An Atmospheric Radiation and Cloud Station in the Tropical Western Pacific

Abstract

The interaction of clouds and radiation is a particularly difficult issue in the study of climate change. Clouds have a large impact on the earth's radiation budget but the range of spatial and temporal scales and the complexity of the physical processes associated with clouds made these interactions difficult to simulate. The Department of Energy's Atmospheric Radiation Measurement (ARM) program was established to improve the understanding of the interaction of radiation with the atmosphere with a particular emphasis on the effects of clouds. To continue its role of providing data for the study of these interactions, the ARM program deployed an Atmospheric Radiation and Cloud Station (ARCS) in the tropical western Pacific. This site began operation in October 1996. The tropical western Pacific is a very important climatic region. It is characterized by strong solar heating, high water vapor concentrations, and active convection. The ARCS is equipped with a comprehensive suite of instruments for measuring surface radiation fluxes and properties of the atmospheric state and is intended to operate for the next 10 years. The ARCS is an integrated unit that includes a data management system, a site monitor and control system, an external communications system, redundant electrical power systems, and containers that provide shelter for the equipment as well as work space for site operators, technicians, and visiting scientists. The dataset the ARCS produces will be invaluable in studying issues related to clouds and radiation in the Tropics. The site is located in Manus Province, Papua New Guinea, at 2.060°S, 147.425°E, 300 km north of the island of New Guinea. Two more ARCS are planned for deployment across the tropical Pacific.

The Tropical Warm Pool International Cloud Experiment

“…Lightning activity provides additional information about convective intensity and the microphysical processes occurring in the convective cores (e.g., Carey and Rutledge 2000). Since 2002, ARM has operated an atmospheric radiation and cloud observing site in Darwin (Mather et al 1998). The site includes measurements of the surface radiation budget, surface meteorology, and vertical distribution of clouds (Table 2).…”

The Radiative, Cloud, and Thermodynamic Properties of the Major Tropical Western Pacific Cloud Regimes

“…Atmospheric Radiation Measurement Program (ARM; Stokes and Schwartz 1994;Ackerman and Stokes 2003) at its TWP Cloud and Radiation Test Bed (CART) site located on Manus Island (Mather et al 1998(Mather et al ) during 1999(Mather et al -2000 are applied to identify the cloud regime properties. Several data sources, such as radiative fluxes at the surface and top of the atmosphere (TOA), cloud characteristics derived from ground-based active remote sensors, and thermodynamic information from radiosondes as well as remotely sensed total column water vapor are used to characterize the TWP cloud regimes identified in JT03.…”

Stratospheric influence on upper tropospheric tropical cirrus

“…Here we focus on optically thin tropopause cirrus, which play a less significant role in Earth's radiation budget than thicker cirrus. However, their impacts on the upper tropospheric thermal structure and vertical velocity, on the lower stratospheric water va- The MPL provides a nearly continuous record of the clouds that pass over the site [Mather et al, 1998]. The MPL at Nauru, with 30 m vertical resolution data averaged over i minute time intervals, is effective at detecting thin cirrus layers near the tropopause, as long as lower clouds are not present to attenuate the signal.…”