Middle Atmosphere Temperature Changes Derived from SABER Observations during 2002-2020

Using temperature data measured by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument from February 2002 to March 2020, the temperature linear trend and temperature responses to the solar cycle (SC), Quasi-Biennial Oscillation (QBO), and El Niño-Southern Oscillation (ENSO) were investigated from 20 km to 110 km for the latitude range of 50°S-50°N. A four-component harmonic fit was used to remove the seasonal variation from the observed monthly temperature series. Multiple linear regression (MLR) was applied to analyze the linear trend, SC, QBO, and ENSO terms. In this study, the near-global mean temperature shows consistent cooling trends throughout the entire middle atmosphere, ranging from -0.28 to -0.97 K/decade. Additionally, it shows positive responses to the solar cycle, varying from -0.05 to 4.53 K/100sfu. A solar temperature response boundary between 50°S and 50°N is given, above which the atmospheric temperature is strongly affected by solar activity. The boundary penetrates deep below the stratopause to ~ 42 km over the tropical region and rises to higher altitudes with latitude. Temperature responses to the QBO and ENSO can be observed up to the upper mesosphere and lower thermosphere. In the equatorial region, 40%-70% of the total variance is explained by QBO signals in the stratosphere and 30%-50% is explained by the solar signal in the upper middle atmosphere. Our results, obtained from 18-year SABER observations, are expected to be an updated reliable estimation of the middle atmosphere temperature variability for the stratospheric ozone recovery period.

Wind turbine operation influences near surface air temperature and humidity

<p>Surface meteorology regulates ecosystem processes, with implications for the supply of important ecosystem services. Wind farms have been shown to alter the local climate, but there have been limited field measurements of the variability of impact in different directions relative to the find farm. In addition, the influence of land coverage variability on atmosphere temperature and humidity has not been eliminated, which will lead to the impact of wind turbines on atmosphere temperature and humidity may be over topped or underestimated. Here, we show the impact of Huitengliang wind power base, China, on air temperature and humidity using data from five automatic meteorological monitoring stations. After eliminating the influences of land surface coverage as much as possible, by comparing the variability of temperature and humidity inside the wind farm, and in the upwind, downwind and side wind directions, daily and seasonal variations in temperature and humidity were obtained. We found that wind turbines increase the temperature and decrease the humidity of the surface atmosphere, the influences are more obvious than the existing results. Particularly, these effects are most obvious in the upwind and downwind directions. The annual average temperature rise was 0.97 °C in the upwind direction and 1.25 °C in the downwind direction. On average throughout the year, humidity decreased by 3.71 % in the upwind direction and 5.66 % in the downwind direction. The magnitudes of these effects are sufficient to alter ecosystem processes, including greenhouse gas emissions, with implications for the carbon intensity of electricity generation. </p>

Middle-Atmosphere Temperature Monitoring Addressed with a Constellation of CubeSats Dedicated to Climate Issues

While meteorological numerical models extend upward to the mesopause, mesospheric observations are required for leading simulations and numerical weather forecasts and climate projections. This work reviews some of the challenges about temperature observation requirements and the limiting factors of the actual measurements associated with atmospheric tides. A new strategy is described here using a limb-scattering technique that is based on previous experiments in space. Such observations can be used with cube satellites. Technical issues are the large dynamic range (4 orders of magnitude) required for the measurements, the accuracy of the limb pointing, and the level of stray light. The technique described here will expect accuracy of 1–2 K with a vertical resolution of 1–2 km. A constellation of 100 platforms could provide temperature observations with space (100 km) and time (3 h) resolutions recommended by the World Meteorological Organization, and tidal issues could be resolved with a minimum of 3–5 platforms with specific orbit maintained to avoid drifts.