Precipitation (falling rain and snow) that occurs around the globe is the source of fresh water on which all life depends. Even in the tropics, much of the precipitation begins as snow in the clouds high above the surface, then generally melts as it falls into warmer temperatures near the surface, except when the surface temperature is below freezing. The heaviest precipitation is found in the persistent band near the Equator, known as the Intertropical Convergence Zone (ITCZ). Just outside the ITCZ, more noticeably in the Northern Hemisphere, the tight swirls of tropical storms (including hurricanes and typhoons) can be seen occasionally in the northern summer. At subtropical latitudes in both hemispheres there are persistent dry areas associated with subtropical high pressure centers. The major deserts of the world occur in the subtropical highs, but these highs also cover vast regions of the oceans. At midlatitudes, the storm tracks display the swirls of low pressure systems and bands of frontal precipitation. [Note the opposite directions of circulation in the Northern and Southern Hemispheres!] Important year-to-year and shorter-interval variations cause strong modifications to local conditions, bringing droughts and floods.
Precipitation changes the naturally occurring microwave energy emitted by the Earth's surface and atmosphere. These signals are detected by satellite instruments that are attuned to specific microwave frequencies. In addition, a few satellites carry weather radars, providing data to adjust the estimates of precipitation from the microwave instruments. Finally, sometimes it is useful to estimate precipitation from information about cloudiness that is provided by infrared sensors flying on geostationary satellites (geo-IR).
This NASA GPM IMERG dataset is provided to Science On a Sphere in near-real time, about six hours after the observation. This dataset uses information from as many satellite microwave sensors as possible, and includes satellite radar data for calibration and geo-IR for additional information. The satellite data provide observations at each location about every three hours or less, and smooth transitions from one observation to the next are computed to give estimates every half hour.
C1 Patterns. Children recognize that patterns in the natural and human designed world can be observed, used to describe phenomena, and used as evidence
C7 Stability and Change. Students observe some things stay the same while other things change, and things may change slowly or rapidly.
C1 Patterns. Students identify similarities and differences in order to sort and classify natural objects and designed products. They identify patterns related to time, including simple rates of change and cycles, and to use these patterns to make predictions.
C7 Stability and Change. Students measure change in terms of differences over time, and observe that change may occur at different rates. Students learn some systems appear stable, but over long periods of time they will eventually change.
C1 Patterns. Students recognize that macroscopic patterns are related to the nature of microscopic and atomic-level structure. They identify patterns in rates of change and other numerical relationships that provide information about natural and human designed systems. They use patterns to identify cause and effect relationships, and use graphs and charts to identify patterns in data.
C4 Systems and System Models. Students can understand that systems may interact with other systems; they may have sub-systems and be a part of larger complex systems. They can use models to represent systems and their interactions—such as inputs, processes and outputs—and energy, matter, and information flows within systems. They can also learn that models are limited in that they only represent certain aspects of the system under study.
C7 Stability and Change. Students explain stability and change in natural or designed systems by examining changes over time, and considering forces at different scales, including the atomic scale. Students learn changes in one part of a system might cause large changes in another part, systems in dynamic equilibrium are stable due to a balance of feedback mechanisms, and stability might be disturbed by either sudden events or gradual changes that accumulate over time
C1 Patterns. Students observe patterns in systems at different scales and cite patterns as empirical evidence for causality in supporting their explanations of phenomena. They recognize classifications or explanations used at one scale may not be useful or need revision using a different scale; thus requiring improved investigations and experiments. They use mathematical representations to identify certain patterns and analyze patterns of performance in order to re-engineer and improve a designed system.
C4 Systems and System Models. Students can investigate or analyze a system by defining its boundaries and initial conditions, as well as its inputs and outputs. They can use models (e.g., physical, mathematical, computer models) to simulate the flow of energy, matter, and interactions within and between systems at different scales. They can also use models and simulations to predict the behavior of a system, and recognize that these predictions have limited precision and reliability due to the assumptions and approximations inherent in the models. They can also design systems to do specific tasks.
C7 Stability and Change. Students understand much of science deals with constructing explanations of how things change and how they remain stable. They quantify and model changes in systems over very short or very long periods of time. They see some changes are irreversible, and negative feedback can stabilize a system, while positive feedback can destabilize it. They recognize systems can be designed for greater or lesser stability
ESS2.C The Roles of Water in Earth's Processes. Water is found in many types of places and in different forms on Earth
ESS2.D Weather & Climate. Weather is the combination of sunlight, wind, snow or rain, and temperature in a particular region and time. People record weather patterns over time
ESS3.B Natural Hazards. In a region, some kinds of severe weather are more likely than others. Forecasts allow communities to prepare for severe weather.
PS4.C Information Technologies and Instrumentation. People use devices to send and receive information.
ESS2.C The Roles of Water in Earth's Processes. Most of Earth’s water is in the ocean and much of the Earth’s fresh water is in glaciers or underground.
ESS2.D Weather & Climate. Climate describes patterns of typical weather conditions over different scales and variations. Historical weather patterns can be analyzed so that they can make predictions about what kind of weather might happen next.
ESS3.B Natural Hazards. A variety of hazards result from natural processes; humans cannot eliminate hazards but can reduce their impacts.
PS4.C Information Technologies and Instrumentation. Patterns can encode, send, receive and decode information.
ESS2.C The Roles of Water in Earth's Processes. Water cycles among land, ocean, and atmosphere, and is propelled by sunlight and gravity. Density variations of sea water drive interconnected ocean currents. Water movement causes weathering and erosion, changing landscape features.
ESS2.D Weather & Climate. Complex interactions determine local weather patterns and influence climate, including the role of the ocean.
ESS3.B Natural Hazards. Mapping the history of natural hazards in a region and understanding related geological forces can help forecast the locations and likelihoods of future events, such as volcanic eruptions, earthquakes and severe weather.
PS4.A Wave Properties. A simple wave model has a repeating pattern with a specific wavelength, frequency, and amplitude, and mechanical waves need a medium through which they are transmitted. This model can explain many phenomena including sound and light. Waves can transmit energy
PS4.C Information Technologies and Instrumentation. Waves can be used to transmit digital information. Digitized information is comprised of a pattern of 1s and 0s.
ESS2.C The Roles of Water in Earth's Processes. The planet’s dynamics are greatly influenced by water’s unique chemical and physical properties.
ESS2.D Weather & Climate. The role of radiation from the sun and its interactions with the atmosphere, ocean, and land are the foundation for the global climate system. Global climate models are used to predict future changes, including changes influenced by human behavior and natural factors
ESS3.B Natural Hazards. Natural hazards and other geological events have shaped the course of human history at local, regional, and global scales. Human activities can contribute to the frequency and intensity of some natural hazards.
PS4.A Wave Properties. The wavelength and frequency of a wave are related to one another by the speed of the wave, which depends on the type of wave and the medium through which it is passing. Waves can be used to transmit information and energy.
PS4.B Electromagnetic Radiation. Both an electromagnetic wave model and a photon model explain features of electromagnetic radiation broadly and describe common applications of electromagnetic radiation.
PS4.C Information Technologies and Instrumentation. Large amounts of information can be stored and shipped around as a result of being digitized.