Blue Sky group presentation Spectra features Francesca, Francesco, Igor, Piotr, Raffaella

Italian: Ecco a voi la stupefacente, meravigliosa e sconvolgente presentazione del famoso gruppo “Cielo Azzurro” German: Wunderbarer Blauhimmelgruppenvortrag French: Maintenant on y va avec l`une des meilleures présentations du fameux grouppe “Ciel Bleu” Hungarian: A „Kek Eg” csoport csodalatos eloadasa Polish: Zaskakująca i zachwycająca prezentacja grupy “Błękitne Niebo”

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Snow Cloud-day Etna Plume Clear Sky Ocean Tunisia desert AIRS

Investigated areas desert snow cloud

AIRS Spectra from around the Globe 20-July-2002 Ascending LW_Window This shows the ascending data (day-time) for the current AIRS “focus day” of 20 July 2002. The image is of a longwave window channel brightness temperature (using a GOES colormap), along with various sample spectra. We’ve had global observations of high spectral resolution before (IRIS and IMG), but they were not really atmospheric profile sounders. The AIRS data is very clean, and the applications are numerous. This is what many of us have been waiting for, and working towards for many years. There are many un-tapped opportunities: SO2 detection from volcanoes, the blue-spike fire detection, new cloud detection techniques, low level inversion detection for severe weather, new spectroscopy investigations, climate change signatures, …

Day? Night? Desert? Ice/Snow? Here the temperature is lower in the window than in the H2O band: Signature of cold surface and dry atmosphere Here the flatness indicates that it could be either snow /ice, or night Low BT points to snow/ice Here two windows channel at similar level exclude desert land Low surface temp. 31 29 23 Very dry atmosphere

Polar ice, very low temperature Polar coastline

Comparison with modis ice/snow pseudochannels 31-23: Snow surfaces have small negative difference of Tb 31-29: snow surfaces have same Tb

Our conclusion Probably ice/snow, clear, very cold, hard to say day/night. (Polar bear chattering with teeth)

be due to bare soil (desert): see picture Land? Ocean? This BT difference may be due to bare soil (desert): see picture Night or lack of clouds (water clouds) Relatively low surface temperature 31 29 32

Tunisia desert - AIRS spectra Daytime No clouds

11 m - 12 m 11m - 8.6 m 31-29 over desert (red surfaces) Sea, land with vegetation (blue surfaces) 31-32: difference over desert is close to 0 Thin clouds (cirrus) brighter 11 m - 12 m 11m - 8.6 m

Our conclusion Probably night, desert, and presence of cirrus clouds. (Muffled sounds of camel hoofs coming from a distance)

Daytime, due to the steep slope from reflected sun radiation: this is very high, so it could be thick clouds, or clouds composed by small droplets (high reflectivity). Presence of clouds: we see that it is ice clouds, because otherwise it would not be so steep 23 31 29 32

AIRS spectra over cloudy area Sun reflection Low temperature

23-31 29-31 31-32 High cloud with ice particles on the top well presented Broken clouds and low water clouds better detected Thin clouds well detected Thick high clouds not detected

Our conclusion High cirrus over a low cloud at the daytime Daytime, probably two layers of clouds, or broken clouds (where we have both ice and water droplet) Final decision High cirrus over a low cloud at the daytime

Clear sky over the sea - AIRS spectra High temperature, similar in all windows

SO2 plume from Etna - AIRS spectra Etna plume: Brightness Temperature Spectra Characteristic slopes of window channels