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1.
Numerical Simulation of the Effect of the SST Anomalies in the Tropical Western Pacific on the Blocking Highs over the Northeastern Asia 总被引：5，自引：0，他引：5
The effects of the sea surface temperature (SST) anomalies in the tropical western Pacific on the atmospheric circulation anomalies over East Asia are simulated by the IAP-GCM with an observed and idealized distributions of the SST anomalies in the tropical western Pacific,respectively.Firstly,the atmospheric circulation anomalies during July and August,1980 are simulated by three anomalous experiments including the global SST anomaly experiment,the tropical SST anomaly experiment and the extratropical SST anomaly experiment,using the observed SST anomalies in 1980.It is shown that the SST anomalies in the tropical ocean greatly influence the formation and maintenance of the blocking high over the northeastern Asia,and may play a more important role than the SST anomalies in the extratropical ocean in the influence on the atmospheric circulation anomalies.Secondly,the effects of the SST anomalies in the tropical western Pacific on the atmospheric circulation anomalies over East Asia are also simulated w 相似文献
2.
Varotsos Costas A. Sarlis Nikos V. Efstathiou Maria 《Theoretical and Applied Climatology》2018,132(1-2):569-578
Theoretical and Applied Climatology - Andean tropical glaciers have shown a clear shrinkage throughout the last few decades. However, it is unclear how this general retreat is associated with... 相似文献
3.
The possibility to use the observations of the total ozone values in the atmosphere (TO) in the end of polar winters as the
indicator of the cold accumulation in the troposphere and the type of its circulation is considered. The influence of TO over
polar regions on the approach of early and late circulation reconstructions in the stratosphere and the following weather
type in spring-summer season is concluded. 相似文献
4.
Andrew Kerr Macintosh 《Climate Policy》2013,13(3):341-355
One of the reasons why the Kyoto Protocol has been environmentally ineffective is the flaws in the land use, land-use change and forestry (LULUCF) accounting rules, including voluntary accounting for Article 3.4 activities, the adoption of a definition of forest management that allowed parties to preferentially include and exclude forest lands, and allowing parties with net emissions from LULUCF in 1990 to include deforestation emissions in their 1990 emissions base year. Three proposed amendments to the LULUCF rules for the post-2012 regime are discussed and analysed: (1) a force majeure rule, (2) a baseline-and-credit system for forest management and (3) an ‘emissions-to-atmosphere’ approach for harvested wood products. Although these proposals have the potential to significantly improve the accounting framework, there are still significant problems such as the failure to account for the biophysical effects of forest activities, uncertainties associated with the application of the forest management baseline-and-credit system and continuing optional coverage of Article 3.4 activities. 相似文献
5.
Tom Quirk 《Asia-Pacific Journal of Atmospheric Sciences》2012,48(4):339-344
The apparent leveling of the global temperature time series at the end of the 1990s may represent a break in the upward trend. A study of the time series measurements for temperature, carbon dioxide, humidity and methane shows changes coincident with phase changes of the Atlantic and Pacific Decadal Oscillations. There are changes in carbon dioxide, humidity and methane measurement series in 2000. If these changes mark a phase change of the Pacific Decadal Oscillation then it might explain the global temperature behavior. 相似文献
6.
In order to study the characteristics of cold frontal motion over the arbitrary topography, the velocity of cold frontal movement is derived by using the one layer shallow-water model. The results show that there exist the retardation in upwind side and rapid descent in the lee slope when the cold front crosses the topography. 相似文献
7.
V. HAMZA C. A. BABU T. P. SABIN 《大气科学进展》2007,24(4):631-643
The marine atmospheric boundary layer （MABL） plays a vital role in the transport of momentum and heat from the surface of the ocean into the atmosphere. A detailed study on the MABL characteristics was carried out using high-resolution surface-wind data as measured by the QuikSCAT （Quick scatterometer） satellite. Spatial variations in the surface wind, frictional velocity, roughness parameter and drag coefficient for the different seasons were studied. The surface wind was strong during the southwest monsoon season due to the modulation induced by the Low Level Jetstream. The drag coefficient was larger during this season, due to the strong winds and was lower during the winter months. The spatial variations in the frictional velocity over the seas was small during the post-monsoon season （-0.2 m s^-1）. The maximum spatial variation in the frictional velocity was found over the south Arabian Sea （0.3 to 0.5 m s^-1） during the southwest monsoon period, followed by the pre-monsoon over the Bay of Bengal （0.1 to 0.25 m s^-1）. The mean wind-stress curl during the winter was positive over the equatorial region, with a maximum value of 1.5×10^-7 N m^-3, but on either side of the equatorial belt, a negative wind-stress curl dominated. The area average of the frictional velocity and drag coefficient over the Arabian Sea and Bay of Bengal were also studied. The values of frictional velocity shows a variability that is similar to the intraseasonal oscillation （ISO） and this was confirmed via wavelet analysis. In the case of the drag coefficient, the prominent oscillations were ISO and quasi-biweekly mode （QBM）. The interrelationship between the drag coefficient and the frictional velocity with wind speed in both the Arabian Sea and the Bay of Bengal was also studied. 相似文献
8.
A. Jayakumar J��r?me Vialard M. Lengaigne C. Gnanaseelan Julian P. McCreary B. Praveen Kumar 《Climate Dynamics》2011,37(11-12):2217-2234
During boreal winter, there is a prominent maximum of intraseasonal sea-surface temperature (SST) variability associated with the Madden?CJulian Oscillation (MJO) along a Thermocline Ridge located in the southwestern Indian Ocean (5°S?C10°S, 60°E?C90°E; TRIO region). There is an ongoing debate about the relative importance of air-sea heat fluxes and oceanic processes in driving this intraseasonal SST variability. Furthermore, various studies have suggested that interannual variability of the oceanic structure in the TRIO region could modulate the amplitude of the MJO-driven SST response. In this study, we use observations and ocean general circulation model (OGCM) experiments to quantify these two effects over the 1997?C2006 period. Observational analysis indicates that Ekman pumping does not contribute significantly (on average) to intraseasonal SST variability. It is, however, difficult to quantify the relative contribution of net heat fluxes and entrainment to SST intraseasonal variability from observations alone. We therefore use a suite of OGCM experiments to isolate the impacts of each process. During 1997?C2006, wind stress contributed on average only about 20% of the intraseasonal SST variability (averaged over the TRIO region), while heat fluxes contributed about 70%, with forcing by shortwave radiation (75%) dominating the other flux components (25%). This estimate is consistent with an independent air-sea flux product, which indicates that shortwave radiation contributes 68% of intraseasonal heat flux variability. The time scale of the heat-flux perturbation, in addition to its amplitude, is also important in controlling the intraseasonal SST signature, with longer periods favouring a larger response. There are also strong year-to-year variations in the respective role of heat fluxes and wind stress. Of the five strong cooling events identified in both observations and the model (two in 1999 and one in 2000, 2001 and 2002), intraseasonal-wind stress dominates the SST signature during 2001 and contributes significantly during 2000. Interannual variations of the subsurface thermal structure associated with the Indian Ocean Dipole or El Ni?o/La Ni?a events modulate the MJO-driven SST signature only moderately (by up to 30%), mainly by changing the temperature of water entrained into the mixed layer. The primary factor that controls year-to-year changes in the amplitude of TRIO, intraseasonal SST anomalies is hence the characteristics of intraseasonal surface flux perturbations, rather than changes in the underlying oceanic state. 相似文献
9.
Fei ZHENG Shuai HU Jiehua MA Lin WANG Kexin LI Bo WU Qing BAO Jingbei PENG Chaofan LI Haifeng ZONG Yao YAO Baoqiang TIAN Hong CHEN Xianmei LANG Fangxing FAN Xiao DONG Yanling ZHAN Tao ZHU Tianjun ZHOU Jiang ZHU 《大气科学进展》2024,(4):581-586
In the boreal summer and autumn of 2023, the globe experienced an extremely hot period across both oceans and continents. The consecutive record-breaking mean surface temperature has caused many to speculate upon how the global temperature will evolve in the coming 2023/24 boreal winter. In this report, as shown in the multi-model ensemble mean(MME) prediction released by the Institute of Atmospheric Physics at the Chinese Academy of Sciences, a medium-to-strong eastern Pacific El Ni?o event wil... 相似文献
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Determination of the Drag Coefficient over the Tibetan Plateau 总被引：7，自引：0，他引：7
Li Guoping Duan Tingyang Wan Jun Gong Yuanf Shigenori Haginoy Chen Longxun Li Weiliang 《大气科学进展》1996,13(4):511-518
In this paper,a preliminary study is given on the drag (i.e.bulk transfer for momentum) coefficient,on the basis of data from four sets of AWS in Tibet during the first observational year from July 1993 to July 1994 according to China Japan Asian Monsoon Cooperative Research Program.The results show that the drag coefficient over the Tibetan Plateau is 3.3 to 4.4×103.In addition,monthly and diurnal variations of drag coefficient and the relationship among the drag coefficients and the bulk Richardson number,surface roughness length and wind speed at 10 m height are discussed in detail. 相似文献
13.
《Climate Policy》2001,1(4):451-464
The paper investigates the role that the clean development mechanism (CDM) could play in enhancing the effectiveness of north–south technology transfer. This is done by first exploring the issue of technology transfer in the context of existing north–south experiences to bring out the basis for the poor and unsatisfactory performance. This is followed by bringing out the intrinsic relevance of appropriate technology transfer for combating the global climate change issue.The paper then analyses the potential for such an appropriate and sustainable transfer, as well as effective diffusion and deployment of technologies under the CDM. Various aspects of the evolving design of the CDM are investigated to analyze the potential for overcoming the historical barriers across the north–south divide.Any potential for technology transfer under the CDM would need to be supported by an effective framework in the developed countries as well as a conducive environment in developing countries. In searching for such a cooperative and complementary model, the paper analyses the current Dutch strategy to bringforth certain salient features that could be applicable for other countries.Finally, a Japanese model for technology transfer is developed which can build upon domestic strengths as adopt applicable features of the Dutch strategy in order to capitalize any latent potential under the CDM. This is done by first investigating the effectiveness of the existing Japanese technology transfer framework and then extending recommendations for adapting it to reflect the shifting resource flow paradigms under the climate change regime. 相似文献
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British summers are known to have become warmer and drier in recent decades, but has there also been a change in the timing of this season’s beginning, as has occurred for spring? This paper addresses this question by examining records of the first blooming date of early summer flowering plants (phenology) and the timing of first occurrences of warm ‘summer’ temperatures, both events that we associate with the onset of summer. This has revealed that the onset of summer in England has been advancing since the mid 1950s. The occurrence of ‘summer’ temperatures has advanced more than early summer flowering, by eleven and three days respectively in the 1990s compared to the period 1954–1963. This may have encouraged drought or heat wave conditions by prolonging the period of warm temperatures and lower rainfall in which these events occur. 相似文献
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《中国气象科学研究院年报》2001,(1)
The Study of the Continent Atmospheric Baseline (SCAB) is one of Fundamental Research Projects of the PRC Ministry of Science and Technology. It was formally started at the beginning of 2000. Scientists from the Chinese Academy of Meteorological Sciences, Mt. Wa Liguan GAW/ WMO baseline observatory (Qinghai Province), atmospheric background stations in Lin'an (Zhejiang Province), Shangdianzi (Beijing) and Longfengshan (Heilongjiang Province) participated in the project. The main stipulated tasks are fulfilled, and the final summery report is being prepared. The main advances and achievements in the SCAB are as follows: 相似文献
18.
A photochemical model of the atmosphere constitutes a non–linear, non–autonomous dynamical system, enforced by the Earth’s rotation. Some studies have shown that the region of the mesopause tends towards non–linear responses such as period-doubling cascades and chaos. In these studies, simple approximations for the diurnal variations of the photolysis rates are assumed. The goal of this article is to investigate what happens if the more realistic, calculated photolysis rates are introduced. It is found that, if the usual approximations—sinusoidal and step fiunctions—are assumed, the responses of the system are similar: it converges to a 2–day periodic solution. If the more realistic, calculated diurnal cycle is introduced, a new 4–day subharmonic appear. 相似文献
19.
Ｉｎｔｅｒａｃｔｉｏｎｓｂｅｔｗｅｅｎｔｈｅ３０－６０ＤａｙＯｓｃｉｌｌａｔｉｏｎ，ｔｈｅＷａｌｋｅｒＣｉｒｃｕｌａｔｉｏｎａｎｄｔｈｅＣｏｎｖｅｃｔｉｖｅＡｃｔｉｖｉｔｉｅｓｉｎｔｈｅＴｒｏｐｉｃａｌＷｅｓｔｅｒｎＰａｃｉｆｉｃａｎｄＴｈｅｉｒＲｅ... 相似文献
20.
Li Shi Harry H. Hendon Oscar Alves Matthew C. Wheeler David Anderson Guomin Wang 《Climate Dynamics》2011,37(1-2):313-324
The importance of initializing atmospheric intra-seasonal (stochastic) variations for prediction of the onset of the 1997/1998 El Ni?o is examined using the Australian Bureau of Meteorology coupled seasonal forecast model. A suite of 9-month forecasts was initialized on the 1st December 1996. Observed ocean initial conditions were used together with five different atmospheric initial conditions that sample a range of possible initial states of intra-seasonal (stochastic) variability, especially the Madden-Julian Oscillation (MJO), which is considered the primary stochastic variability of relevance to El Ni?o evolution. The atmospheric initial states were generated from a suite of atmosphere-only integrations forced by observed sea surface temperatures (SST). To the extent that low frequency variability of the tropical atmosphere is forced by slow variations in SST, these atmospheric states should all represent realistic low frequency atmospheric variability that was present in December 1996. However, to the extent that intra-seasonal variability is not constrained by SST, they should capture a range of intra-seasonal states, especially variations in the activity, phase and amplitude of the MJO. For each of these five states, a 20-member ensemble of coupled model forecasts was generated by the addition of small random perturbations to the SST field at the initial time. The ensemble mean from all five sets of forecasts resulted in El Ni?o but three of the sets produced substantially greater warming by months 4?C5 in the NINO3.4 region compared to the other two. The warmer group stemmed from stronger intra-seasonal westerly wind anomalies associated with the MJO that propagated eastward into the central Pacific during the first 1?C2?months of the forecast. These were largely absent in the colder group; the weakest of the colder group developed strong easterly wind anomalies, relative to the grand ensemble mean, that propagated into the central Pacific early in the forecast, thereby generating significantly weaker downwelling Kelvin waves in comparison to the warmer group. The strong reduction in downwelling Kelvin waves in the weakest case acted to limit the warming in the eastern Pacific, resulting in a ??Modoki?? type El Ni?o that is more focused in the central Pacific. Our results suggest that the intra-seasonal stochastic component of the atmospheric initial condition has an important and potentially predictable impact on the forecasts of the initial warming and flavour of the 1997/1998 El Ni?o. However, to the extent that atmospheric intra-seasonal variability is not predictable beyond a month or two, these results imply a limit to the accuracy with which the strength and perhaps the spatial distribution of an El Ni?o can ultimately be predicted. These results do not preclude a predictable role of the MJO and other intra-seasonal stochastic variability at longer lead times if some aspects of the stochastic variability are preconditioned by the evolving state of El Ni?o or other low frequency boundary forcing. 相似文献