Long-term changes in weekday-holiday temperature difference in central Tokyo: Analysis since the early 20th century

To analyze the long-term trends of weekday-holiday temperature differences in Tokyo, Japan, meteorological data obtained from 1897 to 2021 were used. Negative departure of temperature on holidays from that on weekdays ( T ) was determined for the period after the 1960s. From 1970 to 1990, T had a value of –0.15 to –0.2 °C and –0.2 to –0.3 °C for the daily mean and daily maximum temperatures, respectively. Moreover, a decline in trend of T emerged after the 2000s. Prior to 1960 T was generally less; however, positive values of approximately 0.1 °C were determined as the daily maximum temperature from 1920 to early 1930s, accompanied by a positive anomaly of the frequency of light precipitation defined by a daily precipitation between 0.1 and 1 mm

Influence of Nearby Plants and Artificial Structures on the Surface Air Temperature Statistics : An in-situ Measurement at Central Tokyo (Otemachi) throughout Years

In order to clarify the influence of obstacles on temperature measurement, two years\u27 continuous observation was made in the meteorological enclosure of the Japan Meteorological Agency in central Tokyo (Otemachi), by installing an extra thermometer at a spot that was surrounded by trees and was 20 m distant from the thermometer for operational observation. In the early afternoon of the warm season, the temperature at the spot surrounded by trees was found to be higher than the operational temperature. The temperature difference at 15JST was about 0.5 degrees Celsius on theaverage, and was correlated with daily solar radiation with a correlation coefficient of over 0.7 from March to September. On the other hand, difference of nighttime temperature was generally small, so that the monthly mean difference of daily mean temperatures was less than 0.1 degree Celsius for all the months of the year

Precipitation from persistent extremes is increasing in most regions and globally

Extreme precipitation often persists for multiple days with variable duration but has usually been examined at fixed duration. Here we show that considering extreme persistent precipitation by complete event with variable duration, rather than a fixed temporal period, is a necessary metric to account for the complexity of changing precipitation. Observed global mean annual-maximum precipitation is significantly stronger (49.5%) for persistent extremes than daily extremes. However, both globally observed and modeled rates of relative increases are lower for persistent extremes compared to daily extremes, especially for Southern Hemisphere and large regions in the 0-45°N latitude band. Climate models also show significant differences in the magnitude and partly even the sign of local mean changes between daily and persistent extremes in global warming projections. Changes in extreme precipitation therefore are more complex than previously reported, and extreme precipitation events with varying duration should be taken into account for future climate change assessments