What Is Radiative Forcing?

Radiative forcing refers to changes in net radiation in the vertical direction of the tropopause due to internal changes in the climate system, such as changes in carbon dioxide concentration or changes in solar radiation. The unit is watts per square meter. The radiative forcing is generally calculated after the stratospheric temperature is readjusted to the radiative equilibrium, during which the tropospheric properties have maintained their values before being disturbed. The current radiative forcing is the difference between 2005 and 1750 before industrialization. Radiative forcing is a measure of the degree to which a factor changes the Earth-atmospheric system's impact on the emission and escape energy balance. It is also an index that reflects the importance of the factor in the underlying climate change mechanism. Positive forcing warms the earth's surface, while negative forcing cools it. The contribution of a certain gas to the radiative forcing of climate change depends on the molecular radiation characteristics of the gas, the increase in concentration in the atmosphere, and the residence time after release into the atmosphere. The retention time of greenhouse gases in the atmosphere is closely related to policies. Long-lived greenhouse gases will remain in the atmosphere for at least decades or even thousands of years before the greenhouse gases emitted into the atmosphere are removed by natural processes. Radiative forcing has an irreversible contribution. Once the positive radiative forcing generated by greenhouse gases dominates, the average global surface temperature will rise. ^[1]

Radiative forcing

Cloud long wave radiative forcing refers to the cloud from the Earth's atmospheric system

Regarding the concept and application of radiative forcing, Hansen et al. [10], shine and forster [11] have all elaborate. However, some physical factors can change this radiant energy balance and cause climate change. These factors are called radiative forcing, and the most important of these is the change in greenhouse gas concentration.

Cloud long-wave radiation forcing refers to how much energy the cloud removes from the long-wave radiation energy of the Earth's atmosphere system. It indicates the cloud's blocking effect on long-wave radiation. Its magnitude is equal to the long-wave radiation flux density ejected from the underlying surface in clear sky minus The long-wave radiant flux density emitted by the top of the atmosphere when clouds are covered, the unit is watts / meter.

Generally speaking, the radiation absorbed by the earth from the sun is mainly concentrated on the earth's surface, and then this energy is redistributed through the atmosphere and ocean circulation, and radiates back in a long wave manner.

A large volcanic eruption occurred in 1962, and the sum of the negative radiative forcing and the negative radiative forcing produced by sulfate particles exceeded

Every year, about 100,000 ships are engaged in commercial transportation or military exercises, and they have to sail billions of nautical miles. The fuel used for these navigations leaves a lot of pollution. In addition to direct radiation effects from ship emissions, they can also generate aerosols and form very thin clouds like thin lines in the ocean boundary layer. Studies have shown that this low-cloud local impact is huge and can reach 100 watts per square meter. However, the effect of this effect on the global albedo has not been studied. In a study, German scholars used the full-year ENVISAT environmental satellite AATSR (Advanced Orbit Scanning Radiometer) data to estimate the radiative forcing caused by ship pollution. The results are not as large as those estimated by the previous global model, only 0.4 to 0.6 milliwatts per square meter is not enough to affect the radiative forcing of 0.6 to 2.4 watts per square meter caused by human activities.

In the millennium before the Industrial Revolution, the concentration of greenhouse gases in the atmosphere remained relatively stable. However, since the Industrial Revolution, the concentration of many greenhouse gases has increased significantly due to the direct or indirect effects of human activities.

Carbon dioxide, methane, nitrous oxide, CFC-11,

Ozone is important in both the stratosphere and the troposphere

Cloud long-wave radiative forcing refers to how much energy the cloud removes from the long-wave radiant energy of the Earth's atmospheric system. It indicates the cloud's blocking effect on long-wave radiation. Its magnitude is equal to the long-wave radiant flux density at the top of the underlying surface in clear sky. The long-wave radiant flux density emitted by the top of the atmosphere when there is cloud cover, the unit is watt / meter.

The GMS-5 cloud long-wave radiative forcing data is processed on the basis of the emission long-wave radiant flux density (or OLR) data calculated from the GMS-5 infrared and water vapor channel telemetry data. Its accuracy is the same as the OLR data, which is the maximum The deviation is 8.7 W / m, and the root mean square error of the system is 5.11 W / m. The data is a 601 * 700 2-byte integer array. The first record is the time code, and the second record to the 601 record are cloud long wave radiation forcing data, and the record length is 1400 bytes. The geographic range of the data is 0 ° N-59.9 ° N, 80.1 ° E-150.0 ° E, and the resolution is 0.1 ° * 0.1 ° latitude and longitude, that is, the second record is from 80.1 ° E to 150.0 on the 59.9 ° N latitude circle ° E every 0.1 ° is the cloud forcing data of a grid point (Note: For clear space points, the cloud forcing data is 555, indicating that the point is clear sky; for grid points without satellite data, the cloud forcing data is 999, indicating that the There is no satellite data at the point, and the rest of the values are the size of the cloud forcing data). The data of 700 grid points, ...... Article 601 records 700 grid points of 80.1 ° E, 80.2 ° E, 80.3 ° E, ... 149.9 ° E, 150.0 ° E on the 0 ° N latitude circle. The time of the cloud forcing data is 00:00, 03, 06, 09, 12, 15, 15, 18, and 22 (Universal Time) from June 10 to August 10, 2001.

C the program is used to read out the GMS-5 cloud radiation force data on PC

C

LOGICAL * 1 N (1400)

INTEGER * 2 IYEAR, IMONTH, IDATE, IHOUR, IMIN

INTEGER * 2 OUT (700), CLOUD (600,700)

EQUALENCE (N, OUT)

C

OPEN (1, FILE = 'cl081012.dat', ACCESS = 'DIRECT', RECL = 1400)

READ (1, REC = 1) N

IYEAR = OUT

IMONTH = OUT

IDATE = OUT

IHOUR = OUT

IMIN = OUT

WRITE 6,70 IYEAR, IMONTH, IDATE, IHOUR, IMIN

70 FORMAT (/ 1X, 'TIME INFORMATION:', 5I8)

DO 100 I = 2,601

READ (1, REC = I) N

DO 101 J = 1,700

CLOUD (I-1, J) = OUT (J)

101 CONTINUE

100 CONTINUE

STOP

END