Cirrus in the upper troposphere and its relationship to deep convection

Cirrus in the upper troposphere is formed by several processes: blow-off from deep convection, in-situ formation by rising humid layers, and localized regions of cold temperatures associated with dynamical waves. We use HIRDLS and Calipso/CloudSat observations of cirrus, NOAA outgoing longwave radiation (OLR) data, and European Centre for Medium-Range Weather Forecasts (ECMWF) interim wind fields to relate cirrus (and its formation mechanisms) to deep convection. Laminar cirrus is located preferentially away from deep convection. CALIPSO data reveals that cirrus of small vertical width is located at higher altitudes than thicker cloud structures (i.e. there is a monotonic increase in the heights of the cloud structures as cloud vertical widths decrease). Back trajectory analyses indicate that laminar cirrus near the tropopause is associated with deep convection less often than thicker cloud structures.