New estimates of annual sea level maxima in the Bristol Channel

Observed sea level maxima in the form of annual extremes have been analysed for 4 ports in the Bristol Channel. The data analysed has been extended to include levels recorded in December 1981, when previous estimates of maximum return levels were exceeded.     

On the possibility of forecasting the long-term air temperature variability that determines the hydrophysical structure and ecology of the Black Sea waters

Periods and amplitudes of long-term temperature fluctuations were obtained using the methods of spectral analysis and filtration of secular time series of the air temperature at 13 hydrometeorological stations in the Black Sea region. The prognostic calculations of the long-term air temperature variability are based on the results of processing of time series. The calculations of the air temperature agree with the data of observations. The possibility of the long-term air temperature variability prediction is shown.     

海表温度与海表气温位相关系

采用1982-2012年NOAA最优插值海表温度(第二版)数据资料和NCEP/NCAR再分析海表气温数据资料,利用均方差分析法,分析海表温度和海表气温的年际变化特征。将31年数据按照El Nin軌o/La Nin軌a事件分为a,b,c 3组,利用超前/滞后相关性分析法,将中低纬度海域海表温度异常(SSTA)与海表气温异常(SATA)做超前/滞后相关分析,得到每个格点SSTA与SATA之间相关性最显著的时间,从而确定SSTA与SATA之间的超前/滞后相关关系。研究结果表明:中纬度海域以SATA超前SSTA为主,SATA滞后SSTA主要分布在20°S-20°N的热带海域。SATA与SSTA超前/滞后天数统计结果均呈现双峰型分布,SATA超前峰值出现在10 d左右,SATA滞后峰值出现-7 d左右。El Nin軌o/La Nin軌a事件的出现,对海气超前/滞后相关关系具有一定影响。     

Relationship between the anomalies of temperature and air pressure over the ocean

This paper considers the relationship between multi-year air temperature and pressure fluctuations over the ocean, based on an approximate solution of the problem on the determination of large-scale seawater temperature anomalies from the conditions predominating at the sea surface. The dependence derived is numerically analysed using observations made in the North Atlantic. It is shown that the variability of annual mean air temperature anomalies is largely controlled by the air pressure field which has taken place during the preceding long-term period. The dependence derived may be applied to generate long-term forecasts of the ocean's hydrometeorological regime.Translated by Vladimir A. Puchkin.     

我国华南近海赤潮发生发展的温、压演变模式

通过分析,归纳出3种赤潮发生前后水温、气温和气压的演变模式,并论述各种演变模式与赤潮发生发展的关系。通过数理统计,归纳了华南近海赤潮发生前后阶段水温、气温和气压的变化范围以及演变特征,说明了升温降压天气过程、温压稳定过程以及相对于多年月平均值偏暖的年份或时段均有利于赤潮的发生发展。     

日气温变化下杭州湾水温的数值模拟

杭州湾内水温在不同时间尺度下均存在变化,这对河口生态等会产生影响。由于昼夜气温变化大,空气和海水的热量交换较为频繁。另外,随着气温的逐日下降,水温也随之降低。为研究日气温变化下杭州湾内的水温变化,建立了三维数学模型,通过考虑水面和空气的热交换通量,复演了日气温变化下湾内水温特征。经过和实测潮流数据比较,本文模型很好地模拟出了杭州湾内大、中和小潮期间水流的变化。在综合考虑太阳辐射、长波辐射和水气感热交换下,模型成功再现了日气温变化下水温的变化过程。研究结果一方面有助于认识强潮河口湾内水温变化特征,另一方面将为研究温度对泥沙运动的影响提供前期基础。     

Regional features of the seasonal variability of linear trends of the temperature fields in the Atlantic Ocean and their relation to the large-scale circulation of waters

By using the data array of satellite measurements of the sea-surface temperature (SST), it is shown that the distributions of linear trends of the SST for 17 years (1986–2002) are closely correlated with the specific features of large-scale circulation of waters. The extreme values of trends of the SST are observed in the zones of the Gulf Stream, East-Greenland, Labrador, and North-Atlantic Currents, North Equatorial Countercurrent, South Equatorial and Antarctic Circumpolar Currents. The differences between the distributions of trends of the SST for some months of the year are revealed. In the zones of currents transporting warm surface waters from the tropical areas, positive trends of the SST are observed for the most part of the year. On the contrary, negative trends are predominant in the zones of currents transporting cold upwelling waters. Translated from Morskoi Gidrofizicheskii Zhurnal, No. 4, pp. 32–42, July–August, 2008.     

A simple model for seawater crystallization in the temperature spectrum

A model of sea ice growth as an expanded region of a phase transition (mushy zone) with a linear temperature profile is developed. The linear temperature distribution agrees with the mushy zone by introducing an equivalent porosity determined by its thermodynamical condition. This approach does not require any a priori information about the dependence of the porosity on the temperature and salinity; it rather allows us to obtain this relation from a solution of the mathematical problem. The model makes it possible to calculate the thickness of the growing ice and to estimate its main characteristics as well as the heat capacity of the underice layer under the conditions of undisturbed growth at any moment of the autumn-winter season up to its maximal thickness with account for the snow accumulation, basin depth, varying regime of cooling, and water salinity.     

A simple formula for the estimation of pore pressures and their dissipation

In the soil underneath a heavy structure pore water pressures may be generated by the loads on the structure. Such pore pressures lead to a reduction of the effective stresses, and therefore may influence the stability of the structure. The paper describes the mechanisms involved in the generation and dissipation of pore pressures. Analytical solutions of the complete problem are applicable only to very simple conditions, so that usually recourse has to be made to numerical methods. In order to check the validity of such solutions a simplified analytical method may be used. The establishment of such a simplified solution is illustrated in the paper. The approach provides the possibility of evaluating the influence of the various parameters involved in describing the problem. The simplified solution in principle applies to a wide class of three-dimensional problems, for which the progress of the consolidation process can be estimated.     

Measurements of vertical air temperature gradients with dipmeter

By means of measuring the dips of horizon with a Pulfrich dipmeter, vertical air temperature gradients near the sea surface were obtained with an accuracy of ca. ±0.01°C/m, much better than a conventional method with an array of temperature sensors. The additional advantage of this technique was that the measurements were made on board a ship underway, consequently data from wide oceanic areas could be accumulated rather quickly and easily. From the results of dip measurements at 125 stations on two cruises of the T/V Oshoro Maru of the Hokkaido University, extending from the Bering Sea to the south of Australia, the temperature gradients were computed with a new formula with an assumption that the refractive index of air varied with a height only. It was found that, in the northern North Pacific Ocean, vertical air temperature gradients were positive, while in the subtropical and tropical Pacific Ocean both the negative and positive gradients were observed. Generally, in the same sea region, the temperature profiles had the similar form, irrespective of air-sea temperature differences.     

Regional estimates of POC export flux derived from thorium-234 in the western Arctic Ocean

1Introduction CarboncyclingintheArcticOceanplaysanim- portantroletoglobalchange.Traditionally,marine productivityintheArcticOceanisthoughttobevery low,andthussomebiogeochemicalprocessessuchas particleexportandcyclingofnutrientsarenotsoac- tivebecauseofthembeingcoveredperenniallybyice, lowtemperatureandshorttimeofphotosynthesis (PlattandRao,1975).Afewpreviousestimatesof particulateorganiccarbon(POC)exportindicateda neglectablemagnitudeinthecentralArcticOcean (Baconetal.,1989).However,recen…     

On the possibility of mapping living corals to the species level based on their optical signatures

Several methods (Spectral Angle Mapper, first derivatives, spectral clustering) were used to test the possibility of discriminating live corals at the species level by using reflectance spectra obtained by close range underwater remote sensing. The Spectral Angle Mapper used with an in situ spectral library of 73 coral colonies recognised all corals correctly in an artificial remote sensing image created from the same coral spectra. The results did not change when “grey” noise was added to each pixel in the artificial image or when the artificial image was made from reflectance spectra modelled through a 5-m water column. The results showed that the within-species variability in optical properties of a set of four coral species, for which at least three different specimens were measured, was as high as between-species variability. Thus, it is highly unlikely that hard corals can be discriminated at a species level by means of remote sensing. Cluster analysis showed that it is difficult to recognise corals also at the genus level (Acropora vs. non-Acropora) based on their reflectance spectra. However, visual inspection of the coral spectra and clustering analysis suggest that it is possible to separate three main optical types of corals: green, blue, and brown corals. This may form the basis for an optical classification of corals that is more suited for remote sensing than traditional taxonomy.     

渤海冰面积与营口气温的关系

通过对2000～2004年连续5年冬季渤海逐日冰面积与营口日均气温积温的相关分析,发现二者相关关系较好,同时获得了逐日冰面积与营口日均气温积温的线性回归方程,并用此方程对2005～2006年冬季渤海的冰面积进行了预报试验,试验结果证明该方程具有一定的预报能力.     

Pattern recognition techniques for visualizing the biotropic waveform of air temperature and pressure

It is known that long periods of adverse weather have a negative effect on the human cardiovascular system. A number of studies have set a lower limit of around 5 days for the duration of these periods. However, the specific features of the negative dynamics of the main weather characteristics—air temperature and atmospheric pressure—remained open. To address this problem, the present paper proposes a conjunctive method of the theory of pattern recognition. It is shown that this method approaches a globally optimal (in the sense of recognition errors) Neumann critical region and can be used to solve various problems in heliobiology. To illustrate the efficiency of this method, we show that some quickly relaxing short sequences of temperature and pressure time series (the so-called temperature waves and waves of atmospheric pressure changes) increase the risk of cardiovascular diseases and can lead to serious organic lesions (particularly myocardial infarction). It is established that the temperature waves and waves of atmospheric pressure changes increase the average morbidity rate of myocardial infarction by 90% and 110%, respectively. Atmospheric pressure turned out to be a more biotropic factor than air temperature.     

Sensitivity of amplitude-phase characteristics of the surface air temperature annual cycle to variations in annual mean temperature

The ERA40 and NCEP/NCAR data over 1958–1998 were used to estimate the sensitivity of amplitude-phase characteristics (APCs) of the annual cycle (AC) of the surface air temperature (SAT) T _s. The results were compared with outputs of the ECHAM4/OPYC3, HadCM3, and INM RAS general circulation models and the IAP RAS climate model of intermediate complexity, which were run with variations in greenhouse gases and sulfate aerosol specified over 1860–2100. The analysis was performed in terms of the linear regression coefficients b of SAT AC APCs on the local annual mean temperature and in terms of the sensitivity characteristic D = br ², which takes into account not only the linear regression coefficient but also its statistical significance (via the correlation coefficient r). The reanalysis data were used to reveal the features of the tendencies of change in the SAT AC APCs in various regions, including areas near the snow-ice boundary, storm-track ocean regions, large desert areas, and the tropical Pacific. These results agree with earlier observations. The model computations are in fairly good agreement with the reanalysis data in regions of statistically significant variations in SAT AC APCs. The differences between individual models and the reanalysis data can be explained, in particular, in terms of the features of the sea-ice schemes used in the models. Over the land in the middle and high latitudes of the Northern Hemisphere, the absolute values of D for the fall phase time and the interval of exceeding exhibit a positive intermodel correlation with the absolute value of D for the annual-harmonic amplitude. Over the ocean, the models reproducing larger (in modulus) sensitivity parameters of the SAT annual-harmonic amplitude are generally characterized by larger (in modulus) negative sensitivity values of the semiannual-harmonic amplitude T _{s, 2}, especially at latitudes characteristic of the sea-ice boundary. In contrast to the averaged fields of AC APCs and their interannual standard deviations, the sensitivity parameters of the SAT AC APCs on a regional scale vary noticeably for various types of anthropogenic forcing.     

The reliability of the wind speed, air temperature and humidity observed on ship

Using data of wind speed, air temperature and humidity recorded simultaneously on board and the on the small buoy, the latter is considered as criterion, the paper has discussed the influence of the body of ship on the meteorological data. Owing to the disturbance and the influence of heat radiation from the body of ship, the temperature observed on board is higher by about 2癈 than on buoy, and the relative humidity lower by 10%, wind speed observed on the mast is not only irregular but is less than that on the buoy, the error of which would be 3 m/s. The paper therefore suggests that the data observed on the deck in daytime, especially in fair weather after midday, is less reliable. The reliability of data decreases simultaneously with the increase of the body of ship in size.In addition, this paper also proposes that more reasonable observing points chosen on board should be the key to obtain reliable data. By analysis, it is believed that the meteorological data observed on ship's bow or upwind outs     

Sediment Load of Asian Rivers flowing into the Oceans and their Regional Variation

Study of the major Asian rivers discharge to the ocean reveals variations of their water discharges and sediment loads.and local characteristics of river sediment concentrations.On the basis of this,the Asian rivers fall into three regions,including Eurasia Arctic,East Asia,Southeast and South Asia Regions.The Eurasia Arctic Region is characterized by the lowest sediment concentration and load,while the East Asia Region is of the highest sediment concentration and higher sediment load,and the South-East and South Asia Region yields Higher Sediment concentration and highest sediment load. The sediment loads of these regions are mainly controlled by climate,geomorphology and tectonic activity.The Eurasia Arctc rivers with large basin areas and water discharge,drain low relief which consists of tundra sediment,thus causing the lowest sediment load.The East Asia rivers with small basin areas and lowest water discharges,drain extensive loess plateau,and transport most erodible loess material,which results in highest sediment concentration.The SE and South Asia rivers originating from the Tibet Plateau have large basin areas and the largest water discharges because of the Summer Monsoon and high rainfall influence,causing the highest sediment load.In Asia,tectonic motion of the Tibet Plateau Plays an important role.Those large rivers originating from the Tibet Plateau trasport about 50% of the world river sediment load to ocean annually,forming large estuaries and deltas,and consequently exerting a great influence on sedimentation in the coastal zone and shelves.     

Quantitative estimates of disturbances contributed by a megalopolis to the temperature field of the atmospheric boundary layer

Seasonal and diurnal variations in the temperature of the atmospheric boundary layer (ABL) are analyzed, and the features of spatial and temporal variations in ABL temperature that are caused by the influence of a megalopolis are revealed. The gradients of air temperature for the megalopolis, its vicinity, and background conditions are compared. A multiplicative model of the seasonal diurnal variability of ABL temperature is constructed, and the relative frequencies of unstable ABL-temperature stratification are studied.