CN-121978766-A - Method and system for identifying abnormal event of quality of antarctic ice cover

CN121978766ACN 121978766 ACN121978766 ACN 121978766ACN-121978766-A

Abstract

The invention provides a method and a system for identifying quality anomaly events of a antarctic ice cover, which belong to the technical field of monitoring of polar environments and comprise the steps of acquiring GRACE/FO gravity data of each month in a set time period, acquiring ice cover surface material balance data, dividing an antarctic ice cover AIS (automatic identification system) in an accumulation period and an ablation period, carrying out error assessment based on the GRACE/FO gravity data, setting a significance threshold value, screening to obtain months with significant quality changes, and obtaining the quality anomaly events of the antarctic ice cover from the months with significant quality changes based on the division results of the accumulation period and the ablation period. Based on daily GRACE/FO gravitational field solution, instantaneous ice cap quality anomalies caused by extreme climate events can be monitored, and effective tracking of short-term AIS quality change events is achieved.

Inventors

Jiao Jiashuang
MA PENGFEI
PAN YUANJIN
Mei Dengkui

Assignees

武汉大学

Dates

Publication Date: 20260505
Application Date: 20260126

Claims (8)

1. The method for identifying the abnormal event of the ice cover quality of the south pole is characterized by comprising the following steps of: acquiring GRACE/FO gravity data in a set time period, wherein the set time period takes month, 10 days and daily as scales; Acquiring mass balance (SMB) data of the surface of the antarctic ice cover, and dividing an accumulation period and an ablation period of the antarctic ice cover AIS based on the SMB data; And performing monthly quality change error assessment based on the GRACE/FO gravity data, setting a significance threshold based on the monthly quality change error assessment result, marking the month exceeding the significance threshold as a quality change significant month, and judging as a antarctic ice cover quality abnormal event if the quality change significant month has quality loss in an accumulation period or quality increase in an ablation period.
2. The method for identifying abnormal quality events of the ice cover at the south pole of claim 1, wherein the dividing of the accumulation period and the ablation period of the ice cover at the south pole AIS based on the SMB data comprises the following steps: Taking the average value of SMB time sequences of all months in the set time as ID data; subtracting the ID data from the SMB time sequence of all months in the set time to obtain quality abnormal data; and calculating the annual cycle AC of AIS quality based on the quality abnormal data, wherein if the positive phase of the AC in month is an accumulation period, the negative phase is an ablation period.
3. The method for identifying abnormal ice cover quality events with south poles according to claim 1, wherein the evaluation of the lunar quality change error is performed based on the GRACE/FO gravity data, and specifically comprises the following steps: Calculating the average value of month GRACE/FO gravity data in different data sets, wherein the different data sets are the monthly gravity monitoring data of different institutions; Calculating variance among different data sets by using a triangular cap method, calculating an RMS error based on the variance, and solving a first-order difference of a month average sequence to obtain a month quality change difference sequence and the RMS error corresponding to each month.
4. The method for identifying abnormal ice cover quality events at south poles according to claim 1, wherein the significance threshold is specifically: ; Wherein, the For a change in the monthly quality of the AIS system, Is RMS error; If the relation between the quality change and the error satisfies the above formula and the GRACE/FO observation data of the adjacent month is not missing, the month is considered to have significant quality increase or decrease, and conversely, the quality change is submerged in 3 times of RMS error and is not considered to be significant change.
5. The method for identifying the abnormal quality event of the ice cover with the south pole according to claim 1, further comprising the step of judging the driving duty ratio of the abnormal quality event result, and specifically comprising the following steps: Fitting the long-term trend, the annual period and the half-annual period of the original time sequence to obtain a residual sequence after deducting trend items and period items from the original quality time sequence, and calculating a differential value; Calculating a contribution ratio based on the difference value of the original quality time sequence and the quality difference value after removing the trend component and the periodic component, wherein if the contribution ratio is positive, the quality change becomes more obvious after removing the long-term trend and the periodic fluctuation, the quality change is dominated by a short-term process, and if the contribution ratio is negative, the trend and the periodic component have explanatory force on the quality change of the month, and the quality change is regarded as a forced result of long-term climate.
6. A antarctic ice cap quality anomaly event identification system, comprising: the data module is used for acquiring GRACE/FO gravity data in a set time period, wherein the set time period takes month, 10 days and daily as scales; The abnormal identification module is used for acquiring mass balance (SMB) data of the surface of the antarctic ice cover, dividing an accumulation period and an ablation period of the antarctic ice cover AIS based on the SMB data, performing month quality change error assessment based on the GRACE/FO gravity data, setting a significance threshold based on a month quality change error assessment result, marking months exceeding the significance threshold as significant months of quality change, and judging that the antarctic ice cover has abnormal mass events if the significant months of quality change have mass loss in the accumulation period or mass increase in the ablation period.
7. A computer device comprising a memory, a processor and a computer program stored on the memory, characterized in that the processor executes the computer program to carry out the steps of the method according to any one of claims 1 to 5.
8. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when loaded by a processor, is able to carry out the steps of the method according to any one of claims 1 to 5.

Description

Method and system for identifying abnormal event of quality of antarctic ice cover Technical Field The invention belongs to the technical field of polar environment monitoring, and particularly relates to a method and a system for identifying abnormal quality events of a antarctic ice cover. Background Antarctic ice cover (AIS) is the largest terrestrial ice body system on earth, accounting for about 90% of the global terrestrial ice inventory. Its area is about 1350 ten thousand square kilometers, average thickness is 2450m, total product is about 2650 ten thousand km3, so that the fresh water of nearly 70% of the earth is stored. Complete melting of AIS will result in an elevation of about 58 meters at the global sea level, posing a serious risk to the global human society and natural ecosystem. With the push of global warming, AIS accelerates thawing in recent decades and substantially affects the stability of the global climate system through complex interactions with the atmosphere and the ocean. Accurate monitoring of antarctic ice cap (AIS) mass variation is the basis for elucidating its time-space variability and the physical mechanism controlling its mass budget. These efforts provide key data support for improving sea level rise predictions, perfecting ice cap dynamics modeling, and advancing understanding of climate feedback. Enhanced observation and analysis of AIS mass balance also helps to more fully understand polar environment changes and interactions between ice caps, atmosphere and marine systems. The existing GRACE/FO task provides continuous satellite gravity observation, can track AIS quality change, can provide data support for quick response of extreme climate events. The common monthly GRACE/FO gravitational field does not reliably separate events driven by special weather/hydrologic processes from normal seasonal variations or long term trends. Meanwhile, since the ice cap itself has strong seasonal circulation (weight gain in accumulation period, weight loss in ablation period), it is difficult to statistically and physically judge whether it belongs to abnormality or not even if mass change is observed. Disclosure of Invention In order to solve the problem of abnormal quality identification of the antarctic ice cover, the invention provides a method for identifying abnormal quality events of the antarctic ice cover. In order to achieve the above object, the present invention provides the following technical solutions: a method for identifying abnormal quality events of antarctic ice covers comprises the following steps: acquiring GRACE/FO gravity data in a set time period, wherein the set time period takes month, 10 days and daily as scales; Acquiring mass balance (SMB) data of the surface of the antarctic ice cover, and dividing an accumulation period and an ablation period of the antarctic ice cover AIS based on the SMB data; And performing monthly quality change error assessment based on the GRACE/FO gravity data, setting a significance threshold based on the monthly quality change error assessment result, marking the month exceeding the significance threshold as a quality change significant month, and judging as a antarctic ice cover quality abnormal event if the quality change significant month has quality loss in an accumulation period or quality increase in an ablation period. Preferably, the dividing of the antarctic ice cap AIS into the accumulation period and the ablation period based on the SMB data comprises the following steps: Taking the average value of SMB time sequences of all months in the set time as ID data; subtracting the ID data from the SMB time sequence of all months in the set time to obtain quality abnormal data; and calculating the annual cycle AC of AIS quality based on the quality abnormal data, wherein if the positive phase of the AC in month is an accumulation period, the negative phase is an ablation period. Preferably, the evaluation of the lunar quality change error is performed based on the GRACE/FO gravity data, and specifically comprises the following steps: Calculating the average value of month GRACE/FO gravity data in different data sets, wherein the different data sets are the monthly gravity monitoring data of different institutions; Calculating variance among different data sets by using a triangular cap method, calculating an RMS error based on the variance, and solving a first-order difference of a month average sequence to obtain a month quality change difference sequence and the RMS error corresponding to each month. Preferably, the significance threshold is specifically: ; Wherein, the For a change in the monthly quality of the AIS system,Is the RMS error. If the relation between the quality change and the error satisfies the above formula and the GRACE/FO observation data of the adjacent month is not missing, the month is considered to have significant quality increase or decrease, and conversely, the quality change is submerged i