Results 91 to 100 of about 103,038 (326)

Stratospheric polar vortices

, 2010
The intense cyclonic vortices that form over the winter pole are one of the most prominent features of the stratospheric circulation. The structure and dynamics of these “polar vortices” play a dominant role in the winter and spring stratospheric circulation and are key to determining distribution of trace gases, in particular ozone, and the couplings ...
Waugh, Darryn W., Polvani, Lorenzo M.
openaire   +2 more sources

Assessing the impact of model biases on subseasonal forecast skill

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Relaxation experiments where the nudging was performed towards bias‐corrected integrations of the same model display significantly improved skill at weeks 3 and 4, particularly in the northern extratropics. This indicates that there is a large potential for improving dynamical subseasonal forecasting skill by improved treatment of model biases.
Frédéric Vitart, Magdalena Balmaseda
wiley   +1 more source

All‐sky assimilation impacts of the Tomorrow.io microwave sounder constellation on global weather forecasts

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Key Findings: An assimilation methodology is established for the Tomorrow.io microwave sounder (TMS) flying on CubeSats in sun‐synchronous and inclined orbits, and in all cloud scenes. The TMS has a significant impact on weather forecast lead times up to 3 days in the Tropics in a research‐quality numerical weather prediction setting, and yields water ...
Jonathan J. Guerrette, Ryan Honeyager, Stephen Joseph Munchak, Xiaoxu Tian   +3 more
wiley   +1 more source

The impact of dehydration and extremely low HCl values in the Antarctic stratospheric vortex in mid-winter on ozone loss in spring [PDF]

Atmospheric Chemistry and Physics
Simulations of Antarctic chlorine and ozone chemistry in previous work show that in the core of the Antarctic vortex (16–18 km, 85–55 hPa, 390–430 K) HCl null cycles (initiated by reactions of Cl with CH4 and CH2O) are effective.
Y. Zhang-Liu, R. Müller, R. Müller, J.-U. Grooß, J.-U. Grooß, S. Robrecht, S. Robrecht, B. Vogel, B. Vogel, A. M. Zafar, A. M. Zafar, R. Lehmann   +11 more
doaj   +1 more source

Observation of mesospheric air inside the arctic stratospheric polar vortex in early 2003 [PDF]

, 2005
During several balloon flights inside the Arctic polar vortex in early 2003, unusual trace gas distributions were observed, which indicate a strong influence of mesospheric air in the stratosphere.
A. Engel, G. Wetzel, H. Bönisch, H. Oelhaf, H.-P. Haase, H.-P. Haase, I. Levin, K. Grunow, M. Pirre, N. Huret, T. Möbius, T. Reddmann, T. Wetter, U. Schmidt   +13 more
core   +3 more sources

Forecast verification using information and noise

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Verification of weather forecasts is usually expressed in terms of total error metrics. This is useful for end users of the forecasts but does not allow evaluation of the intrinsic information content of the forecasts. To overcome this limitation, we propose a new total error decomposition into information and noise error measures, connect it to ...
Massimo Bonavita, Alan J. Geer
wiley   +1 more source

Quantifying transport into the lowermost stratosphere using simultaneous in-situ measurements of SF6 and CO2 [PDF]

, 2008
The seasonality of transport and mixing of air into the lowermost stratosphere (LMS) is studied using distributions of mean age of air and a~mass balance approach, based on in-situ observations of SF6 and CO2 during the SPURT (Spurenstofftransport in der
Birner, Thomas, Bönisch, Harald, Curtius, Joachim, Engel, Andreas, Hoor, Peter   +4 more
core  

Development of an atmospheric N2O isotopocule model and optimization procedure, and application to source estimation [PDF]

, 2015
This paper presents the development of an atmospheric N2O isotopocule model based on a chemistry-coupled atmospheric general circulation model (ACTM). We also describe a simple method to optimize the model and present its use in estimating the isotopic ...
Jan, Kaiser, Kaiser, Jan, KENGO, SUDO, KENTARO, ISHIJIMA, MASAYUKI, TAKIGAWA, NAOHIRO, YOSHIDA, Roeckmann, Thomas, Sakae, Toyoda, SATOSHI, SUGAWARA, Shinji, Morimoto, Shuji, Aoki, Takakiyo, Nakazawa, Thomas, Roeckmann, 中澤, 高清, 吉田, 尚弘, 森本, 真司, 滝川, 雅之, 石島, 健太郎, 菅原, 敏, 豊田, 栄, 青木, 周二, 須藤, 健悟   +21 more
core   +1 more source

Operational all‐sky assimilation of geostationary infrared water‐vapour channels in the regional ICON‐D2 model with an ensemble Kalman filter

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Though many studies have shown potential benefit in assimilating all‐sky infrared radiances from geostationary satellites, at numerical weather prediction centres it is still common practice to assimilate clear‐sky radiances. We present the operationalization of the all‐sky assimilation of the spinning enhanced visible and infrared imager (SEVIRI ...
Annika Schomburg, Christoph Schraff, Christina Köpken‐Watts, Klaus Stephan, Liselotte Schühl, Robin Faulwetter   +5 more
wiley   +1 more source

The isotopic composition of methane in the stratosphere : high-altitude balloon sample measurements [PDF]

, 2011
The isotopic composition of stratospheric methane has been determined on a large suite of air samples from stratospheric balloon flights covering subtropical to polar latitudes and a time period of 16 yr.
Borchers, Reinhard, Brass, Marc, Engel, Andreas, Röckmann, Thomas   +3 more
core   +1 more source