State of the Climate
In early August, the NOAA National Centers for Environmental Information released its 28th annual State of the Climate report for 2017, with input from more than 500 scientists in more than 60 countries. Among this global research community, several UW-Madison researchers with the Space Science and Engineering Center (SSEC), Cooperative Institute for Meteorological Satellite Studies (CIMSS), as well as the Department of Atmospheric and Oceanic Sciences (AOS) have contributed to the comprehensive report.
SSEC contributions include analyses and observations of various aspects of the Earth’s atmosphere including global cloudiness, atmospheric circulation observations over Antarctica, and new ways hurricane researchers are using the latest GOES satellites to improve hurricane forecasts:
Global cloudiness: Global cloud cover is an important regulator for the Earth’s atmosphere, influencing the exchange of thermal energy as well as the distribution of water vapor. After examining satellite cloud data collected from detectors like PATMOS-x/AVHRR and Aqua MODIS C6, analysis reveals a decrease in overall cloudiness from 2016-2017 between .1% – .34%. With regional variations occurring in certain areas, some parts of the world experienced weak La Niña conditions, which can influence cloud cover over those regions.
Contributing authors: Steve Ackerman (SSEC), Michael Foster (CIMSS), Andrew Heidinger (CIMSS), Richard Frey (CIMSS), Paul Menzel (CIMSS), Coda Phillips (AOS)
Atmospheric circulation observations: The atmospheric circulation over the Antarctic continent can have impacts over a wide-range of weather and climate factors, like sea ice, precipitation, and ocean circulation. An analysis of the atmospheric circulation uncovered numerous anomalies for both temperature and windspeed across the continent. Although different regions can have drastically different conditions, temperatures were generally below average for the continent. Some areas however, like West Antarctica recorded above average temperatures (2-5 C°) at the Byrd Automatic Weather Station (AWS) during the period of February-May. Record high monthly-mean winds were recorded at other AWS, with Ferrell station measuring 10.6 meters per second in the month of August.
Contributing authors: Matthew Lazzara (SSEC), Carol Costanza (formerly SSEC), Linda Keller (AOS)
GOES satellites and improved hurricane forecasts: Employing the new GOES-R series of satellites, hurricane forecasters are putting the data to good use for improving intensity and track predictions. After launching in 2016, GOES-16 witnessed the destructive hurricane season of 2017 before being declared operational later that year. According to UW-CIMSS researcher Chris Velden, GOES-16 has already demonstrated the ability to better resolve hurricane features like the warm eye, as well as fixing the storm center especially during genesis stages. Velden also sees the increased spatiotemporal resolution of the Advanced Baseline Imager instrument as a way to improve analytical methodologies to estimate hurricane intensity such as the Dvorak Technique and the Advanced Dvorak Technique. In the coming series, GOES-T and GOES-U will provide nationwide coverage from Hawaii to the Atlantic Ocean extending to 2035.
Contributing author: Chris Velden (CIMSS)
- Greenhouse Gases Highest on Record
Major greenhouse gas concentrations, including carbon dioxide (CO2), methane and nitrous oxide, rose to new record high values during 2017. The global annual average atmospheric CO2 concentration was 405.0 parts per million (ppm).
- Global Surface Temperature Near-Record High
Global surface temperatures were 0.68°-0.86°F (0.38°-0.48°C) above the 1981-2010 average, depending on the dataset used. This places 2017 as the second or third warmest annual global temperature since records began in the mid- to late 1800s. It was also the warmest non-El Niño year on record, as El Niño–Southern Oscillation (ENSO) conditions were neutral through much of 2017, with weak La Niña conditions at the start and end.
- Global Lower Tropospheric Temperature Near-Record High
In the region of the atmosphere just above Earth’s surface, the globally averaged lower troposphere temperature was also second or third highest on record, depending on the dataset used.
- Sea Surface Temperatures Near-Record High
While the global average sea surface temperature (SST) in 2017 was slightly below the 2016 value, the long-term trend remained upward, with the last three years seeing the three highest annual average SSTs on record.
- Global Upper Ocean Heat Content Record High
Globally, upper ocean heat content reached record highs in 2017, reflecting the continuing accumulation of thermal energy in the top 2,300 feet (700 meters) of the ocean.
- Global Sea Level Highest on Record
Global average sea level rose to a new record high in 2017 and was about 3.0 inches (7.7 cm) higher than the 1993 average, the year that marks the beginning of the satellite altimeter record. Levels have risen year-to-year for six consecutive years and in 22 of the last 24 years. Global sea level is rising at an average rate of 1.2 inches (3.1 cm) per decade.
- Extremes Were Observed in Precipitation
After a significant peak in global drought area in 2016, the drought area fell sharply in early 2017 before rising to above-average values once again later in the year. On the high end of the precipitation spectrum, Severe Tropical Cyclone Debbie (March 27-April 6) in Australia and New Zealand and Hurricane Harvey (August 25-September 1) in the U.S. produced unprecedented impacts from heavy rainfall.
The State of the Climate is a peer-reviewed series published annually as a special supplement to the Bulletin of the American Meteorological Society.
By Eric Verbeten