06 May 2022
23 March 2020
It provides information on the vertical structure of the atmospheric temperature and humidity in an unprecedented accuracy of 1K and a vertical resolution of 1km, which is needed to decisively improve NWP. The use of Metop data in NWP accounts for 40% of the impact of all space based observations in NWP forecasts.
What is IASI?
IASI measures in the infrared part of the electromagnetic spectrum at a horizontal resolution of 12km over a swath width of about 2,200km. With 14 orbits in a sun-synchronous mid-morning orbit (9:30 Local Solar Time equator crossing, descending node) global observations can be provided twice a day.
The temperature of the troposphere and lower stratosphere is measured under cloud-free conditions with a vertical resolution of 1km in the lower troposphere; a horizontal resolution of 25km, and an accuracy of 1K.
The humidity of the troposphere is measured under cloud-free conditions, with a vertical resolution of 1–2km in the lower troposphere; a horizontal resolution of 25km, with an accuracy of 10%.
IASI also measures the fractional cloud cover and cloud top temperature and pressure.
The total amount of ozone under cloud-free conditions is measured with a horizontal resolution of 25km and an accuracy of 5%, and total column-integrated content of CO, CH4 and N2O with an accuracy of 10% and a horizontal resolution of 100km.
The IASI programme is led by CNES in association with EUMETSAT. Alcatel Alenia Space is the instrument Prime Contractor. For more in-depth information, see the IASI Level 1 product guide.
