Observations are a crucial ingredient in understanding the earth's climate and its variation, including long-term climate change. For example, observed climate records can be analyzed to search for evidence of greenhouse warming trends and other changes. Observations of the present-day climate are also essential for evaluating weather and climate models and for improving model forecasts.

GFDL has made valuable contributions to observational data sets used internationally for climate and weather research. For nearly three decades, Abraham Oort has led efforts at GFDL to compile and analyze observations of the atmospheric and oceanic components of the earth's climate system.

Satellites and other advanced technologies today are providing rich sources of data for weather and climate research. At GFDL, intensive research by Ngar-Cheung Lau and others is underway to exploit these new sources of data, and to develop innovative ways of using observations to evaluate and improve climate and weather models.

Observed global atmospheric temperature record from 1963 to 1989 for the lower stratosphere (upper panel; 100-50mb) and troposphere (lower panel; 850-300mb), based on radiosonde records. Note the warming in the troposphere and the cooling in the lower stratosphere. [Source: Abraham Oort and Huanzhu Liu, Journal of Climate, February 1993].

SATELLITE CLOUD CLIMATOLOGY

Satellite-derived climatological distributions of the relative abundances of various cloud types during the October-March and April-September seasons. For each 2.5° x 2.5° grid box, the fractional coverage by a cloud type is indicated by filling a corresponding fraction of that box with the color designated for the cloud type in question (see cloud-type legend beneath the figure). [Source: Ngar-Cheung Lau and Mark Crane, Monthly Weather Review, July 1995.]