石河子棉区不同热量条件对棉花纤维品质影响研究

为定量评估不同热量条件对石河子棉区棉纤维品质的影响,以当地主栽品种为材料, 2003至2007年在莫索湾气象站和乌兰乌苏农业气象试验站内进行分期播种试验,并收集同期气象观测资料,分析不同播期内开花- -裂铃期间的日最高、日最低温度、日平均温度和≥10℃、15℃、20℃活动积温等热量条件与棉花主要纤维品质特征的相关性。结果表明：①该棉区棉花纤维断裂比强度与热量条件相关最为明显,②限制该地区棉花纤维品质档次提高的主要纤维品质指标是断裂比强度,③当地主栽品种断裂比强度都具有随播期延后而减小的趋势,不同品种的比强度随播期延后反应表现不一致。     

不同气候生态棉区化学调控适宜期的试验及其应用

在山东省气候条件下,棉花生长发育主要受热量条件制约．由积温推算出在不同气候生态棉区以及不同品种、种植方式、密度和产量水平下的棉田物候期,由此得到相应棉田各次化调期,可改变田间小气候,提高成铃率１０％～１５％,单铃重增加０．３～０．９ｇ,使棉田因蕾期缩短而改变播期及种植品种,扩大麦棉两熟种植区域,提高棉花品质．     

2003年新疆棉花农业气象条件评述

2003年南疆大部棉区开春偏早，但开春后多回寒天气，使部分棉区的棉花播种进度缓慢；北疆大部棉区开春期正常略偏晚，气温回升缓慢，棉花播种期一再推迟。出苗期间冷空气活动频繁，致使全疆大部棉区棉苗发育迟缓，且部分早播的棉田还出现不同程度的烂种、烂芽及烂根现象。出苗以后的大部分时间，全疆大部棉区光热充足，对棉花生长有利，但期间7月下旬的低温天气对北疆部分棉花的产量及品质造成一定影响。综合来看，2003年全疆大部棉区春季热量条件及棉花生长的基本热量     

1998年新疆棉花农业气象条件评述

1998年新疆棉花获得了历史性大丰收,单产1401kg／hm2,总产达到140×104t,再创历史记录。能取得这样高的产量,与全疆棉区棉花生长最关键时段蕾铃期充足适宜的光热水条件,南疆棉花播种早、出苗好及吐絮期良好的光热配置密不可分。里播种出苗期南疆和东疆棉区：开春偏早,大部分棉区10℃界限温度初日比常年早4－10d。播种期间多晴少雨,气温比常年偏高,有利于棉花早播快播,大部分地区棉花于4月上、中旬播种．播期比常年提前2－6d,播种进度快于常年且质量普遍较好。出苗期间,南疆大部棉区气温接近常年或偏高,光照充足,出苗情况明显好…     

1999年新疆棉花农业气象条件评述

虽然１９９９年春季的低温冷害、风灾及霜冻灾害十分严重 ,使棉花生产遭受了很大损失 ,但全疆大部棉区棉花生长期间的光热水条件好于常年 ,尤其后春和秋季光热条件明显偏好 ,因此 ,１９９９年新疆棉花生产再获丰收 ,单产１４１３ｋｇ／ｈ ,总产达１４０．７×１０４ｔ ,单、总产均比大丰收的１９９８年略有提高。１播种出苗期南疆和东疆棉区：开春期偏早,早春气温回升迅速 ,播种期间多晴少雨,气温比常年偏高,有利于棉花早播,大部分地区棉花于４月上、中旬播种,播期比常年提前２～９ｄ。播种后,南疆大部棉区气温偏高 ,光照充足 ,棉花…     

2002年新疆棉花农业气象条件评述

2002年全疆大部棉区开春偏早。南疆棉区开春后气温持续偏高,降水偏少,有利于棉花早播;但北疆棉区因4月份持续的低温多雨天气,致使大部棉区播种期较常年偏晚,部分早播的棉田还出现了烂种烂芽现象。出苗后,全疆大部棉区光热充足,虫害较轻,对棉花生长有利,播种至停止生长≥10℃积温也比常年偏多。综合来看,2002年南疆棉区棉花生长气象条件明显好于常年;北疆棉区虽然前期热量条件略显不足,但后期(尤其是裂铃吐絮时多晴好天气)光热充足,有利于棉花成铃的完全吐絮,棉花生长期的气象条件好于常年。再加上高密度栽培技术的广泛应用,2002年棉花单产再…     

1995年新疆棉花农业气候条件评述

4月北疆棉区气温明显偏高，有利于早播，整体播期是历史上最早年份。南疆播种期间气温比常年和1994年偏低，喀什大部地区降水偏多，影响了播种速度，播期比常年偏晚。棉花出苗至裂铃期（5～8月）全疆大部棉区各月气温正常或偏高，温度波动小，光热配置好。北疆棉区花铃期内有几场适量的降水，降水时间配置比较合理。初秋（9月上旬），北疆大部及东疆棉区气温比常年与1994年同期偏低2～4℃，对棉花生产有些影响。但随后气温正常或偏高，尤其是北疆和东疆棉区气温明显比常年偏高，全疆棉花停止生长期比常年偏晚，保证了棉花充分吐絮成熟收获。…     

昌吉州棉区棉花生育期气候条件分析

为了深入开展棉花气象服务,对昌吉州主要棉区的气温、降水和日照等与棉花生长发育密切相关的气候资料进行了全面的统计分析,得出昌吉州主要棉区影响棉花生长发育的主要气象因素:播种期的霜冻、苗期的低温、花铃期的高温和吐絮期的低温和全生育期的热量。     

2005年新疆棉花农业气象条件评述

2005年,全疆大部棉区开春期偏早,开春后气温回升迅速。播种出苗期间,南疆和东疆大部气温偏低,对当地棉花的早播有一定影响,并延缓了早播棉花的出苗速度;而北疆大部降水偏多,对棉田补墒、棉花播种及出苗有利。出苗至开花期间,全疆大部棉区的光、温、水配置对棉花生长较有利,部分棉区形成了“四月苗、五月蕾、六月花”的丰产格局。棉花花铃生长期和裂铃吐絮期,大部棉区温高少雨、光照充足,气象条件对棉花花铃生长及吐絮采摘有利。但喀什部分棉区由于前期高温干旱,部分棉田未能及时浇灌头水,且蚜虫发生严重,造成开花期及裂铃期均较常年明显推迟…     

农气预报是夺取棉花优质高产的重要依据

北疆棉区是世界上纬度最靠北的一个棉区.它有日照充足,灌溉用水较为稳定等优越的植棉条件,因而常常能获得优质棉花,受到国内外用户的欢迎.但热量条件较差,农业技术措施掌握不好常造成减产.1985年北疆各地棉花产量、等级下降,就是热量条件较差造成的.在北疆棉区要想夺取棉花优质高产,必须克服热量条件较差的不利气候影响.所以,准确的农业气象预报对夺取棉花优质高产十分重要. 一、热量条件较差的具体表现与全国及世界各棉区比较,北疆棉区生长季短,生长季内温度偏低已为人所共知.     

CHARACTERISTICS AND TRENDS OF CLIMATIC EXTREMES IN CHINA DURING 1959–2014

The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics.     

ANALYSIS OF “BIMODAL PATTERN” STORM ACTIVITY CHARACTERISTICS OF THE BAY OF BENGAL

Storms that occur at the Bay of Bengal (BoB) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the BoB are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the BoB storm activity, and the “bimodal period” of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the “bimodal pattern” storm activity in the BoB. The analysis on sea surface temperature (SST) shows that the SSTs of all the year around in the BoB area meet the conditions required for the generation of tropical cyclones (TCs). However, the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a “two-peak” storm activity pattern. The genesis potential index (GPI) quantifies and reflects the environmental conditions for the generation of the BoB storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms.     

LOW-FREQUENCY CIRCULATION AND EXTENDED-RANGE FORECAST IN CONNECTION WITH AUTUMN EXTREME HEAVY RAINFALL PROCESS IN HAINAN

Observed daily precipitation data from the National Meteorological Observatory in Hainan province and daily data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis-2 dataset from 1981 to 2014 are used to analyze the relationship between Hainan extreme heavy rainfall processes in autumn (referred to as EHRPs) and 10–30 d low-frequency circulation. Based on the key low-frequency signals and the NCEP Climate Forecast System Version 2 (CFSv2) model forecasting products, a dynamical-statistical method is established for the extended-range forecast of EHRPs. The results suggest that EHRPs have a close relationship with the 10–30 d low-frequency oscillation of 850 hPa zonal wind over Hainan Island and to its north, and that they basically occur during the trough phase of the low-frequency oscillation of zonal wind. The latitudinal propagation of the low-frequency wave train in the middle-high latitudes and the meridional propagation of the low-frequency wave train along the coast of East Asia contribute to the ‘north high (cold), south low (warm)’ pattern near Hainan Island, which results in the zonal wind over Hainan Island and to its north reaching its trough, consequently leading to EHRPs. Considering the link between low-frequency circulation and EHRPs, a low-frequency wave train index (LWTI) is defined and adopted to forecast EHRPs by using NCEP CFSv2 forecasting products. EHRPs are predicted to occur during peak phases of LWTI with value larger than 1 for three or more consecutive forecast days. Hindcast experiments for EHRPs in 2015–2016 indicate that EHRPs can be predicted 8–24 d in advance, with an average period of validity of 16.7 d.     

AN ATTRIBUTION ANALYSIS OF CHANGES IN POTENTIAL EVAPOTRANSPIRATION IN THE BEIJING–TIANJIN–HEBEI REGION UNDER CLIMATE CHANGE

Based on the measurements obtained at 64 national meteorological stations in the Beijing–Tianjin–Hebei (BTH) region between 1970 and 2013, the potential evapotranspiration (ET0) in this region was estimated using the Penman–Monteith equation and its sensitivity to maximum temperature (Tmax), minimum temperature (Tmin), wind speed (Vw), net radiation (Rn) and water vapor pressure (Pwv) was analyzed, respectively. The results are shown as follows. (1) The climatic elements in the BTH region underwent significant changes in the study period. Vw and Rn decreased significantly, whereas Tmin, Tmax and Pwv increased considerably. (2) In the BTH region, ET0 also exhibited a significant decreasing trend, and the sensitivity of ET0 to the climatic elements exhibited seasonal characteristics. Of all the climatic elements, ET0 was most sensitive to Pwv in the fall and winter and Rn in the spring and summer. On the annual scale, ET0 was most sensitive to Pwv, followed by Rn, Vw, Tmax and Tmin. In addition, the sensitivity coefficient of ET0 with respect to Pwv had a negative value for all the areas, indicating that increases in Pwv can prevent ET0 from increasing. (3) The sensitivity of ET0 to Tmin and Tmax was significantly lower than its sensitivity to other climatic elements. However, increases in temperature can lead to changes in Pwv and Rn. The temperature should be considered the key intrinsic climatic element that has caused the "evaporation paradox" phenomenon in the BTH region.     

Could the Recent Taal Volcano Eruption Trigger an El Ni?o and Lead to Eurasian Warming?

正The Taal Volcano in Luzon is one of the most active and dangerous volcanoes of the Philippines. A recent eruption occurred on 12 January 2020(Fig. 1a), and this volcano is still active with the occurrence of volcanic earthquakes. The eruption has become a deep concern worldwide, not only for its damage on local society, but also for potential hazardous consequences on the Earth's climate and environment.     

Revisiting the Concentration Observations and Source Apportionment of Atmospheric Ammonia

正While China’s Air Pollution Prevention and Control Action Plan on particulate matter since 2013 has reduced sulfate significantly, aerosol ammonium nitrate remains high in East China. As the high nitrate abundances are strongly linked with ammonia, reducing ammonia emissions is becoming increasingly important to improve the air quality of China. Although satellite data provide evidence of substantial increases in atmospheric ammonia concentrations over major agricultural regions, long-term surface observation of ammonia concentrations are sparse. In addition, there is still no consensus on     

COMPARATIVE ANALYSIS OF VARIOUS DATA OF AIR–SEA TEMPERATURE DIFFERENCE AND ITS VARIATION ACROSS SOUTH CHINA SEA IN THE PAST 35 YEARS

Using the International Comprehensive Ocean-Atmosphere Data Set(ICOADS) and ERA-Interim data, spatial distributions of air-sea temperature difference(ASTD) in the South China Sea(SCS) for the past 35 years are compared,and variations of spatial and temporal distributions of ASTD in this region are addressed using empirical orthogonal function decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect actual distribution characteristics of ASTD in the SCS, but values of ASTD from the ERA-Interim data are smaller than those of the ICOADS data in the same region. In addition, the ASTD characteristics from the ERA-Interim data are not obvious inshore. A seesaw-type, north-south distribution of ASTD is dominant in the SCS; i.e., a positive peak in the south is associated with a negative peak in the north in November, and a negative peak in the south is accompanied by a positive peak in the north during April and May. Interannual ASTD variations in summer or autumn are decreasing. There is a seesaw-type distribution of ASTD between Beibu Bay and most of the SCS in summer, and the center of large values is in the Nansha Islands area in autumn. The ASTD in the SCS has a strong quasi-3a oscillation period in all seasons, and a quasi-11 a period in winter and spring. The ASTD is positively correlated with the Nio3.4 index in summer and autumn but negatively correlated in spring and winter.     

Information for Authors

正AIMS AND SCOPE Atmospheric and Oceanic Science Letters (AOSL) publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome.SUBMISSIONAll submitted     

Information for Authors

AIMS AND SCOPE Atmospheric and Oceanic Science Letters （AOSL） pub- lishes short research letters on all disciplines of the atmos- phere sciences and physical oceanography. Contributions from all over the world are welcome.