What is climate?

Climate and weather are two terms used to describe the same atmospheric conditions (temperature, precipitation, etc) on two different time scales: long-term (climate) and short-term (weather). Climate is the long-term weather pattern, typically assessed by a 30 year average of weather. Climate allows us to anticipate general trends for locations throughout the year. For example, two regional climate patterns are:

• Western WA and OR receives more rain in one year than Eastern WA and OR
• The majority of rainfall in western Oregon and Washington will fall during October through March

Weather is what happens on a day to day basis. It cannot be predicted more than a few days to weeks in advance. Weather is much more variable and can have a different pattern than climate. For example, on a given day, the weather in Eastern WA or OR could be wetter than the same day in Western WA or OR.

The ocean and climate

The ocean has an intimate relationship with atmosphere and as such influences climate and weather strongly. The ocean plays a major role in regulating several geochemical cycles on our planet, including the heat and water cycles. Most of the heat on the surface of the Earth is stored in the tropical waters of the ocean. Atmospheric circulation, such as trade winds, are set up by the release of heat from the ocean into the atmosphere through evaporation and then the release of heat from the atmosphere back down to the ocean or land through condensation and precipitation. Where dry or wet areas of the planet are found is caused in part by the ocean’s affects on atmospheric circulation. Thus, the ocean influences how much rain hits land and fuels hurricanes in the Atlantic Ocean and cyclones in the Pacific Ocean. Disruptions to this heat flow, like during an El Niño or La Niña year, change global weather patterns.

What is climate change?

The United Nation's Intergovernmental Panel on Climate Change (IPCC) defines climate change as "a change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties, and that persists for an extended period, typically decades or longer." What this means is that we know that climate change is happening when the 30 year average shows a statistical, persistent change over several decades. Climate change has happened throughout the Earth's history - as an example: around 20,000 years ago, the climate of Western Washington allowed a mile-high glacier to cover Puget Sound for about 3,000 years.

Climate change is triggered by a disruption to the Earth's energy balance. Causes of this disruption include changes in the energy:

• Coming into the Earth's atmosphere
• Factors: amount of incoming solar radiation from the Sun; scattering in the atmosphere
• When it hits the Earth
• Factors: energy absorption and reflection due to land and ice cover
• Leaving the Earth
• Factors: atmospheric concentrations of greenhouse gases and aerosols

Greenhouse gases are essential to maintaining a livable on the Earth. However, the IPCC and other scientists have shown that carbon dioxide, a type of greenhouse gas, has increased sharply since the beginning of the Industrial Revolution in the 1800's due mostly to the burning of fossil fuels by humans. The amount of carbon dioxide in the air has increased from 280 parts per million (ppm) in 1750 to 388 ppm in 2010, the highest level it's ever been in the past 650,000 years. This, along with similar increases in other greenhouse gases and changes to land cover, has contributed to the warming of air and ocean temperatures over the past several decades. One of the impacts of this warming is that most major ice sheets and glaciers, including on Greenland and Antarctica, are melting and causing a global rise in sea level.

What is climate variation?

Climate variation is when climate patterns are disrupted by phenomenon like the El Nino-Southern Oscillation (ENSO) or Pacific Decadal Oscillation (PDO). In both cases these phenomenon are not directional, but rather vary between positive and negative phases of state. With El Nino, the positive state of ENSO, the PNW winters are often warmer, coastal upwelling can be reduced, and coastal waters are often measurably warmer. With La Nina, the negative phase of ENSO, PNW temperatures are usually colder, both in the air and the ocean. The typical duration of either phase of ENSO is about a year or less. The PDO is similar, but operates on a longer timescale, usually about 20 years between the cold, wet versus the warm, dry phases.

Climate Change in the Ocean and Coastal Areas of the Pacific Northwest

Two major groups in Oregon and Washington - the Oregon Climate Change Research Institute at OSU and the Climate Impacts Group at UW - are actively researching climate change in the Pacific Northwest, They have listed potential impacts of climate change on ocean and coastal communities:

• Sea level rise and increased winter storms, precipitation, and river flow can result in increased risk of coastal hazards (flooding, erosion, landslides)
• Rising ocean temperatures can alter ecosystems and animal communities
• Increased ocean stratification can result in more frequent phytoplankton blooms, including Harmful Algal Blooms
• Ocean acidification will make it harder for calcifying organisms to grow shells
• Changes to ocean currents will effect larval dispersal and other ecosystem components

Climate Special Topics

Coastal & Marine Spatial Planning

Related NANOOS Products

NDBC Buoy Anomalies

NOAA Pacific Marine Environmental Lab (PMEL) Carbon Program

Puget Sound ORCA

Cha'ba Buoy

NANOOS members involved in this effort include: