The tilt is the primary reason that different latitudes experience different weather patterns or climates. Outer planets, such as Saturn, have similar tilts, but they don't experience latitude-dependent climate variations in the same way because they aren't as close to the sun.
Primarily owing to the tilt of the Earth's axis, temperatures cool with increasing latitude, which is a measure of angular distance from the equator. This phenomenon creates three distinct climatic zones on the planet. Any point on the surface of the Earth can be defined by a pair of angular coordinates known as longitude and latitude.
Longitude is a line stretching from pole to pole with a given angular displacement from the Prime Meridian, which runs through Greenwich, England. Latitude is defined as the angular distance from the equator and is designated North or South depending on the hemisphere. The equator defines zero degrees latitude, which locates the North and South Poles at 90 degrees North and South respectively. As latitude increases, the sun shines more obliquely and provides less warming energy. The equator always faces the sun directly, so the climate is warm year-round, with the average day and night temperature hovering between At the poles, however, winter and summer temperatures show a wider variation.
The average temperature in the Arctic varies from zero C 32 F in summer to C F in winter, while in the Antarctic, the temperature varies from The Antarctic is colder for two reasons: it's a landmass, and it's at a higher elevation than the Arctic. The Earth's tilt affects the angle of incident sunlight on a particular location, but if that were its only effect, you would expect higher temperatures at each pole in summer.
Changes in temperatures are not as pronounced around the tropics because this region is not highly seasonal, the researchers say. In contrast, the difference between summer and winter temperatures around the poles has shrunk over the past four decades, the map shows. In these regions, winter temperatures are rising faster than summer temperatures, the research finds.
In the Arctic, this winter warming is partly influenced by the diminishing presence of sea ice during summer months, the researchers say. With less sea ice present, the ocean absorbs more heat — which is later released during the winter, the researchers say.
The reason that winter atmospheric warming may have accelerated above Antarctica is less clear. However, previous research suggests that the presence of polar clouds in the stratosphere which sits above the troposphere could be playing a role. To understand to what extent the observed seasonal changes were influenced by human-caused climate change, the researchers compared the satellite results to climate models.
The likely range of global temperatures by for RCP8. The model simulations, which ran from , included a range of natural factors that can influence tropospheric temperature, including the cooling effect of volcanic eruptions and aerosols. The results show that only simulations that include the impact of human-caused climate change could correctly predict the patterns of seasonal temperature change recorded by the satellites. The researchers say:. In an accompanying perspectives article, he writes:.
However, it is not clear how temperature changes in the troposphere could affect conditions at the land surface, he adds:.
One possible effect could be changes to the timing and likelihood of extreme weather events, says Prof Neil Harris , from the Centre for Environment and Agricultural Informatics at Cranfield University , who was not involved in the research. If you suffer from spring allergies, this is bad news! However, an early blooming season may be even more damaging to the plants themselves.
Even when plants bloom early, the risk of frost during late winter and early spring remains high. It only takes one bad frost to damage frost-sensitive plants, which can impact their ability to produce nuts, seeds, and fruit in the future. Plants take their cues about when to bloom from the temperature of their environment, but most animals take a bit longer to adjust to a new seasonal cycle. Plants and animals live in a careful balance with their environment, and changing temperatures can harm their ability to survive and reproduce.
Seasonal changes have already given us hotter, longer summers. In the western and central United States, drought has become a serious problem due to changes in precipitation patterns. Climate change causes increased rainfall in areas already prone to storms, like the southern coastal states.
But it also reduces rainfall in already dry areas like the southwest. Remember the snowfall shortage caused by shorter winters? This also leads to droughts in the summertime because there is not enough water to sustain soil moisture through the dry season.
Low soil moisture, in turn, produces the conditions for extremely hot temperatures that we call heat waves. Heat waves are becoming more frequent in the summer, especially in desert areas.
By the end of the century, extreme heat waves that normally occur every twenty years are expected to occur every two to three years. Climate change is a global phenomenon, but we can feel its effects on a local scale. Warmer temperatures mean that our seasons will shift in unfamiliar ways, causing harmful changes to our ecosystems, wildlife, and human health.
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