(1) water vapour in the troposphere and stratosphere acts as a greenhouse gas responsible for a large part of the absorption of outgoing long wave radiation in the atmosphere.Water vapour in the stratosphere is an efficient greenhouse gas and may reside for months in this layer with decadal variations which still need to be represented in climate models.
(2) when water condenses into clouds or freezes to ice on the earth’s surface, it modifies the Earth’s albedo, affecting the reflection of energy from the sun back into space.
(1) water vapour enters the lowest stratosphere through the tropical tropopause along with slowly ascending air masses. This pathway is thought to be responsible for the major part of water input to the stratosphere. The water content of the ascending air is essentially determined by the temperature and pressure of the last cloud on its path, where the partial pressure of waterIt is currently being debated to what extent each of these components controls the water input to the stratosphere. Especially the relative importance of the two first components is a subject of discussion. However recent publications suggest that clouds extend further than expected from visual identification and that this aspect is poorly researched, in particular at the top of very high clouds (Koren et al., 2007; Lane and Sharman, 2014).
vapour was adjusted to the equilibrium water vapour pressure over ice at the cloud temperature. This process is referred to as “dehydration”.
(2) Ice particles enter the stratosphere through deep convective overshoots during tropical thunderstorms.
Occasionally convective up-draft in cumulus nimbus clouds gets so severe that the cloud penetrates the tropopause for a shorter range of time, typically less than an hour, creating the “cloud turrets”. The amount of water vapour released during such an event depends on the amount of ice transported to the stratosphere, and its ability to mix with the surrounding air before the cloud sinks back to the troposphere.
(3) Water is produced in the stratosphere from oxidation of methane. This process is progressing gradually as the air rises through the stratosphere, causing an increase of water vapour content with altitude. This water flux is determined by the methane mixing ratio of the upper troposphere, and is as such well understood.
RO1: understand how lightning activity powers cloud turretsNear-term TECHNICAL OBJECTIVES are to:
RO2: understand how lightning activity powers gravity waves
RO3: understand the structure of TLEs above thunderstorms
By: measuring cloud turrets, TLEs, and gravity waves and in the stratosphere and mesosphere above thunderstorms from the ISS, and relating the observations to lightning activity measured by global lighting detection systems and to meteorological satellite observations of cloud properties.
TO1: identify camera system elements and functionalities that optimize observations of cloud turrets, TLEs and gravity wavesJustification for Need of Space Experiment
TO2: test the experimental concept
TO3: make recommendations for future comprehensive experiments by ISS astronauts
1. The Science Team on the ground will follow the global thunderstorm activity. A window in space and time for observations from the ISS of a target thunderstorm will be predicted 72 hours in advance and be communicated to the BUSOC. It is desired that the window can be refined as the target time approaches. Simultaneously, the Science Team will communicate the RO-number requested for the target and the specifications for the camera system.Parameters Measured
2. The BUSOC notifies the science team if a requested target observation can be accommodated.
3. If the target observation can be accommodated the science team will provide 48 hours in advance the confirmation of the event occurrence. This confirmation will allow the start of the observation set-up.
4. If the target observations can be accommodated, the refined target information will be uplinked to the ISS not less than 24 hours in advance.
5. The astronaut mounts the camera system with the requested optics and implements the requested camera setting.
6. The astronaut remains with the camera system to take the requested images. It is expected that the astronaut will adjust the pointing to capture scientific events if they are off the estimated, uplinked target location.
7. The astronaut stops recording at the end of the time window.
8. The astronaut dismounts the camera system if needed.
9. Three images from the sequence should be down-liked to the science team within 3 hours or shorter (desired). This allows the science team to assess the instrument settings and adjust these if needed for the next observation sequence.
10. All data should be saved and made available for the project.
11. The science team should be notified within 3 hours (desired) if an observation sequence was not implemented.
1. The image data will be calibrated using star fields.
2. The accuracy of the pointing direction will be improved by using optical ground features and lightning activity together with the location of the ISS.
3. From the image data, the science features and their intensities are extracted (science data).
4. The science data are correlated with information taken from other sources.
5. Scientific papers and reports will be written relating to the research objectives RO1-3.
(1) to observe enough thunderstorms from the ISS to address the scientific questions with statistical significance. The data will allow for inputs into global atmospheric climate on water vapour transport in the atmosphere.
(2) to obtain enough data to be able to discriminate between models proposed for jets and gigantic jets. The required number of observations and data taken are given in subsection
"ASIM - Atmosphere-Space Interactions Monitor", http://www.asim.dk/.
A.N. Belyaev, V.V. Alpatov, E. Blanc, V.E. Melnikov, (2006), "Space-based observations of O2 A (0,0) band emission near the solar terminator and their interpretation", Advances in Space Research, 38, 11, pp. 2366-2373.
E. Blanc, T. Farges, R. Roche, D. Brebion, T. Hua, A. Labarthe, V. Melnikov, (2004), "Nadir observations of sprites from the International Space Station", Journal of Geophysical Research - Space Physics, 109, doi: 10.1029/2003JA009972, pp. A02306.
M.A. Geller, H.L. Liu, J.H. Richter, D. Wu, F.Q. Zhang, (2006), "Gravity Waves in Weather, Climate, and Atmospheric Chemistry: Issues and Challenges for the Community", Inspired by the June 2006 Gravity Wave Retreat hosted by The Institute for Integrative and Multidisciplinary Earth Studies (TIIMES) at the National Center for Atmospheric Research (NCAR) in Boulder, CO, U.S.A..
P.B. Hays, J.F. Kafkalidis, W.R. Skinner, R.G. Roble, (2003), "A global view of the molecular oxygen night glow", Journal of Geophysical Research - Atmosphere, 108, D20, doi: 10.1029/2003JD/003400, pp. 4646.
I. Koren, L.A. Remer, Y.J. Kaufman, Y. Rudich, J.V. Martins, (2007), "On the twilight zone between clouds and aerosols", Geophysical Research Letters, 34, L08805, doi:10.1029/2007GL029253.
B.E. Mapes, (1993), "Gregarious tropical convection", Journal of the Atmospheric Sciences, 50, 13, pp. 2026-2037.
S.B. Mende, G.R. Swenson, P. Geller, K.A. Spear, (1994), "Topside observation of gravity waves", Geophysical Research Letters, 21, DOI: 10.1029/94GL01696, pp. 2283-2286.
S.B. Mende, H. Frey, S.P. Geller, G.R. Swenson, (1998), "Gravity wave modulated airglow observation from spacecraft", Geophysical Research Letters, 25, DOI: 10.1029/97GL03224, pp. 757-760.
J.K. Nielsen, M. Foster, A. Heidinger, (2011), "Tropical stratospheric cloud climatology from the PATMOS-x dataset: An assessment of convective contributions to stratospheric water", Geophysical Research Letters, 38, doi: 10.1029/2011GL049429, pp. L18801.
T.A. Shaw, T.G. Shepherd, (2008), "Raising the roof", Nature Geoscience, 1, pp. 12-13.
S. Solomon, K.H. Rosenlof, R.W. Portmann, J.S. Daniel, S.M. Davis, T.J. Sanford, G.K. Plattner, (2010), "Contributions of stratospheric water vapor to decadal changes in the rate of global warming", Science, 327, 5970, doi:10.1126/science.1182488, pp. 1219-1223.
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Figure 1: Thunderstorm clouds with turrets; observed from the ISS.
Figure 2: Cloud modulation by gravity waves generated by wind turbulence over the Sandwich Islands; observed from the ISS.
Figure 3: The air glow layer of the mesosphere modulated by gravity waves; observed from the ground with a fish-eye objective.
Figure 4: Transient Luminous Events (TLEs).
Figure 5: The annual lightning flash density; observed by the OTD and LIS instruments.
Table 1: Cloud turrets characteristics