arctic upper troposphere: Topics by Science.govAbstractTheupperhalocline of theArcticOcean has a distinct chemical signature with high nutrient concentrations as well as low oxygen and pH values. This signature is formed in the Chukchi and East Siberian seas, by a combination of mineralization of organic matter and release of decay products to the sea ice brine enriched bottom water. Salinity and total alkalinity data show that the fraction of sea ice brine in the nutrient-enrichedupperhalocline water in the centralArcticOcean is up to 4%. In the East Siberian Sea the bottom waters with exceptional high nutrient concentration and low pH have typically between 5 and 10% of sea ice brine as computed from salinity and oxygen-18 values. On the continental slope, over bottom depths of 150-200 m, the brine contribution was 6% at the nutrient maximum depth (50-100 m). At the same location as well as over the deeper basin the silicate maximum was found over a wider salinity range than traditionally found in the Canad canada goose arctic program

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  1. Florida Thunderstorms: A Faucet of Reactive Nitrogen to the Upper Troposphere

    NASA Technical Reports Server (NTRS)

    Ridley, B.; Ott, L.; Emmons, L.; Montzka, D.; Weinheimer, A.; Knapp, D.; Grahek, F.; Li, L.; Heymsfield, G.; McGill, M.


    During the NASA Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE) enhanced mixing ratios of nitric oxide were measured in the anvils of thunderstorms and in clear air downwind of storm systems on flights of a Wl3-57F high-altitude aircraft. Mixing ratios greater than l0 - 20 times background were readily observed over distances of 25-120 km due to lightning activity. In many of the Florida storms deposition of NO occurred up to near the tropopause but major deposition usually occurred 1 - 2 km below the tropopause, or mostly within the visible anvil volume formed prior to storm decay. Observations from two storms of very different anvil size and electrical activity allowed estimates of the total mass of NO, vented to the middle and upper troposphere. Using the cloud-to ground (CG) flash accumulations from the National Lightning Detection Network, climatological intra-cloud (IC) to CG ratios, and assuming that CG and IC flashes were of equivalent efficiency for NO production, the ranges of production per flash for a moderate-sized and a large storm were (0.51 - 1.0) x l0(exp 26) and (2.3 - 3.1) x 10(exp 26) molecules NO/flash, respectively. Using the recently determined average global flash rate of 44 8, a gross extrapolation of these two storms to represent possible global annual production rates yield 1.6 - 3.2 and 7.3 - 9.9 Tg(N)/yr, respectively. If the more usual assumption is made that IC efficiency is l/l0th that of CG activity, the ranges of production for the moderate-sized and large storm were (1.3 - 2.7) x l0(exp 26) and (6.0 - 8.1) x l0(exp 26) molecules NO/CG flash, respectively. The estimates from the large storm may be high because there is indirect evidence that the IC/CG ratio was larger than would be derived from climatology. These two storms and others studied did not have flash rates that scaled as approx. H(sup 5) where H is the cloud top altitude. The observed CG flash accumulations and NO

  2. A Comprehensive Data Composite of NO and NOy in the Upper Troposphere and Lower Stratosphere from CARIBIC Airborne Measurements

    NASA Astrophysics Data System (ADS)

    Stratmann, G.; Ziereis, H.; Stock, P.; Brenninkmeijer, C. A. M.; Zahn, A.; Rauthe-Schoech, A.; Schlager, H.


    As a key precursor for tropospheric ozone, nitrogen oxides (NOx) play an important role in atmospheric chemistry. The NOx distribution in the upper troposphere and lower stratosphere (UTLS) is controlled by different sources and processes, such as long-range transport, uplift of emissions from the boundary layer, lightning, and air traffic emissions. The combination of comparatively short lifetime, variety of sources, and complex chemistry entails large spatial variations in the abundance of nitrogen oxides. Insufficient knowledge of the NOx background concentrations in the UTLS implicates uncertainties in the determination of the ozone production, which depends non-linear on the background NOxmixing ratios. To evaluate model simulations, a sound observational data base of nitrogen oxides in the UTLS is required. Within the framework of CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) nitrogen oxide measurements are performed regularly aboard a passenger aircraft. A total of 330 flights were conducted from May 2005 through April 2013 between Frankfurt/Germany and destinations in the USA, Canada, Brazil, Venezuela, Chile, Argentina, Colombia, South Africa, China, South Korea, Japan, India, Thailand, and the Philippines. We present data averages of NO and NOy for the different regions and for different seasons. At mid-latitudes, observed NOy and NO generally show clear seasonal cycles in the upper troposphere with a maximum in summer and a minimum in winter. Mean NOy mixing ratios vary between 1.36 nmol/mol in summer and 0.27 nmol/mol in winter. Mean NO mixing ratios range between 0.05 nmol/mol and 0.22 nmol/mol. Regions in the sub-tropics and tropics show no consistent seasonal dependence of the NO and NOyabundance. These measurements represent one of the most comprehensive NO and NOy dataset presently available for the tropopause region and is a suitable basis for establishing a climatology. It can be used

  3. Aircraft measurements of gravity waves in the upper troposphere and lower stratosphere during the START08 field experiment

    NASA Astrophysics Data System (ADS)

    Zhang, Fuqing; Wei, Junhong; Zhang, Meng; Bowman, K. P.; Pan, L. L.; Atlas, E.; Wofsy, S. C.


    This study analyzes in situ airborne measurements from the 2008 Stratosphere-Troposphere Analyses of Regional Transport (START08) experiment to characterize gravity waves in the extratropical upper troposphere and lower stratosphere (ExUTLS). The focus is on the second research flight (RF02), which took place on 21-22 April 2008. This was the first airborne mission dedicated to probing gravity waves associated with strong upper-tropospheric jet-front systems. Based on spectral and wavelet analyses of the in situ observations, along with a diagnosis of the polarization relationships, clear signals of mesoscale variations with wavelengths ~ 50-500 km are found in almost every segment of the 8 h flight, which took place mostly in the lower stratosphere. The aircraft sampled a wide range of background conditions including the region near the jet core, the jet exit and over the Rocky Mountains with clear evidence of vertically propagating gravity waves of along-track wavelength between 100 and 120 km. The power spectra of the horizontal velocity components and potential temperature for the scale approximately between ~ 8 and ~ 256 km display an approximate -5/3 power law in agreement with past studies on aircraft measurements, while the fluctuations roll over to a -3 power law for the scale approximately between ~ 0.5 and ~ 8 km (except when this part of the spectrum is activated, as recorded clearly by one of the flight segments). However, at least part of the high-frequency signals with sampled periods of ~ 20-~ 60 s and wavelengths of ~ 5-~ 15 km might be due to intrinsic observational errors in the aircraft measurements, even though the possibilities that these fluctuations may be due to other physical phenomena (e.g., nonlinear dynamics, shear instability and/or turbulence) cannot be completely ruled out.

  4. Measurement of nitrogen oxides (NOx) measurements in the Upper Troposphere and Lowermost Stratosphere within IAGOS - Instrument Performance and First Results

    NASA Astrophysics Data System (ADS)

    Berkes, Florian; Houben, Norbert; Pätz, Hans-Werner; Berg, Marcel; Blomel, Torben; Rupsch, Günther; Tappertzhofen, Marlon; Volz-Thomas, Andreas; Petzold, Andreas


    NOx (sum of NO and NO2) play a central role in atmospheric chemistry related to ozone and oxidation capacity (OH and NO3 radicals). The most important sources of NOx in the upper troposphere are lightning, transport from the boundary layer (combustion processes, from biomass burning, agriculture, and industry) and aircraft emissions. Measurements of NOx in the upper troposphere and lower stratosphere (UTLS) are rare but important for understanding the local photochemistry and for the assessment of the impact of aircraft on the budgets of greenhouse gases such as ozone and methane, and for validation of satellite observations of NO2. The European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System) operates on a global-scale monitoring system for atmospheric temperature, trace gases, aerosols and clouds in the UTLS at high spatial resolution by passenger aircrafts. The IAGOS NOx instrument is designed for the autonomous measurement of nitrogen oxides in the atmosphere. The measurement principle is based on the well-established chemiluminescence technique. For installation on commercial aircraft and for long deployment periods, the instrument is designed with one chemiluminescence channel and operably on a low measurement flow. Hence, measurements of NO and NO2 are made sequentially every 50 s. We present the instrument performance and first results from more than 200 flights in May to November 2015 over the North Atlantic. We focus on night time observations and discuss the occurrence and distribution of NO2 within the UTLS region.

  5. MLS and CALIOP Cloud Ice Measurements in the Upper Troposphere: A Constraint from Microwave on Cloud Microphysics

    NASA Technical Reports Server (NTRS)

    Wu, Dong L.; Lambert, Alyn; Read, William G.; Eriksson, Patrick; Gong, Jie


    This study examines the consistency and microphysics assumptions among satellite ice water content (IWC) retrievals in the upper troposphere with collocated A-Train radiances from Microwave Limb Sounder (MLS) and lidar backscatters from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). For the cases in which IWC values are small (less than 10mg m(exp-23)), the cloud ice retrievals are constrained by both MLS 240- and 640- GHz radiances and CALIOP 532-nm backscatter beta(532). From the observed relationships between MLS cloud-induced radiance T(sub cir) and the CALIOP backscatter integrated gamma532 along the MLS line of sight, an empirical linear relation between cloud ice and the lidar backscatter is found: IWC/beta532=0.58+/-0.11. This lidar cloud ice relation is required to satisfy the cloud ice emission signals simultaneously observed at microwave frequencies, in which ice permittivity is relatively well known. This empirical relationship also produces IWC values that agree well with the CALIOP, version 3.0, retrieval at values, less than 10mg m(exp-3). Because the microphysics assumption is critical in satellite cloud ice retrievals, the agreement found in the IWC-beta532 relationships increase fidelity of the assumptions used by the lidar and microwave techniques for upper-tropospheric clouds.

  6. Predictability of the summer East Asian upper-tropospheric westerly jet in ENSEMBLES multi-model forecasts

    NASA Astrophysics Data System (ADS)

    Li, Chaofan; Lin, Zhongda


    The interannual variation of the East Asian upper-tropospheric westerly jet (EAJ) significantly affects East Asian climate in summer. Identifying its performance in model prediction may provide us another viewpoint, from the perspective of upper-tropospheric circulation, to understand the predictability of summer climate anomalies in East Asia. This study presents a comprehensive assessment of year-to-year variability of the EAJ based on retrospective seasonal forecasts, initiated from 1 May, in the five state-of-the-art coupled models from ENSEMBLES during 1960-2005. It is found that the coupled models show certain capability in describing the interannual meridional displacement of the EAJ, which reflects the models' performance in the first leading empirical orthogonal function (EOF) mode. This capability is mainly shown over the region south of the EAJ axis. Additionally, the models generally capture well the main features of atmospheric circulation and SST anomalies related to the interannual meridional displacement of the EAJ. Further analysis suggests that the predicted warm SST anomalies in the concurrent summer over the tropical eastern Pacific and northern Indian Ocean are the two main sources of the potential prediction skill of the southward shift of the EAJ. In contrast, the models are powerless in describing the variation over the region north of the EAJ axis, associated with the meridional displacement, and interannual intensity change of the EAJ, the second leading EOF mode, meaning it still remains a challenge to better predict the EAJ and, subsequently, summer climate in East Asia, using current coupled models.

  7. An upper tropospheric and stratospheric water vapor data set produced by combining records from multiple satellite platforms

    NASA Astrophysics Data System (ADS)

    Rosenlof, K. H.; Davis, S. M.; Anderson, J.; Hurst, D. F.; Oltmans, S. J.


    Vertical profiles of humidity from the upper troposphere to stratosphere have been retrieved from several different limb sounding and solar occultation satellite instruments since the 1980’s. Instruments retrieving water vapor include the SAGE and POAM instruments, UARS MLS, UARS HALOE, and more recently, ACE-FTS and Aura MLS. Here, we present ongoing work aimed at combining these measurements into a geographically gridded data set that can be used for quantifying variability and long-term changes in water vapor, and also for assessing the radiative impact of changes in upper tropospheric and stratospheric humidity. At the present time, we have combined the newest V20 HALOE retrieval and the MLS version 2 retrieval and have compared tropical water with that inferred from the newest NCEP reanalysis, the Climate Forecast System Reanalysis. Results from that comparison, comparisons with the Boulder water vapor sonde data set, and discussion of the radiative and climate impact of trends and decadal variability in UTLS water vapor will be presented.

  8. Atmos/Atlas 3 Infrared Profile Measurements of Trace Gases in The November 1994 Tropical and Subtropical Upper Troposphere

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Gunson, M. R.; Wang, P.-H.; Arduini, R. F.; Baum, B. A.; Minnis, P.; Minnis, P.; Goldman, A.; Abrams, M. C.; Zander, R.; Mahieu, E.; Mahieu, E.; Salawitch, R. J.; Michelsen, H. A.; Irion, F. W.; Newchurch, M. J.


    Vertical mixing ratio profiles of four relatively long-lives gases, HCN, C2H2, CO, and C2H6, have been retrieved from 0.01/cm resolution infrared solar occultation spectra recorded between latitudes of 5.3degN and 31.4degN. The observations were obtained by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform spectrometer during the Atmospheric Laboratory for Applications and Science (ATLAS) 3 shuttle flight, 3-12 November 1994. Elevated mixing ratios below the tropopause were measured for these gases during several of the occultations. The positive correlations obtained between the simultaneously measured mixing ratios suggest that the enhancements are likely the result of surface emissions, most likely biomass burning and/or urban industrial activities, followed by common injection via deep convective transport of the gases to the upper troposphere. The elevated levels of HCN may account for at least part of the "missing NO," in the upper troposphere. Comparisons of the observations with values measured during a recent aircraft campaign are presented.

  9. Model Study of the Sources of Upper Tropospheric Ozone Over The Atlantic, with Emphasis on Interhemispheric Asymmetries

    NASA Technical Reports Server (NTRS)

    Pawson, Steven; Thompson, Anne M.; Lin, Shian-Jiann; Einaudi, Franco (Technical Monitor)


    Measurements of ozone and aerosols from ships transecting the Atlantic Ocean reveal considerable interhemispheric asymmetries in the vertical structure of the ozone distribution. There is much more upper tropospheric ozone to the South of the Equator than in the northern hemisphere. These profiles suggest that the air in the southern hemispheric tropics and subtropics has a source in the stratosphere, while that in the northern hemisphere originates in the boundary layer. A model experiment designed to investigate this problem will be discussed. They are based on a new general circulation model, based on a Finite-Volume dynamical core and the physical parametrizations from the Community Climate Model at the National Center for Atmospheric Research (NCAR). The model simulates a climatological state in reasonable agreement with observations, comparable to other contemporary climate models, but has a much more accurate transport capability than most other present-day models. The experiment involves using a suite of tracers, designed to highlight air from different source regions. Some of these (water vapor and ozone) represent real atmospheric quantities, while others are markers which indicate whether the air originates in the stratos jnxekntj. Canada Goose Vancouverphere, the boundary layer, or has traversed regions of convection (for example). The experiments were run for periods of up to one month, initialized from snapshots from a long climate integration of the model. A sample of results will be presented, chosen to illustrate the different sources of air in the upper troposphere and the physical mechanisms by which these air parcels arrived there.

  10. Measurements of the upper troposphere and lower stratosphere during tropical cyclones using the GPS radio occultation technique

    NASA Astrophysics Data System (ADS)

    Biondi, Riccardo; Neubert, Torsten; Syndergaard, Stig; Nielsen, Johannes


    Water vapour transport to the upper troposphere and lower stratosphere by deep convective storms affects the radiation balance of the atmosphere and has been proposed as an important component of climate change. The aim of the work presented here is to understand if the GPS radio occultation technique is useful for characterization of this process. Our assessment addresses the question if severe storms leave a significant signature in radio occultation profiles in the upper troposphere/lower stratosphere. Radio occultation data from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) were analyzed, focusing on two particular tropical cyclones with completely different characteristics, the hurricane Bertha, which formed in the Atlantic Basin during July 2008 and reached a maximum intensity of Category 3, and the typhoon Hondo, which formed in the south Indian Ocean during 2008 reaching a maximum intensity of Category 4. The result is positive, suggesting that the bending angle of a GPS radio occultation signal contains interesting information on the atmosphere around the tropopause, but not any information regarding the water vapour. The maximum percentage anomaly of bending angle between 14 and 18 km of altitude during tropical cyclones is typically larger than the annual mean by 5-15% and it can reach 20% for extreme cases. The results are discussed in connection to the GPS radio occultation receiver which will be part of the Atomic Clock Ensemble in Space (ACES) payload on the International Space Station.

  11. Atmos/Atlas 3 Infrared Profile Measurements of Trace Gases in The November 1994 Tropical and Subtropical Upper Troposphere

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Gunson, M. R.; Wang, P.-H.; Arduini, R. F.; Baum, B. A.; Minnis, P.; Minnis, P.; Goldman, A.; Abrams, M. C.; Zander, R.; hide


    Vertical mixing ratio profiles of four relatively long-lives gases, HCN, C2H2, CO, and C2H6, have been retrieved from 0.01/cm resolution infrared solar occultation spectra recorded between latitudes of 5.3degN and 31.4degN. The observations were obtained by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform spectrometer during the Atmospheric Laboratory for Applications and Science (ATLAS) 3 shuttle flight, 3-12 November 1994. Elevated mixing ratios below the tropopause were measured for these gases during several of the occultations. The positive correlations obtained between the simultaneously measured mixing ratios suggest that the enhancements are likely the result of surface emissions, most likely biomass burning and/or urban industrial activities, followed by common injection via deep convective transport of the gases to the upper troposphere. The elevated levels of HCN may account for at least part of the "missing NO," in the upper troposphere. Comparisons of the observations with values measured during a recent aircraft campaign are presented.

  12. Origin of a 'Southern Hemisphere' geochemical signature in the Arctic upper mantle.


    Goldstein, Steven L; Soffer, Gad; Langmuir, Charles H; Lehnert, Kerstin A; Graham, David W; Michael, Peter J


    The Gakkel ridge, which extends under the Arctic ice cap for approximately 1,800 km, is the slowest spreading ocean ridge on Earth. Its spreading created the Eurasian basin, which is isolated from the rest of the oceanic mantle by North America, Eurasia and the Lomonosov ridge. The Gakkel ridge thus provides unique opportunities to investigate the composition of the sub-Arctic mantle and mantle heterogeneity and melting at the lower limits of seafloor spreading. The first results of the 2001 Arctic Mid-Ocean Ridge Expedition (ref. 1) divided the Gakkel ridge into three tectonic segments, composed of robust western and eastern volcanic zones separated by a 'sparsely magmatic zone'. On the basis of Sr-Nd-Pb isotope ratios and trace elements in basalts from the spreading axis, we show that the sparsely magmatic zone contains an abrupt mantle compositional boundary. Basalts to the west of the boundary display affinities to the Southern Hemisphere 'Dupal' isotopic province, whereas those to the east-closest to the Eurasian continent and where the spreading rate is slowest-display affinities to 'Northern Hemisphere' ridges. The western zone is the only known spreading ridge outside the Southern Hemisphere that samples a significant upper-mantle region with Dupal-like characteristics. Although the cause of Dupal mantle has been long debated, we show that the source of this signature beneath the western Gakkel ridge was subcontinental lithospheric mantle that delaminated and became integrated into the convecting Arctic asthenosphere. This occurred as North Atlantic mantle propagated north into the Arctic during the separation of Svalbard and Greenland.

  13. Zonal mean properties of Jupiter's upper troposphere from Voyager infrared observations

    NASA Astrophysics Data System (ADS)

    Gierasch, P. J.; Magalhaes, J. A.; Conrath, B. J.


    Voyager IRIS spectra of Jupiter are used to derive zonal averages for 270- and 150-mb temperatures, as well as optical depths through the troposphere at two temperatures, ammonia concentrations near the 680-mb level, and the parahydrogen fraction near the 270-mb level. Simple modeling of an axisymmetric circulation incorporating the linear damping of perturbations from a uniform state for both winds and temperature yields results that are consistent with observed thermal wind shears and with the vertical motion field.

  14. Evaluation and Sensitivity of Climate Model Representation of Upper Arctic Hydrography

    NASA Astrophysics Data System (ADS)

    DiMaggio, D.; Maslowski, W.; Osinski, R.; Roberts, A.; Clement Kinney, J. L.; Frants, M.


    The satellite-derived rate of Arctic sea ice extent decline for the past decades is faster than those simulated by the models participating in the Coupled Model Intercomparison Project (CMIP5). In addition, time-varying Arctic sea ice concentration and thickness distribution in those models are often poorly represented, suggesting that predicted sea ice decline might be modeled in the wrong place or time and for the wrong reasons. We hypothesize that these limitations are in part the result of an inadequate representation of critical high-latitude processes controlling the accumulation and distribution of sub-surface oceanic heat content and its interaction with the sea ice cover, especially in the western Arctic. For the purpose of this study, we define the sub-surface ocean as that below the surface mixed layer and above the Atlantic layer. Those limitations are evidenced in the CMIP5 multi-model mean exhibiting a cold temperature bias near the surface and a warm bias at intermediate depths. In particular, CMIP5 models are found to be inadequately representing the key features of the upper ocean hydrography in the Canada Basin, including the near-surface temperature maximum (NSTM) and the secondary temperature maximum associated with Pacific Summer Water (PSW). To identify the sensitivity of upper Arctic Ocean hydrography to physical processes and model configurations, a series of experiments are performed using the Regional Arctic System Model (RASM), a high-resolution, fully-coupled regional climate model. Analysis of RASM output suggests that surface momentum coupling (air-ice, ice-ocean, and air-ocean) and brine-rejection parameterization strongly influence thermohaline structure down to 700 m. The implementation of elastic anisotropic plastic sea ice rheology improves mixed layer properties, which is also sensitive to changes in numerical convective viscosity and diffusivity. Sea ice formation during model spin-up essentially destroys the initial

  15. Regular in situ measurements of HDO/H216O in the northern and southern hemispherical upper troposphere reveal tropospheric transport processes.

    NASA Astrophysics Data System (ADS)

    Christner, Emanuel; Dyroff, Christoph; Sanati, Shahrokh; Brenninkmeijer, Carl; Zahn, Andreas


    influence of convection on the isotopic composition of water in the upper troposphere. This finding is consistent with the well-known regions of deep convection over Africa, Malaysia and South America.

  16. Analysis of the latitudinal variability of tropospheric ozone in the Arctic using the large number of aircraft and ozonesonde observations in early summer 2008

    NASA Astrophysics Data System (ADS)

    Ancellet, Gerard; Daskalakis, Nikos; Raut, Jean Christophe; Tarasick, David; Hair, Jonathan; Quennehen, Boris; Ravetta, François; Schlager, Hans; Weinheimer, Andrew J.; Thompson, Anne M.; Johnson, Bryan; Thomas, Jennie L.; Law, Katharine S.


    12 ppbv is observed in the same altitude range over Greenland not because of an increasing latitudinal influence of STE, but because of different long-range transport from multiple mid-latitude sources (North America, Europe, and even Asia for latitudes higher than 77° N). For the Arctic latitudes (> 80° N), free tropospheric O3 concentrations during summer 2008 are related to a mixture of Asian pollution and stratospheric O3 transport across the tropopause.

  17. Comparison of in situ N2O and CH4 measurements in the upper troposphere and lower stratosphere during STRAT and POLARIS

    NASA Astrophysics Data System (ADS)

    Hurst, D. F.; Dutton, G. S.; Romashkin, P. A.; Elkins, J. W.; Herman, R. L.; Moyer, E. J.; Scott, D. C.; May, R. D.; Webster, C. R.; Grecu, J.; Loewenstein, M.; Podolske, J. R.


    Nitrous oxide (N2O) and methane (CH4) were measured in the upper troposphere and lower stratosphere by multiple instruments aboard the NASA ER-2 aircraft during the 1995-1996 Stratospheric Tracers of Atmospheric Transport (STRAT) and 1997 Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) campaigns. Differences between coincidental, in situ measurements are examined to evaluate the agreement and variability in the agreement between these instruments during each flight. Mean N2O measurement differences for each flight were much smaller than limits calculated from quoted values of N2O measurement accuracy and for all but two flights were ≤8.7 ppb (3.5%). Mean CH4 measurement differences for flights were similarly much smaller than calculated limits and for all but three flights were ≤65 ppb (4.4%). Typical agreement between instruments during flights averaged 6.2 ppb (2.5%) for N2O and 43 ppb (2.9%) for CH4. In contrast, for about half of the flights, the variability of N2O and CH4 measurement differences exceeded limits calculated from quoted values of measurement precision. The typical measurement difference variability (1σ) during a flight averaged ±8.0 ppb (3.2%) for N2O and ±43 ppb (2.9%) for CH4. For some flights, large differences or variations in differences are attributable to the poor measurement accuracy or precision of one instrument. It is demonstrated that small offsets between the computer clocks of these instruments can result in significant differences between their "coincidental" N2O and CH4 data, especially when there is high spatial variability in tracer abundance along a flight track.

  18. A strong phase reversal of the Arctic Oscillation in midwinter 2015/2016: Role of the stratospheric polar vortex and tropospheric blocking

    NASA Astrophysics Data System (ADS)

    Cheung, Hoffman H. N.; Zhou, Wen; Leung, Marco Y. T.; Shun, C. M.; Lee, S. M.; Tong, H. W.


    In January 2016, Asia and North America experienced unusual cold temperatures, although the global average of surface air temperature broke the warmest record during a strong El Niño event. This was closely related to the remarkable phase transition of the Arctic Oscillation (AO), which can be explained by stratosphere-troposphere interactions. First, the quasi-biennial oscillation changed to its westerly phase in summer 2015 and the stratospheric polar vortex was stronger in early to midwinter 2015/2016. As blocking did not occur in December, the associated downward propagation signal resulted in a strongly positive AO in late December 2015. Second, after late December, the positive phase of Pacific-North America pattern became apparent in El Niño event, which strengthened the Aleutian anticyclone in the stratosphere. In addition, an equivalent barotropic ("blocking") anticyclone was established in the troposphere over Asia. The coexistence of blocking over Asia and North America characterized the negative AO and a strong zonal wave number 2 pattern. Due to stronger zonal wave number 2 signals from the troposphere, the stronger stratospheric polar vortex was elongated, with two cyclonic centers over Asia and the North Atlantic in January. The resultant southward displacement of polar vortices was followed by rare snowfall in the subtropical region of East Asia and a heavy snowstorm on the East Coast of the United States.

  19. Validation of Aura MLS retrievals of temperature, water vapour and ozone in the upper troposphere and lower-middle stratosphere over the Tibetan Plateau during boreal summer

    NASA Astrophysics Data System (ADS)

    Yan, Xiaolu; Wright, Jonathon S.; Zheng, Xiangdong; Livesey, Nathaniel J.; Vömel, Holger; Zhou, Xiuji


    We validate Aura Microwave Limb Sounder (MLS) version 3 (v3) and version 4 (v4) retrievals of summertime temperature, water vapour and ozone in the upper troposphere and lower-middle stratosphere (UTLS; 10-316 hPa) against balloon soundings collected during the Study of Ozone, Aerosols and Radiation over the Tibetan Plateau (SOAR-TP). Mean v3 and v4 profiles of temperature, water vapour and ozone in this region during the measurement campaigns are almost identical through most of the stratosphere (10-68 hPa), but differ in several respects in the upper troposphere and tropopause layer. Differences in v4 relative to v3 include slightly colder mean temperatures from 100 to 316 hPa, smaller mean water vapour mixing ratios in the upper troposphere (215-316 hPa) and a more vertically homogeneous profile of mean ozone mixing ratios below the climatological tropopause (100-316 hPa). These changes substantially improve agreement between ozonesondes and MLS ozone retrievals in the upper troposphere, but slightly worsen existing cold and dry biases at these levels. Aura MLS temperature profiles contain significant cold biases relative to collocated temperature measurements in several layers of the lower-middle stratosphere and in the upper troposphere. MLS retrievals of water vapour volume mixing ratio generally compare well with collocated measurements, excepting a substantial dry bias (-32 ± 11 % in v4) that extends through most of the upper troposphere (121-261 hPa). MLS retrievals of ozone volume mixing ratio are biased high relative to collocated ozonesondes in the stratosphere (18-83 hPa), but are biased low at 100 hPa. The largest relative biases in ozone retrievals (approximately +70 %) are located at 83 hPa. MLS v4 offers substantial benefits relative to v3, particularly with respect to water vapour and ozone. Key improvements include larger data yields, reduced noise in the upper troposphere and smaller fluctuations in the bias profile at pressures larger than 100

  20. Sub-seasonal temperature variability in the tropical upper troposphere and lower stratosphere observed with GPS radio occultation

    NASA Astrophysics Data System (ADS)

    Scherllin-Pirscher, Barbara; Randel, William J.; Kim, Joowan


    We investigate sub-seasonal temperature variability in the tropical upper troposphere and lower stratosphere (UTLS) region using daily gridded fields of GPS radio occultation measurements. The unprecedented vertical resolution (from about 100 m in the troposphere to about 1.5 km in the stratosphere) and high accuracy and precision (0.7 K to 1 K between 8 km and 25 km) make these data ideal for characterizing temperature oscillations with short vertical wavelengths. Long-term behavior of sub-seasonal temperature variability is investigated using the entire RO record from January 2002 to December 2014 (13 years of data). Transient sub-seasonal waves including eastward-propagating Kelvin waves (isolated with space-time spectral analysis) dominate large-scale zonal temperature variability in the tropical tropopause region and in the lower stratosphere. Above 20 km, Kelvin waves are strongly modulated by the quasi-biennial oscillation (QBO). Enhanced wave activity can be found during the westerly shear phase of the QBO. In the tropical tropopause region, however, sub-seasonal waves are highly transient in time. Several peaks of Kelvin-wave activity coincide with short-term fluctuations in tropospheric deep convection, but other episodes are not evidently related. Also, there are no obvious relationships with zonal winds or stability fields near the tropical tropopause. Further investigations of convective forcing and atmospheric background conditions along the waves' trajectories are needed to better understand sub-seasonal temperature variability near the tropopause. For more details, see Scherllin-Pirscher, B., Randel, W. J., and Kim, J.: Tropical temperature variability and Kelvin-wave activity in the UTLS from GPS RO measurements, Atmos. Chem. Phys., 17, 793-806, doi:10.5194/acp-17-793-2017, 2017.

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Today's edition of the T3 Agenda includes a new collection of wind-breaking jackets from Canada Goose, a new portable chair that's not what you're expecting and more...

Canada Goose's new 'Chance Nothing' collection gets you prepared for a cold Spring 2017 

With winter still in full swing, and the spring still seemingly nowhere to be seen, there's never been a better time to invest in some quality threads to keep you warm before things heat up.

Take the new Spring 2017 collection from Canadian luxury Arctic apparel manufacturer Canada Goose, entitled 'Chance Nothing' and filled with the kind of jackets that look as swish they do cosy.

The collection includes 18 new styles with five new proprietary fabrics, including the Heavy and UltraLight Windwear (to help break those gales and keep the cold out), the refined look of the Ultralight Down and the ultimate mobility of the Lightweight Soft Shells.

The collection varies in price so head on over to Canada Goose's official store and start shopping today!

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Ensure you can always take a breather with the unique portable seat, the SitPack

Every been out on a run and needed to stop for a quick sit and a breather, but found nowhere in sit to park your behind? Sick and tired of waiting on your feet at the station while you wait for your train home? Well, frown no more because the new SitPack is here to bring portable seats to the masses.

The compact design might look like a large can, but it's actually a seat and telescopic stand that folds out in seconds. Its 16.8cm in height with a 6.5cm diameter, enabling you to comfortably take the weight off your foot in a variety of settings.

It supports up to 100kg of weight and has a rubberised foot to ensure it doesn't slip when you sit down. You can order one today from Amazon for as little as £50.

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TomTom's new sports app arrives in the UK

TomTom has just launched its new Sports app, which replaces the firm's old MySports software. The new smartphone program includes new motivational messages, activity trends and performance stats all dressed up in a brand new interface.

It can track up to 12 different activity types ranging from running, cycling and swimming to skiing, trail running and hiking. It can also help you track past achievements and events so you can see how well you're doing over time.

It also offers data sharing with a range of third party platforms such as Strava, Nike+, Endomondo, MapMyFitness, Runkeeper and many more. You can download it today for free on Android and iOS.

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Canada Goose kurtka puchowa arctic program, gesie pierze, jenot, męska

Warszawa, Mazowieckie, Bielany Dodane o 19:42, 13 września 2017, ID ogłoszenia: 294600211
240 zł
Oferta od Osoby prywatnej
Stan Używane
Rodzaj Męskie
Rozmiar M

Sprzedam oryginalna kurtkę męską puchową z gęsim pierzem znanej i cenionej firmy Canada Goose model expedition arctic program, jest w stanie bardzo dobrym, niewielkie ślady użytkowania, bardzo ciepła, niezastąpiona na mrozy. Będzie dobra zarówno na rozmiar M jak i L. Kolor to granat. Futerko z jenot przy kapturze jest odpinany. Posiada duże kieszenie, zapinana również w środku, co dodatkowo chroni przed zimnem. Najwyższa jakoś, zresztą świadczą też o tym ceny tych kurtek. sJedynauwak jest dwustronny, moze zapinac od góry i od dołu, jedynie górną część zamka ma urwany uchwyt, co jest pokazane na zdjęciu, ale to nie przeszkadza zbytnio w użytkowaniu, w razie czego można wymienić.
#kurtkapuchowa #canadagoose #gęsie pierze
#kurtkazimowazkapturem #męska #bardzociepłakurtka

Canada Goose kurtka puchowa arctic program, gesie pierze, jenot, męska Warszawa - image 2
Canada Goose kurtka puchowa arctic program, gesie pierze, jenot, męska Warszawa - image 3
Canada Goose kurtka puchowa arctic program, gesie pierze, jenot, męska Warszawa - image 4
Canada Goose kurtka puchowa arctic program, gesie pierze, jenot, męska Warszawa - image 5
Canada Goose kurtka puchowa arctic program, gesie pierze, jenot, męska Warszawa - image 6
Canada Goose kurtka puchowa arctic program, gesie pierze, jenot, męska Warszawa - image 7
Canada Goose kurtka puchowa arctic program, gesie pierze, jenot, męska Warszawa - image 8

RRSO oznacza Rzeczywistą Roczną Stopę Oprocentowania. Pożyczkodawcą jest Vivus Finance sp. z o.o. Przyznanie pożyczki zależy od wyniku oceny zdolności kredytowej wnioskodawcy.

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