Combined Effects of Temperature and Salinity on the Zoeal Development of the Crab Liocarcinus puber (Decapoda: Portunidae)

Abstract. Larval development of the crab Liocarcinus puber was studied from hatching to the megalopa stage under 12 different temperature and salinity combinations, 10°C, 15°C, and 20°C (T): 20, 25, 30, and 35% (S), with a view to establishing optimum conditions for zoeal development. High larval mortalities were recorded at 10°C in all the experimental salinities, indicating the sensitivity of the larvae to low temperatures. Highest zoeal survival was obtained in the higher salinity and temperature combinations. First zoeae completed their development in all T-S combinations tested, while successive stages showed increased sensitivity and suffered high mortalities in lower salinities at 15° and 20°C and in all salinities at 10°C. The duration of zoeal development decreased with increasing temperature, whilst the lower salinities delayed development. Q₁₀ values did not differ much at higher salinities, with values ranging from 1.5 to 2.6.     

FY-3C/MWHTS资料反演陆地晴空大气温湿廓线

针对风云三号C星微波湿温探测仪(FY-3C/MWHTS)的陆地晴空观测资料,建立了一维变分反演系统,对大气的温湿廓线进行反演。为了更好地描述温湿廓线的相关性,同时减小温度和湿度在反演过程中相互之间的误差传递,提出了使用背景协方差矩阵的联合矩阵和单独矩阵进行组合反演的方法。对于MWHTS模拟亮温和观测亮温之间的偏差,使用逐扫描点的统计回归方法进行校正。选择中国部分陆地区域的晴空观测亮温进行温湿廓线的反演,并利用欧洲中期天气预报中心(ECMWF)再分析数据、美国国家环境预报中心(NCEP)分析数据以及无线电探空观测(RAOB)数据对反演结果进行验证,温湿廓线的反演结果与ECMWF再分析数据验证的最大均方根误差分别是2.59 K和11.87%,与NCEP分析数据验证的最大均方根误差分别是1.88 K和21.50%,与RAOB数据验证的最大均方根误差分别是3.43 K和25.48%,验证结果表明了反演结果的可靠性。另外与国外同类载荷AMSU观测亮温的物理方法和统计方法反演精度进行了对比,结果表明:MWHTS具有较强的湿度廓线以及高空温度廓线的探测能力,且针对MWHTS的观测亮温建立的一维变分反演系统具有较高的反演精度。与NCEP 6小时预报廓线的验证结果表明:反演的湿度廓线可以提高预报廓线的精度。     

Vortex erosion in a shallow water model of the polar vortex

The erosion of a model stratospheric polar vortex in response to bottom boundary forcing is investigated numerically. Stripping of filaments of air from the polar vortex has been implicated in the occurrence of stratospheric sudden warmings (SSWs) but it is not understood in detail what factors determine the rate and amount of stripping. Here a shallow water vortex forced by topography is used to investigate the factors initiating stripping and whether this leads the vortex to undergo an SSW. It is found that the amplitude of topographic forcing must exceed some threshold (of order 200–450 m) in order for significant stripping to occur. For larger forcing amplitudes significant stripping occurs, but not as an instantaneous response to the forcing; rather, the forcing appears to initiate a process that ultimately results in stripping several tens of days later. There appears to be no simple quantitative relationship between the amount of mass stripped and the topography amplitude. However, at least over the early stages of the experiments, there is a good correlation between the amount of mass stripped and the global integral of wave activity, which may be interpreted as a measure of the accumulated topographic forcing. Finally there does not appear to be a simple correspondence between amount of mass stripped and the occurrence of an SSW.     

IMPACT OF SUMMER WARMING ON DYNAMICS-STATISTICS-COMBINED METHOD TO PREDICT THE SUMMER TEMPERATURE IN CHINA

Based on NCEP/NCAR daily reanalysis data, climate trend rate and other methods are used to quantitatively analyze the change trend of China's summer observed temperature in 1983—2012. Moreover, a dynamics-statistics-combined seasonal forecast method with optimal multi-factor portfolio is applied to analyze the impact of this trend on summer temperature forecast. The results show that: in the three decades, the summer temperature shows a clear upward trend under the condition of global warming, especially over South China, East China, Northeast China and Xinjiang Region, and the trend rate of national average summer temperature was 0.27℃ per decade. However, it is found that the current business model forecast(Coupled Global Climate Model) of National Climate Centre is unable to forecast summer warming trends in China, so that the post-processing forecast effect of dynamics-statistics-combined method is relatively poor. In this study, observed temperatures are processed first by removing linear fitting trend, and then adding it after forecast to offset the deficiency of model forecast indirectly. After test, ACC average value in the latest decade was 0.44 through dynamics-statistics-combined independent sample return forecast. The temporal correlation(TCC) between forecast and observed temperature was significantly improved compared with direct forecast results in most regions, and effectively improved the skill of the dynamics-statistics-combined forecast method in seasonal temperature forecast.     

1960-2015年中国绿洲胡杨生长季对全球变暖的时空响应及原因

基于中国绿洲胡杨（Populus euphratica Oliv.）分布区48个地面气象站1960-2015年逐日平均气温数据,采用线性趋势法、Mann-Kendall检验、ArcGIS反距离加权插值法（IDW）、Morlet小波功率谱和相关分析等方法,分析了中国绿洲胡杨年生长季的起止日及生长期长短对气候变暖的时空响应特征及原因。结果表明：近56年来,中国绿洲胡杨年生长季具有起始日提前、终止日推迟、生长期延长的变化趋势,变化倾向率分别为-1.34 d/10a、1.33 d/10a、2.66 d/10a（α ≥ 0.001）;空间差异十分显著,呈现出由西南向东北起始日越迟,终止日越早,生长期越短的变化规律。胡杨生长季起止日及生长期分别在2001年、1989年和1996年发生突变,且分别存在3.56~7.14 a不等的短周期,与厄尔尼诺2~7 a的周期一致,起始日3.56 a和4.28 a的周期与大气环流2~4 a的周期吻合。原因分析表明亚洲极涡面积指数、青藏高原指数、西风指数和年均二氧化碳排放量是影响胡杨生长季变化的主要因素;此外,纬度对胡杨生长季的影响要明显大于海拔高度,且起始日受纬度和海拔高度的影响比终止日更加显著;胡杨生长季起止日和生长期分别与对应月份的平均气温呈显著的高相关性,且3月均温每升高1 ℃,起始日提前2.21 d,10月均温每升高1 ℃,终止日推迟2.76 d,3-10月均温每升高1 ℃,生长期延长7.78 d,表明胡杨生长季的变化对全球增暖的区域响应十分敏感。     

Monitoring ecosystem dynamics in northwestern Ethiopia using NDVI and climate variables to assess long term trends in dryland vegetation variability

Dryland ecosystems are highly vulnerable to environmental changes. Monitoring is vital in order to evaluate their response to fluctuating rainfall and temperature patterns for long-term ecosystem safeguarding. Monitoring of long term changes of normalized difference vegetation index (NDVI) and climate variables are fundamental for better understanding of change trajectories in dryland ecosystem, and to ascertain their potential interaction with anthropogenic drivers. In this study, we identify determinant factors of dryland changes by using MODIS NDVI, precipitation and temperature data for Breaks for Additive Seasonal and Trend (BFAST) and Mann Kendall test statistic. BFAST predicts iteratively time and number of changes within a time series data to depict the size and direction of changes. Analysis of NDVI, precipitation and temperature time series data showed substantial changes during the study period of 2000–2014. There is a reduction trend in vegetation showed by the decline in NDVI, with significant breakpoints till 2009 and recovery afterwards, without a significant change in annual trends of precipitation (α < 0.05) for the same study period. Furthermore 2 positive climate trends were founded: a) a significant positive trend on long term annual rainfall during the main rainy seasons and; 2) a significant (α < 0.05) annual increment of the long term mean minimum and mean maximum temperature of 0.03 °C/year and 0.04 °C/year, respectively. This assessment showed that climate variables cannot be considered as the main factors in explaining the observed patterns of vegetation dynamics. Seasonal and interannual precipitation changes have a lower weight as driving factors for the reduction in vegetation trends. Hence, the decline in vegetation productivity of the region can be attributed to the increasing pressure of human activities.     

CO2 seasonal variation and global change: Test global warming from another point of view

CO₂ and temperature records at Mauna Loa, Hawaii, and other observation stations show that the correlation between CO₂ and temperature is not significant. These stations are located away from big cities, and in various latitudes and hemispheres. But the correlation is significant in global mean data. Over the last five decades, CO₂ has grown at an accelerating rate with no corresponding rise in temperature in the stations. This discrepancy indicates that CO₂ probably is not the driving force of temperature change globally but only locally (mainly in big cities). We suggest that the Earth''s atmospheric concentration of CO₂ is too low to drive global temperature change. Our empirical perception of the global warming record is due to the urban heat island effect:temperature rises in areas with rising population density and rising industrial activity. This effect mainly occurs in the areas with high population and intense human activities, and is not representative of global warming. Regions far from cities, such as the Mauna Loa highland, show no evident warming trend. The global monthly mean temperature calculated by record data, widely used by academic researchers, shows R²=0.765, a high degree of correlation with CO₂. However, the R² shows much less significance (mean R²=0.024) if calculated by each record for 188 selected stations over the world. This test suggests that the inflated high correlation between CO₂ and temperature (mean R²=0.765-0.024=0.741) used in reports from the Intergovernmental Panel on Climate Change (IPCC) was very likely produced during data correction and processing. This untrue global monthly mean temperature has created a picture:human emission drives global warming.     

Comparison of precipitation and evapotranspiration of five different land-cover types in the high mountainous region

Many rivers originate in high mountainous regions. However, the effects of climate warming on the runoff and water balance in these regions remain unclear due to the lack of observational data from harsh environments, and the variable influences of climate change on alpine land-cover types with different water balances. Using observations and simulations from CoupModel, water-balance values collected at five alpine land-cover types (steppe, shrub meadow, moist meadow, swamp meadow, and moraine) in a small alpine watershed, the Qilian Mountains in Northwest China, from October 2008 to September 2014, were compared. Measured evapotranspiration, multilayer soil temperatures and water contents, and frozen-depth data were used to validate CoupModel outputs. The results show that elevation is the primary influence on precipitation, evapotranspiration, and runoff coefficients in alpine regions. Land-cover types at higher elevations receive more precipitation and have a larger runoff coefficient. Notably, climate warming not only increases evapotranspiration but also particularly increases the evapotranspiration/precipitation ratio due to an upward shift in the optimum elevation of plant species. These factors lead to decrease runoff coefficients in alpine basins.     

东海陆架区的温、盐度逆转现象(Ⅰ)

本文根据国家海洋局1975—1979年标准断面调查资料,对东海陆架区出现的温、盐度逆转现象进行定义和划分;通过统计分析得出,在东海陆架区出现两个逆转现象高频海区,一个位于江苏、浙江近海和外海的一狭长海域内,另一个位于济州岛以南和以西海域。通过对逆转现象成因的讨论认为,前者高频区主要是由于几个不同水团的叠置、交汇、相互作用的结果;由于气旋型涡旋的存在和黄海暖流水附近冷水块的出现而伴生的海水上升运动是导致后者高频区的因素。