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1.
In the Polish Carpathian Mountains two altitudinal profiles were chosen. Ranging from 200 to 1,000 m asl along 20°00 and 21°30E their spatial patterns of the topographical types in the mountains and uplands, geometric configuration of concave topographies and direction of their course are different.The effects of topography on the mesoclimatic conditions in the area investigated were analyzed by the diurnal air temperature records at the 28 meteorological stations in the years 1951 – 1970. Along the two profiles, taking the points situated at the same height asl and similar altitude, the mean extreme temperatures in the particular months, as well as the values of the first and ninth deciles of the maximum and minimum temperatures were analyzed. Special consideration was given to the spatial distribution of the minimum temperature and characteristics derived, because it reflects the influence of topography in a higher degree than the maximum temperature. Since low air temperatures are the main factor for the plant growth in the Polish Carpathians, spatial differentiation of the minimum temperature regulates the rate of development of the wild and cultivated plants during the growing season.  相似文献   

2.
《Comptes Rendus Geoscience》2014,346(9-10):213-222
Two and a half decade (1985–2009) surface air temperature from Giovanni database available for the Naradu valley at High Himalaya Mountain range of Himachal Pradesh has been analysed to determine the changes in the maximum, minimum and mean air temperatures. The analysis was subjected for seasonal, annual and monthly basis and revealed a tendency towards warmer years all around, with significantly warmer winter and more significant increase in minimum temperatures. The annual maximum, minimum and mean temperatures have increase by 1,41 °C, 1,63 °C and 1,49 °C, respectively. The seasonal analysis indicates that the tendency is more pronounced in winter followed by post-monsoon, pre-monsoon and monsoon season. The trends were also examined on a maximum temperatures, and it showed a significant warning in all the months in annual mean, minimum and maximum temperatures, except February during the period of 1985–2009 in the valley. Different trend detection statistical tools have been exercised by using variety of non-parametric tests and all are in agreement.  相似文献   

3.
Urban universities are a microcosm of urban built-up areas, such as cities, but with a much smaller scale of spatial resolution. Within universities, there are many types of landscape features exhibiting different heat absorption and transmission capacities. These landscape features generate spatial–temporal heat signatures, and the knowledge about landscape features and urban heat hazard on university campuses is limited. The objective of this research is an assessment of landscape features and the potential heat hazard threats of two urban universities in ASEAN, located in the centre of the equatorial region. The focus of this research is on urban heat hazards in two urban universities in ASEAN, the University of Malaysia in Kuala Lumpur and the University of Indonesia in Jakarta, within the context of the spatial–temporal behaviour of urban heat and the urban heat effects on the environment and human well-being on campuses. The spatial and temporal analysis used to answer the objective of this research via data-gathering methods from image satellite, ground trough, and human perception study. The UM campus and UI campus, both urban campuses, had similar landscape features but had different total percentage areas of these features. The UM campus was 59.1% covered by the densely vegetated surface landscape feature, a percentage lower than that of the UI campus, which was 65.3% vegetation covered. The temporal results for the UHS of the UM campus in 2013–2016 show a maximum temperature of 39 °C. Therefore, the UHS of the UI campus demonstrated temporal behaviour in 2013–2016, with a maximum temperature of 38 °C. The UHS behaviour of the UM campus and UI campus had an air surface temperature with a maximum average temperature of 33 °C. The air surface temperatures exceeding 32 °C at the UM campus (12 pm until 6 pm?=?5 h) lasted for a longer time than those at the UI campus (12 pm until 3 pm?=?3 h). This study showed that, based on the perceptions on both campuses, if temperatures exceeded 30 °C, respondents were very hot and very uncomfortable, which will impact health and decrease work or academic achievements, as perceptions of heat intensity impact human well-being. Students perceived that heat intensity impacted their health and they reported becoming tired and lethargic under maximum temperatures and were very hot and very uncomfortable, and this condition impacted their work activity. These results indicated that, at both the UM and UI campuses, heat intensity impacts human well-being, with risks associated with hot temperatures. These two urban campuses are significant for ASEAN university awareness of the urban heat hazard of the equatorial area.  相似文献   

4.
东南极中山站-昆仑站断面最高和最低气温变化特征   总被引：1，自引：1，他引：0  
利用中山站-昆仑站断面自动气象站2 m气温和同期再分析资料分析了南极沿海到内陆高原的最高和最低气温的变化特征, 并通过个例讨论了气温出现极端过程的天气背景. 结果表明: 南极中山站-昆仑站断面最高和最低气温季节变化趋势基本相似, 年际变化不明显. 最高气温标准偏差大于最低气温, 冬季气温标准偏差明显大于夏季, 且夏季气温变化幅度远小于冬季. 随海拔的增加, 最高气温年较差逐渐增大, 最低气温年变化的无芯率(气温没有明显的最小值程度)呈增大趋势, 夏季气温变化幅度逐渐增大, 冬季气温变化幅度的区域性差异不明显; 2005年7月25-31日的极端降温过程主要受到极涡、地面冷高压及下降风的共同影响.  相似文献   

5.
A.L. Washburn 《Earth》1980,15(4):327-402
Permafrost features indicate certain upper limits for annual air and ground temperatures, with the air temperatures being usually the lower because of insulating snow and vegetation. The following features generally imply mean annual air temperatures no higher than those indicated and commonly lower: permafrost itself, large sorted forms of patterned ground, palsas, and rock glaciers, 0°C; ice-wedge polygons and well-developed soil-wedge polygons, ?5°C; open-system pingos, ?2°C; closed system pingos, ?6°C; the implication of cryoplanation terraces remains to be established, with estimates ranging from near 0° to ?12°C.Use of fossil permafrost features as temperature indicators is complicated by problems of correct identification and dating, soil type, and local and regional environmental variables such as precipitation and vegetation. Nevertheless the fact that certain maximum paleotemperatures can be reasonably established in places warrants expanded research in former periglacial areas to evaluate temperature increases to the present. The majority of determinations in Europe, where most of the work has been done to date, indicate minimum air temperature increases of 13°–18° since the maximum of the last glaciation.  相似文献   

6.
黄河源区气温变化特征及预估分析   总被引：1，自引：0，他引：1  
利用黄河源区青海段9个代表性站点1961-2017年逐日气温资料和未来RCP4.5排放情景下的预估数据,分析和预估了黄河源区年平均、年平均最高、年平均最低和极端气温变化特征。结果表明：近57年来年平均最高、年平均、年平均最低气温均呈显著上升趋势且倾向率依次增大。年平均气温和年平均最高气温在1997年存在显著突变。通过分析1961-1997年、1998-2007年以及2008-2017年阶段性变化可知,年平均气温持续上升,年平均最高气温先上升后趋于稳定,而年平均最低气温升温速率在1998-2007年最大,2008-2017年升温速率较1998-2007年有所降低。暖昼日数持续增多,霜冻日数和冰封日数持续减少,冷夜日数在1998-2007年减少速率最低,近10年来减少速率增大。未来33年黄河源区年平均、年平均最高、年平均最低气温和极端暖事件均呈明显的增加趋势,极端冷事件呈减少趋势。对黄河源区过去和未来气温变化规律进行了探讨,将为该区域气温变化对策的制定与实施提供理论依据。  相似文献   

7.
This study was conducted to reveal the trends of the air temperature and soil temperature for 51 years (1960–2010) and their relationship in four of Korea’s largest metropolitan cities (Seoul, Incheon, Busan and Daejeon). Also, the trends of the air and soil temperatures between the studied metropolitan cities and a rural area (Chupungryong) were compared to examine the effect of urban heat. Among the metropolitan cities, the long-term mean soil temperatures (depth 0.0, 0.5, 1.0, 1.5, 3.0, 5.0 m) were lowest (13.34–14.80 °C) in Seoul and highest (16.24–16.54 °C) in Busan, which is mainly the effect of the latitude. The soil temperature exponentially increased with depth in the three cities except for Busan and was closely related to the air temperature. The soil temperatures responded well to the air temperature change (maximum correlation coefficients 0.88–0.98) but this response was slightly delayed with depth. The air and soil temperatures increased at the rates of 0.24–0.40 and 0.11–0.73 °C/decade, respectively, for the period. The increasing rate of the soil temperature was the largest in Daejeon as 0.39–0.73 °C/decade, which was almost 2–4 times greater than those of the other cities (0.11–0.40 °C/decade), and it rose with depth. The increase of the soil temperature was coincident with the increase of the air temperature, which indicates that the soil temperature was largely affected by the increasing of the air temperature. In contrast, the increase in air temperature in Chupungryong (0.06 °C/decade) was significantly lower than in the metropolitan cities. In addition, the increase of the soil temperature in the rural area (0.13 °C/decade) was also much lower than that in the inland cities (0.20–0.27 °C/decade) while it showed no substantial difference from that in the coastal cities (0.11–0.15 °C/decade). Therefore, it is inferred that the soil temperature of the metropolitan cities increased with the increase of the air temperature due to global warming as well as the anthropogenic urban heat.  相似文献   

8.
地下浅层地温和近地表空气温度存在着必然的内在联系,地面温度变化的信息随着时间推移向下传播并叠加到稳态地温场上,因此通过对现今地温剖面的分析可以重建过去地面温度变化的历史。为了研究西安地区地下和地上的温度变化,本文在西安开展了钻孔温度测量,获得了16个钻孔的地温剖面,同时收集整理了西安气象站1951～2010年气温数据。对1951～2010年气温数据进行回归分析得到西安地区年平均气温、年平均最高气温和最低气温增温率分别为3.71 ℃/100a、2.03 ℃/100a和5.14 ℃/100a,均高于全国和全球平均水平,其中1986～2010年间平均气温增温更是显著,达到9.01 ℃/100a。从钻孔测温曲线中筛选出西安城郊6个传导型地温剖面进行分析,结果表明西安地区钻孔温度记录的地面温度变化趋势与气象台记录的气温变化趋势基本吻合。根据利用钻孔温度剖面下段回归分析得到的地表稳态温度和地温梯度以及25年间西安地区平均气温增温率推算得到钻孔理论地温剖面与实测地温数据总体上具有较好的一致性。对实测地温数据的进一步精确拟合分析显示,西安城郊6个选定的钻孔所在区域地面温度变暖分别起始于20年、24年、26年、28年、30年和30年前,对应的地表增温幅度分别为0.4 ℃、0.72 ℃、2.18 ℃、4.2 ℃、2.4 ℃和2.4 ℃。市区和周边郊区钻孔所在区域在增温幅度上存在明显的差异,市区增温强度明显高于郊区,而城郊结合部介于两者之间。  相似文献   

9.
基于甘肃省及周边地区46个气象站点的气温和降水年值、月值数据,对数据进行均一化检验和订正后,采用气候倾向率法、Mann-Kendall 非参数检验法对甘肃近50a气候变化时空特征进行了分析。结果表明：甘肃省平均气温、平均最低气温、平均最高气温、极端最高气温、极端最低气温均升温明显,其中以最低气温升温最为显著。气温的季节变化空间差异较大,空间上四季最低气温和极端最低气温升温最显著,春、冬季平均最低气温升温最显著;夏、秋季极端最低气温升温最为显著。降水变化的区域差异大,降水气候倾向率最小值达-22.2mm·（10a）-1,最大值14.1 mm·（10a）-1,乌鞘岭以东表现为减少趋势,以西增加。河西地区气温突变时间为1986年,早于河东气温突变时间（1993年）。甘肃气候变化时空差异明显,乌鞘岭是近50a甘肃气候转型分异的一条重要分界线。  相似文献   

10.
The low annual and seasonal variability of the shallow groundwater temperature in the alluvial plain aquifers of the Piemonte region (NW Italy) confirmed the potentiality of the low-enthalpy open-loop groundwater heat pumps (GWHP) diffusion to contribute to the reduction of regional greenhouse gas emissions. The distribution of mean groundwater temperatures ranged from a minimum of 10.3°C to a maximum of 17.9°C with a mean of 14.0°C. Differences among diverse areas were slight according with the modest variations in the general climatic condition. Like the air, temperature distribution of the shallow groundwater temperatures is generally similar to topographic elevations in reverse manner. Higher temperature values recorded were typical of summer months (June, July). On the opposite lower values were measured in January and February. No significant difference phase (time) difference between air and groundwater temperature appeared in the data analysis. Besides air-temperature influence (seasonal variability) seemed strictly connected to the depth to groundwater in the measure point and it was negligible when the value was over 9.5 m. For the application of the open-loop systems, extensive examinations of the hydrogeological local conditions should be conducted at site scale and groundwater heat transport modelling should be developed.  相似文献   

11.
The palynology of stratigraphic sections from road-cut and gravel-pit exposures and from a fen and sphagnum bogs in the southern part of the Chilean lake district (40° 53′ S, 72°37′ W-41°24′ S, 72°53′ W) is the basis for interpreting vegetation and climate during the last interglaciation and glaciation (named Llanquihue Glaciation) and during the post-glacial. To help interpretation, modern pollen rain was studied in relation to vegetation and altitude along a transect on the west slope of the Andes, and average January (summer) temperatures were interpreted. The upper limit of closed Andean forest, where wind is a determinant, appears to be close to the 12°C January isotherm; parkland in southern Chile does not exceed the January isotherm of 9°C.Grassland and later southern beech forest are evident during the interglaciation that is dated at more than 39,900 radiocarbon yr. Climate of the grassland was relatively dry; during the forest phase, it was wet, cool, and approximately the same as at present. During Llanquihue Glaciation, average January temperature is estimated to have been about 8°C colder than today at 19,450 BP, some 5° colder shortly before 36,300 BP, and around 4° colder at 10,000 BP. Antarctic-alpine tundra or parkland, under colder, drier climate, is mostly in evidence in the vicinity of the study sites before about 12,000 BP. During the postglacial, forest communities occupied the lake district, and temperatures there were probably 1–2°C above (by 6500 BP) and as much as 2° below (4500-0 BP) the present-day average of about 16°.This pattern of climatic changes finds accord, in general terms, in other parts of the Southern Hemisphere where palynological, chronological, and glacial geological studies are reported. Postulated as a cause of these changes are shifts in the intensity of air mass circulation in antarctic latitudes.  相似文献   

12.
The Laguna Lagunillas basin in the arid Andes of northern Chile exhibits a shallow aquifer and is exposed to extreme air temperature variations from 20 to ?25 °C. Between 1991 and 2012, groundwater levels in the Pampa Lagunillas aquifer fell from near-surface to ~15 m below ground level (bgl) due to severe overexploitation. In the same period, local mean monthly minimum temperatures started a declining trend, dropping by 3–8 °C relative to a nearby reference station. Meanwhile, mean monthly maximum summer temperatures shifted abruptly upwards by 2.7 °C on average in around 1996. The observed air temperature downturns and upturns are in accordance with detected anomalies in land-surface temperature imagery. Two major factors may be causing the local climate change. One is related to a water-table decline below the evaporative energy potential extinction depth of ~2 m bgl, which causes an up-heating of the bare soil surface and, in turn, influences the lower atmosphere. At the same time, the removal of near-surface groundwater reduces the thermal conductivity of the upper sedimentary layer, which consequently diminishes the heat exchange between the aquifer (constant heat source of ~10 °C) and the lower atmosphere during nights, leading to a severe dropping of minimum air temperatures. The observed critical water-level drawdown was 2–3 m bgl. Future and existing water-production projects in arid high Andean basins with shallow groundwater should avoid a decline of near-surface groundwater below 2 m bgl and take groundwater-climate interactions into account when identifying and monitoring potential environmental impacts.  相似文献   

13.
Geothermal water sources located within The Erzurum province were identified and hot water samples were taken from four different geothermal areas. The results of in situ and hydrogeochemical analyses of these hot water samples were interpreted and the properties of hot water, water–rock associations, estimated reservoir temperature and hot water usage areas were determined. The temperatures of the samples collected from the study area vary between 26.2 and 57.7 °C, while pH values change from 6.09 to 7.33, EC values obtained from in situ measurements are between 1829 and 9480 µS/cm and Eh values are (??190) to (26.3) mV. Total dissolved solids of the hot waters have a range from 838.7 to 3914.1 mg/l. The maximum estimated reservoir temperature is calculated as 250 °C by applying chemical geothermometers. However, considering the actual temperatures of Pasinler, Köprüköy, Horasan and Il?ca thermal waters and wells, the most reliable temperature range depending on the applied geothermometers’ results indicate minimum and maximum reservoir temperatures 85–158.9 °C, respectively, taking in account the errors. According to the isotope analysis, the waters circulating within the geothermal system are of meteoric origin and modern waters. In addition, two samples taken from clayey levels observed in the field were analyzed and the mineralogy of the clays was evaluated.  相似文献   

14.
In the present study, an investigation has been made to study the spatial and temporal variability in the maximum, the minimum and the mean air temperatures at Madhya Pradesh (MP), in central India on monthly, annual and seasonal time scale from 1901 to 2002. Further, impact of urbanization and cloud cover on air temperature has been studied. The annual mean, maximum and minimum temperatures are increased by 0.60, 0.60 and 0.62 °C over the past 102 years, respectively. Seasonally, the warming is more pronounced during winter than summer. The temperature decreased during the less urbanized period (from 1901 to 1951) and increased during the more urbanized period (1961 to 2001). It is also found that the minimum temperature increased at higher rate (0.42 °C) followed by the mean (0.36 °C) and the maximum (0.32 °C) temperature during the more urbanized period. Furthermore, cloud cover is significantly negatively related with air temperature in monsoon season and as a whole of the year.  相似文献   

15.
新疆北疆地区季节性冻土结冻过程与日积温的关系   总被引：6，自引：2，他引：4  
白磊  李兰海  李倩  包安明 《冰川冻土》2012,34(2):328-335
传统的度日因子模型很难分辨在结冻期土壤每日结冻和解冻的过程,而日小时积温可以区分正积温和负积温对土壤冻结过程的影响.利用北疆地区1951-2010年气象站数据和决策树算法,分析计算日小时积温及表层5cm和10cm土壤冻结状态数据及日小时积温对季节性冻土冻结现象的影响.结果表明:在北疆范围年小时正积温以每年平均160℃增长,而年小时负积温以每年平均153℃减少.季节性冻土发生冻结现象所需的临界值分布与北疆地区气候和土壤分布基本一致,但仍存在空间差异性.北疆地区5cm土壤结冻所需的日小时负积温为-50℃以下,而5cm到10cm土壤结冻所需日小时负积温的平均值差值为-15℃左右.与日最低气温和日平均气温作为土壤结冻判据相比,日小时积温临界值作为判据可获得较高的精确度.在昌吉地区和阿勒泰地区冻土的平均深度随着日小时负积温临界值的增加而减少.  相似文献   

16.
黑龙江省春季浅层(0～20cm)地温变化特征及预报   总被引：9，自引：4，他引：5  
利用1981-2012年黑龙江省74个气象观测站的气温、0 cm、10 cm、20 cm地温春季(3-5月)逐日资料,分析了黑龙江省春季浅层地温、气温变化特征.结果表明:0 cm地温年际间波动大,全省平均1987年最低,2008年最高;全省变化存在明显的空间一致性;尽管气候变暖使1990年代以后春季0 cm地温偏低年出现相对减少,但是出现春季浅层地温偏低的年份比例仍超过三分之一,并具有南部、北部反向变化的特征,2005年以后南北差异有减小的趋势.各地3月份开始解冻,主要农区10 cm地温稳定通过6℃的日期主要集中在4月中下旬.以10 cm地温为预报量,利用黑龙江省逐日气温、20 cm地温资料建立春季浅层地温预报模型,回代和2013年预报检验平均绝对误差平均为1.05℃,绝对误差最大值为1.9℃,4月份的预报结果要好于3、5月,可以应用于业务指导.  相似文献   

17.
Based on NEX-BCC_CGM1.1 global daily statistics downscaling climate data set, the latest release by American National Aeronautics and Space Administration (NASA), which has representative concentration path, by using linear fitting and empirical orthogonal function (EOF) analysis methods, the simulation capacity on precipitation and temperature in Qinling and its surrounding areas of this data sets was estimated and the possible changes of the precipitation, daily maximum and minimum temperature in the next stage under the two scenarios of Rcp4.5 and Rcp8.5 were analyzed. Results showed that: ①The inter-annual trend of average daily precipitation, maximum temperature, minimum temperature is simulated well by NEX-BCC_CGM1.1. The spatial distribution was in accordance with the observations. The deficiency is that the elements value and extreme frequency have systemic bias compared with the observations. ②Average daily precipitation will have increasing trend in the future in Qinling and its surrounding areas under the two scenarios of Rcp4.5 and Rcp8.5. For different level precipitation frequency, light rains will reduce and rainstorms will increase in the future. The spatial modes of precipitation in the future are shown as the variation of the uniform increase in the whole region (EOF1) and anti-phase change in northern and southern Qinling (EOF2). EOF1 will be positive phase in medium-term in the Mid-21st century, where there will be significantly more means precipitation. ③Under the two scenarios, temperature warming trend is obvious, daily maximum temperature increasing trend is greater than minimum temperature, and the amplitude of temperature increase under Rcp8.5 is higher than Rcp4.5. The frequency of daily maximum temperatures greater than 36 ℃ will increase and low temperature less than -15 ℃ will reduce in the future, at the same time, high temperature (low temperature) increase (decrease) rate is more pronounced under Rcp8.5. Average daily maximum and minimum temperatures are shown uniform warming in the whole region (EOF1) and anti-phase change in northern and southern Qinling under two scenarios, but the spatial distribution has great difference.  相似文献   

18.
Late Quaternary paleotemperatures and paleosalinities of surface waters of the Gulf of Mexico were estimated using a multivariate statistical analysis of census data of planktonic foraminifera. Two climatic extremes were selected for detailed basinwide study, the climatic optimum 125,000 yr ago and the glacial maximum 18,000 yr ago. In addition, patterns of climatic change were examined in seven piston cores from 127,000 yr ago to the present day. During the climatic optimum 125,000 yr ago temperature distributions in surface waters were similar to those of the present. The 22°C winter isotherm trended northeastward across the central basin and paleotemperatures decreased northward. Summer distributions were nearly homogeneous and ranged between 28° and 29°C. Winter salinities were 1‰ fresher than present values in the northmost Gulf and 0.4‰ fresher in the central basin. Summer salinities were similar during both times. In contrast, during the last glacial maximum temperatures were 1° to 2°C cooler in winter and 1°C cooler in summer, and isotherms formed a circular pattern in the Gulf during both seasons. Salinity was 0.3‰ fresher in winter than at present but 0.6‰ saltier in summer. Conditions deteriorated from the climatic optimum to the glacial maximum. In the Mexico Basin, winter temperatures were 2°C cooler from 75,000 to 45,000 yr ago (Y6 to Y3 Subzones), summer temperatures reached a minimum (3°C cooler) 32,000 yr ago (Y2–Y3 boundary), and seasonality reached minimal values (5°C) from 45,000 to 15,000 yr ago. All three parameters became similar in value to those in the Straits of Florida from 45,000 to 15,000 yr ago, suggesting that the exchange of surface waters was enhanced at this time between the two regions. Summer salinities remained similar to present conditions in the Mexico Basin, whereas, winter salinities increased 2‰ by 32,000 yr ago and then fell 0.5‰ until the glacial maximum ended. The Westerlies may have migrated southward over the Mexico Basin in winter from 32,000 to 15,000 yr ago.  相似文献   

19.
This paper presents the first chironomid‐inferred mean July air temperature reconstruction for the Late‐glacial in Britain. The reconstruction suggests that the thermal maximum occurred early in the interstadial, with temperatures reaching about 12°C. There was then a gradual downward trend to about 11°C, punctuated by four distinct cold oscillations of varying intensity. At the beginning of the Younger Dryas, mean July temperatures fell to about 7.5°C but gradually increased to about 9°C before a rapid rise at the onset of the Holocene. The chironomid‐inferred temperature curve agrees closely, both in general trends and in detail, with the GRIP ice‐core oxygen‐isotope curve. The reconstructed temperatures are 2–4°C lower than coleopteran‐inferred temperatures but are closer to those inferred from plant macrofossils and glacial equilibrium‐line altitudes during the Younger Dryas. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

20.
Extreme-temperature events have a great impact on human society. Thus, knowledge of summer temperatures can be very useful both for the general public and for organizations whose workers operate in the open. An accurate forecasting of summer maximum and minimum temperatures could help to predict heatwave conditions and permit the implementation of strategies aimed at minimizing the negative effects that high temperatures have on human health. The objective of this work is to evaluate the skill of the regional atmospheric and modelling system (RAMS) model in determining daily summer maximum and minimum temperatures in the Valencia Region. For this, we have used the real-time configuration of this model currently running at the Centro de Estudios Ambientales de Mediterráneo Foundation. This operational system is run twice a day, and both runs have a 3-day forecast range. To carry out the verification of the model in this work, the information generated by the system has been broken into individual simulation days for a specific daily run of the model. Moreover, we have analysed the summer forecast period from 1 June to 31 August for 2007, 2008, 2009 and 2010. The results indicate good agreement between observed and simulated maximum temperatures, with RMSE in general near 2 °C both for coastal and inland stations. For this parameter, the model shows a negative bias around ?1.5 °C in the coast, while the opposite trend is observed inland. In addition, RAMS also shows good results in forecasting minimum temperatures for coastal locations, with bias lower than 1 °C and RMSE below 2 °C. However, the model presents some difficulties for this parameter inland, where bias higher than 3 °C and RMSE of about 4 °C have been found. Besides, there is little difference in both temperatures forecasted within the two daily RAMS cycles and that RAMS is very stable in maintaining the forecast performance at least for three forecast days.  相似文献   

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