On the decadal increase in the tropical mean outgoing longwave radiation for the period 1984-2000

Title (Dublin Core)

Description (Dublin Core)

In the present paper, we have calculated the outgoing longwave radiation at the top of the atmosphere (OLR at TOA) using a deterministic radiation transfer model, cloud data from ISCCP-D, and atmospheric temperature and humidity data from NCEP/NCAR reanalysis, for the seventeen-year period 1984-2000. We constructed anomaly time-series of the OLR at TOA, as well as of all of the key input climatological data, averaged in the tropical region between 20°N and 20°S. We compared the anomaly time-series of the model calculated OLR at TOA with that obtained from the ERBE S-10N (WFOV NF edition 2) non-scanner measurements. The model results display very similar seasonal and inter-annual variability as the ERBS data, and indicate a decadal increase of OLR at TOA of 1.9±0.2Wm<sup>-2</sup>/decade, which is lower than that displayed by the ERBS time-series (3.5±0.3Wm<sup>-2</sup>). Analysis of the inter-annual and long-term variability of the various parameters determining the OLR at TOA, showed that the most important contribution to the observed trend comes from a decrease in high-level cloud cover over the period 1984-2000, followed by an apparent drying of the upper troposphere and a decrease in low-level cloudiness. Opposite but small trends are introduced by a decrease in low-level cloud top pressure, an apparent cooling of the lower stratosphere (at the 50mbar level) and a small decadal increase in mid-level cloud cover.

Creator (Dublin Core)

Hatzidimitriou, D.

Vardavas, I.

Pavlakis, K. G.

Hatzianastassiou, N.

Matsoukas, C.

Drakakis, E.

Date (Dublin Core)

2018-06-28

Type (Dublin Core)

Text

Format (Dublin Core)

application/pdf

Identifier (Dublin Core)

10.5194/acp-4-1419-2004

https://acp.copernicus.org/articles/4/1419/2004/

Source (Dublin Core)

eISSN: 1680-7324

Language (Dublin Core)

eng

Item