Fog/low clouds detection over the Delhi Earth Station using the Ceilometer and the INSAT-3D/3DR satellite data

Abstract

Fog is a meteorological phenomenon in which cloud has its base near to the surface which disrupts public health and transportation due to decrease in visibility. In the present study, a collective method has been implemented for detection of fog/low clouds over the Delhi Earth Station during fog season for the years 2016 and 2017. A detailed comparison has been performed with the use of ground-based cloud-base height measurements from the Ceilometer and the Indian National Satellites (INSAT-3D/3DR)-retrieved fog product. Fog/low clouds have been effectively detected by both the Ceilometer and the INSAT-3D/3DR during single-layer cloud in the range of 0–200 m in most of the cases. Since the INSAT-3D/3DR fog product is derived under clear sky condition, fog detection during multilayer clouds is a challenging task. Results indicate that the Ceilometer can capture fog/low clouds effectively even in presence of single- and multilayer clouds. Remote-sensing technology can provide better opportunity by providing complete temporal and spatial coverage of fog. The present technique which incorporates both ground-based Ceilometer and space-based INSAT-3D/3DR measurements is observed to be more promising than other conventional methods for an improved detection and monitoring of fog/low clouds.