Earth Observing System

Earth Observing System. It is a comprehensive program of NASA dedicated to long-term global observations of the land surface, biosphere, solid Earth, atmosphere, and oceans. Conceived in the 1980s and launched from the 1990s onward, the program represents a cornerstone of the United States Global Change Research Program. The coordinated fleet of satellites and scientific instruments provides a wealth of data critical for understanding the complex interactions within the Earth system.

Overview

The program was developed as a central component of NASA's Mission to Planet Earth, later renamed the Earth Science Enterprise. Its design philosophy centers on deploying a coordinated series of polar-orbiting and low-inclination satellites carrying sophisticated remote sensing instruments. This architecture allows for simultaneous measurements of interrelated Earth system processes, a concept championed by scientists like James Hansen and supported by bodies such as the National Research Council. The data collected supports international research efforts coordinated by the Intergovernmental Panel on Climate Change and the World Climate Research Programme.

Satellites and instruments

The fleet consists of several major satellite platforms, each with a specialized focus. The flagship Terra satellite, launched in 1999, carries instruments like MODIS and MISR to monitor land, oceans, and atmosphere. The Aqua satellite, launched in 2002, focuses on the water cycle with its AIRS and AMSR-E sensors. The Aura satellite studies atmospheric chemistry with instruments such as the OMI and HIRDLS. Other key platforms include the CloudSat and CALIPSO missions for cloud and aerosol profiling, and the ICESat series for ice sheet topography. These missions often involve collaboration with agencies like the National Oceanic and Atmospheric Administration and international partners including the Japan Aerospace Exploration Agency and the Canadian Space Agency.

Scientific objectives and discoveries

Primary objectives include quantifying global climate change, understanding the global carbon cycle, and monitoring natural hazards. Data from the program's sensors have been instrumental in documenting the decline of Arctic sea ice, the retreat of glaciers in the Himalayas and Greenland, and rising global sea surface temperatures. Observations have tracked the expansion of the Antarctic ozone hole and measured tropospheric pollution plumes across Asia and North America. The system has also monitored deforestation in the Amazon rainforest, urban heat island effects in cities like Los Angeles, and the health of coral reefs in the Great Barrier Reef.

Data system and applications

A critical element is the EOS Data and Information System, which manages the immense data flow from the satellites. Data is processed, archived, and distributed through centers like the Goddard Space Flight Center and the National Snow and Ice Data Center. This information is used operationally by agencies including the United States Geological Survey for land management and the Federal Emergency Management Agency for disaster response. Applications range from improving numerical weather prediction models at the European Centre for Medium-Range Weather Forecasts to assisting agricultural monitoring by the United States Department of Agriculture and public health studies of air quality.

Program history and future missions

The concept emerged from the 1980s, with formal planning accelerated after the Earth System Science Committee published its influential report. The first launches began in the late 1990s following the deployment of the Upper Atmosphere Research Satellite. The program has evolved through subsequent NASA initiatives like the Earth Systematic Missions program. Future missions that continue its legacy include the recently launched Landsat 9 and the upcoming NISAR mission, a collaboration with the Indian Space Research Organisation. These efforts ensure the continuity of critical long-term data records essential for climate science and global environmental monitoring. Category:NASA programs Category:Earth observation satellites Category:Earth science