Restore Page
View Single Image
Image Animation
(49 possible images)

Cloud Top Pressure over conterminous US

Cloud properties derived from GOES Sounder data are provided in this series of images and animations. The available products are described below.

Combined GOES-East and GOES-West Cloud Top Pressure

Cloud top pressure (CTP) is derived from GOES-East and GOES-West Sounder radiance information routinely at hourly intervals. Calculations, using the CO2 Absorption Technique, are made at each field of view. The image is then color enhanced to display 50 hPa intervals where clouds have been identified. Due to the low-level atmospheric signal being dominated by surface emissions, this technique is less reliable for near surface clouds. For a more detailed explanation of this technique, see the CIMSS GOES Automated Service Observing System (ASOS) page.

A wider view of the CTP DPI is obtained using all available sectors observed from both the GOES-East and GOES-West Sounders.

Cloud Top Pressure over conterminous US

These images display the cloud top pressure at a higher effective resolution and focus only on the 48 conterminous US states and their immediate environs.

Effective Cloud Amount over conterminous US

A closer look is also provided for the effective cloud amount (ECA) DPI as well, again with an emphasis on the 48 conterminous US states and their immediate environs. The ECA is a measure of the "radiative thickness" or the opacity of the cloud: an ECA of 100% allows no radiation from below to pass through, while an ECA of 10% allows considerable radiation from below to pass through the cloud, to the satellite sensor.

GOES Sounder cloud top pressure listings in text format

Simple hourly "ascii" text listings of cloud parameters derived with the GOES vertical sounding data, including cloud top pressure and temperature and effective cloud amount, are made available on-line to be downloaded. The files available for about the last week are labeled by: date, time (UT), satellite (12-East, 10-West, 9-far Pacific), and data type ("cld") and region (a-Atlantic; c-CONUS; p-Pacific).