-averaged index of wind-induced surface water mixing, and monthly-averaged upwelling index for the period from 1975 to 1989 failed to show any definite pattern. However, more red tide events occurred in months with high mixing index values. The absence of definable patterns could be due to the use of monthly, rather than daily, values in the calculations.  相似文献   

顾及板块内部形变的抗差估计异常测站筛选方法及应用     

雷前坤  张俊  范成成  武宇  黄康钰 《大地测量与地球动力学》2020,40(7):677-681

采用块体运动的整体旋转与线性应变模型（RELSM）描述块体内部形变，利用具有高崩溃污染率的抗差估计方法，对中国大陆构造环境监测网络在环渤海区域的GPS观测速度场数据进行测站筛选及拟合分析。结果表明，本文方法不仅能较好地兼顾块体整体运动的平滑性和局部构造运动的差异性，还能抑制粗差的影响，可获得较好的速度场拟合结果。  相似文献   

Seasonal Variation and Meteorological Control of CO2 Flux in a Hilly Plantation in the Mountain Areas of North China          下载免费PDF全文

HUANG Hui  ZHANG Jinsong  MENG Ping  FU Yuling  ZHENG Ning  GAO Jun 《Acta Meteorologica Sinica》2011,25(2):238-248

The carbon cycle of terrestrial ecosystems is an important scientific issue in global climate change re- search. Plantation forest plays an important role in terrestrial carbon budget in China. In this study, eddy covariance flux data measured at Xiaolangdi forest ecosystem research station (XLD) in 2007 and 2008 are used to analyze the seasonal variation and meteorological control of CO2 flux in a 30-yr-old mixed plantation. The plantation forest mainly consists of Quercus variabilis, Platycladus orientalis, and Robinia pseudoacacia. The results show that the seasonal variations of net ecosystem exchange of CO2 (NEE), gross primary production (GPP), and ecosystem respiration (Re) display single-peak curves. The maximum of carbon sequestration appears during May and June each year. The relative contribution of carbon re- lease from ecosystem respiration to GPP varied slightly between 2007 and 2008. The relationship between NEE and photosynthetic active radiation (Qp) accords with the rectangular hyperbola model on diurnal scale, and shows a good linear correlation on monthly scale. The ecosystem photosynthetic parameters: the maximum photosynthetic rate (Pmax), the ecosystem photosynthetic photonyield (α), and the daytime ecosystem respiration (Rd) exhibit seasonal variations. Pmax reaches the maximum in August each year, with small interannual di?erence. The interannual differences of α and Rd are obvious, which is attributed to the changes of meteorological factors, such as solar radiation, vapor pressure deficit (D), precipitation, etc. Parameters Re, GPP, and NEP (net ecosystem production) have obvious exponential relations with temperature on monthly scale. There is a hysteresis in the response of GPP and NEP to temperature, i.e., the carbon sequestration is not the maximum when the temperature reaches the peak value. The Q10 values were 1.37 and 1.45 in 2007 and 2008, respectively. On monthly scale, Re, GPP, and NEE increase as D increases, but rise slowly and even decrease when D is higher than 1.5 kPa.  相似文献   

Use of mixed bivariate distributions for deriving inter‐station correlation coefficients of rain rate     

Eunho Ha  Chulsang Yoo 《水文研究》2007,21(22):3078-3086

Even though rain rate is notorious for its spatial and temporal intermittency, its effect on the second‐order statistics of rain rate, especially the inter‐station correlation coefficients, has not been intensively evaluated before. This study has derived and compared the inter‐station correlation coefficient of rain rate for three cases of data: (1) only the positive measurements at both locations; (2) the positive measurements at either one or both locations; (3) all the measurements including zero measurement at both locations. For these three cases, the inter‐station correlation coefficients are analytically derived by applying the mixed bivariate log‐normal distribution. As an application example, the model parameters are estimated using the rain rate data collected at the Geum River basin, Korea, and the resulting inter‐station correlation coefficients are evaluated and compared with those estimated by applying the Gaussian distribution. We could find that highly biased inter‐station correlation coefficients are unavoidable when simply estimating them under the assumption of Gaussian distribution, or even when using the log‐transformed rain rate data. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

三峡库首区最小一维速度模型研究   总被引：3，自引：0，他引：3  

赵旭  李强  蔡晋安 《大地测量与地球动力学》2007,27(Z1):1-7

根据三峡台网2001～2006年记录的490个地震事件中的7 330条P波和3 524条S波到时资料,利用Kissling方法得到了三峡库区最小一维P波和S波速度模型以及台站校正值,并应用于地震的精定位.重新定位后地震走时残差均方根从原来的0.56 s下降到0.41 s,地震定位精度在经度、纬度、深度方向上有了较大提高.  相似文献   

̩��̨��ײ�Ӧ��۲��ʵ�ر궨   总被引：4，自引：2，他引：2  

阚宝祥  邱泽华  唐磊 《大地测量与地球动力学》2007,27(6):119-123

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李祖宁  刘序俨  吴绍祖  陈光 《大地测量与地球动力学》2007,27(5):18-21

????1995~2003????GPS????????????????????????? ?????????GPS????????????????????????????仯????????????????????????????????????????????????????,??1995~1997???2001~2003???????????????????????????????????????????????????С??????н??仯??????仯????????1999????弯??7.6?????????????????????????  相似文献   

Quantitative effects of changes in agricultural irrigation on potential evaporation     

Congying Han  Baozhong Zhang  Songjun Han 《水文研究》2021,35(2):e14057

Evaporation is a key element to the basin's water cycle. Agricultural irrigation has resulted in a significant variation of regional potential evaporation (E_pen). The spatiotemporal variation of E_pen and influencing factors in natural, agricultural, and desert areas in different developmental stages of irrigation in Heihe River Basin (HRB) from 1970 to 2017 were comparatively analysed in this study. This work focused on the correction effect of irrigation on the variation of E_pen. Agricultural water consumption in HRB significantly varied around 1998 due to agricultural development and water policy. Under the influence of irrigation, annual variations of E_pen in agricultural, natural, and desert areas were significantly different. From 1970 to 1998, the annual trend slope of E_pen in natural area only reduced by 1 mm decade⁻¹, while that in agricultural area significantly decreased by 39 mm decade⁻¹. After the implementation of water-saving irrigation, E_pen in natural and agricultural areas increased by 11 and 54 mm decade⁻¹, respectively, from 1998 to 2017. In contrast with natural and agricultural areas, E_pen in desert area decreased by 80 mm decade⁻¹ from 1970 to 1998 and continuously decreased by 41 mm decade⁻¹ from 1998 to 2017. However, the regulatory effect of irrigation on E_pen in desert area started to manifest due to the expansion of cultivated land area from 2010 to 2017. Irrigation had a significant regulatory effect on the variation of E_pen in HRB. The regulatory effect was mainly reflected on the aerodynamic term (E_aero). Results indicated that the main meteorological factors influencing E_pen in each region were wind speed, which is 2 m above the surface (U₂), and water vapour deficit (VPD).  相似文献