Sea Surface Temperature & Water Vapor Comparison

Sea surface temperatures have a large influence on climate and weather. Even changes of just a few degrees Celsius can influence large-scale weather phenomena, such as El Niño or tropical cyclones. One reason for this big influence is that evaporation from the oceans is the primary source of water vapor in the atmosphere. The warmer the water, the greater the evaporation.

These sea surface temperature maps are based on observations by the MODIS sensor on NASA's Aqua satellite. The sensor measures the temperature of the top millimeter of the ocean surface. In this map, the coolest waters appear in blue (approximately -2 degrees Celsius), and the warmest temperatures appear in pink-yellow (35 degrees Celsius). Landmasses and the large area of sea ice around Antarctica appear in shades of gray, indicating no data were collected.

The water vapor maps show the total amount of water vapor in the column of air between the surface and the top of the atmosphere on average for the month. The observations were also made by the MODIS sensor on NASA's Aqua satellite. Places where the air was dry are white, while places where water vapor was abundant are blue.

The most obvious relationship between sea surface temperature and water vapor is that both are driven by seasonal changes; both increase in the hemisphere experiencing summer. Seasonal changes in water vapor, however, are more evident over land, and this results largely from changes in land surface temperature. Landmasses — especially large ones like Eurasia — experience more extreme seasonal temperature changes than oceans experience.