The tropics receive the most incoming heat from the sun, and this heat is redistributed poleward driving much of the circulation, climate and weather we experience. As a result, what happens in the tropics is very important to understanding how weather and climate will change at the mid-latitudes and at the poles. Moreover, understanding variability on the sub-seasonal scale is important to close the gap between weather and climate timescales and create seamless prediction capabilities at NOAA. Understanding the Madden-Julian Oscillation (30-90 day cycles) increases intraseasonal projection skill.The Madden-Julian Oscillation is the key process we focus on in this area, as it is the dominant influence in the tropics at this timescale, and improved modeling of this phenomenon increases predictability across the United States. Image Source: NOAA ATOMIC, Courtesy Elizabeth Thompson

Using observations to improve understanding and representation of Pacific climate (ENSO, MJO, etc...) in models. At present, climate models exhibit a number of errors in the tropical Pacific in fields such as sea surface temperature, wind velocity, and cloud microphysics. This leads to representations of the Earth system that are not realistic, thus degrading our ability to forecast weather and climate. For example, many models do not yet accurately simulate the correct placement of the Intertropical Convergence Zone (ITCZ) - a belt of clouds and precipitation near the equator - and in fact may produce two ITCZs at times when this is not realistic. This leads to models not representing natural variability modes such as El Niño and the Madden-Julian Oscillation well. These biases in turn reduce prediction skill of temperature and precipitation, and lead to increased uncertainty in projections of future climate.

Image Source: www.ospo.noaa.gov/Products/ocean/sst/anomaly

Prediction of climate at the decadal timescale is essential to long-term planning in a number of fields - from water resource management to urban planning and emergency management - but predictions at this scale face unique challenges when compared to short-term weather forecasts and long-term climate projections. While operational weather forecasts rely on proper initialization using observations, and while climate projections rely on scenarios of external forcing and a well-calibrated climate model, decadal-scale projections require that all of these perform well, skillfully simulating phenomena such as the Atlantic Meridional Overturning Circulation (AMOC). Image

Source: www.gfdl.noaa.gov/visualizations-oceans