基于高空气球平台的下投探空:系统研发和青藏高原实验（英文）

为提高复杂地理环境和极端天气条件下的大气廓线探测能力,本文自主研发了基于平流层高空气球平台台的下投探空系统,并在青藏高原开展探测评估实验.该系统主要由下投探空舱,携带降落伞的下投探空仪,下投施放装置,数据接收通讯天线和GPS模块等组成.下投探空仪测量数据通过卫星通信链路和无线电信号实时发送至数据接收机存储处理.2020年青藏高原实验中8枚下投探空仪全部成功施放,提供了合理有效的大气廓线探测数据.后续会进一步提高下投探空仪传感器性能,全面评估其探测准确性和精度.     

飞机下投探空在台风探测中的应用

在海洋探测方面,利用飞机进行下投探空拥有巨大的潜力去弥补全球高空探测网的空白。台风形成后,飞机飞入台风中心或绕台风飞行,下投配有全球卫星定位(GPS)装置的"探空仪",探空仪上安装有温度、气压、湿度传感器,通过GPS定位测风,对台风实施立体观测。多年来,飞机下投探空能够充分掌握台风的整体气象要素分布结构,从而提高对台风强度和移动路径等预报的准确性,飞机下投探空在国际上已经从科学试验转变成业务应用,并且形成新型的探测技术——目标观测。本文主要总结了国际上利用飞机搭载下投式探空仪进行台风探测的发展历程,为我国开展下投探空,特别是台风监测提供可借鉴的经验。     

球载式下投国产北斗探空仪测风性能评估

基于球载式下投北斗探空仪测风观测试验,建立了针对下投式的测风试验评估方法.试验结果表明上升段北斗测风的准确度接近RS92探空仪的探测准确度要求,两者一致性较好;下降段RS92测风误差基本上与上升段的属于同一量级水平,下降初期测风数据在使用时需要做预处理或者有效控制;下降段BD探空仪测风误差与下降段RS92的基本相当,除了球炸初期外,基本上接近WMO的测量要求,此外初期的急速下降对导航定位测风提出了更高的技术要求.整体而言,球载式下投探空观测在时间上可以实现对原有的1次探空进行加密,在空间上可以增加1个区域的探测,并为对现有探空站网分布进行合理优化提供依据,具有良好的应用前景.     

两种探空仪判别云垂直结构的对比研究

利用广东省阳江地区2010年7—8月WMO组织的国际高性能探空系统对比试验数据,对Vaisala RS92型探空仪和国产长峰探空仪的测云性能进行对比分析,并利用同步观测的Vaisala云高计和毫米波雷达数据进行了分析和验证。结果表明:两种探空仪判别的云层垂直结构都能较好地反映阳江的实际的云层情况。对于低云,两种探空仪的探测结果比较接近;对于不密实的云层,两种探空仪都会误判为多层云;对于高云,两种探空仪的判别效果均不理想,长峰探空仪还容易漏判云层。RS92探空仪探测的高云的云底和云顶的平均高度要高于长峰探空仪的探测结果。     

L波段探空雷达探测高度偏低分析

海拉尔站L波段雷达探测高度经常出现偏低现象,为弄清探测高度偏低的具体原因,通过ASOM系统统计分析了该站探空和测风数据,并从多个可能造成雷达探测高度偏低的成因分别进行分析,发现造成海拉尔站L波段雷达探测高度偏低的主要原因为:(1)探空仪突然变性;(2)1600g探空气球在冬季的施放高度偏低;(3)海拉尔站值班大楼在固定方位、仰角区间内会对探空信号造成遮挡。     

微型无人驾驶飞机气象探空系统

微型无人驾驶飞机气象探空系统由微型无人驾驶飞机,数字化探空仪和地面接收控制处理系统组成。微型无人驾驶飞机采用ＧＰＳ导航,具有自动导航,、自动驾驶功能,它能在机载自动控制系统控制下完成预定航线的飞行,并实时地浆飞机的飞行轨迹和探测数据传送到地面。     

VAISALA探空技术及中国探空技术的发展

VAISALA公司推出的数字化探空仪RS92标志着VAISALA探空技术有了全新的发展,探空系统和探空仪完全实现数字化.RS92采用了数字技术,在提高测量精度、提高信息传输的抗干扰能力上都将获益.RS92的发射机占用带宽大约是RS80的十分之一.测风采用GPS扩频技术,大幅度提高测风数据获取率.温、压、湿传感器都有明显改进.中国探空技术要加强传感器和探空仪传感器测量手段的发展.     

国产GPS探空仪国际比对试验结果

通过2010年7月12日—8月1日第8届世界气象组织阳江国际探空比对,采取同球比对施放方式,选择芬兰Vaisala探空仪作为比对标准,对中国参加国际比对的长峰探空仪与华云探空仪,使用共29次同球比对数据,从典型个例分析与统计分析两方面开展系统性评估。初步评估结果表明:对于温度探测,中国长峰探空仪整体系统偏差在0.4℃之内,标准偏差在0.7℃之内,中国华云探空仪在30 km高度以下性能与长峰探空仪相当,但是30 km高度以上偏差明显增大;对于气压与风的探测,两者系统偏差与标准偏差均较小,表明GPS定位以及气压与风的算法准确;对于湿度探测,与芬兰Vaisala探空仪相比,还存在一定差距,特别是低温性能需要提高。     

下投探空资料在台风莫拉克路径预报的应用试验

2009年8月7日中国大陆举行了首次利用机载下投式探空仪观测台风的试验,飞机在台风莫拉克与天鹅之间的云带相对稀薄区释放11个下投式探空仪。基于下投探空观测资料、常规探空资料和1°×1°分辨率的NCEP再分析资料,分析下投探空资料的可用性,并以下投探空资料初步分析了两台风间南海上空的风场、湿度场等大气特性;分别进行了有无以同化下投探空为初始场的GRAPES模式的模拟试验,以了解下投探空资料对台风莫拉克预报的影响作用。初步结论表明,台风天鹅与莫拉克之间的南海上空对流层中低层为深厚的西南气流,对流层低层及高层湿度小,中间层大;同化下投探空资料后,观测地区(下投探空点及其附近)800 hPa以下西南风减弱,以上加强,湿度中低层减小;有无同化下投探空资料的初值场差异随模式积分向下游传播,影响台风的环境场,改变了台风的引导气流:同化后500 hPa台风引导气流偏东、偏北分量加强,使台风的路径更接近实况路径,48 h台风路径预报误差比原来减少18%。     

L波段雷达探空系统镁电池浸泡技术

新一代高空气象探测系统采用镁电池供给GTS1型探空仪电源,镁电池出现故障,GTS1型探空仪的智能转换板和发射机就不能正常工作,地面雷达就接收不到探空仪信号,影响探空球炸率、探测高度或造成探测高度不足500hPa重放球。因此镁电池的正确浸泡是新一代高空气象探测系统成功运行的关键因素。对镁电池的浸泡技术进行总结,指导探空观测员正确浸泡该电池,保证探空施放成功率。     

Stratospheric balloon-based dropsonde technology: Development and preliminary assessment over the Tibetan Plateau: 基于高空气球平台的下投探空:系统研发和青藏高原实验

To complement the atmospheric profile measurements under complex geographical environments and extreme weather conditions, a stratospheric balloon-based dropsonde technology, which is carried by a stratospheric balloon platform from the Earth's surface to the upper troposphere and lower stratosphere (UTLS) to release the dropsonde for measurements, is independently developed and preliminarily assessed over the Tibetan Plateau (TP) in this study. The dropsonde system is mainly composed of the dropsonde chamber, dropsonde with a parachute, data receiving and communication antennas, dropsonde-releasing device, and GPS (Global Positioning System) modules. The dropsonde measurements can be sent in real time through satellite communication links and by radio signals to a data receiver at the ground control center for storage and processing. A total of eight dropsondes aboard the stratospheric balloon were successfully released during the TP campaign in 2020. A preliminary assessment was conducted based on a case comparison between the dropsonde and radiosonde measurements, which indicated that the dropsonde technology we developed can generally provide reasonable atmospheric profiles. However, further efforts are still required to improve the detection performance of the dropsonde sensors after long-term locating in the UTLS and to assess the accuracy and precision of the detection technology more carefully.摘要为提高复杂地理环境和极端天气条件下的大气廓线探测能力, 本文自主研发了基于平流层高空气球平台的下投探空系统, 并在青藏高原开展探测评估实验.该系统主要由下投探空舱,携带降落伞的下投探空仪,下投施放装置,数据接收通讯天线和GPS模块等组成.下投探空仪测量数据通过卫星通信链路和无线电信号实时发送至数据接收机存储处理.2020年青藏高原实验中8枚下投探空仪全部成功施放, 提供了合理有效的大气廓线探测数据.后续会进一步提高下投探空仪传感器性能, 全面评估其探测准确性和精度.     

Evaluating the Ozone Valley over the Tibetan Plateau in CMIP6 Models

Total column ozone (TCO) over the Tibetan Plateau (TP) is lower than that over other regions at the same latitude, particularly in summer. This feature is known as the “TP ozone valley”. This study evaluates long-term changes in TCO and the ozone valley over the TP from 1984 to 2100 using Coupled Model Intercomparison Project Phase 6 (CMIP6). The TP ozone valley consists of two low centers, one is located in the upper troposphere and lower stratosphere (UTLS), and the other is in the middle and upper stratosphere. Overall, the CMIP6 models simulate the low ozone center in the UTLS well and capture the spatial characteristics and seasonal cycle of the TP ozone valley, with spatial correlation coefficients between the modeled TCO and the Multi Sensor Reanalysis version 2 (MSR2) TCO observations greater than 0.8 for all CMIP6 models. Further analysis reveals that models which use fully coupled and online stratospheric chemistry schemes simulate the anticorrelation between the 150 hPa geopotential height and zonal anomaly of TCO over the TP better than models without interactive chemistry schemes. This suggests that coupled chemical-radiative-dynamical processes play a key role in the simulation of the TP ozone valley. Most CMIP6 models underestimate the low center in the middle and upper stratosphere when compared with the Microwave Limb Sounder (MLS) observations. However, the bias in the middle and upper stratospheric ozone simulations has a marginal effect on the simulation of the TP ozone valley. Most CMIP6 models predict the TP ozone valley in summer will deepen in the future.     

平流层大气环流的典型系统及变化特征综述

随着大气探测技术以及计算机性能的不断提高,近年来平流层探测数据日渐丰富,中层大气模式也得到了快速发展,平流层中一些重要的物理、化学以及动力过程得以深入研究,对平流层大气环流的认识也进一步加深。本文分析了平流层准2 a振荡（Quasi-Biennial Oscillation,QBO）、平流层残余（Brewer-Dobson,BD）环流和平流层极地环流等主要的平流层大气环流系统和信号的气候态特征、形成机制、年际变率以及长期趋势等,阐述了它们的主要影响因子和过程,讨论并展望了与平流层环流有关的一些主要科学问题。     

青藏高原地区大气红外探测器（AIRS）资料质量检验及揭示的上对流层水汽特征

上对流层水汽（UTWV）是大气中最重要的温室气体,对全球气候变暖有重要贡献; 而青藏高原被认为是UTWV进入平流层的重要通道,在平流层－对流层水汽交换及平流层水汽变化中扮演着重要角色。首先利用高原探空站资料对大气红外探测器（AIRS）反演的水汽数据在高原地区的质量进行了检验,发现AIRS反演的水汽数据与探空实测数据是相当一致的。其中全年和夏半年AIRS的可信度较好,而冬半年,尤其是上对流层AIRS水汽可信度相对较低,但在缺乏高精密数据时仍部分可用。利用AIRS资料对青藏高原地区UTWV季节变化特征进行了分析,结果表明,高原冬季偏干,而夏季显著偏湿,并且空间分布具有明显的不均匀性。经验正交函数(EOF)分析显示,夏季高原UTWV主要存在三种空间分布型,即全区一致型,高原东西偶极型和南北带状偶极型。一致型分布具有明显的季节变化,而偶极型则以季节内振荡为主。在此基础上,重点研究夏半年高原地区UTWV季节内振荡特征,结果表明,UTWV季节内振荡的显著周期位于10～20天和30～60天。前者主要表现为纬向东传,并且可以越过高原进入我国江淮流域上空;而后者主要向南移动,基本表现为高原局地振荡。最后,进一步探讨了高原UTWV季节内振荡的可能机制,结果表明,高原地区UTWV的低频变化主要与高原热状况、南亚高压活动及其与二者相耦合的对流活动有关。     

基于往返式平漂探空的FY-3D卫星反演温度检验

往返式平漂探空观测（以下简称平漂探空）可实现对流层至平流层低层大气温度廓线垂直探测以及平流层低层内持续4 h的水平温度分布探测。该文介绍利用平漂探空试验数据对风云3号气象卫星D星（FY-3D）反演温度数据的检验评估算法,基于该算法和2021年3—9月长江中下游平漂探空试验数据完成对卫星反演大气温度数据的检验。结果显示:FY-3D卫星反演的温度数据准确度总体较高,与平漂探空上升段数据平均绝对偏差约为1.34℃,与下降段数据平均绝对偏差约为1.93℃;卫星反演的100 hPa以上和850 hPa以下温度误差分别偏大0.59℃和0.33℃;卫星反演平流层温度准确度低于温度廓线,平均绝对偏差约为3.92℃;与平漂探空数据相比,卫星大气温度廓线分辨率较低、趋势较平滑,无法显示大气温度垂直分布和平流层温度水平分布的细节特征。     

边界层微型火箭气象探空系统研制与应用

首次介绍了国内自主研制的边界层微型火箭气象探空系统,系统包括火箭发射装置、探空仪、降落伞、地基接收设备和数据接收处理软件,其温度、湿度和气压测量采用数字式传感器,风速和风向由北斗/GPS全球定位信息获得。火箭升空至顶点后,将探空仪和降落伞从仪器舱弹出,在下降过程中测量大气的温度、湿度、气压和风速、风向等参数,通过无线发射机传送至地面接收机,由处理软件实现数据存储和参数分析。不同地区、不同气象条件下多次外场比较试验和实际应用结果表明,该系统性能稳定,探测技术指标和功能满足使用单位的设备研制要求,可应用于气象保障、大气探测、环境监测及海洋气象要素廓线的观测。     

Effects of the Tibetan Plateau on total column ozone distribution

The relatively low total column ozone (TCO) above the Tibetan Plateau (TP) observed in summer is only partly due to the thinness of the atmospheric column. In this paper the effect of the TP on the TCO is further investigated using satellite data [Total Ozone Mapping Spectrometer (TOMS) ozone column and Stratospheric Aerosol and Gas Experiment II (SAGE II) ozone profiles], ECMWF ERA-40 reanalysis data and a 3-D chemistry-climate model (CCM). It is found that the low TCO over the TP is also closely related to large-scale uplift and descent of isentropic surfaces implied by seasonal and longitudinal variations in the tropopause height. The variations in tropopause height, with a maximum in summer, can be driven by various processes including convective activity, air expansion as well as the monsoon system. While previous studies have showed an important role of troposphere-to-stratosphere transport in contributing to the observed low ozone column over the TP, the mechanism revealed in this study is an alternative amendment to the causes of the TCO low over the TP. It is also found that the monsoon anticyclone circulation induces an isentropic transport of trace gases from high latitudes towards the TP in the lower stratosphere and hence modifies tracer distributions. For the vertical distribution of ozone, the modulation by the TP is most significant below ∼20 km, that is, in the upper troposphere and lower stratosphere (UTLS). The smaller differences in NO _x between Eastern TP and TP compared to large dynamically caused differences in ozone and methane imply the TCO low over the TP is mainly due to transport processes rather than chemistry.     

Applications of AMSR-E Measurements for Tropical Cyclone Predictions Part Ⅰ： Retrieval of Sea Surface Temperature and Wind Speed

Existing satellite microwave algorithms for retrieving Sea Surface Temperature （SST） and Wind （SSW） are applicable primarily for non-raining cloudy conditions. With the launch of the Earth Observing System （EOS） Aqua satellite in 2002, the Advanced Microwave Scanning Radiometer （AMSRoE） onboard provides some unique measurements at lower frequencies which are sensitive to ocean surface parameters under adverse weather conditions. In this study, a new algorithm is developed to derive SST and SSW for hurricane predictions such as hurricane vortex analysis from the AMSRoE measurements at 6.925 and 10.65 GHz. In the algorithm, the effects of precipitation emission and scattering on the measurements are properly taken into account. The algorithm performances are evaluated with buoy measurements and aircraft dropsonde data. It is found that the root mean square （RMS） errors for SST and SSW are about 1.8 K and 1.9 m s^- 1, respectively, when the results are compared with the buoy data over open oceans under precipitating clouds （e.g., its liquid water path is larger than 0.5 mm）, while they are 1.1 K for SST and 2.0 m s^-1 for SSW, respectively, when the retrievals are validated against the dropsonde measurements over warm oceans. These results indicate that our newly developed algorithm can provide some critical surface information for tropical cycle predictions. Currently, this newly developed algorithm has been implemented into the hybrid variational scheme for the hurricane vortex analysis to provide predictions of SST and SSW fields.     

A study on the motion characteristics and their impact on the wind measurement post-processing of the GPS dropwindsonde. Part II: impacts of post-processing/composition schemes

When the Global Positioning System dropwindsonde wind measurements are used, post-processing and composition approaches are necessary to calculate the vertical profiles of wind statistics. In order to understand the impacts of post-processing/composition schemes on the wind statistics calculated based on dropwindsonde measurements, various post-processing/composition schemes were utilized to post-process and to composite pseudo-dropsonde measurements resulting from numerical simulation of dropsonde motions in a pseudo-stochastic wind field. Since the wind statistics of the pseudo-stochastic wind field were specified, the comparison between wind statistics calculated based on pseudo-dropsonde measurements and the specified values provided some insights into the impacts of different post-processing/composition schemes. The post-processing/composition schemes investigated include the low-pass filter to reduce high-frequency dropsonde measurement noises, the finite difference scheme to calculate dropsonde accelerations, which is needed to dynamically correct dropsonde measurements and composition data size.     

上对流层-下平流层交换过程研究的进展与展望

上对流层和下平流层(UTLS)区域的高度范围大致为5～20 km.UTLS区域大气成分的分布及变化对于认识气候长期变化也极为重要,因为该区域的臭氧是一种有效的温室气体,其中的水汽、卷云和气溶胶对太阳短波辐射和地球长波辐射有很强的调制作用,因而对于天气和气候变化产生不可忽略的辐射强迫作用; UTLS区域中,还有航空业的飞机排放,强对流云云中与云上闪电产生相当量的NOx,这些都对UTLS区域乃至更高及更低层大气的化学成分与分布产生重大影响.该文介绍上对流层和下平流层区域的交换过程研究的意义和手段,同时介绍有关研究的进展,重点回顾近年来国内一些学者开展的工作.另外,还列举一些研究问题和方向,最后重点展望青藏高原上空上对流层-下平流层区域的研究,因为该地区UTLS交换过程不仅具有显著区域特征,而且在全球平流层-对流层交换中可能有重要贡献.